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Hall, Rebecca. "Environmental pH adaptation in the nematode Caenorhabditis elegans." Thesis, University of Kent, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497538.
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Microorganisms are constantly adapting to changes within their environment. The soil dwelling nematode Caenorhabditis elegans encounters a multitude of environmental conditions during its lifetime including hypoxia, UV exposure, temperature fluctuations and starvation. However, living in a soil environment C. elegans will also encounter fluctuations in environmental pH, a condition to which the adaptive response has not been characterised. The aim of this study was to analyse the global transcriptional response to both acid and alkaline conditions, to identify how the nematode adapts to these environments. Caenorhabditis elegans were resistant to pH conditions between pH3-10 over a four-hour period and the environmental pH influenced the expression of genes whose products are involved in cell signalling, metabolism, cuticle biosynthesis and ion/nutrient transport. The majority of genes that were differentially regulated in acid and alkaline environments encoded uncharacterised proteins and represented 33 and 39% of the genes. Post-transcriptional gene silencing of targets did not confer pH sensitivity, which was attributed to remaining transcripts. As a result of alternative splicing, the gene RO1E6.3 encodes two alpha carbonic anhydrases named, CAH-4a and CAH-4b. Biochemical analysis confirmed that CAH-4b, which showed up regulation at the transcriptional level in alkaline conditions (5-fold), was also the most active CA isoform. Crystallisation studies are being performed on CAH-4b to aid in the identification of the protein's biological function.
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Romppanen, T. (Tatu). "Valuma-aluetekijöiden vaikutus virtavesien pH- ja lämpötila-arvoihin." Master's thesis, University of Oulu, 2016. http://urn.fi/URN:NBN:fi:oulu-201604081410.
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Pohjoisen vesistöissä happamuus tuottaa usein ongelmia vesien ekologiselle tilalle ja virkistyskäytölle. Kausittaista happamuutta esiintyy yleensä alueilla, joilla sijaitsee turvepitoisia happamia sulfaattimaita. Tässä työssä pyritään löytämään uusien paikkatietoihin perustuvien menetelmien avulla happamuuden lähteitä ja keinoja happamuuspiikkien ennakoimiseksi. Pohjois-pohjanmaalla Oulun lähistöllä sijaitseva Sanginjoki on yksi kausittaisesta happamuudesta kärsivistä vesistöistä. Sanginjoen happamuuden lähteitä ja arvoja on tutkittu Suomen ympäristökeskuksen Kaupunki ja vesi — Sanginjoen virkistyskäyttöarvon parantaminen ja ekologinen kunnostus -hankkeessa, jonka koko valuma-alueen kattavaan ja jatkuvatoimiseen pH-mittausaineistoon tämä työ pohjautuu. Työssä verrataan Sanginjoen valuma-alueelta saatuja veden minimi pH-arvoja kunkin pH-mittauspisteen muodostaman alivaluma-alueen paikkatietoihin/valuma-aluetekijöihin. Sanginjoen alueen valuma-aluetekijätiedot saatiin CSN:n PaITuli ja GTK:n Hakku -paikkatietojen latauspalveluista. Paikkatietojen käsittely ja mittapisteiden alivaluma-alueiden muodostaminen työssä tehtiin ArcGIS:n karttapohja ArcMap:lla. Työn tuloksissa löytyi yhteys happamien sulfaattimaiden, suoalueiden ja eräiden maaperäluokkien happamuutta vahvistavasta vaikutuksesta. Lisäksi eräät maaperäluokat ja laajemmat vesistöalueet työn tulosten perusteella vähentävät happamuutta virtavesissä. Tulosten pohjalta luotiin happamuutta kuvaava usean muuttujan regressiomalli, jonka avulla voidaan ennustaa lähes puolet (42,3 %) veden minimi pH-arvon suuruudesta. Tulokset antavat tukea jo aiemmin tunnetuille toimenpiteille happaman kuormituksen synnyn ehkäisemiseksi. Tietoja tulisi hyödyntää maankäytön suunnittelussa erityisesti Suomen rannikkoseutujen sulfaattimaavyöhykkeelläAcidification of water courses is a serious problem to the ecological status and the recreational use of lakes and rivers. Seasonal acidity is a common phenomenon in the northern areas which consists of peatlands and sulphate soils. This thesis includes new geographical information system (GIS) based methods to identify the sources of acidity and ways to predict the acidification peaks of streams. River Sanginjoki at Northern Ostrobothnia, Finland is one of the river systems where periodic acidity occurs frequently. The sources and rates of acidity in the River Sanginjoki have been studied in previous projects. This thesis is utilize previous databases and is based on the whole river basin. The relations between the minimum pH-values of each measurement and the properties of their sub-catchments were studied in this thesis. The data of the catchment properties were downloaded from Finnish GIS databases PaITuli and Hakku. The processing of the catchment data and the formation of the sub-catchment areas were performed using the ArcGIS software package. The results showed acidity increasing effects with presence of the sulphate and four other soil types, and peatlands in the catchment area. Also evidence of decreasing acidity with certain soils types and water areas were found. A multiple regression model, which can be used to predict a sample’s minimum pH-value. The regression model can determine almost half (42.3%) of the variation of the minimum pH-value. The results of this thesis support the known methods of preventing the formation of acid loads. Further on they can be suitable for planning the land use, especially in the coastal areas of Finland sulphate soils are common
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Tibbits, Matthew A. Budd Ann F. "The effects of decling environmental pH on coral microstructure and morphology." [Iowa City, Iowa] : University of Iowa, 2009. http://ir.uiowa.edu/etd/445.
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Tibbits, Matthew A. "The effects of decling environmental pH on coral microstructure and morphology." Thesis, University of Iowa, 2009. https://ir.uiowa.edu/etd/445.
