Dissertations / Theses: 'Acid sulfate soils'

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Yvanes-Giuliani, Yliane. "Aluminium geochemistry in coastal lowland acid sulfate soils (CLASS) : speciation, reactivity and mobility." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4364.

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Ce projet de thèse vise à étudier les processus géochimiques de l'aluminium dans les sols acides à sulfates. Les résultats obtenus avec le dispositif de dialyse de Donnan montrent que l'aluminium dans la solution du sol est presque exclusivement (> 98%) présent sous forme de complexes de charge négative, vraisemblablement des organo-complexes d'aluminium. Les concentrations d'aluminium isotopiquement échangeables (valeurs-E) et les concentrations obtenues par extractions chimiques révèlent qu'une solution de 1 M KCl sous-estime systématiquement les valeurs E. Une méthode d'extraction séquentielle a révélé qu'une quantité importante de minéraux primaires (initialement présents dans les sols) a déjà été dissoute, comme en témoignent les concentrations élevées d'aluminium présentes en tant que minéraux secondaires d'aluminium. Ces études permettent de mieux comprendre la géochimie de l'aluminium dans les sols CLASS et de pouvoir intégrer ces connaissances dans la gestion des sols
The aim of this thesis was to further understanding on Al geochemistry in coastal lowland acid sulfate soils (CLASS). It was observed that Al was present almost solely (> 98%) as negatively charged complexes in CLASS pore-waters, presumably with natural organic matter. Isotopically exchangeable concentrations (E-values) of Al and extraction solutions used to estimate the exchangeable pool showed that 1 M KCl always underestimated isotopically exchangeable Al concentrations in these soils and that 0.2 M CuCl2 improved agreement between both methodologies but sometimes overestimated corresponding E values. A sequential extraction procedure showed that substantial amounts of Al have already been dissolved from primary aluminosilicates initially present in the soils and remain in the soils mostly as reactive secondary Al minerals. The outcomes of this thesis significantly further our understanding of Al geochemistry in CLASS environments and how this knowledge can be incorporated into land management practices

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Reynolds, Jason Kurt Faculty of Science UNSW. "Hydrogel determined metal bioaccessibility in acid sulfate-affected landscapes." Awarded by:University of New South Wales, 2008. http://handle.unsw.edu.au/1959.4/41436.

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Exposure of sulfidic sediments to atmospheric conditions can under various environmental and anthropogenic influences. The oxidation of sulfides results in the production of acidity, dissolution of aluminosilicates and pedogenci development. This process has acid sulfate landscapes throughout the world identified as major emitters of elevated concentrations of chemical metals. This emission of acidity and metals alters the bioaccessibility and subsequently has a deleterious impact on the surrounding biologic environment. Despite this, the examination of the biologic impact in these landscapes has received only minimal attention. Passive and dynamic hydrogel techniques were used to measure the bioaccessibility of metals in sediments and waters. The technique involved the construction of a restricted pore-size thin-film hydrogel that allowed for the diffusion of the bioaccessible fraction, composed of the free-ion and easily dissociable metal-complexes. The dynamic hydrogel technique contained a resin sink, which allowed for a time-integrated flux concentration to be calculated. The dynamic hydrogel technique was trialled and found to correlate with the pygmy mussel (Xenostrobus securis) aluminium uptake for short exposure periods (24 hours).The dynamic hydrogel metal concentration was also found to correlate to indpendantly measured pore water and simultaneously extracted metal (SEM) concentrations. The hydrogel techniqe was further applied to investigate the sediment-water interface in drained and non-drained acid suflate landscapes. The studied Australian and Finnish acid sulfate landscapes showed contrasting relationships between the acid volatile sulfides (AVS) and SEM fractions. In the Australian sediments, a conversion of AVS-S to FeS2-S occurs with depth driven by a polysulfide pathway, whilst the Finnish sediments displayed a persistence of AVS-S with depth with limited conversion to FeS2-S. Distinct variations exist at the sediment-water interface of the two contrasting landscapes, with AVS-S to FeS2-S ratios of 2.5 for the Australian and 0.2 in the Finnish sediments. The sediment geochemistry regulated metal mobility. A two-dimensional passive and dynamic hydrogel approach illustrated microniches and supply zones of aluminium iron, manganese and zinc at varying depths near the sediment-water interface. The measurement of bioaccessibility using an in situ technique in acid sulfate landscapes is a first for both Australia and Finland, and this research provides an important avenue for future water and sediment quality monitoring.

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Karczewska, Hanna. "The effects of acid leaching on some physico-chemical properties of Quebec soil /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=64017.

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Gunnarsson, Niklas. "Mineralogical speciation of sulfur in acid sulfate soils from Luleå, Sweden." Thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71759.

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Marine sulfide – bearing sediments that oxidize when in contact with oxygen and leach outelements in high concentrations to small watercourses have been a problem for many years allover the world especially around the Bothnian Bay. The purpose of this study was to furtherinvestigate the sulfur mineralogy present in acid sulfate soils in the area of Luleå, Sweden. Asecondary aim was to see if elements leach out and accumulate in an acid sulfate soil closer tothe recipient. Samples were taken in two profiles (one oxidized and one waterlogged) fromfour sites (sites A-D) and were analyzed for whole rock geochemistry. Two sites were furtherinvestigated for mineralogy in polished samples with an optical microscope, Ramanspectroscopy and SEM-EDS. Each profile consisted of three layers: oxidation zone, transitionzone and reduced zone. The oxidation zone above the groundwater table was light grey withbrown iron hydroxide staining. Parts that lied under the water table were dark grey-black within general strong odor (“rotten eggs”) due to its sulfur content. It was usually straightforwardto distinguish and separate the layers from each other directly in the field, however in somecases pH was needed for confirmation.A general feature of investigated polished samples is the presence of abundant framboidalpyrites that are common in reduced marine sediments. The transition zone was formed in suboxicconditions and this feature is reflected by the mineralogy. Many morphologies of theframboidal pyrite were observed in this layer and signs of both dissolution and formationoccur. In the sample from site C one could observe elemental sulfur in form of large (up to 50μm) euhedral crystals. In the samples with pH<4, no sulfides occur as they have been replacedby jarosite (site B). Site C lacks these sulfur-bearing hydroxides which is thought to be due toa sulfur concentration of <0.2 %. Sulfur shows extensive leaching at most sites but at site B andD1, it accumulates in the transition zone. Elements like cobalt (Co), nickel (Ni) and zinc (Zn)are leached out or are accumulated further down in the profile. Elements that could have beentransported and have accumulated in the waterlogged profiles are Co, Ni, Zn and chromium(Cr) and in some profiles also copper (Cu) and vanadium (V).
Coastal watercourses in Bottenviken: Method development and ecological restoration- A cross-border Swedish-Finnish cooperation project

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Mustafa, Akhmad Biological Earth &amp Environmental Sciences Faculty of Science UNSW. "Improving acid sulfate soils for brackish water aquaculture ponds in South Sulawesi, Indonesia." Awarded by:University of New South Wales. Biological, Earth & Environmental Sciences, 2007. http://handle.unsw.edu.au/1959.4/40619.

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Brackish water aquaculture is one of the largest coastal industries in Indonesia. This farming system involves the construction of ponds m coastal sediments. Many ponds in Indonesia have been abandoned due to past development of ponds in acid 8ulfate soils (ASS); these soils produce sulfuric acid through the oxidation of pyrite du ring and after the sediments have been excavated. The soils also contain elevated concentrations of metal such as iron and aluminium which are harmful to farmed fish and shrimp. Acidification of pond soil causes recurrent fish and shrimp mortalities, poor growth rate in fish and shrimp, soft shell syndrome in shrimp and low plankton densities, Pond maintenance costs in ASS are also significantly higher than non-ASS ponds. There are over 6.7 million ha of ASS In Indonesia of which 35% has been developed for brackish water aquaculture. This study developed and trialled methods of soil remediation to restore abandoned ASS-affected ponds. The main objective was to develop methods at remediation that were scientifically sound but also practical and inexpensive for farmers. The research involved characterising, in detail, the chemical and physical properties of ponds soil followed by laboratory-based experiments to improve soil properties. The results of laboratory trials were the basis for large-scale field experiments to test soil remediation strategies. The study showed that pond bottoms could be improved by forced oxidation, flooding and water exchange followed by Iiming and fertilising. Up to 500% increases in productivity were achieved by this method and soils conditions Improved significantly. A further twofold productivity increase was achieved by an integrated liming method in which lime is added to rebuilt or new dykes in layers. A juvenile shrimp production system was developed for ponds that were too severely degraded or costly to remediate. The research developed methods of preventing metal toxicity in Juvenile shrimp. The study showed that aquaculture ponds built in ASS could be remediated and returned to viable production systems. Importantly, the study has developed a more detailed understanding of chemical properties In ASS-affected ponds.

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Nguyen, Nga. "Multivariate analysis and GIS in generating vulnerability map of acid sulfate soils." Thesis, KTH, Mark- och vattenteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-170472.

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The study employed multi-variate methods to generate vulnerability maps for acid sulfate soils (AS) in the Norrbotten county of Sweden. In this study, the relationships between the reclassified datasets and each biogeochemical element was carefully evaluated with ANOVA Kruskal Wallis and PLS analysis. The sta-tistical results of ANOVA Kruskall-Wallis provided us a useful knowledge of the relationships of the preliminary vulnerability ranks in the classified datasets ver-sus the amount of each biogeochemical element. Then, the statistical knowledge and expert knowledge were used to generate the final vulnerability ranks of AS soils in the classified datasets which were the input independent variables in PLS analyses. The results of Kruskal-Wallis one way ANOVA and PLS analyses showed a strong correlation of the higher levels total Cu2+, Ni2+ and S to the higher vulnerability ranks in the classified datasets. Hence, total Cu2+, Ni2+ and S were chosen as the dependent variables for further PLS analyses. In particular, the Variable Importance in the Projection (VIP) value of each classified dataset was standardized to generate its weight. Vulnerability map of AS soil was a result of a lineal combination of the standardized values in the classified dataset and its weight. Seven weight sets were formed from either uni-variate or multi-variate PLS analyses. Accuracy tests were done by testing the classification of measured pH values of 74 soil profiles with different vulnerability maps and evaluating the areas that were not the AS soil within the groups of medium to high AS soil probability in the land-cover and soil-type datasets. In comparison to the other weight sets, the weight set of multi-variate PLS analysis of the matrix of total Ni2+& S or total Cu2+& S had the robust predictive performance. Sensitivity anal-ysis was done in the weight set of total Ni2+& S, and the results of sensitivity analyses showed that the availability of ditches, and the change in the terrain sur-faces, the altitude level, and the slope had a high influence to the vulnerability map of AS soils. The study showed that using multivariate analysis was a very good approach methodology for predicting the probability of acid sulfate soil.

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Diallo, Ndeye Helene. "Improved Management of Acid Sulfate Soils for Rice Production in Casamance, Senegal." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/81697.

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Casamance is a region in southern Senegal that traditionally produces rainfed rice, but Senegal produces only 1/3 of its rice consumption. Lowland areas, where rice is primarily produced, have acid sulfate soils with low pH and potential aluminum and iron toxicity. The goal of this work was to determine if soil amendments can alleviate soil acidity, counteract the negative biogeochemical effects that occur in flooded conditions, and increase rice yield. A two-year experiment was conducted to test the following soil treatments – agricultural lime, pulverized oyster shell, biochar, and control (no amendment) – in flat and raised beds. Plots amended with lime and shell materials had increased soil pH, base saturation, Ca, and cation exchange capacity. Meanwhile, biochar elevated particulate organic matter and C:N ratios. Exchangeable Fe and Al were negatively correlated with soil pH, while Geobacteraceae populations (Fe reducing bacteria) increased with pH. A greater proportion of the total Fe was strongly bound in fractions that were less bioavailable in plots amended with shell or lime, and overall rice yields were significantly higher following amendment with shell or lime. During the second growing year these effects diminished, suggesting that liming effects did not persist as expected. These results demonstrate the benefits of soil amendments that raise soil pH and suggest that this effect operates by influencing overall soil nutrient availability to rice plants, but further research is needed regarding the timing and sustainability of the beneficial liming effect.
Master of Science

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Bryson, Autumn Leah. "Sulfate sorption of acidified forest soils in the Otter Creek Wilderness area." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4900.

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Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains vi, 36 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 31-36).

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Lindström, Carola. "Acid Sulfate Soils and Metal Accumulation in Sediments in Rosån Catchment, Northern Sweden." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325213.