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Coral reefs are faced and will be faced with many challenges this century. One danger is the rapid decline of oceanic pH due to anthropogenic sources. The more acidic the environment becomes, the harder reefs and coral (order: scleractinia) in particular will be hit. Experiments to measure the effect on scleractinian coral were performed to glean a better understanding of the processes that will be affected by our acidifying oceans. Additionally, the search for and analysis of coral microstructure and micromorpholgy were carried out in an attempt to understand homology within an environmentally responsive taxa.
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Martin, Christopher S. "Controlled Release of Alkalinity Using pH-Responsive Polymer Carriers." Thesis, Tufts University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10165326.
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Low groundwater pH is frequently cited as inhibiting the performance of in-situ bioremediation of chlorinated solvents at contaminated sites. A common method of pH control is injection of solutions containing alkalinity, but alternatives for prolonged, passive pH control are needed. This work explores pH-responsive hydrogel coatings on MgO nanoparticles as vehicles for controlled release of alkalinity. Chitosan cross-linked with glutaraldehyde was evaluated as a representative hydrogel coating. The effects of coating thickness and cross-linking on the rate of alkalinity release were experimentally evaluated using batch dissolution experiments. Dissolution rates were found to be up to an order of magnitude slower for coated particles than for uncoated particles. A diffusion model was developed for the dissolution rate of coated particles, and the model was able to account for the dissolution rate as a function of coating thickness over a range of pH.
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Rankin, Ashley. "The Effects of Reduced pH on Decorator Crab Morphology, Physiology and Behavior." Thesis, University of California, San Diego, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10634897.
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Crabs in the family Majoidae camouflage by decorating their exoskeletons with organisms and debris from their environment. This form of camouflage, involving both the act of decorating and carrying of these decorations, is thought to be energetically costly, and may present a trade-off under stressful environmental conditions. The energetic cost of decoration behavior has been evinced by reduced organic content due to elevated metabolism. In the context of previous research demonstrating that many marine calcifiers experience metabolic costs under experimental ocean acidification conditions, we hypothesized that decorator crabs exposed to reduced pH will have insufficient energy to support regulatory processes along with decoration behavior. Thus, we predicted that energy will be allocated towards growth and calcification at the expense of decoration behavior. Dwarf teardrop crabs, Pelia tumida, were exposed to ambient (pH = 8.0, pCO2 = 613 µatm) and reduced (pH = 7.75, pCO2 = 894 µatm) pH conditions for five weeks. Half of the animals in each treatment were given two sponge species, Halichondria panacea and Haliclona permollis, to decorate with, whereas the remaining animals were not allowed to decorate. At the end of the experiment, all animals were analyzed for exoskeleton mineral content (Ca and Mg) using EDX and ICP-MS, organic content (a proxy for metabolism) using TGA, and decoration behavior by quantifying sponge mass and percent cover. Overall, decorator crabs showed no signs of energy limitation under reduced pH conditions. Neither growth, exoskeleton mineral content, nor organic content of crabs differed among pH or decoration treatments. In addition, both sponge mass and percent cover remained the same across pH treatments, indicating no effect of reduced pH on decoration behavior, and thus the ability to camouflage. The maintenance of physiological processes without metabolic costs in P. tumida exposed to reduced pH radiates from the emerging trends on the susceptibility of crustaceans to changes in ocean chemistry associated with ocean acidification.
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Len, Alice Chen Liang. "Effect Of Environmental Ph On The Proteome Of The Dental Pathogen Streptococcus Mutans." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/4968.
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Gundersen, Jennifer Lisa. "Acid dissociation of chloroguaiacols and pH dependent sorption to estuarine sediments." W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539616676.
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Chloroguaiacols are common components of bleached kraft pulp mill effluent known to bioaccumulate in aquatic organisms, and sorb onto particulate material and sediments. Ionization properties of the chloroguaiacols must be known in order to explain their sorptive behavior in aquatic systems. to obtain this information, thermodynamic acid dissociation constants (p&K\sb{lcub}\rm a{rcub})& of guaiacol (o-methoxyphenol) and nine chloroguaiacols have been determined by spectrophotometric methods. These experimental p&K\sb{lcub}\rm a{rcub}& values have been compared with literature values, values predicted by the Hammett equation and predictions by quantum chemical calculations using MOPAC 6.0 with AM1 and MNDO Hamiltonian operators. Experimental and predicted acidities were linearly related, and the correlation and regression equations obtained have been used to calculate p&K\sb{lcub}\rm a{rcub}& values for those chloroguaiacols that were unavailable for experimental measurement. Sorption of chloroguaiacols onto sediments may result in reduced bioavailabilty to aquatic species, increased degradation rates or rapid burial. Conversely, it may result in increased exposure to deposit feeding species with subsequent transfer to higher trophic levels. The sorption of four chloroguaiacols (5-chloroguaiacol, 4,6-dichloroguaiacol, 4,5,6-trichloroguaiacol and tetrachloroguaiacol) with p&K\sb{lcub}\rm a{rcub}& values ranging from 9.06 to 6.06 was investigated on four estuarine sediments. The effect on sorption of aqueous phase pH, sediment organic carbon content and degree humification was investigated. Sorption coefficients, &K\sb{lcub}\rm d{rcub}&, were determined at two pH values (6.6 and 7.8). Linear relationships were observed between &K\sb{lcub}\rm d{rcub}& and both % total organic carbon(TOC) and % humic acids at each pH. &K\sb{lcub}\rm oc{rcub}& and &K\sb{lcub}humic{rcub},& sorption coefficients normalized to % TOC and % humic acids, were calculated. In addition to the amount of TOC present, the type of organic matter (ie. humic acids) is an important factor in sorption. Aqueous phase pH governs the ionization of chloroguaiacols. Sorption of the ionized and molecular species are different due, in part, to the different solubilities of the species and was reflected in the different &K\sb{lcub}\rm d{rcub}& values determined at each pH.