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Global environmental concerns arise when marine deposits with fine-grained iron sulfide-rich sediments (FeS and FeS2), now situated above sea level, oxidize from anthropogenic lowering of the groundwater table. The oxidation of iron sulfides decreases the soil pH and the acidic environment of these Acid Sulfate Soils (AS) soils increase weathering and mobilization of metals into adjacent watercourses, lakes and estuaries. Low pH and enhanced concentrations of metals are known to influence water quality negatively, causing fish kills and reduced aquatic diversity. Sulfide rich sediments were deposited in the Baltic Sea after the last glaciation and are now abundantly found along the coasts of for example the Bothnian Bay as a result of isostatic rebound. Recent studies from Finland have stated associations between leached (AS) soils and increased concentrations of metals in estuary sediments, thus the effects are likely to be similar in Sweden. With financial support from the Interreg Nord project “Ecological restoration in coastal river basins in the Bothnian Bay” in cooperation with the Geological Survey of Sweden (SGU), sediments from three lakes and two estuarine sites in the Rosån catchment in Norrbotten county, northern Sweden, were sampled and analyzed with fpXRF, ICP-MS and LOI methods. Elemental concentrations and organic contents were compared to establish accumulation trends over time and relationships between metal concentrations in recently deposited sediments and potential influence from previously sampled (AS) soils. Correlations in time, to anthropogenic activity, such as ditching were also considered. A primary allover trend with increasing concentrations of Aluminum (Al), Arsenic (As), Cadmium (Cd), Cobalt (Co), Cupper (Cu), Iron (Fe), Manganese (Mn), Nickel (Ni), Lead (Pb), Rare Earth Elements (REE) and Zinc (Zn), was noticed in a majority of the lake and estuary sediment samples. With some site variation, also two discrete peaks at different depth, were found in the upper 20 to 30 cm of the sampled sediments. Significant correlations to organic matter were also found for a considerable amount of the elements. Soil samples from (AS) soils in areas related to Rosån show pH values as low as 2.62 and oxidation depths down to 170 cm. Substantial elemental depletion in the oxidized zone suggest increased weathering, leaching and mobilization of Al, Cd, Co, Mn, Ni, REE, Zn and to some extent As, Cu, Fe and Pb from the soil, as a consequence of the acidic environment. A relationship between (AS) soils and increased metal concentrations is therefore likely. The sedimentation rate of roughly 0.2 cm/year was calculated from the separation age of the lakes and the sediment depth to an interpreted transition from more marine environment to lake settings. Consequently the distinct peaks of increased metal concentrations are thus suggested to be related to anthropogenic activities as for example improved drainage methods after the Second World War, but proper dating of the sediments is needed to establish any certain correlations.
På senare tid har man uppmärksammat de miljöproblem som uppstår när finkorniga sediment, innehållande järnsulfider, oxiderar på grund av mänsklig påverkan, t ex. dikning, eller annan typ av aktivitet som sänker grundvattennivån. När järnsulfiderna oxiderar bildas svavelsyra som gör att pH- värdet i marken blir väldigt lågt. Den sura miljön i dessa så kallade sura sulfatjordar, gör i sin tur att mineraler i marken vittrar fortare med påföljden att både surt vatten och ökade mängder metaller, sprids till närliggande vattendrag, sjöar och hav. Lågt pH och höga halter av metaller i vatten påverkar även vattenkvalitén negativt och har rapporterats orsaka fiskdöd och minskad akvatisk mångfald. Sura sulfatjordar är globalt förekommande och återfinns bland annat längs Bottenvikens kuster. De har kunnat bildas genom att sulfidhaltiga sediment, som avsattes i Östersjön efter den senaste istiden, nu befinner sig ovan havsnivån på grund av landhöjningen. I Finland har man i flera studier sett ett samband mellan sura sulfatjordar och ökade metallhalter i nyligen avsatta kustsediment och man kan anta att liknande förhållande gäller även i Sverige. Med finansiellt stöd från EU-projektet “Kustmynnande Vattendrag i Bottenviken-Metodutveckling och Ekologisk Restaurering” (Interreg Nord) genom Sveriges geologiska undersökning (SGU) och i samarbete med Länsstyrelsen i Norrbotten, har bottensediment från tre sjöar och två fjärdar i Rosåns avrinningsområde i Norrbotten provtagits och analyserats. För att fastställa hur koncentrationerna har förändrats över tiden har metallhalterna i de nyligen avsatta sedimenten jämförts med koncentrationerna i äldre sediment. Även jordprofiler från sura sulfatjordar i området har studerats för att kunna utvärdera ett ev. samband mellan urlakade ämnen i jordarna och ökade halter i sedimenten. Granskning av hur långt metallerna transporteras i systemet har gjorts, liksom försök att hitta kopplingar i tiden till mänsklig påverkan som t.ex. dikning. I de översta sedimenten kan man, förutom en generellt ökande trend av aluminium (Al), arsenik (As), kadmium (Cd), kobolt (Co), koppar (Cu), järn (Fe), mangan (Mn), nickel, (Ni) bly (Pb), sällsynta jordartsmetaller (REE) och zink (Zn), också se tydliga toppar med ökade halter av dessa ämnen på minst två specifika djup. De sura sulfatjordarna, som uppmätte pH-värden ner till 2,62, visade tecken på urlakning av Al, Cd, Co, Ni, Mn, REE, Zn och till viss del också As, Cu, Fe och Pb, varpå en trolig relation mellan sura sulfatjordar och ökade metallhalter i nyligen avsatta sediment kan fastställas. En uppskattning av ackumulationshastigheten, som gjordes utifrån när de provtagna sjöarna skiljdes från havet, och sedimentdjupet som visar övergången från hav till sjö, visar att de observerade topparna av ökade metallkoncentrationer i sedimenten skulle kunna vara förknippade med dikning i början av 1900-talet och efter andra världskriget. För en säker bestämning av sambandet till specifika händelser behövs dock en riktig datering.

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Courchesne, François. "Mechanisms regulating sulfate movement in some podzols from Quebec." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75774.

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The reaction of sulfate with six podzolic horizons of the Southern Laurentians (Quebec) was investigated using batch reaction techniques. It was demonstrated that sulfate sorption increased with decreasing solution pH to a maximum sorption capacity at around pH 4.0; below this pH retention decreased. This drop in sorption capacity was related to the partial dissolution of Al surface coatings. Indeed, the amount of native sulfate and the maximum sorption during the experiment were positively correlated (R$ sp2$ = 0.982, 0.800) with the oxalate extractable Al content of these forested soils. In all six horizons, the increase in sulfate sorption as a function of equilibrium sulfate concentration was best described by the Gunary equation. Kinetic experiments showed the presence of two major stages in both sorption and desorption reactions with an initial quick change (first 6 h) in solution concentration being followed by a second step where the reactions between sulfate and the soil matrix were much slower. The time-dependence of these reactions emphasized the appropriateness of kinetic equation in describing field situations. Moreover, kinetics studies performed under highly acidic conditions demonstrated that the amount of sulfate sorbed decreased with time after an initial sorption step due to the partial dissolution of Al surface materials. Thermodynamic calculations further suggested the subsequent precipitation of jurbanite. It was then concluded that surface dissolution and mineral formation should be considered in the interpretation of results obtained from experiments aimed at determining the effect of pH on sulfate retention.

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McBroom, Mark David. "Kinetics and community profiling of sulfate-reducing bacteria in organic carbon treated mine tailings." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/mcbroom/McBroomM0505.pdf.

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Morgan, Marcus John. "Optimal prediction of coastal acid sulphate soil severity using geographic information systems." Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20070208.153133/index.html.

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Banasiak, Laura Joan. "The role of a subsurface lime-fly ash barrier in the mitigation of acid sulphate soils." Access electronically, 2004. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20050706.121221/index.html.

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Kozhukhar, Nazariy, and Назарій Кожухар. "Microbial communities of soils and acid mine drainage bioremediation." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/50768.

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1. В. Бузило, А. Павличенко, С. Кулина, В. Кіященко. Шляхи забезпечення екологічної безпеки при ліквідації вуглевидобувних підприємств. Розробка родовищ. 2013. С. 437-440. 2. Costa M.-C., Duarte J.-C. Bioremediation of acid mine drainage using acidic soil and organic wastes for promoting sulphate-reducing bacteria activity on a column reactor. Water, Air, and Soil Pollution. 2005. Vol. 165. P. 325-345. 3. Bhupinder D. Biotechnological Tools for Remediation of Acid Mine Drainage. Bio-Geotechnologies for Mine Site Rehabilitation / eds. MNV Prasad Paulo Jorge de Campos Favas Subodh Kumar Maiti. Elsevier. 2018. 730 p. 4. Ford K.L. Passive treatment systems for acid mine drainage. U.S. Bureau of Land Management Papers. 2003. 19 p.
As a result of restructuring in 1990-2000 and occupation in 2014 the coal-rich Donetsk Basin saw massive mine closures. Leaving behind acid mine drainage, dam failures, non-remediated areas and cases of direct discharges into waterways that could lead to serious and long-term environmental impacts. The elimination of mines leads to changes in natural conditions for the living organisms and the formation of unfavorable environmental situations, such as. Acidic mine drainage occurs naturally in some environments as part of rock weathering, but is enhanced by large-scale soil disturbances common in mining. Acid mine drainage neutralization depends on its chemistry, electron donors / receptors, temperature, and pH. Iron-reducing bacteria and sulfate-reducing bacteria form the root component of these bioreactors. Acidophilic heterotrophic bacteria promote the oxidation of ferrous to ferric iron in acidic waters.
В результаті реструктуризації в 1990-2000 рр. та окупації в 2014 р. багатого вугіллям Донецький басейн побачив масове закриття шахт. Залишаючи за собою дренаж кислотних шахт, аварії дамб, не відновлювані ділянки та випадки прямих скидів у водні шляхи, які можуть призвести до серйозних і довгострокових впливів на навколишнє середовище. Ліквідація шахт призводить до змін природних умов для живих організмів та формування несприятливих екологічних ситуацій. Кислотний дренаж шахт природним чином відбувається в деяких середовищах як частина вивітрювання гірських порід, але посилюється широкомасштабними ґрунтовими порушеннями, характерними для гірничодобувних робіт. Нейтралізація дренажу кислотних шахт залежить від його хімії, донорів / акцепторів електронів, температури та рН. Основним компонентом цих біореакторів є залізоредукуючі бактерії та сульфатредукуючі бактерії. Ацидофільні гетеротрофні бактерії сприяють окисленню заліза(ІІ) до заліза(ІІІ) в кислих водах.

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Landin, Nils Charles. "Acid sulfate weathering in natural glacially derived soils of north western Indiana and the environmental implications." Thesis, Purdue University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10159495.

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Northwestern Indiana has land surfaces and soils that are around 15,000 years old, resulting from sediments deposited from the Wisconsinan Glaciation during the late Pleistocene period. These geologically young soils exhibit depletion of base cations and low pH's (near 4.0) which are chemically similar to much older and more intensely weathered soils. We hypothesize that FeS2 (iron pyrite) within the shale fragments of the glacial deposits was oxidized upon exposure of oxygen near the earth's surface and resulted in naturally occurring acid sulfate weathering. To test our hypothesis, we isolated the area with ArcGIS, collected clast samples from gravel pits, utilized historic soils databases, and analyzed samples with X-ray diffraction to determine if associated properties and soil minerals would support acid sulfate weathering as the cause of the current soil chemical properties. Soil samples and glacial outwash cobble-sized clasts were collected and X-ray diffraction was used to determine the presence of pyrite or of pyrite weathering products jarosite and gypsum. Existing soil databases and lab data were examined to obtain further details of the occurrence of the potential acid sulfate weathering. A review of the geologic literature was also conducted to put the acid sulfate weathering processes into a landscape perspective and geologic context. The clast samples and some soil samples indicated the presence of jarosite and gypsum which are commonly associated with acid sulfate weathering. This research also found that ultic soil properties and low pH soils were associated with sandy glacial outwash and this information was displayed spatially. The sandy outwash has a lower CEC and lower buffering capacity when compared to nearby higher clayey glacial till. There was inferential evidence of acid sulfate weathering in calcareous glacial which is illustrated by iron oxide pseudomorphs. The lack of initial pyritic shale combined with the neutralizing potential for the calcareous till prevented these soils from developing ultic properties and low pH's. Additionally, this research assessed the potential for naturally occurring arsenic in the soils. Elevated arsenic levels were found in soils that occurred in the lowest part of the landscape. Understanding the process of naturally occurring acid sulfate weathering and associated elevated arsenic within this landscape will provide more information on use and management of these areas.

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Job, Thomas Anthony. "A systemic investigation of coastal acid sulfate soil acidification in the River Murray Estuary, South Australia." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23474.