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Elzahabi, Malak. "The effect of soil pH on heavy metal transport in the vadose zone /." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36804.
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This research study provides the experimental information necessary for numerical analyses, structured to account for vadose zone transport of heavy metals. Particular attention is payed to the effect of degree of saturation, the presence of carbonate, soil pH and heavy metals concentrations. In addition, attention is directed to an evaluation of the coupled solute-water transport mechanisms. A method that fully describes the coupling effects on the transport coefficient based on experimental evidence provides successful predictions of the rate of transport of the heavy metals through the unsaturated soil in a pH-controlled environment.In the experimental part of this research, one dimensional solute and moisture flow (leaching) tests, using different heavy metal permeants, were conducted on an unsaturated illitic soil at varying pH values. Experimental results showed that the retention and migration of heavy metals are highly dependent on the soil pH, the presence of carbonates, the degree of saturation, the influent concentration and the time duration. At high soil pH and carbonate content, heavy metals were retained in the soils if the buffering capacity was high enough to resist the acidic input solution, and sorption processes will prevail in the carbonate phase. As the soil pH decreases, the dissolution of carbonates increases and cation exchange capacity becomes the more dominant process in heavy metals retention.
The numerical study developed a model to analyse and predict the transport of the contaminant in unsaturated clayey soils in which some of the species were adsorbed on clay particles surfaces. The proposed mathematical model was based on the postulates of irreversible thermodynamics and is also applicable in a one-dimensional case. In this model, various solute transport mechanisms such as diffusion and sorption were considered. Results indicated that the diffusion coefficient is necessary to provide a good agreement between the experimentally measured and the theoretically predicted values of contaminant transport through the soil. The numerical results of the coupled solute and moisture equations showed that the transport coefficients strongly and accurately depend on solute and volumetric content. (Abstract shortened by UMI.)
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Al, Minshid Alaa Hani Naser. "Surface chemistry of metal oxide nanoparticles in biological and environmental media of varying pH." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6359.
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Investigate the interaction of nanomaterials with biological systems, known as nano-bio interaction is of great interest for the assessment of the concern arising from nanomaterials progressive use. Such interaction determines nanomaterials potential effect on human and environment becomes more and more important to understand how they interact with living organisms and the environment. The novel physicochemical characteristics of nanomaterials, such as their small size, large surface area to volume ratio and surface energy, may initiate new toxicological effects due to nanomaterials ability to enter into the biological systems through adsorption and dissolution and modify the structure of various macromolecules An example of these interactions is the adsorption of proteins on nanoparticles surface forming what is known as the 'protein corona'. Therefore, being able to understand how these molecules and other biologically important species are adsorbed and interact, should help us to reduce any adverse impacts of nanoparticles on human health and the environment.
Due to the importance of surface composition and surface functionality in nanotoxicology, analytical tools that can probe the change in the structure and composition of the nanoparticles in aqueous media are crucial but remain limited. Therefore in this work, in situ characterization of the liquid–solid interface to probe surface adsorption of environmentally and biologically relevant media on nanoparticle surfaces has been conducted. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy provides the molecular information that allows for the determination of the adsorption mode such as conformational and structural changes of the coordinating ligand. Surface adsorption of titanium dioxide (TiO2) nanoparticles have been investigated in different biological media typically used for toxicity studies and show that the surface composition of TiO2 nanoparticles depends to a large extent on the composition of the medium due to surface adsorption. Moreover, hydrodynamic diameter and surface charge of TiO2 NPs were evaluated using dynamic light scattering DLS. The results indicated that TiO2 NPs undergo different trends in aggregation upon the adsorption of biological media on its surface and zeta potential measurements showed surface charge alterations which are consistent with the aggregation study.
In order to understand the dynamic transformations of nanomaterials in biological environments, the effect of dissolution has been predicted. Copper oxide CuO and zinc oxide ZnO nanoparticles were used to study dissolution due to their instability in biological media. Once these particles exposed to solutions they release their ions and tend to aggregate. Therefore, the dissolution of these materials was conducted at size ca. 24 nm and nanoparticles coated with proteins and humic acid employing simulated lung fluids as models to develop a better understanding of how these properties effect the solubility and stability in biological systems. From this study, it was found that both copper oxide and zinc oxide NPs showed different trends in dissolution. Cu and Zn ions once coated with proteins and HA highly dissolved in ALF at low pH 4.5 compared with other fluids (Gamble’s solution and water) at extracellular pH which shows only slightly enhanced in the basal condition. The acidity of ALF may explain the higher solubility of metals that are phagocytized versus those that remain extracellular. Some general conclusions can be drawn from these investigations. It seems that analytical tools to characterize the interfacial region between nanopaerticles and these complex systems provide a reasonably good qualitative and quantitative description of the interactions.
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Castellan, Paolo. "The role of chelating agents and soil pH on heavy metals removal from contaminated soil." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23873.
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Batch washing experiments were used to evaluate extractive decontamination of heavy metal polluted illite soils using ethylenediamine-tetraacetic acid (EDTA) and trans 1,2 cyclohexylenedinitrilo-tetraacetic acid (CDTA). Five series of contaminated illite soils were prepared through adsorption tests using four single-specie 5000 ppm heavy metal solutions of Pb, Cu, Zn, or Cd and one multi-species solution containing 1250 ppm of each heavy metal. The five contaminated illite soils that were prepared contained the following levels of heavy metals per kilogram of soil: (i) 5000 mg Pb, (ii) 3490 mg Cu, (iii) 1566 mg Zn, (iv) 700 mg Cd, (v) 1186 mg Pb; 379 mg Cu; 151 mg Zn; and 125 mg Cd. The soil washing results revealed that EDTA and CDTA are equally effective in releasing heavy metals from the contaminated illite soils, with removal efficiencies ranging from 35% to 99% for the 10$ sp{-5}$ M and 10$ sp{-1}$ M solutions, respectively. The optimum pH range for all chelate concentrations and all heavy metal contaminants is between 3-5. Competition between heavy metals in the soil for the adsorption sites of EDTA and CDTA did not have an impact on the removal efficiencies attained. In addition, the heavy metal preferential adsorption sequence demonstrated by the illite soil was $ rm Pb>Cu>Zn>Cd$ for the single-specie pollutant solutions and $ rm Pb>Cu>Zn approx Cd$ for the multi-species heavy metal pollutant solution, and were shown to be mainly bound to the carbonates and Fe and Mg oxides.
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Mullan, M. A. "Low pH-induced polyphosphate accumulation by environmental microorganisms and its application in biological phosphate removal." Thesis, Queen's University Belfast, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273240.
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Chen, Haigang. "Ortho ester-based pH-sensitive cationic lipoplexes for gene delivery." Scholarly Commons, 2006. https://scholarlycommons.pacific.edu/uop_etds/2629.
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Endosome is a major barrier to efficient gene transfection by synthetic vectors because if the vectors are trapped in the endosome, they will traffic to the lysosome where the DNA is enzymatically degraded. Our hypothesis which serves as the rationale for the design of ortho ester-based lipids and lipoplexes is that cationic lipids which can quickly hydrolyze into membrane-destabilizing fragments in response to a small drop of pH should improve the gene transfection efficiency by facilitating the endosome escape. We designed and synthesized five ortho ester-based acid-labile cationic lipids ( 1-5 ) and developed nine lipoplexes comprising the five lipids. HPLC and LC/MS studies revealed that the ortho ester linkage in lipids ( 1-5 ) hydrolyzed at mildly acidic endosomal pH 5.5. Dioleyl glycerol was identified to be the major hydrolysis product of lipids 1, 2, and 3 . Oleoyl alcohol and 1-oleyloxy-2-trimethylamionium-3-propanol were identified to be the major hydrolysis products of lipids 4 and 5 . Photon Correlation Spectrometry (PCS) studies revealed that acidic endosomal pHs triggered the aggregation of lipoplexes comprising 1, 2, and 3 . Lipoplexes comprising 4 and 5 retained their size over 50 hours at acidic pHs. The fluorescence assay indicated that the ortho ester-based lipoplexes comprising lipids 1, 2, and 3 quickly destabilized a model biomembrane in response to the acidic pH. Acidic pH did not cause the membrane destabilization by lipoplexes comprising 4 and 5 . These results demonstrate that ortho ester-based lipoplexes comprising lipids 1, 2, and 3 hydrolyze into membrane-destabilizing fragments in response to acidic pH. Luciferase gene transfection was conducted on CV-1cultured cells. The lipoplexes comprising ortho ester-based cationic lipids 1, 2, and 3 significantly enhanced the luciferase gene expression. Two lipoplexes 2 /DOPE/DNA and 3 /DOPE/DNA mediated 45-fold and 116-fold, respectively, higher luciferase expression in CV-1 cells compared to the pH-insensitive lipoplex DOTAP/DOPE/DNA. The gene transfection efficiency correlates well with the pH-triggered membrane-destabilization by the ortho ester-based lipoplexes.
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Sandrin, Todd Ryan. "Naphthalene biodegradation in a cadmium cocontaminated system: Effects of rhamnolipid, pH, and divalent cations." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/289199.
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Forty percent of hazardous waste sites on the U.S. Environmental Protection Agency's National Priority List (NPL) are cocontaminated with organic and metal pollutants. Conventional approaches to remediating these sites are costly and often ineffective. Bioremediation is a promising, cost-effective alternative but metal toxicity at cocontaminated sites may limit its efficacy. The research described in this dissertation provides two new possible approaches to enhance the bioremediation of cocontaminated environments and sheds light on the relationship between metal concentration and inhibition of organic pollutant biodegradation. In Objective 1, a rhamnolipid biosurfactant was employed to increase naphthalene biodegradation in the presence of cadmium. The biosurfactant reduced bioavailable cadmium concentrations and increased naphthalene bioavailability. Neither of these phenomena, however, fully accounted for the ability of rhamnolipid to reduce cadmium toxicity. The ability of rhamnolipid to alter the cell surface appeared critical to its ability to mitigate toxicity. In Objective 2, pH was lowered to increase naphthalene biodegradation in the presence of cadmium. Reductions in pH had previously been reported to mitigate metal toxicity, but the mechanism of such reductions warranted elucidation. Previous studies implicated the formation of monovalent hydroxylated metal in the mechanism by which pH mediates toxicity. Results of this study, however, suggest that the importance of such species in determining toxicity may be much less than that of the increased competition between hydrogen and metal ions for binding sites on the cell surface at reduced pH. An indirect relationship between metal concentration and inhibition of organic biodegradation was revealed in Objective 3. Naphthalene biodegradation was more sensitive to cadmium concentrations of 10 and 37.5 mg/L than 100 mg/L. For this reason, we investigated whether naphthalene biodegradation could be increased in the presence of a toxic concentration of cadmium by raising the total metal concentration to a higher, but relatively less toxic concentration. Only elevated concentrations of zinc reduced cadmium toxicity. High but less toxic levels of metal may more rapidly induce the transcription of a gene(s) important in metal efflux than lower more toxic concentrations.
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Shannon, James Murray. "Partial nitritation-anammox using pH-controlled aeration in submerged attached growth bioreactors." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/4749.