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Extensive coastal acid sulfate soil (CASS) oxidation was observed in the River Murray Estuary (RME), South Australia, during an extreme drought (the Millennium Drought, 1996–2010). CASS oxidation causes significant surface water and porewater acidity, and the mobilisation of toxicants, negatively impacting proximal ecosystems and infrastructure. In this thesis I argue that the Millennium Drought acidification event provides a test case globally for how meteorological drought triggers extreme CASS oxidation, and how other variables can exacerbate the issue. I therefore present a systemic investigation of CASS acidification within the RME and identify the boundary conditions and exogenous variables that control acidification risk. Elements mobilised from oxidised CASS (Fe, Mn, Al, V, Cr, Co, Ni, Cu, Zn, Cd, Pb, and REE) are accumulating in the sediments of the RME, and spatial patterns of enrichment and REE fractionation can be used as environmental tracers of acidic drainage. Transport and accumulation of these elements is controlled by hydrodynamic and geomorphic processes in the estuary. Multiple depositional regimes apparent in the sediment record show that hydrodynamic and geomorphic processes have, however, changed during the history of the RME in response to sea-level and anthropogenic impacts, impacting the formation of CASS and the likelihood of extreme acidification within the system. Adopting a systems approach, it is apparent that the extremity of the Millennium Drought acidification event was intensified by factors other than drought, and that the triggering of extreme CASS acidification often exhibits a non-linear relationship to boundary condition changes, meaning negative impacts can be sudden and disastrous. Wave-dominated estuaries are particularly vulnerable systems, and changes predicted for an anthropogenically heated future will likely shift estuarine systems closer to thresholds where severe acidification can be expected.

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Diatta, Sekouna. "Improving Pearl Millet (Pennisetum glaucum (L.) R.Br.) Productivity in Salt-affected soils in Senegal: A Greenhouse and Field investigation." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/81975.

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The primary soil limitations to crop yield in the Senegalese "Peanut Basin" include salinity, acidity, and fertility. Crop yield may be increased by use of soil amendments and salt-tolerant cultivars. Objectives of this research were to evaluate salt tolerance of various millet (Pennisetum glaucum (L.) R.Br.) cultivars and compare effects of soil amendments on millet growth and yield in greenhouse and field studies. The research included two greenhouse experiments (i) comparing the salt tolerance of seven pearl millet cultivars (IBMV 8402, SOSAT C88, ICMV-IS 88102, IKMP1, IKMP2, IKMV 8201 and GAWANE) using five levels of electrical conductivity (0.3. 2.1, 4.2, 5.2 and 6.3 dS m-1) and (ii) assessing SOSAT C88 responses to various organic (compost and peanut shells) and inorganic (phosphogypsum; PG) amendments in manufactured saline soils (4.2 dSm-1); and (iii) a two-year (2014-2015) field experiment in Senegal evaluating the effects of local organic amendments (peanut shells and compost) on the responses of three millet cultivars (SOSAT C88, GAWANE and IBMV 8402) under low and high soil salinity. Cultivars SOSAT C88 and IBMV 8402 performed best in saline greenhouse media. The soil amendments that elicited the best millet plant responses in the greenhouse experiment were yard waste compost and peanut shells. Phosphogypsum exacerbated salinity effects by increasing electrical conductivity. In the field study, there were no differences among treatments. Cultivars IBMV 8402 and SOSAT C88 could be cultivated in saline soils amended with peanut shells.
Master of Science

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18

Wu, Xiaofen. "Structure and function of microbial communities in acid sulfate soil and the terrestrial deep biosphere." Doctoral thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-52538.

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This thesis describes the use of different DNA sequencing technologies to investigate the structure and function of microbial communities in two extreme environments, boreal acid sulfate soil and the terrestrial deep biosphere. The first of the two investigated environments was soils containing un-oxidized metal sulfides that are termed ‘potential acid sulfate soil’ (PASS) materials. If these materials are exposed to atmospheric oxygen by either natural phenomena (e.g., land uplift) or human activities (e.g., drainage) then the metal sulfides become oxidized and the PASS becomes acidic and is defined as an ‘acid sulfate soil’ (ASS). The resulting acid and metal release from metal sulfide oxidation can lead to severe environmental damage. Although acidophilic microorganisms capable of catalyzing acid and metal release have been identified from many sulfide mineral containing environments, the microbial community of boreal PASSs/ASSs remains unclear. This study investigated the physicochemical and microbial characteristics of PASSs and ASSs from the Risöfladan experimental field in Vasa, Finland. Sanger sequencing of 16S rRNA gene sequences of microorganisms present in the PASSs and ASSs were mostly assigned to acidophilic species and environmental clones previously identified from acid- and metal-contaminated environments. Enrichment cultures inoculated from the ASS demonstrated that the acidophilic microorganisms were responsible for catalyzing acid and metal release from PASSs/ASSs. Lastly, the study investigated how to mitigate metal sulfide oxidation and the concomitant formation of sulfuric acid by treating ASSs in situ with CaCO3 or Ca(OH)2 suspensions. The DNA sequencing still identified acidophilic microorganisms after the chemical treatments. However, the increased pH during and after treatment suggested that the activity of the acidophiles might be inhibited. This study was the first to identify the microbial community present in boreal PASSs/ASSs and suggested that treatment with basic compounds may inhibit microbial catalysis of metal sulfide dissolution. The second studied environment was the deep, dark terrestrial subsurface that is suggested to be both extremely stable and highly oligotrophic. Despite the scarcity of carbon and energy sources, the deep biosphere is estimated to constitute up to 20% of the total biomass on earth and thus, represents the largest microbial ecosystem. However, due to the difficulties of accessing this environment and our inability to cultivate the indigenous microbial populations, details of the diversity and metabolism of these communities remain largely unexplored. This study was carried out at Äspö Hard Rock Laboratory, Sweden and utilized second-generation sequencing to identify the taxonomic composition and genetic potential of planktonic and biofilm populations. Community DNA sequencing of planktonic cells from three water types at varied age and depth (‘modern marine’, ‘undefined mixed’, and ‘old saline’) showed the existence of ultra-small cells capable of passing through a 0.22 μm filter that were phylogenetically distinct communities from the >0.22 μm fraction. The reduced cell size and/or genome size suggested a potential adaptation to the oligotrophic environment in the terrestrial deep biosphere. The identified planktonic communities were dominated by Proteobacteria, Candidate divisions, unclassified archaea, and unclassified bacteria. Functional analysis of the assembled genomes showed that the planktonic population from the shallow modern marine water demonstrated a predominantly anaerobic and heterotrophic lifestyle. In contrast, the deeper, old saline water was more closely aligned with the hypothesis of a hydrogen-driven deep biosphere. Metagenomic analysis of subsurface biofilms from ‘modern marine’ and ‘old saline’ water types suggested only a subset of populations were involved in initial biofilm formation. The identified biofilm populations from both water types were distinct from the planktonic community and were suggested to be dominated by hydrogen fed, chemolithoautotrophic and diazotrophic populations.

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Groves, Sarah Anne Biological Earth &amp Environmental Sciences Faculty of Science UNSW. "Spatial and temporal variation in the hydrochemistry of marine prawn aquaculture ponds built in acid sulfate soils, Queensland, Australia." Publisher:University of New South Wales. Biological, Earth & Environmental Sciences, 2008. http://handle.unsw.edu.au/1959.4/43273.

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Many brackish water aquaculture ventures in Australia and overseas have established ponds in coastal regions with acid sulfate soils (ASS). Acid sulphate soils are known to leach relatively high concentrations of metals, acid (metal and H+ ion) and sulfur, however very little is known about how these leached elements affect the water quality of aquaculture ponds. The main objective of this thesis was to describe the hydrochemical processes controlling the water chemistry in the water column and sediment pore water in the studied aquaculture ponds over time and space. Water samples providing the spatio-temporal data were collected from the ponds with the use of adapted sampling methods commonly used in the groundwater environment. A transect of five nested piesometers was installed in two prawn ponds at Pimpama, south east Queensland, Australia. Each piesometer nest contained a multilevel with eight outtakes, a mini ?? horizontal, and a slotted piesometer. Water samples were collected from each nested piesometer on a bi-monthly basis over the prawn-growing season. The unstable elements and water quality variables (pH, Eh, DO, EC, water temperature) were measured in the field. Stable elements were analysed in the laboratory using ICP-OES and ICP-MS. Soil samples were collected at the end of the season for elemental analysis. A number of key sediment/water interactions and processes such as precipitation/dissolution reactions, oxidation-reduction reactions, photosynthesis, adsorption and seawater buffering were identified as important controls on pond water conditions. This is the first study to provide detailed hydrochemcial analysis of the pond water over time and space and aided in identifying that even shallow water bodies can be chemically heterogeneous. Analysis of the water and sediment highlighted the selection of metals that can be associated with ASS and that are mobilised from pond sediments under certain chemical conditions. In Pond 7 Al, As, Ni and Zn concentrations were generally higher at the beginning of the grow-out season. Variability of the metal concentration was observed between the water column (0 ?? 1500 mm) and the pore-water (0 - -1000 mm). The highest concentration of Al (1044 ??g/L) and Zn (104 ??g/L) were sampled in the water column (approximately 400 mm from the surface of the pond). The highest concentration of As (130 ??g/L) and Ni (73 ??g/L) were sampled in the pore water sediment (associated with ASS). Elevated Mn and Fe2+ concentrations were also associated with the sediment pore water. The highest concentrations of Mn and Fe2+ were 4717 ??g/L and 5100 ??g/L respectively. In Pond 10, Ni concentrations (167 ??g/L) were the highest at the beginning of the grow-out season. However, As (97 ??g/L), Al (234 ??g/L) and Zn (308 ??g/L) were most concentrated during the middle of the cycle. The highest mean concentrations of these elements are As (63 ??g/L), Al (91 ??g/L) and Zn (69 ??g/L) which are each associated with the sediment-water interface. These metals are integral in degrading the pond water quality and lead to a loss of beneficial algal blooms, a reduction in pond water pH, poor growth rates and high mortality in shrimp. It is also possible that the dissolved ions and precipitated compounds that are leached from the ASS are discharged into the adjacent coastal estuary of Moreton Bay. With knowledge obtained from this PhD study, effective management and treatment systems can be developed and implemented to minimise the impact of these soils on the pond system and the water discharging into natural coastal ecosystem.

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Isyrini, Rantih. "The effects of geochemical conditions on the establishment and growth of mangrove seedlings in acid sulfate soil environments." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/78681/1/Rantih_Isyrini_Thesis.pdf.

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Acid sulfate soils (ASS) is a stress factor that is responsible for the failure of some mangrove restoration projects, including abandoned aquaculture ponds converted from mangrove ecosystems. Through experimental and field studies, this research provides a better understanding of the biogeochemistry of ASS disturbance and the response of mangrove seedlings (Rhizophoraceae) under high metal levels and acidic conditions. This study found that mangrove restorations under ASS disturbance can work but with lower numbers of survived seedlings. To prevent toxicity under high levels of metal, seedlings retained metals in their roots and sparingly distributed them into aerial parts with low mobility. The presence of high levels of potential acidity parameters would allow pyrite to oxidise, thus increasing metal levels and acidity, which in turn affected the survival and growth of the seedlings.

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21

Blomkvist, Bella. "Temporal and spatial trends of heavy metal leakage from acid sulfate soils : Leakage of Ni, Zn, Cu and Fe to freshwater and marine sediments, North-eastern Sweden." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-174837.

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Acid Sulfate soils (AS) are recognized for being a source of acidity in freshwaters in America, Europe, Australia, and Asia. Apart from the problematic acid leachate, AS soil serves as a possible source of toxic heavy metals in freshwaters, a problem which has received far less attention than problems related to acid leachate. This study assessed to what extent heavy metals enriched in sediments from the area around lake Persöfjärden (North-eastern Sweden) could be attributed to export from AS soils. I found that: i) Nickel (Ni), Zink (Zn), Copper (Cu) and Iron (Fe) in the sediments had a partial likely origin from AS soils; ii) vertical variations in Ni, Zn, Cu and Fe concentrations suggested events of increased metal transport in the past; and iii) there is a tendency that Zn and Ni assumed from AS soils have caused elevated metal concentration in marine sediment deposited in Persöfjärden. Inferred sediment rates suggest that elevated metal concentrations occurred in sediment deposited during the 18-19th and 20th century. I argue that these periods correspond to periods of increased drainage of the AS soils during past agricultural activities in the catchment.

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22

Markström, Jimmy. "Is mercury mobilized from acid sulfate soils? : Interpreting the mercury record from lake- and marine sediments in Persöfjärden and adjacent sea bay." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171611.