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Machek, Edward Joseph Jr. "Iopamidol as a Precursor to Iodinated Disinfection Byproduct (DBP) Formation as a Function of NOM concentration, pH, and Chlorinated Oxidants." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1439045967.
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Dyball, D. "The effects of temperature and low environmental pH on the osmoregulation of the amphipod Gammarus duebeni." Thesis, University of Southampton, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356765.
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Schneider, James D. "pH Effects on the Sorption of Fluoxetine and Sulfamethoxazole by Three Powdered Activated Carbons." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7037.
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Pharmaceuticals and personal care products (PPCPs) are widely used throughout the world. PPCPs are emerging as pollutants of concern and may pose a risk in the future to drinking water supplies. Two such compounds are sulfamethoxazole (SMXL) and fluoxetine (FLX). These ionizable compounds are not readily removed from water by conventional water treatment technologies. Powdered activated carbon (PAC) is a useful material for removing contaminants from water and is currently used in many water treatment applications. PACs may carry either a net positive or negative surface charge depending on the pH of solution. This study examined the hypothesis that the electrostatic interactions between three PACs’ surface charges and the charges of sulfamethoxazole’s and fluoxetine’s ionizable functional groups would lead to greater sorption efficiency than non-electrostatic interactions alone. Samples containing SMXL or FLX, were treated with varying doses of PAC, and mixed for three hours. The pH of samples were adjusted between experiments to determine if interaction between the polar contaminants and charged surface of PAC significantly impacted removal of the contaminant from solution. Analysis of the treated samples showed the effects of pH and varying PACs on the removal of SMXL and FLX from solution. It was observed that pH of the solution did play a significant role in the removal of contaminant in a number of the experiments, but that under other conditions where greater removal was anticipated based on predicted electrostatic interactions, it did not. These conditions included pH conditions where the contaminant existed predominantly in a negatively charged form. While not the initial focus of this study, it was observed that pore size distribution of the PACs may play a more significant role in the removal of ionizable compounds, especially in the case of fluoxetine, than electrostatic interactions.
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Pokhrel, Lok R., Brajesh Dubey, and Phillip R. Scheuerman. "Natural Water Chemistry (dissolved Organic Carbon, Ph, and Hardness) Modulates Colloidal Stability, Dissolution, and Antimicrobial Activity of Citrate Functionalized Silver Nanoparticles." Digital Commons @ East Tennessee State University, 2014. https://doi.org/10.1039/C3EN00017F.
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Knowledge about whether/how natural water chemistry influences the fate, dissolution, and toxicity of silver nanoparticles (AgNPs) should contribute to ecological risk assessment and informed decision making. The effects of three critical water chemistry parameters – dissolved organic carbon (DOC), pH, and hardness – were investigated on the colloidal stability, dissolution dynamics, and antimicrobial activity of citrate-functionalized AgNPs (citrate–AgNPs) against Escherichia coli. Toxicities of citrate–AgNPs and AgNO3 were also determined in the river water samples collected across three seasons (for seven months). Detectable changes in hydrodynamic diameter, surface charge, and plasmonic resonance revealed the modulating effects of the water chemistry parameters on the colloidal stability of citrate–AgNPs. Although, overall Ag release from citrate–AgNPs was low (0.33–3.62%), it increased with increasing DOC concentrations (0–20 mg L−1) but decreased with increasing pH (5–7.5) or hardness (150–280 mg L−1). Citrate–AgNP toxicity was 3–44 fold lower than of AgNO3 (Ag mass basis). Notably, higher DOC or pH conferred protection to E. coli against citrate–AgNPs or AgNO3; increasing solution hardness tended to enhance toxicity, however. Citrate–AgNPs or AgNO3 toxicity in the river water matrix revealed no seasonality. Generalized linear models developed, by parameterizing particle properties, could fairly predict empirically-derived nanotoxicity. Our results show that particle size, surface properties, ion release kinetics, and toxicity of citrate–AgNPs can be modified upon release into aquatic environments, suggesting potential implications to ecosystem health and functions.
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Wei, Haoran. "Surface-Enhanced Raman Spectroscopy for Environmental Analysis: Optimization and Quantitation." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/93204.
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Fast, sensitive, quantitative, and low-cost analysis of environmental pollutants is highly valuable for environmental monitoring. Due to its single-molecule sensitivity and fingerprint specificity, surface-enhanced Raman spectroscopy (SERS) has been widely employed for heavy metal, organic compound, and pathogen detection. However, SERS quantitation is challenging because 1) analytes do not stay in the strongest enhancing region ("hot spots") and 2) SERS reproducibility is poor. In this dissertation, gold nanoparticle/bacterial cellulose (AuNP/BC) substrates were developed to improve SERS sensitivity by increasing hot spot density within the laser excitation volume. Environmentally relevant organic amines were fixed at "hot spots" by lowering solution pH below the analyte pKa and thus enabling SERS quantitation. In addition, a new SERS internal standard was developed based upon the electromagnetic enhancement mechanism that relates Rayleigh (elastic) and Raman (in-elastic) scattering. Rayleigh scattering arising from the amplified spontaneous emission of the excitation laser was employed as a normalization factor to minimize the inherent SERS signal variation caused by the heterogeneous distribution of "hot spots" across a SERS substrate. This highly novel technique, hot spot-normalized SERS (HSNSERS), was subsequently applied to evaluate the efficiency of SERS substrates, provide in situ monitoring of ligand exchange kinetics on the AuNP surface, and to reveal the relationship between the pKa of aromatic amines and their affinity to citrate-coated AuNPs (cit-AuNPs). Finally, colloidally stable stable pH nanoprobes were synthesized using co-solvent mediated AuNP aggregation and subsequent coating of poly(ethylene) glycol (PEG). These nanoprobes were applied for pH detection in cancer cells and in phosphate buffered aerosol droplets. The latter experiments suggest that stable pH gradients exist in aerosol droplets.PHD
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Miller, Stephanie A. "Investigation of Lead Solubility and Orthophosphate Addition in High pH Low DIC Water." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406821208.