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Acid sulfate (AS) soils are characterized by a large pool of sulfates which may provide significant amounts of acidity and heavy metals – commonly nickel (Ni), Cobolt (Co), Zinc (Zn) and Arsenic (As) - to surrounding surface waters. The occurrence of AS soils is widespread, covering 17 million ha globally, and they are known for threatening freshwaters in Australia, North America as well as in many tropical regions. Mobilization of mercury (Hg) from AS soils is however poorly studied and could potentially be an environmental problem of concern due to its toxicity and capacity of bioaccumulating in food webs. In this study I investigated whether Hg is mobilized from AS soils by conducting chemical analyses on sediment samples from a 1,6 m deep lake core and a transect of surficial sediment samples in an adjacent sea bay. Here, I used zircon (Zr) and zinc (Zn) as proxies for silicate sources and sulfide soil sources, respectively. I found that Zn and Hg concentrations normalized to the organic matter content (LOI) showed a significant correlation in the lake core; hence, Hg in the sediment co-varied with my sulfide proxy and showed no correlation to my silicate proxy, and I then conclude that a considerable fraction of mercury in the studied sediment has a likely origin from AS soils.

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MENDONÇA, Suzana Kelly Gomes de. "Caracterização de Solos Tiomórficos da várzea do Rio Camocim, Caaporã, PB." Universidade Federal Rural de Pernambuco, 2011. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5353.

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Submitted by (lucia.rodrigues@ufrpe.br) on 2016-08-16T14:23:12Z No. of bitstreams: 1 Suzana Kelley Gomes de Mendonca.pdf: 1457356 bytes, checksum: 55d06ce86944cd3f69644577e424587d (MD5)
Made available in DSpace on 2016-08-16T14:23:13Z (GMT). No. of bitstreams: 1 Suzana Kelley Gomes de Mendonca.pdf: 1457356 bytes, checksum: 55d06ce86944cd3f69644577e424587d (MD5) Previous issue date: 2011-02-25
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Low lands in Brazil have a great potential for agriculture, however, they have some limitations due to the presence of high water table and severe risk of flooding. When located near by the sea cost, these floodplains can have influence of the sea water, resulting in the presence of sulfide soils, which, if drained, can develop sulfuric horizons. The sulfuric horizons are mainly characterized by high levels of acidity and exchangeable aluminum, which can result in serious environmental impact to the ecosystem. The agriculture use of these soils requires a deep knowledge of soil physical, chemical and mineralogical properties, in order to support the development of sustainable management practices. The objective of this work was to study chemical and mineralogical properties of acid sulfate soils formed in the floodplain of Camocim river, Caaporã municipality, state of Paraíba. The main aim was to support decisions on the viability of sugarcane cropping in these areas. Soils were characterized morphologically and samples were collected along a transect from the high land towards the river channel. Besides the routine physical, chemical and mineralogical analysis, other determinations were carried out involving total sulfur, incubation pH, soluble anions, electrical conductivity of the saturation extract and sequential iron extraction. The soils were classified as: Argisolic,Dystric Tb Haplic Gleysol (P1) Typic Sapric Sulfide Organosol (P2), Organosolic Orthic Sulfide Gleysol (P3 and P4). Soil distribution in the landscape of the Camocim river floodplain is mainly related to the relief, which determines drainage, water table and, consequently, the soil forming processes related to water excess. The presence of sulfuric horizons occur at the surface, in the very poorly drained soil profiles, and at 43 cm depth in the poorly drained soils close to the river channel. The studied acid sulfate soils do not have salinity at present time, and the high electrical conductivity is determined by the formation sulfuric acid (H+ + SO4 2-) from pyrite oxidation. Sugarcane crop decay in the floodplain of Camocim River, after one year of cultivation was a consequente of the sulfuric horizon formation after the implementation of the drainage system in soils with sulfide materials. The main soil minerals, indentified by X-ray diffraction, in the clay fraction were jarosite quartz, feldspars, kaolinite, smectite (essentially montmorillonite), illite and gibbsite. Quartz and feldspars were the minerals identified in sand and silt fractions. The results of the iron sequential extraction showed predominance of non crystalline iron oxides and very low amounts or absence of iron associated with pyrite, reflecting the advanced oxidation stage determined by the drainage system.
As áreas de várzeas no Brasil apresentam um grande potencial para a agricultura, no entanto, estas áreas apresentam algumas limitações ao uso agrícola devido à presença de lençol freático elevado e risco freqüente de inundação. Quando localizadas em áreas litorâneas, estas áreas podem sofrer influência marinha podendo apresentar solos tiomórficos que, quando drenados, formam horizonte sulfúrico, caracterizados principalmente pela elevada acidez, elevados teores de alumínio trocável, podendo causar sérios impactos ambientais no ecossistema onde ocorrem. A incorporação destas áreas no processo produtivo depende de um profundo conhecimento das propriedades físicas, mineralógicas e principalmente químicas, de forma a subsidiar o desenvolvimento de técnicas sustentáveis de manejo. Neste contexto, foi realizada a caracterização física, química, mineralógica, além da extração sequencial de ferro de solos tiomórficos desenvolvidos na várzea do rio Camocim, no município de Caaporã, PB. O objetivo do estudo foi identificar a ocorrência de solos tiomórficos e caracterizá-los, com o fim de obter subsídios para a tomada de decisão de incorporar estas áreas ao cultivo de cana-de-açúcar ou mantê-las nas condições naturais. Para tanto foi feito um transecto perpendicular ao canal principal do rio, a partir das terras altas, onde foram descritos e coletados quatro perfis de solo. Em campo foi realizada a caracterização morfológica dos perfis e coletadas amostras para as análises físicas, químicas e mineralógicas de rotina, além de análises específicas para determinação do enxofre total, pH de incubação, ânions solúveis, CE do extrato da pasta saturada e extração sequencial de ferro. Os solos foram classificados como Gleissolo Háplico Tb Distrófico argissólico (P1), Organossolo Tiomórfico Sáprico típico (P2) e Gleissolo Tiomórfico Órtico organossólico (P3 e P4). A distribuição dos solos na várzea do rio Camocim guarda estreita relação com o relevo, que condiciona a drenagem e, consequentemente, os processos de formação relacionados com o excesso de água. A presença de horizonte sulfúrico foi constatada a partir do horizonte superficial nos perfis muito mal drenados da planície de inundação, e a partir de 43 cm, nos solos mal drenados da ombreira. Os solos tiomórficos estudados não apresentam salinidade, sendo a alta condutividade elétrica resultante da formação de ácido sulfúrico proveniente da oxidação da pirita (H+ e SO4 2-). A degradação do canavial em grandes áreas da várzea do rio Camocim, após um ano de cultivo, foi consequência da formação do horizonte sulfúrico com a drenagem da área, tendo em vista que os materiais sulfídricos ocorrem desde a superfície. Os minerais identificados por DRX foram: jarosita, quartzo, feldspatos, caulinita, esmectita (essencialmente montmorilonita), ilita e gibbsita, na fração argila. Quartzo e feldspatos foram os minerais identificados nas frações areia e silte. Os valores da extração sequencial de ferro mostraram predomínio de formas não cristalinas de óxidos de ferro e baixíssimos teores ou ausência de ferro associado à pirita, indicando que os solos tiomórficos estudados apresentam avançado estágio de oxidação, promovido pela drenagem realizada na área de estudo na tentativa de viabilizar o cultivo da cana-de-açúcar.

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24

Johansson, June. "Sediment chemistry and the potential toxicity to benthic invertebrates in sediments affected by acid sulfate soils : A study on freshwater and marine sediments in Västerbotten, Sweden." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-172323.

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The leakages of metals from acid sulfate soils and their potential toxicity to benthic invertebrates were studied in the sediment profiles of Lillkvasjön and Lövselefjärden - a lake and an estuary known to be affected by acid sulfate soils - in Västerbotten, northern Sweden. The concentrations of 25 different elements were analyzed throughout both sediment profiles through X-Ray Fluorescence (XRF) Spectrometer analysis. Organic matter was measured through loss-on-ignition (LOI). By performing correlation analysis and normalizations to LOI on all sediment variables, Cu, Fe, Ni, Pb, S and Zn were found to be leached from acid sulfate soils to both sites, while Mg and Mn were related to leakages from acid sulfate soils in Lövselefjärden. The concentrations of Cu (195 mg kg-1), Ni (55 mg kg-1), Pb (90 mg kg-1) and Zn (398 mg kg-1) in the surface sediment of Lövselefjärden were classified as potentially toxic to benthic invertebrates. In Lillkvasjön, Cu (210 mg kg-1) and Ni (87 mg kg-1) were classified to have an increased risk of negative impacts on benthic invertebrates, while the concentrations of Pb (121 mg kg-1) and Zn (329 mg kg-1) were likely to low to have any negative effects. These results strengthen previous finds of impacts from acid sulfate soils in the two catchment areas and elucidate the importance of further studies on the impact of acid sulfate soils on benthic invertebrates.

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Harris, Mark Anglin. "Some organic amendments for heavy metal toxicity, acidity and soil structure in acid-sulphate mine tailings /." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phh3148.pdf.

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26

Lusk, Mary Gilchrist. "Sulfate Dynamics and Base Cation Release in a High Elevation Appalachian Forest Soil." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36692.

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Two soils from the Fernow Experimental Forest near Parsons, West Virginia were characterized and evaluated in terms of their susceptibility to enhanced soil acidification via acidic atmospheric inputs. After initial physical, chemical, and mineralogical characterization, the soils were analyzed for their ability to adsorb and retain sulfate (SO42-) through a series of batch adsorption and desorption experiments. Reconstructed soil profiles were then subjected to water leaching as the preliminary step to a base release study in which each soil will be placed under simulated acid rain and evaluated for base cation release and subsequent changes in soil chemistry.

Experiments with SO42- adsorption and desorption divide the soils into two categories: (i) shallow surface horizons with high organic matter and little Fe oxide content which had little ability to adsorb additional SO42- and low capacity to retain SO42-; and (ii) deeper subsurface soils with low organic matter and high Fe oxide content which could adsorb SO42- at solution concentrations above 0.5 mmol/L. All soil horizons desorbed SO42- and had no ability for additional adsorption at solution concentrations below 0.5 mmol/L, which implies that the site may be saturated with respect to natural conditions. Initial mass (IM) and Langmiur modeling were used to illustrate SO42- dynamics and make correlations with soil physical, chemical, and mineralogical properties. Fe oxides and Al-saturated organic matter were shown to be the preferential sites for SO42- adsorption but may be already saturated or very near saturation.

Preliminary results from the base release study indicate that the two soils are dominated by different chemical processes and hence release ions into soil solution at different rates. Ion release is shown to be a function of both reactions on the exchange complex and the dissolution of mineral components.
Master of Science

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27

Belkacem, Saïd. "Étude de la restauration des sols acides soumis à de forts apports acides : effet des formes et doses d'amendements sur le fonctionnement d'un sol acide forestier." Nancy 1, 1993. http://www.theses.fr/1993NAN10282.

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La restauration des sols forestiers acides et leur dynamique sont abordées par l'étude des effets des formes et quantités d'amendements apportés, en interaction avec la qualité de l'humus. Le caco#3, caco#3+mgo et caso#4 sont apportés en surface avec des doses de 0, 0. 56, 2. 8 et 5. 6 t/ha équivalent cao et les principaux résultats sont: le sol: la valeur du ph du sol est augmentée de 4 unités ph dans les couches de surface (a#1) et d'une unité ph en moyenne en profondeur (b) avec les amendements carbonates. La restauration a été rapide (moins de 7 mois) dans les premiers centimètres du sol avec une migration également de particules de carbonates (>40% du ca) de la litière vers la couche a#1#1 (-3 cm). La saturation n'est pas modifiée dans les couches inferieures du (b) (16 a 21 cm), sauf pour la forme sulfate où elle a augmente de 50% par rapport au témoin. Les mécanismes d'échanges de l'aluminium par le calcium expliquent ces changements sur les surfaces d'échange; la solution du sol: par rapport au témoin, la composition des eaux a été modifiée rapidement (2 mois) par le sulfate avec un enrichissement du flux d'aluminium et de calcium. L'effet des carbonates sur la solution, sous (b) (-21 cm), a été moins rapide (7 mois). Les analyses des eaux montrent une modification de la dynamique de l'azote. Dans le traitement carbonate le mécanisme reste le même et l'anion dominant est le nitrate. Dans le traitement caso#4, l'anion vecteur est le sulfate, 52% de l'azote d'azote est transporté hors du profil sous forme d'ammonium

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Avenius, Joel. "Sänkta sjöars inverkan på ytvatten i Västerbottens kustland : Samband mellan sänkningsnivåer och vattenkemi i sjöar på sulfidrika sedimentjordar." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-62140.