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Samsonova, Olga [Verfasser], and Thomas [Akademischer Betreuer] Kissel. "Self-assembling polycations for gene delivery : Effects of polymer structure and environmental pH / Olga Samsonova. Betreuer: Thomas Kissel." Marburg : Philipps-Universität Marburg, 2012. http://d-nb.info/1021498904/34.
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Zazaitė, Gitana. "Ūkininkavimo įtaka šachtinių šulinių vandens kokybei." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070816_153513-10951.
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Magistro darbe yra tiriama Kauno rajone, Mitkūnų kaime esančių 5 šachtinių šulinių vandens užterštumas azoto junginiais ir organinėmis medžiagomis. Darbo objektas – šachtinių šulinių vandens kokybės parametrai: nitratai (NO3ˉ ), nitritai (NO2ˉ ), permanganatinė oksidacija (ChDSMn), pH. Darbo tikslas – įvertinti ūkininkavimo įtaką geriamo vandens kokybei ir ryšio tarp sodybos dirbtinių vandens telkinių ir šachtinių šulinių vandens kokybės nustatymas.. Darbo metodai – mokslinės literatūros analizė; cheminės vandens kokybės parametrų kiekybiniai analizės metodai; statistinė analizė, panaudojant EXCEL ir STATISTCA programinius paketus. Darbo rezultatai :atlikus tyrimus nustatyta, kad vanduo užterštas nitratais. Šachtinių šulinių vandens kokybės kitimui būdinga sezoninė tarša.Subject of research – shallows water quality indicators: nitrate (NO3ֿ), nitrite (NO2ֿ), organic matter (ChDSMn), water pH. Aim of research – to evaluate farming influence of drinking water quality and contact between homestead pond and shallows water quality. Methodology – analysis of scientific literature; chemical water quality analizes methods; statistical analysis using EXCEL, STATISTICA programs. Results of research – the results of scientific research showed, that water is polluted with nitrate. The tendency of water quality variations during seasons was observed.
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He, Yongtian. "Chromate reduction and immobilization under high pH and high ionic strength conditions." Columbus, OH : Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1047476794.
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Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xix, 219 p.: ill. (some col.). Includes abstract and vita. Advisor: Samuel J. Traina, Environmental Science Graduate Program. Includes bibliographical references (p. 201-219).
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Chen, Chien-Cheng. "OPTICAL MEASUREMENT OF ENVIRONMENTAL URANIUM USING POROUS SILICA MATERIALS." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2241.
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The focus of this research is on the optical measurement of uranyl in a solid matrix using fluorescence spectroscopy. Nanoporous silica-based materials were used to extract uranyl from contaminated soil and to enhance the fluorescence intensity and lifetime. The fluorescence lifetime and intensity of uranyl ions adsorbed on porous silica-based materials of varying pore size was measured as a function of pH and in the presence of fluoride. The feasibility of uranyl fluorescence detection on the top of soil by silica gel is carried out by four types of natural soil. The results show that the uranyl fluorescence intensity can be enhanced by approximately two orders of magnitude by the silica nanoporous matrix from pH 4-12 with the greatest enhancement occurring from pH 4-7. The enhanced fluorescence lifetime can be used in time-gated measurements to help minimize the influence of background environmental fluorophores. The pH and the fluoride variation causes different uranyl speciation and results in a peak shift in the fluorescence spectrum. The mechanism of the uranyl ion on the silica nanoporous matrix was studied through 15 different silica materials with different water content ratios and various concentrations of uranium on different silica structures. The result shows that the particle size, pore size, water content and uranyl concentration on silica surfaces are all important factors for optimizing the fluorescence intensity. The spacing between silica materials, either the pore inside materials or the space between particles, causes the variety of uranyl distribution on the material surface and changes the fluorescence performance. Also, X-Ray Photoelectron Spectroscopy (XPS) is used to identify the possible uranyl surface species on silica. The fluorescence emission spectra from silica materials and the XPS results are consistent with the presence of two different uranyl compounds. The specific surface area of silica materials plays an important role on uranyl adsorption mechanism. To further enhance the sensitivity, an optical ball lens was used to preferentially direct the fluorescence signal toward the excitation source in standoff measurements. The application of the ball lens was found to increase the detection distance up to 14 times.
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Cardona, Claudia. "Uranium Sequestration by pH Manipulation using NH3 Injection in the Vadose Zone of Hanford Site 200 Area." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3352.
Full textAbstract:
Past nuclear weapon production activities have left a significant legacy of uranium (U) contamination in the vadose zone (VZ) of the Department of Energy (DOE) Hanford Site. This U is a source of groundwater (GW) contamination. There is a concern that elevated U concentration would slowly infiltrate through the VZ, reach the GW water table, and then end up in nearby rivers and lakes. Remediation of U-contaminated low moisture content soil is a challenging task considering the VZ depth, where contamination is found between 70 and 100 m below the ground surface, and the formation of highly soluble and stable CaUO2CO3 complexes is influenced by Hanford’s soil rich in carbonate.
Injection of reactive gasses (e.g., NH3) is a promising technology to decrease U migration in through the VZ. The NH3 injection creates alkaline conditions that would alter the pore water chemistry (e.g., dissolving some aluminosilicates). Over time as the pH neutralizes, U(VI) could precipitate as uranyl mineral (e.g., Na-boltwoodite). Also, the dissolved U(VI) could be incorporated into the structure of some mineral phases or be coated by non-U minerals. These chemical reactions could control the U(VI) mobility to the GW. However, there is a lack of knowledge on how the VZ pore water constituents (e.g., Si, Al3+, HCO3-, and Ca2+) would affect U(VI) removal/precipitation in alkaline conditions.
This study quantified the role of the major pore water constituents on the U(VI) removal and evaluated the uranyl minerals that could precipitate from a variety of SPW solutions. Results showed that the percentage of U(VI) removal was controlled by Si/Al ratios and Ca2+ concentration regardless of HCO3- concentration tested. XRD revealed the presence of uranyl minerals by analyzing precipitates formed from SPW solutions, but none of them were identified as uranyl silicates as expected from speciation modeling. The SEM images displayed dense amorphous regions high in silica content, where EDS elemental analysis unveiled higher U atomic percentage in some samples. U(VI) silicate and carbonate minerals were predicted by the speciation modeling.
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MAGINNIS, ALEXANDER R. "THE USE OF MICROELECTRODES FOR THE MEASUREMENT OF pH AND DO AT THE WALL OF DRINKING WATER PIPES." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin998062134.
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Killinger, Alexis. "Iodinated X-ray contrast media (ICM) as precursors to disinfection byproduct (DBP) formation and enhanced toxicity as a function of pH and chlorinated oxidant." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1460375515.
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Ekholm, Niklas. "Mineralogical characterization of oresamples of different pH in the Björkdal golddeposit, northern Sweden – implications formineral processing." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-86424.
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The Björkdal gold deposit is situated in the Skellefte mining district, northern Sweden. The ore is mined from a complex system of quartz veins ranging from a few cm to a meter in width. The mineral processing steps at Björkdal comprises a flotation circuit, which performance is dependent on the pH of the ore feed. A total of ten samples from five different ore zones from the underground development was investigated with the purpose of improving the understanding of factors that causes the pH value of rock samples to vary which is deleterious to the metal recovery. The samples were investigated with optical microscopy together with scanning electron microscopy (SEM) and automated mineralogy (QEMSCAN) to carry out the modal mineralogy. The analyses identified a total of 37 different minerals in the samples. Chlorite was identified with significantly higher values in parts of the investigated ore zones and especially in the sample with the highest pH value, suggesting chlorite-hosting shear zones that crosscut the sampled ore zones to be a contributing factor that could be affecting the elevated pH values, resulting in a decreased recovery of gold.
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Karlsson, Lovisa. "Release of elements from unprocessed- and processed shale from Kvarntorp : Effect from different pH." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-28628.
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The alum shale of Sweden is a sulphidic black shale which was mined for its contents of alum during the 17th-19th centuries. During the thirst half of the 20th century alum shale from Kvarntorp was pyrolysed for refinement of its organic matter. The refuse from the pyrolysis process were deposited in a deposit area which is today known as Kvarntorpshögen. This deposit is still hot due to on-going oxidation of the organic matter, pyrite oxidation and the neutralisation of acid by limestone. This heat generation prevents percolation of water to any greater extent due to evaporation. Once it cools the deposit will be susceptible to extraction. Three materials from the Kvarntorp deposit and a block of alum shale were sampled from the Kvarntorp area. These four materials were crushed, sieved and extracted. The extraction experiment was performed at controlled pH which corresponded to dissolution equilibrium of pyrite, carbon dioxide/oxygen, calcite and slaked lime. In the fifth extraction series the material was allowed to set the pH of the water phase. The extraction procedure lasted for 26 days. Metal content of the four shale materials were analysed by XRF (including contents of sulphur, phosphorous and chloride) and by digestion followed by ICP-MS analysis. Mineralogy of the four materials and the extraction residues were studied by XRD analysis. Metal concentrations of the aqueous samples were analysed by ICP-MS and concentrations of dissolved organic- and inorganic carbon by TOC. Electrical conductivity and concentrations of sulphate was also analysed in aqueous phases with non-manipulated pH. Sulphate and calcium concentrations were highest in aqueous samples from weathered fines indicating the presence of gypsum. Presence of gypsum was also confirmed by XRD. Gypsum indicates weathering since it is a neutralisation product of calcite and the sulphuric acid generated by pyrite oxidation. Concentrations of dissolved organic carbon in samples with pH 12.5 were found to be highest from red processed shale and lowest from samples of shale. This indicates different hydrolysis properties or origin of the organic matter in the materials. The majority of analysed metals had highest solid solution distribution under acidic, i.e. pH 3.0, conditions. Under these conditions it was samples from the relatively non-weathered shale that had the highest release of metals, with a few exceptions. At pH 12.5 high concentrations of V, As and Mo was extracted from almost all four materials. The red processed shale released the highest percentages of its total contents of V, As and Mo under these conditions; 28 %, 55 % and 61 % respectively. The high release of V, As and Mo from red processed shale was most likely a result from the pyrolysis process. The roasting induced the formation of oxides which then easily forms vanadate, arsenate and molybdate when exposed to water. Water percolating the Kvarntorp deposit in the future will initially most likely have a near neutral or slightly acidic pH. Lowest concentrations of metals were found in aqueous samples with pH between 5.5-8.5. There is a great risk that the pH of the drainage from the Kvarntorp deposit will in time become acidic due to depletion of buffering capacity. Thus the environmental threat will increase.
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Kanu, S., and Dakora FD. "Thin-layer chromatographic analysis of lumichrome, riboflavin and indole acetic acid in cell-free culture filtrate ofPsoralea nodule bacteria grown at different pH, salinity and temperature regimes." Symbiosis, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001481.
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Abstract
Using thin-layer chromatography, 16 bacterial isolates from root nodules of 8 different Psoralea species were quantitatively
assessed for their exudation of the metabolites lumichrome, riboflavin and IAA in response to pH, salinity and temperature.