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Lake lowering in sulphide-rich areas is currently a major environmental impact for surface water. This study focuses on whether there is a relationship between a gradient of lake lowering and surface water impacts in areas of sulphide-rich sediments, in order to better understand their contribution of heavy metals and sulfuric acid. Also, is it a reasonable method to use the reduced lake area in order to quantify the gradient? The survey was conducted by collecting water samples from reference lakes and lowered lakes from south to north in coastal areas within the county of Västerbotten. Water samples were then analyzed for TOC, pH, conductivity, anions, base cations, alkalinity, acidity, sulfate, Al, Cd, Fe, Mn, Cu, Zn and Pb. These parameters were then compared statistically using regression analysis and t-tests. The results show that no gradient was discernible in response to the reduced lake area. However, significant differences (p < 0,05) between the reference lakes and all the reduced lakes were visible for pH, conductivity, Cd, Cu, Zn and Al. The study shows that there is a correlation between lake lowering and negative impacts on surface water. However, to calculate a gradient from the reduced lake area is deficient as it is limited by the lakes volume reduction, and how the area around the lake has been affected. Further studies on the subject are therefore necessary.
FLISIK (för livskraftiga småvatten i kvarkenregionen)

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Eriksson, Blomberg Malin. "Sjöars inverkan på metallackumulationen i havsvikar - En undersökning av metallmobilisering från sura sulfatjordar." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-174671.

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Acid sulfate soils covers an area area about 600 km-2 along the coast line of Northern Sweden. These soils originate from land uplift and oxidized sulfide soils. The oxidation process releases sulfur and Fe(III) and will lower the pH-value and mobilize metals that will cause toxic environments for water living organisms. Concerns of how higher occurrence of extreme weather conditions will affect the mobilization of metals has occurred. Understanding of the mobilizations of metals in different catchment conditions is therefore important knowledge for preparation of risk analyzes to protect ecosystems from toxic effects. The aim of this study is to compare accumulation of metals in sediments from marine and limnic environments to investigate how lakes effects the mobilization of metals in catchments consisting of acid sulfate soil. Answering the questions of accumulation differences between the catchments and how organic matter affects the mobilization and accumulation of metals. Sediment cores were collected in two different catchment areas, known to be affected by acid sulfate soils, in Västerbotten county. 22 different elements were analyzed by x-ray fluorescence spectroscopy and Loss-on-ignition (LOI) was used as a proxy for organic matter. The results indicate that draining of land areas, often due to agriculture and deforestation, increases mobilization and accumulation of metals correlated with both organic and lithogenic fractions to a large extent. However, elements such as S, Ni, Zn, Fe, Cu, Na, Mg, Al, Rb, Sr and Zr are derived from mobilization from acid sulfate soils where elements with high correlation with organic matter accumulates in limnic environment conditions.

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Hägglund, Emma. "Misstänkt sulfidjord i deponi vid Stöcke, Umeå." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-112707.

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In the north of Sweden lots of the soil is naturally contaminated by acid sulfate. When soil gets in contact with oxygen an oxidation process begins which releases elements that may be harmful to the surroundings. When the Botniabanan was built, soil had to be transported from the railroad area to deposit sites. This study was made to investigate the suspicions a landowner had regarding if his estate had been contaminated sulphide soil soil during the building of the Botniabanan. To do that four pits were dug in the area where the soil had been deposited. Then the soil was analyzed to see the content of sulfate, iron, organic matters and water. When the results was compared to other studies it showed that the content of sulfate and organic matters was to low to classify the soil as an acid sulfate soil.

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31

Tran, Van Van. "Burkholderia vietnamiensis sp. Nov. , une protéobactérie fixatrice d'azote de la rhizosphère du riz isolée d'un sol sulfate acide : taxonomie et effets de l'inoculation sur la croissance et le rendement du riz." Nancy 1, 1994. http://www.theses.fr/1994NAN10369.

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Douze souches, parmi les plus abondantes dans la population des bactéries fixatrices d'azote, ont été isolées à l'aide du modèle spermosphère, de la rhizosphère du riz cultive sur un sol sulfate acide vietnamien. Les critères phénotypiques montrent que les souches appartiennent au genre burkholderia. L'absence de fixateurs d'azote dans ce genre a conduit à l'utilisation d'une approche polyphasique intégrant les hybridations ADN:ARNR, ADN:ADN, / et l'analyse auxanographique. Cette approche a permis de distinguer ces souches des espèces b. Cepacia et b. Gladioli et a conduit à la création d'une nouvelle espèce nommée b. Vietnamiensis. La production, par les souches de b. Vietnamiensis et de b. Cepacia, de sid »rophores d'un type nouveau, nommes ornibactines, et l'inhibition de la croissance de champignons phytopathogénes par ces souches ont été mises en évidences au laboratoire. La souche b. Vietnamiensis tvv75 a une activité fixatrice d'azote supérieure à celle des autres souches en présence de la plante. L'effet de promotion de croissance des plantes par b. Vietnamiensis est très fort, en particulier pour la souche tvv75 sur le sol alune acide. Dans un autre sol de type alluvial, les souches d'azospirillum autochtones ont un effet de promotion de croissance sur le riz supérieur aux b. Vietnamiensis. La souche tvv75 a été sélectionnée pour réaliser des essais d'inoculation du riz à grande échelle au Viêt-Nam sur trois sites alunes acides. L'inoculation a produit des augmentations significatives du rendement, entre 13 et 22%. Les mécanismes mis en jeu pouvant expliquer ces effets sont, la capacité de cette souche à fixer l'azote atmosphérique, à produire un puissant siderophore, et enfin, a inhiber certains champignons pathogènes. La constitution de mutants isogéniques permettra de vérifier ces hypothèses de façon claire

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HAMA, PATRICIA. "Estudo da influencia da chuva acida na concentracao de aluminio em solos proximos a uma termoeletrica a carvao." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10951.

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Made available in DSpace on 2014-10-09T12:46:00Z (GMT). No. of bitstreams: 0
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Matson, Johan. "Coffee grounds as an adsorbent for heavy metals in water treatment : Study based on the environment around Vattenriket, Kristianstad." Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-96299.

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One of the modern times worst environmental problem are polluted water resources. An example of source of pollution to water resources are, heavy metal leached from acid sulfate soils (ASS). When these soils are stable, which they are if they are left underwater in an anoxic environment (for example below the water table), they are often sought after since they consist of high amount of nutrients which farmers use as farmlands. ASS is therefore created when farmers drain their land and the sulfide soil gets exposed to air, resulting in its oxidation and therefore formation of sulfuric acid. In a previous study performed by scientists from Linnaeus University, it was concluded that a natural reserve located in Vattenriket, Kristianstad was possibly damaged by the drainage discharge of an adjacent acid sulfate soil. For remediation of acid sulfate soil, notably removal of metals from drainage waters, grounded coffee has been suggested to be able to perform well as an adsorbent. This study was performed to investigate how well grounded coffee could be used as an adsorbent, for calcium (Ca) and zinc (Zn), from water samples collected in Vattenriket, Kristianstad. It was also studied to see if grounded coffee could be cleaned using a sodium hydroxide solution to increase its adsorption capacity. To be able to evaluate how well it could be used as an adsorbent, it went through two different cleaning procedures and total organic carbon and pH readings was performed. The used method for this paper was to clean the grounded coffee in two different stages. The first stage consisted of using distilled water and letting it run through the residues until the water came out as transparent. Cleaning using a NaOH solution consisted of suspending the residues in a NaOH solution for 45 minutes and swapping the solution 6-8 times. After the grounded coffee had dried in an oven at 30o for 48 hours, it was put into different fraction sizes, weighed and bagged. The water samples then had to be filtered using a pump and Filtropur S 0.45 filters. Lastly, 45 falcon tubes containing 15 different amounts of grounded coffee had 50 ml of filtered water sample added to them. For analysis, atomic absorption spectroscopy was used. The results showed that the maximum amount of adsorbed calcium was achieved at 1.5g of grounded coffee in a 50 ml water solution which managed to adsorb 99.53% of calcium. The maximum amount of adsorbed zinc was achieved at 1.25g of grounded coffee in a 50 ml solution which resulted in 99.16% of adsorbed zinc. The study also showed that when the total organic carbon-content was decreasing, due to excessive cleaning, the pH was increasing. This was further proof that the grounded coffee still had residues onto its surface that could inhibit its adsorption capabilities.

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Tshibanda, Kabumana Dieudonne. "Contribution à la recherche d'un modèle de gestion d'un passif envronnemental issu d'un traitement métallurgique des minerais sulfurés cuivre zinc en République Démocratique du Congo." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209618.

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Ce travail traite d’un problème de pollution liée à la présence de métaux de base dans des passifs environnementaux issus d’un traitement métallurgique des minerais sulfureux cuivre – zinc provenant de la mine de Kipushi en République Démocratique du Congo. L’objectif principal de ce travail a été d’arriver à proposer des scénarios de gestion durable au passif environnemental de la filière présentant les risques environnementaux les plus élevés. Pour cela, on a d’abord procédé à une identification des différents problèmes environnementaux tout au long de la filière de traitement sur les quatre sites d’exploitation. Ensuite on a prélevé des échantillons puis procéder par des tests de disponibilité à la lixiviation à l’eau déminéralisée pour évaluer les fractions solubles des métaux de base présents et aussi par des tests de conformité de mise en décharge afin de classer ces rejets conformément à la directive européenne 2003-33-CE. Ainsi, les rejets Ex – UZK ont été identifiés comme les plus dangereux de la filière au regard de cette directive, car les quantités lixiviées de cuivre et de zinc dans ces rejets ont dépassé largement les limites fournies par la directive, et donc ils ne peuvent même pas être mis en décharge de classe I sans traitement métallurgique préalable pouvant permettre leur dépollution.

Par contre, les autres rejets de la filière, en l’occurrence les rejets de flottation de Kipushi et les scories de fusion pour matte de cuivre, peuvent eux être acceptés en décharge de classe I, sans traitement préalable au regard des limites fournies par la même directive. Les procédés de lixiviation acide chaude et de digestion ont été proposés et retenus comme scénarios de gestion durable à appliquer à ces rejets Ex – UZK, car ils se réalisent tous deux en milieu acide sulfurique d’une part et d’autre part leur application et surtout leur faisabilité en République Démocratique du Congo reste possible ;en outre ils aboutissent à des nouveaux rejets contenant le fer sous forme d’hématite, pouvant être stocké aisément et durablement dans la nature, ce qui est conforme au principe du développement durable. Nous avons tenté de modéliser ces deux scénarios en discutant et comparant la circulation des flux de matière dans les deux procédés, d’abord autour de chaque opération métallurgique unitaire, et ensuite sur l’ensemble du procédé. Ainsi nous avons pu chiffrer tous les flux entrant et sortant dans le système étudié, en considérant 1000 kg de rejets Ex –UZK alimentés. Cette quantification nous a permis de comparer les coûts opératoires de ces deux procédés. Les résultats obtenus dans la présente étude sont encourageants et nous ont permis de formuler des recommandations pour les études ultérieures éventuelles dont les résultats pourront l’enrichir davantage, notamment sur les aspects technologiques, économiques et environnementaux, de manière à faciliter les applications sur terrain.

This work deals with environmental liabilities consisting of base metals pollution due to metallurgical processing of copper – zinc sulphide ores in Kipushi mine in Democratic Republic of Congo. The main objective of this work was to propose sustainable management scenarios for the most important environmental liabilities from metallurgical sector. For this purpose, liabilities were first identified on four metallurgical plants. Then, leaching tests with deionized water were carried out to assess the soluble fractions of base metals. These effluents were also classified according to the test described in european decision 2003-33-EC, which determines the conformity of waste to landfill. Ex – UZK effluents are the most dangerous from this sector, according to this directive, since the quantities of leached copper and zinc were far beyond the limits :they cannot be sent to class I landfill without prior metallurgical processing. However, other effluents like flotation wast and Lubumbashi slag originating from melting for copper matte, are acceptable without prior treatment. Hot acid leaching and digestion were proposed as sustainable management scenarios for to these Ex – UZK waste because :both can be performed in sulfuric acid and they are feasible in Democratic Republic of Congo. They also lead to an iron – rich waste consisting of hematite that can be stored easily and sustainably in nature, which is consistent with the principle of sustainable development. We have modeled these two scenarios by discussing and comparing the flows in both processes, first for each individual metallurgical unit process, and then for the whole chain of value. So we could assess all the inputs and outputs of the studied system, expressed per ton of Ex – UZK waste. The operating costs of both processes were calculated and compared. The results are encouraging. Recommendations were proposed for further studies, in order to investigate more deeply the technological, economical and environmental aspects, to facilitate the final application.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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Lindquist, Thérese. "Undersökning av mängden organiskt kol i ett område med sura sulfatjordar i Kristianstads kommun." Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-89373.

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I Fredriksdalsvikens naturreservat i Kristianstads kommun skedde omfattande metalläckage efter en översvämning sommaren 2007 som orsakade skador på djur- och växtliv. De kraftiga metalläckagen misstänks härledas till sura sulfatjordar. Sura sulfatjordar tillhör de miljöskadligaste jordarna i världen på grund av de kraftiga metalläckagen och försurningen som jordarna orsakar till omgivningen. Mot bakgrund till humusämnens centrala roll för metalltransport i naturliga miljöer, syftade denna studie till att kartlägga hur organiskt kol är fördelat, sprids samt hur det kan förklaras i ett område nära det drabbade naturreservatet. Studien är en del av ett pågående forskningsprojekt i området som bedrivs på Linnéuniversitetet. I studiens undersökningsområde dominerar jordbruksmark som dräneras av ett dikessystem från norr till söder. Vattnet som avleds i dikessystemet pumpas slutligen till en våtmark i Fredriksdalsvikens naturreservat. I studien analyserades jord från åkermark, dikessediment, porvatten och dikesvatten från området på totalt organiskt kol med metoderna glödförlust och kyvett-test. Totalhalterna jämfördes med pH och grundvattennivå i åkermark. Resultat och slutsatser av studien är att högst halter löst organiskt kol uppmättes i dikesvattnet uppströms i dikessystemet och beror troligtvis på bottenfauna som inte växer i andra delar av systemet. I dikessediment ökar den organiska halten nedströms i dikessystemet och kan förklaras genom tillförsel av organiskt kol från två diken som dränerar åkermark rik på organiskt kol. De högsta halterna organiskt kol i jord beror på ett tunt torvlager. I åkermark visar inte resultaten någon tydlig statistisk korrelation mellan pH och totalt organiskt kol, men kraftig pH-sänkning tillsammans med höga totalhalter organiskt kol i torvjord beror troligtvis snarare på humusämnen än på sur sulfatjord. I åkermark väster om dikessystemet ökar den organiska halten med djupet under grundvattenytan. I samma åkermark ökar halterna av totalt organiskt kol lateralt mot dikessystemet, parallellt med att pH sjunker som troligen påverkas av starkare bindningsmekanismer till mineral, lägre mikrobiell aktivitet och minskad urlakning av löst organiskt kol. Men fler undersökningar i området krävs då markanvändning, erosion, jordarternas textur och sammansättning samt vattnets spridningsvägar också är avgörande faktorer för fördelning och spridning av organiskt kol i naturliga miljöer.
In the nature reserve Fredriksdalsviken in Kristianstad municipality, extensive metal leakage occurred after a flood in the summer of 2007 that caused damage to wildlife and plant life. The heavy metal leaks are suspected to be derived from acid sulphate soils in the area. Acid sulphate soils are among the most environmentally harmful soils in the world due to its extensive acidification and leaching of metals to the environment. In the light of humic substances key role for metal transport in natural environments, this study aimed to investigate how organic carbon is distributed, spread and how it can be explained in an area near the affected nature reserve. The study is part of an ongoing research project in the area conducted at Linnaeus University. The study area is dominated by agriculture land which is drained by a ditch system from north to south. The drained water in the ditch system is finally pumped to a wetland in the Fredriksdalsviken nature reserve. In the area, total organic carbon was analysed on soil from arable land, ditch sediment, pore water and ditch water with the methods loss of ignition and cuvette-test. Total levels were compared with pH and the groundwater level in arable land. The results and conclusions of the study are that the highest content of dissolved organic carbon in the ditch water upstream the ditch system is probably due to benthic fauna that doesn’t grow in other parts of the system. In the ditch sediment, the organic content increases downstream in the ditch system and can be explained by the supply of organic carbon from two ditches that drain arable land rich in organic carbon. In arable land are the highest levels of organic carbon due to a thin peat layer. The results does not show a clear statistical correlation between pH and total organic carbon in soil, but a sharp decrease in pH together with high total levels of organic carbon in peat soil is probably due to humic substances rather than to acid sulphate soil. In the western arable land of the ditch system, levels of total organic carbon increase laterally towards the ditch system at the same time as the pH decreases, which is probably affected by stronger binding mechanisms to minerals, lower microbial activity and reduced leaching of dissolved organic carbon. However, more research is required in the study area, since land use, erosion, soil texture and constitution together with the flow paths of water also are crucial factors for the distribution and pathways of organic carbon in natural environments.

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Hagenby, John. "Sura sulfatjordar och vattenkvalitet Vattenmätningar från Vörå å 1969–2017." Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-75741.

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Sura sulfatjordar (SSJ) bildas på tidigare havsbottnar med sulfidhaltiga sediment som med landhöjningen har lyfts upp ur havet och genom grundvattensänkande aktiviteter exponerats för syre. Vörå å är ett vattendrag i västra Finland som är kraftigt SSJ-påverkat. Närings-, trafik- och miljöcentralen i Österbotten har gjort vattenmätningar i Vörå å i flera decennier och syftet med detta arbete var att strukturera, beskriva och tolka tidigare obehandlade data från vattenmätningar som gjorts mellan 1969 och 2017 och därmed synliggöra årstidsvariationer och förändringar i vattnets kemiska sammansättning över tid. Vattenkvaliteten i Vörå å var allra sämst under höst och vår: pH <5, höga sulfathalter och konduktivitet om 25–100 mS/m. Suspenderat material och turbiditet var som högst i april medan pH, konduktivitet, järnhalt och COD var som högst under sommaren. Variationerna i vattnets kemiska sammansättning var minst under våren och störst under sommaren då flera variabler uppvisade en mycket stor spridning. I slutet av mätperioden uppvisade många variabler en liten bättring och vad denna beror på är oklart. I och med klimatförändringar har årsmedeltemperaturerna i Finland stigit vilket skulle kunna tänkas påverka tiden för högflöden. Det finns tecken i datan som tyder på sådana förändringar sedan 1970-talet. Metallmätningar som gjorts under 2000-talet jämfördes mot bakgrundsvärden, vissa uppvisade förhöjda värden.
Acid sulphate soils (ASS) form in sulphide bearing marine sediments that have been exposed to atmospheric oxygen caused by eustatic uplift and draining of cultivated fields. The river Vörå å, in western Finland, is a small stream that is severely affected by ASS. Finnish authorities have during decades sampled and analysed the water, but the data has not been interpreted. The objective of this study was to structure, describe and interpret previously untreated analyses data of the water samples from the years 1969 to 2017. Wa-ter quality was in general very bad and the worst situations occurred during springs and late autumns with pH <5, high sulphate concentrations and EC between 25–100 mS/m. Suspended solids and turbidity peaked in April while pH, EC, iron concentration and COD were highest during the summer. The variations in the chemical composition of the water were lowest during the spring and most widespread during the summer. At the end of the measurement period, many variables showed a slight improvement, the reason for this is unclear. Due to climate change the mean temperatures in Finland have increased, this may possibly affect the timing for snow melt in the spring and the time for flooding during the autumn. There are signs in the data indicating such changes. Metal concentra-tions from samples collected since 2005/2010 were compared with regional background values. Some metals demonstrated high concentrations.

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Reilly, Richard John. "Nitrate reduction in agricultural acid sulfate soil." Phd thesis, 2011. http://hdl.handle.net/1885/149927.

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A significant proportion of Australia's sugarcane crop is grown on east-coast estuarine floodplains underlain by pyritic gel-clay subsoils. At the current study site these agricultural acid sulfate soils are typically characterised by a topsoil horizon of river alluvium, a subsoil of oxidised actual acid sulfate soil (AASS), a zone of partially oxidised AASS and a deep sulfidic horizon of pyritic potential acid sulfate soil (PASS). Addition of nitrogenous fertiliser at key points in the sugarcane cropping cycle can create soil nitrogen levels in excess of immediate soil flora/fauna and crop requirements. In high rainfall tropical and sub-tropical regions conditions are thus suitable for nitrate, a strong oxidising agent, to leach down to the sulfidic soil layers with the consequent risk of pyrite oxidation. Little information is available on the fate of nitrogenous fertilisers in these pyritic subsoils. The purpose of this field and laboratory study was to evaluate the potential for nitrate reduction to occur in the presence of pyrite in sugarcane soils in the Tweed River valley, northern NSW, Australia. The study focus was on examining the soil profile hydrology including leaching mechanisms and nitrate concentrations down the profile to the AASS/PASS interface, as well as evaluating the potential for nitrate to increase the rate of pyrite oxidation in this generally anoxic soil zone. Following an investigative nitrogen field trial to gather initial data, a second replicated urea fertiliser treatment trial with a nil-treatment control plot and three nitrogen (N) treatments was set up on a plant-cane-block in collaboration with a Tweed region cane grower, Robert Quirk. Installed loggers recorded rainfall, air and soil temperature, soil moisture and watertable data. Separate surveys and analytical work characterised selected soil physical, morphological and geochemical aspects. Soil profile sampling on four occasions over the twelve month crop cycle was analysed for N-species, NH{u2084}{u207A} and N0{u2083}{u207B}. Hydraulic data analysis showed the watertable generally varying between 0.2 and 1.4 m below ground level with observed strong and rapid responses to rainfall events greater than approximately 15 mm per day. This and associated data supports the postulate that soil nitrate could move down the profile under even moderate precipitation events in these soils. Temperature, pH, redox potential and biological substrate soil data demonstrated the biogeochemical suitability of these subsoil zones to support nitrate reduction. Soil-N analysis revealed significant differences between N-trial treatments using urea fertiliser and also significant nitrogen transformation and movement within the soil profile. Over a period of weeks, the urea fertiliser was rapidly transformed and appeared in the upper profile as elevated levels of ammonium and nitrate ions. The initial high ammonium levels quickly declined to be replaced almost completely by nitrate in the upper layers of the cane soil. Subsequently, increasing soil nitrate concentrations were evident deeper in the soil profile on higher nitrogen treatment plots during the middle phase of the crop cycle. In no instances were significant levels of nitrate detected below the soil redoxcline (the oxic-anoxic boundary) at around 1.0 m depth, nor was nitrate pooling evident anywhere in the AASS transition zone. Laboratory experimental work was undertaken to evaluate nitrate reduction coupled with pyrite oxidation under the biogeochemical conditions existing in the AASS transition zone. Results indicated that nitrate reduction associated with pyrite oxidation does take place in pyritic gel clay from the field site.

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Yuan, Chaolei. "Remediation of acid sulfate soils by organic matter addition." Thesis, 2015. http://hdl.handle.net/2440/104712.

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Acid sulfate soils (ASS) are soils containing iron sulfide minerals (predominantly pyrite) and/or their oxidation products. ASS have a large distribution in the world (10⁷−10⁸ ha coastal ASS) and in Australia (215,000 km²). Sulfide in ASS is formed from sulfate in sea water or fresh water under anaerobic conditions by sulfate-reducing bacteria, which need organic matter (OM) as the energy source. Sulfide then reacts with dissolved Fe(II) to form pyrite. Sulfuric material (containing sulfuric acid) is formed during oxidation of ASS with sulfidic material (containing sulfide minerals), resulting in significant release of acid and dissolved metals that can have detrimental effects on soil and water quality and thus ecosystem services. Remediation of sulfuric material and prevention of oxidization of sulfidic material are therefore of great environmental concern. Conventional remedial strategies, such as liming sulfuric material and covering sulfidic material with water or non-ASS soil, can be costly or not practically feasible due to the large amount of lime, water or soil required. Organic matter (OM) is the energy source for sulfate reducers, which play a critical role in the formation of sulfidic material and generate alkalinity during sulfate reduction. OM could influence the oxidation of pyrite through oxygen consumption by OM decomposers, complexation of ferric iron, and coating of pyrite. OM can also buffer acid generated from pyrite oxidation. However, the availability of native OM in ASS can be low due to binding to clay particles, occlusion in aggregates, or complexion by dissolved metals. Therefore application of OM may be an economical and environmentally friendly option to remediate ASS. But systematic studies are required on the effectiveness of OM application for the management of ASS. Ten ASS with sulfuric material, with pH increased to 5.5 and OM (finely ground mature wheat straw) added at 2% (w/w) separately or combined, were incubated submerged for 36 weeks. Unamended soils served as controls. Only the combined treatment (pH increased and OM added) increased the concentration of reduced inorganic sulfur significantly compared to the control and had higher soil pore water pH than the treatment with only pH increased. But the stimulation of sulfate reduction compared to the control of the combined treatment differed among soils which could be attributed to the initial soil properties. Stimulation of sulfate reduction in the combined treatment was negatively correlated with soil clay content and initial nitrate concentration. Clay can limit the availability of the added OM by binding and nitrate is a competing electron acceptor for sulfur reduction. In a subsequent experiment, ASS with smaller increase in sulfate reduction compared with other soils in the previous study were incubated with up to 6% (w/w) OM added for 36 weeks. The concentration of reduced inorganic sulfur increased with OM addition rate, with the increase between 4% and 6% being smaller than that between 2% and 4%, suggesting that besides OM other factors influenced sulfate reduction. Further, the impact of nitrate (competing electron acceptor) at different OM addition rates on sulfate reduction was examined. Nitrate addition inhibited sulfate reduction but the extent was smaller with OM added at 4% compared to 2%, indicating that the inhibition by nitrate was overcome by higher OM addition. In the two following experiments, the effect of OM addition on oxidation and acidification of sulfidic material was investigated by laboratory incubation under oxidizing conditions for 6 weeks. In the first experiment, OM (finely ground mature wheat straw) was added to a sulfidic material at 3% (w/w) as a layer on the soil surface or by mixing into soil. Soil pH decreased by 0.9 unit in the unamended control, increased by 0.2 unit in the treatment with OM as a layer, and increased by 0.8 unit in the treatment with OM mixed into the soil. In the second experiment, 1, 2, 3, and 4% (w/w) OM was mixed into the sulfidic material. The pH decrease was strongest in the unamended control and was smaller with 1% and 2% OM. Only 3% and 4% OM addition prevented acidification. However, the increase in soil sulfate concentration was similar in all the amended treatments. Prevention of acidification of sulfidic material by OM addition can be explained by consumption of oxygen by OM decomposers and pH buffer capacity of OM.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Agriculture, Food and Wine, 2015.

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Gröger, Jens [Verfasser]. "Acid sulfate soils : processes and assessment / vorgelegt von Jens Gröger." 2010. http://d-nb.info/1011005603/34.

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Chen, Huey-Shan, and 陳慧珊. "Spatial distribution of slopeland acid sulfate soils in northeastern Taiwan." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/61067130394141621168.

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碩士
國立中興大學
水土保持學系所
105
Generally, grasses are the pioneer plant in disturbed area and then successes to woody plants under subtropical and high humidity climate in northeastern Taiwan. However, Rui-Fang is a mining area with abandonment coal mine. Because the mining activity from 1895 to 1990, tailings of coal mine with high sulfides is vulnerable to oxidized to sulfuric acid and then cause Acid Sulfate Soils (ASS). Therefore, vegetation growth and succession will be disturbed by ASS so the distribution of ASS can be an important index for retarding vegetation succession. In this study, the areas of grass land were delineated by imageries of SPOT and Google Earth. Furthermore, the reason of grass land distribution would be discussed with topographical factors (elevation, slope and aspect) and the distance from coal mines coupled with cluster and discrimination analysis. Finally, the verification of delineation results for ASS which is potential area of mines tailings was compared with field survey and environment geology map draught by Industrial Technology Research Institute. The results showed that the overall accuracy of grass land reached 92.8%. The higher ratio of grass land in a subdivision has, the higher discrimination accurate it is. According to the study results, the grass land could be extracted by satellite images. The potential distribution of mines tailings would be delineated by environment indices such as topographical factors and the distance from coal mines coupled with statistical analysis in order to avoid secondary use of mines tailings.

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Kinsela, Andrew Stephen School of Biological Earth &amp Environmental Sciences UNSW. "Volatile sulfur compounds in coastal acid sulfate soils, northern N.S.W." 2007. http://handle.unsw.edu.au/1959.4/40889.

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The cycling of biogenic volatile sulfur compounds (VSCs) within marine and terrestrial ecosystems has been shown to play an integral role in atmospheric chemistry; by influencing global climate change through the creation of cloud condensation nuclei and controlling acid-base chemistry; as well as influencing sediment chemistry including the interactions with trace metals, particularly regarding iron sulfide formation. Despite this, the examination of VSCs within Australian coastal acid sulfate soils (ASS) is an unexplored area of research. As ASS in Australia occupy an area in excess of 9 M ha, there is a clear need for a greater understanding of the cycling of these compounds within such systems. This thesis looks at the concentrations of several VSCs within agricultural and undisturbed ASS on the east coast of Australia. Initial measurements of sulfur dioxide (SO2) were made using passive diffusion samplers, which were followed by two detailed field-based studies looking at the concentrations and fluxes of both SO2 and hydrogen sulfide (H2S) using flux-gradient micrometeorological techniques. These novel results indicated that this agricultural ASS was a substantial source of atmospheric H2S (0.036-0.056 gSm-2yr-1), and SO2 (0.095-0.31 gSm-2yr-1), with flux values equating to many other salt- and freshwater marshes and swamps. The flux data also suggested that the ASS could be a continual source of H2S which is photo-oxidised during the daytime to SO2. Measurements of both compounds showed separate, inverse correlations to temperature and moisture meteorological parameters indicating possible contributing and / or causal release factors. Further identification of these and other VSCs within ASS samplers was undertaken in the laboratory using gas chromatography in combination with solid-phase microextraction. Although SO2 and H2S were not discovered within the headspace samples, two other VSCs important in atmospheric sulfur cycling and trace metal geochemistry were quantified; dimethylsulfide (DMS; > 300??g/L) and ethanethiol (ESH > 4??g/L). The measurements of H2S, DMS and ESH are the first quantifications with Australian ASS, and they may be important for refining regional or local atmospheric sulfur budgets, as well as interpreting previous SO2 emissions from ASS. Ultimately this thesis further enhances our understanding of the cycling of VSCs within acid sulfate systems.

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Poolpipatana, Sunthorn. "Chemistry and mineralogy of acid sulfate soils and potential utilization of green manures as acid soil amendments." Thesis, 1994. http://hdl.handle.net/10125/9266.

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Broughton, John D. "Element behaviour in inundated actual acid sulfate soils, East Trinity, Cairns." Thesis, 2008. https://researchonline.jcu.edu.au/2126/1/01front.pdf.

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Actual Acid Sulfate Soils (AASS) undergoing inundation with seawater were examined for: 1) element distributions; 2) element mobilisation during seawater inundation; 3) the fate of elements mobilised during inundation; and 4) element phytoavailability. Seawater inundation is a potential method of ameliorating the acidic soil conditions and on-going release of elements in toxic concentrations frequently associated with AASS. The key research question to be answered by the study was: What are the effects of seawater inundation on the distribution, hosting, fate and phytoavailability of elements in actual acid sulfate soils? Elements examined were Al, As, Co, Cr, Cu, Fe, Mn, Na, Ni, Pb, Sc, V and Zn. Barium, Ga, Nb, S, Ti, and Zr were also frequently determined to assist with interpretation of geochemical processes in the ASS. This project focused on the behaviour of elements in selected soil profiles and sites at East Trinity, north Queensland. A statistical description of Acid Sulfate Soils (ASS) properties and quantitative modelling of the element losses and gains for the entire East Trinity site were beyond the scope of the project. The study site was the Firewood/Magazine Creek catchment of East Trinity. East Trinity is a 900 ha parcel of coastal lowland opposite Cairns city on Trinity Inlet in North Queensland. In the 1970s, East Trinity was reclaimed ostensibly for sugar cane production using a 7.2 km bundwall and one-way floodgates. The site contained large areas of Potential ASS (PASS) that oxidised and acidified during the reclamation to form AASS. AASS is PASS that has acidified (due to oxidation) to a soil pH of less than four. PASS typically has near neutral soil pH values. Widespread AASS formation led to extensive vegetation death on the site and the discharge of drainage waters with high loads of Al, Fe and Zn. Frequent fish kills were reported in creeks receiving waters from the AASS. In 2000, the Queensland State Government acquired the site with a view to rehabilitation. The ASS rehabilitation method selected used repeated seawater inundation of the AASS and management of water quality with lime dosing. Seawater inundation of AASS theoretically neutralises the soil acidity of, and stops further oxidation/starts reduction in, the AASS. By neutralising soil acidity and stopping oxidation/starting reduction, seawater inundation addresses the acidity and element mobilisation issues that are the source of the environmental harm associated with AASS. However, seawater inundation also has the potential to cause a second event of element mobilisation because of the formation of reducing conditions in the previously oxidised AASS. The geochemistry of seawater Inundated AASS (IAASS) had not been documented in the literature. Thus, a geochemical characterization of IAASS was developed based on the following principles: 1) IAASS formed from AASS, and both IAASS and AASS formed from PASS; therefore IAASS and AASS should contain similarly low concentrations of elements (e.g. Co, Mn, and Zn) that are lost during PASS oxidation; 2) IAASS would have a near neutral soil pH, because soil acidity would be neutralised by seawater inundation; and 3) IAASS would be enriched in Na (particularly in the water-soluble and exchangeable fractions) compared to AASS, because of increased contact with seawater. Using these principles, ASS matching the proposed properties was identified in an ASS profile taken from a seawater inundated area of the Firewood Creek catchment. The geochemistry of the AASS, IAASS and PASS from Firewood Creek was dominated by Si, Al and Fe. Comparison of the ASS compositions with ANZECC and ARMCANZ (2000) sediment quality and the NEPC (1999) soil quality guidelines identified environmentally significant concentrations of As (> EIL, ISQG-Low), Ni (> ISQL-Low) and V (> EIL). Isocon Analysis (IA) was used to identify element enrichment/depletion in an inundated (IAASS containing) and a non-inundated (AASS containing) ASS profile. IA used the immobile elements Ba and Ti to establish the isocon relationship between altered and parent samples. Cobalt, Mn, Ni and Zn were extensively depleted from both ASS profiles, likely during PASS oxidation. Sodium was depleted in the dry ASS profile and enriched in the wet ASS profile. Iron was depleted from the middle sections of both ASS profiles, with the depletion in the wet ASS profile being more extensive. The probable cause of the increased depletion of Fe in the wet ASS profile was extended periods of reducing conditions caused by more extensive seawater inundation. Copper and Pb displayed similar behaviour to Fe, suggesting they were associated with Fe in the ASS, likely by sorption onto oxidised Fe phases. Examination of element hosting using two Sequential Extraction Procedures (SEPs) identified reductive dissolution as the geochemical process responsible for Fe depletion in the IAASS. The two SEPs were the Geological Survey of Canada (GSC) SEP and the Modified BCR (MBCR) SEP. Iron was largely hosted by the reducible fraction in the AASS (i.e. oxides). In the IAASS, the size of the Fe reducible fraction was smaller by a third compared to the AASS. This indicated that Fe in the IAASS was mobilised by the reductive dissolution of Fe oxides during inundation. A combination of seawater inundation and organic matter likely generated reducing conditions in the inundated ASS profile and was hence the probable cause of the reductive dissolution of the oxidised Fe phases. The Fe mobilised from the IAASS was transported by egressing soil-waters and precipitated in the drains servicing the inundated areas. The Fe that precipitated from the egressing waters flocculated as chemical sediments in the drains. The drain sediments consisted of Fe precipitates in various states of oxidation/reduction. The geochemistry of the drain sediments was variable, but uniformly dominated by Fe, Si, Al and LOI. The mineralogy was largely crystalline and amorphous Fe oxides and detrital silicates. Trace element concentrations in the drain sediments were generally low compared to the ASS. Arsenic was the only trace element that demonstrated substantial enrichment. Comparison of the drain sediment geochemistry with the ANZECC and ARMCANZ (2000) sediment guidelines identified environmentally relevant concentrations of As, Cu and Ni. More than 75 % of the drain sediments sampled contained more As than the ISQG -Low, and the largest value from the drain sediments exceeded the ISQG-High. Copper and Ni concentrations in the drain sediments were also greater than the ISQG-Low values in more than 25 % of samples. The drain sediments were found to be a potential source of rapid acidification and element release in the Firewood Creek catchment. Soil pH (pHF) and oxidised soil pH (pHFOx) values indicated that the drain sediments rapidly acidified on oxidation, likely because of sulfide oxidation and Fe hydrolysis. Examination of element hosting and pHF and pHFOx data from the drain sediments indicated that the greatest threat with regard to element mobilisation was oxidation. This was because oxidation and the resultant acidification of the drain sediments would cause the release of elements from both the oxidisable fraction and the acid extractable fraction. Sediments from the mouth of Firewood Creek were found to have increased their concentration of As, Fe, Ni and Pb between July 2002 and April 2004. This period coincided with increased seawater inundation of the Firewood-Magazine Creek catchment. This indicated that more extensive seawater inundation of the Firewood Creek catchment caused an increase in the transfer of As, Fe, Ni and Pb from the ASS to the mouth sediments. Plant samples growing in the IAASS were collected for element bioavailability assessment. Species collected were the mangrove fern Acrostichum speciosum and the grass Paspalum vaginatum. Comparison of element concentrations in the stems from the Acrostichum speciosum samples collected from IAASS with the background samples showed larger median concentrations of Co, Cr and Zn. Median concentrations of Cu and Zn were higher in the stems Paspalum vaginatum from the IAASS than the background locations. This indicated that Co, Cr, Cu and Zn were potentially more phytoavailable in the IAASS. Comparison of element concentrations in the stems of Paspalum vaginatum with the NRC (1980) animal feed guidelines identified Al concentrations toxic to cattle (> 1,000 ppm), horses and pigs (> 200 ppm). However, the toxic Al concentrations did not appear to be related to AASS inundation. The research showed that seawater inundation was rehabilitating AASS in the Firewood-Magazine Creek catchment on East Trinity. This was demonstrated by the near neutral soil pH values of IAASS. However, Fe was mobilised during AASS inundation. The mobilised Fe contributed to the formation of chemical sediments in the drains servicing areas of IAASS. Furthermore, inundation of the Firewood Creek catchment may have increased the concentration of As, Fe, Ni and Pb in mouth sediments of Firewood Creek. Based on the findings of the project, it is recommended that controlled seawater inundation (i.e. inundation to a constant elevation) of Firewood Creek be maintained and closely monitored. Inundating the AASS of Firewood-Magazine Creek catchment to a constant elevation will continue the rehabilitation of the AASS, as well as mitigate the risk of oxidation of the drain sediments. Plants should be monitored for element concentrations. Site management should include minimising wild and domestic animal exposure to toxic element concentrations from plants growing in the areas of AASS inundation. Finally, the mouth sediments of Firewood Creek showed increased concentrations of elements mobilised during seawater inundation of AASS. Monitoring of the sediments of Firewood Creek should be conducted to assess the changes in the element concentrations of the sediments during the rehabilitation.

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44

Heath, Lance. "An integrated approach to the remediation and management of coastal acid sulfate soils." Phd thesis, 2004. http://hdl.handle.net/1885/146393.

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45

Mayakaduwage, Sonia Samanthi. "Influence of pH, phosphorus addition and soil water content on phosphorus pools in acid sulfate soils." Thesis, 2020. http://hdl.handle.net/2440/128818.

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Acid sulfate soils (ASS) are common in wetlands and important for crop production. However, little is known about P availability in ASS which is constrained due to high Fe content and changing redox potential. This thesis aimed to investigate the effect of P addition, pH and soil water content on P pools in ASS. A sandy sulfuric ASS (pH 3.2) was used in the experiments. In the first experiment, the ASS was amended with NaOH or Ca(OH)2) to achieve soil pH 4 or 5.5, without or with addition of inorganic P equivalent to 20 kg ha−1. Soils were incubated in either submerged or moist conditions (100% of maximum water holding capacity). After two weeks, P pools and Fe /Al oxides were determined. P pools were higher with P addition than without. The increase in pH enhanced Fe oxides but had little effect on labile P. Added soluble P was available after two weeks of addition under submerged conditions. In Experiment 2, the ASS (pH adjusted to 5.5) was amended with phosphate at 0, 96, 385, 578 and 770 mg P kg−1 and incubated under submerged conditions. P pools were measured after two and four weeks. Sorption and release of P were determined in incubated soils and jarosite, separately. The maximum sorption capacity of the soil was 350 mg P kg-1. Jarosite had a high capacity to bind P and contributed about 50% to P binding in this soil. Labile P represented more than 50% of added P at P rates above 350 mg P kg-1. The third chapter included two experiments. In the first experiment, the ASS (pH adjusted to 5.5) was amended with 400 mg P kg-1 as inorganic P, manure or combinations of inorganic P/manure and was incubated submerged. After two and four weeks, labile P was measured. Labile P in treatments with 50% of P added as manure was about half of that in treatments with a greater proportion of inorganic P. In the second experiment, treatments (inorganic P alone: 100F, manure alone: 100M, combination of manure and inorganic P: 50M/50F and unamended control) were kept submerged, then moist, followed by resubmergence. At the end of first submergence, labile P was two-fold higher in 100F than in manure treatments. But in the moist period and after resubmergence, labile P did not differ between 100F and 100M. Oxalate extractable Fe was higher in 100M than 100F and remained unchanged until the end of the experiment. In experiment 4, the ASS (without or with pH increase to 5.5) was amended with mangrove roots to achieve an organic carbon (OC) addition of 50% or 150% of native soil OC and incubated under submerged, moist and then resubmerged conditions. At the end of each four-week period, P pools, amorphous Fe/Al and potential P sorption were measured. Mangrove roots addition decreased the redox potential and increased labile P under submerged conditions, but only at pH 5.5. P binding was enhanced by root addition during the first 8 weeks, but not after re-submergence.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2020

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46

Baker, Andrew K. M. "New approaches to investigate and construct biogeochemical models of inland acid sulfate soils: linkages to environmental degradation processes and mineral exploration." 2007. http://hdl.handle.net/2440/57109.

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Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library.
"Inland acidic sulfate soils under fresh water conditions where contemporary clearning of native vegetation has caused erosion, rising of local water tables and excess discharge of saline-sulfatic groundwater. A new systematic and interactive web-based approach was used to improve acquisition, collation, integration and communication of diverse soil-regolith data ... Successful application of the interactive web-based data site, as part of this study, resulted in its uptake as a standard tool for coordinating and reporting on a number of current and future national and international soil-regolith studies." -- from Abstract.
http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1289208
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Enviromental Sciences, 2007

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47

Baker, Andrew Kenneth Martin. "New approaches to investigate and construct biogeochemical models of inland acid sulfate soils: linkages to environmental degradation processes and mineral exploration." Thesis, 2007. http://hdl.handle.net/2440/57109.

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"Inland acidic sulfate soils under fresh water conditions where contemporary clearning of native vegetation has caused erosion, rising of local water tables and excess discharge of saline-sulfatic groundwater. A new systematic and interactive web-based approach was used to improve acquisition, collation, integration and communication of diverse soil-regolith data ... Successful application of the interactive web-based data site, as part of this study, resulted in its uptake as a standard tool for coordinating and reporting on a number of current and future national and international soil-regolith studies." -- from Abstract.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Enviromental Sciences, 2007

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48

D{u00FC}rr, Mira. "Biogeochemistry of acid sulfate soils : an investigation of the molecular characteristics of the bacterial and archaeal community." Phd thesis, 2008. http://hdl.handle.net/1885/150961.

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49

Trueman, Austin. "Exploring the Composition, Dissolution Kinetics and Passivation of Jarosite from an Acid Sulfate Soil." Thesis, 2020. http://hdl.handle.net/2440/130120.

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Jarosite minerals (XFe(SO4)2(OH)6, where X is typically K or Na) are common secondary reaction products of iron sulfide oxidation. Consequently, jarosite is a diagnostic feature of sulfuric material (pH < 4) in acid sulfate soils (ASS), where it constitutes the principal source of retained acidity: an operationally defined pool of potential acidity associated with the hydrolysis of Al3+ and Fe3+ from minerals such as jarosite and schwertmannite. Soils containing considerable quantities of jarosite tend to exhibit hazardous properties (e.g. acidic and metalliferous drainage) for years to decades after the sulfuric material formed. This appears to be related to the slow mineral dissolution rate coupled with the ability of jarosite to buffer the soil solution between pH 3-4. Effectively managing such soils requires an accurate understanding of jarosite-rich sulfuric material, its long-term behaviour and effects on soil and water quality, and potential remediation strategies. However, the results described in the literature concerning jarosite solubility and jarosite kinetics are highly variable. Furthermore, there are currently no effective means of directly nullifying the environmental risks associated with jarosite in soils. Conventional ASS management strategies such as liming or dewatering and filling/capping ASS may be costly, have limited ability to effectively nullify jarosite while preventing acidity export, and may limit land-use options. Mineral surface passivation techniques – where retained acidity remains in situ, but dissolution is slowed or prevented – may be an effective alternative remediation strategy. However, the efficacy of these techniques has not been trialled for jarosite in ASS. Therefore, the work described in this thesis relates to three principal objectives: (1) to characterise jarosite-rich sulfuric material, (2) to provide a better understanding of how this material affects and is affected by the chemistry of the solution in which it dissolves; (3) to test potential jarosite passivation strategies. In order to carry out these objectives, jarosite-rich segregations were extracted from an ASS in the Gillman area within the southern Barker Inlet estuary, South Australia. A range of chemical and physical assays were conducted, and showed that the jarosite-rich segregations were primarily composed of jarosite (KFe3(SO4)2(OH)6), and were admixed with minor amounts of quartz, halite, gypsum, muscovite and organic matter. A gradient perfusion technique was utilised to describe the dissolution chemistry of this jarosite sample under constant flow conditions and at a range of pH values. The rate of dissolution (R) ranged from 3.16E-13 to 3.16E-11 mol/m2s, and was strongly correlated to pH by the function: log10R = 0.099pH2 – 0.966pH – 9.914. Monitoring differences between eluant (input) and eluate (output) pH clearly demonstrated that jarosite dissolution has a strongly acidifying effect, and should buffer soil pH around 4. Regardless of pH, the initial 12-24 hours of dissolution was characterised by the rapid release of Ca, Mg, Na and S (due to the dissolution of soluble minerals such as gypsum and halite). Consequently, flushing acidity from even highly weathered soils containing jarosite-rich sulfuric material is not advisable, as the resulting acidic, saline drainage may cause severe offsite environmental impacts. However, the dissolution experiments also suggest that the dissolution of jarosite under alkaline conditions is characterised by the formation of poorly-crystalline, ferric (oxyhydr)oxides that may possibly coat jarosite surfaces and hindered further dissolution. Therefore, promoting alkaline soil conditions may reduce the export of acidity by altering jarosite, or its surface, to more chemically benign and environmentally stable ferric (oxyhydr)oxides. This study was published in Chemical Geology (Trueman et al., 2020). In light of these conclusions, I examined the composition and dissolution kinetics of jarosite that was treated with a view to produce passivating coatings of ferric (oxyhydr)oxide (e.g. goethite, 𝛼-FeOOH) and ferric phosphate (e.g. strengite, FePO4.2H2O). I confirmed that under alkaline conditions jarosite readily decomposes to yield poorly-crystalline ferric (oxyhydr)oxides (i.e. two-line ferrihydrite). Moreover, these ferric (oxyhydr)oxides reacted with phosphoric acid to produce ferric phosphate; and reacted with monoammonium phosphate (MAP) to produce spheniscidite: an extremely rare ferric hydroxyphosphate. The direct alteration of jarosite to a ferric phosphate was constrained under ambient conditions. However, at elevated temperatures, jarosite reacted with phosphoric acid to produce phosphosiderite (a metastable dimorph of strengite) and gengenbachite (KFe3(HPO4)4(HPO4)2.6H2O); and reacted with MAP to produce an unnamed ammonium ferric phosphate (H2(NH4)Fe(PO4)2). The dissolution kinetics of the NaOH- and MAP-treated jarosite was examined using column perfusion experiments, which suggest these treatments do not offer any distinct advantages in terms of curtailing the release of potentially hazardous elements. However, the study provides key insights into jarosite alteration pathways, and sets a solid foundation upon which to further explore alternative methods of remediating jarosite-rich soils. This study was published in Chemical Geology (Trueman e al. 2021). The findings presented in this thesis can be utilised to better predict the behaviour of jarosite in the environment and its effects on soil and water quality, and to design more effective remediation strategies for ASS with jarosite-rich sulfuric material. References Trueman, A.M., Fitzpatrick, R.W., Mosley, L.M., Mclaughlin, M.J., 2021. Exploring passivation-based treatments for jarosite from an acid sulfate soil. Chemical Geology, 561: 120034. https://doi.org/10.1016/j.chemgeo.2020.120034. Trueman, A.M., Mclaughlin, M.J., Mosley, L.M., Fitzpatrick, R.W., 2020. Composition and dissolution kinetics of jarosite-rich segregations extracted from an acid sulfate soil with sulfuric material. Chemical Geology, 543: 119606. https://doi.org/10.1016/j.chemgeo.2020.119606.
Thesis (MPhil) -- University of Adelaide, School of Agriculture, Food and Wine, 2020

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50

Miller, Karen S. "Jarosite Formation at the Davis Mine, Rowe, Massachusetts." 2011. https://scholarworks.umass.edu/theses/700.

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This study investigates jarosite formation and stability patterns at the abandoned Davis Pyrite Mine in Rowe, Massachusetts. Jarosite, an iron-sulfate hydroxide, is found in acid mine drainage (AMD) environments, in acid sulfate soils, and on Mars. Jarosite and the iron oxides goethite and hematite are present at the site. Soil samples from the site were examined by XRD, SEM, and EDS. Five mineralogical areas were found, based on mineral abundance patterns. Jarosite exists in four of these areas. Two jarosite morphologies were identified. “Variable” jarosite, with partly-dissolved crystals of about 0.5 to 5 micrometers diameter, exists in spoil pile samples. “Donut” jarosite, with tightly-packed, sharp-edged crystals less than 0.5 micrometers that form a thin mantle on the surface of a second mineral, exists in native soil samples. Donut jarosite has not been previously characterized. These jarosite morphologies are controlled by the presence and relative mobility of pyrite oxidation products Fe and SO4, which in turn are controlled by water saturation levels. Three pathways are possible. On Path 1, both ions are mobile, go into solution, and variable jarosite forms at a distance from the pyrite source. On Path 2, only sulfur ions are mobile, an iron-oxide gossan develops. No jarosite forms. On Path 3, neither ion is mobile, and donut jarosite forms. On this path, Fe and SO4 ions are trapped in a thin film of stagnant water covering the pyrite. When sufficient ions are present, donut jarosite precipitates.

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