Our data showed that the bacterial strains tested differed in their levels of secretion of the three metabolites. For example,
strain AS2 produced significantly greater amounts of lumichrome at both pH 5.1 and 8.1, while strains RTl and PI
produced more lumichrome per cell at only pH 8.1. Strains API and RP2 also produced more riboflavin at pH 5.1 than at pH
8.1; conversely strain RTl secreted more riboflavin at pH 8.1 than at pH 5.1. Two P. repens strains (RPI and RP2) isolated
from very saline environments close to the Indian Ocean produced significant levels of lumichrome and riboflavin at both
low and high salinity treatments. However, strains ACI and Ll (from P. aculeata and P. laxa) even produced greater
amounts of lumichrome and riboflavin at higher salinity (i.e. 34.2 mM NaCl) and probably originated from naturally saline
soils. In this study, high acidity and high temperature induced the synthesis and release of high levels of IAA by bacterial
cells. In contrast, there was greater strain secretion of lumichrome at lower temperature (10°C) than at high temperature
(30°C). The variations in the secretion of lumichrome, riboflavin and IAA by bacterial strains exposed to different pH,
salinity and temperature regimes suggest that genes encoding these metabolites are regulated differently by the imposed
environmental factors. The data from this study also suggest that natural changes of pH, salinity and/or temperature in plant
rhizospheres could potentially elevate the concentrations of lumichrome, riboflavin and IAA in soils. An accumulation of
these molecules in the rhizosphere would have consequences for ecosystem functioning as both lumichrome and riboflavin
have been reported to act as developmental signals that affect species in all three plant, animal, and microbial kingdoms.
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Kanu, S., and FD Dakora. "Thin-layer chromatographic analysis of lumichrome, riboflavin and indole acetic acid in cell-free culture filtrate ofPsoralea nodule bacteria grown at different pH, salinity and temperature regimes." Balaban, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001676.
Full textAbstract:
Abstract
Using thin-layer chromatography, 16 bacterial isolates from root nodules of 8 different Psoralea species were quantitatively
assessed for their exudation of the metabolites lumichrome, riboflavin and IAA in response to pH, salinity and temperature.
Our data showed that the bacterial strains tested differed in their levels of secretion of the three metabolites. For example,
strain AS2 produced significantly greater amounts of lumichrome at both pH 5.1 and 8.1, while strains RTl and PI
produced more lumichrome per cell at only pH 8.1. Strains API and RP2 also produced more riboflavin at pH 5.1 than at pH
8.1; conversely strain RTl secreted more riboflavin at pH 8.1 than at pH 5.1. Two P. repens strains (RPI and RP2) isolated
from very saline environments close to the Indian Ocean produced significant levels of lumichrome and riboflavin at both
low and high salinity treatments. However, strains ACI and Ll (from P. aculeata and P. laxa) even produced greater
amounts of lumichrome and riboflavin at higher salinity (i.e. 34.2 mM NaCl) and probably originated from naturally saline
soils. In this study, high acidity and high temperature induced the synthesis and release of high levels of IAA by bacterial
cells. In contrast, there was greater strain secretion of lumichrome at lower temperature (10°C) than at high temperature
(30°C). The variations in the secretion of lumichrome, riboflavin and IAA by bacterial strains exposed to different pH,
salinity and temperature regimes suggest that genes encoding these metabolites are regulated differently by the imposed
environmental factors. The data from this study also suggest that natural changes of pH, salinity and/or temperature in plant
rhizospheres could potentially elevate the concentrations of lumichrome, riboflavin and IAA in soils. An accumulation of
these molecules in the rhizosphere would have consequences for ecosystem functioning as both lumichrome and riboflavin
have been reported to act as developmental signals that affect species in all three plant, animal, and microbial kingdoms.
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Morris, Raymond Anthony. "Investigation of the Optimal Dissolved CO2 Concentration and pH Combination for the Growth of Nitrifying Bacteria." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3256.
Full textAbstract:
Ammonium (NH4+) is a biological nutrient that is transformed in a wastewater treatment plant (WWTP) in a process called activated sludge. This is accomplished in an aerobic environment using microorganisms and inorganic carbon that convert the ammonium to nitrate (NO3-). This process is termed nitrification. Removal of ammonium is necessary due to its oxygen demand and toxicity to the environment.
Nitrification is considered a slow process due to the slow growth rate of the nitrifying bacteria. Ammonia oxidizing bacteria (AOB) first covert the ammonium (NH4+) to nitrite (NO2-) followed by conversion to nitrate (NO3-) by nitrite oxidizing bacteria (NOB). These slow rates limit the treatment capacity of the WWTP.
The initial hypothesis suggested that these slow rates were due to limited carbon in the aeration basin of a WWTP. A series of designed experiments and observational studies revealed substantial dissolved CO2 exists throughout a WWTP. Based on these findings, the central research focused on determining if an optimum dissolved CO2 concentration/ pH combination exists that maximizes nitrification.
Experimentation conducted at a pH of 7.0 and varying concentrations of dissolved CO2 concentration revealed inhibition at low (<5 mg/l) and high (>30 mg/l) dissolved CO2 concentration levels. Further research found that optimum nitrification can be attained in a dissolved CO2 concentration range of 10 - 15 mg/l and a pH range of 7.5 - 8.0. A maximum specific growth rate of 1.05 - 1.15 days-1 was achieved. A partitioning of the sums of squares from these designed experiments found that pH accounts for approximately 83 percent of the sums of squares due to treatment with the dissolved CO2 concentration accounting for 17 percent. This suggests that pH is the dominant factor affecting nitrification when dissolved CO2 concentration is optimized.
Analysis of the growth kinetics for two of the designed experiments was conducted. However, a set of parameters could not be found that described growth conditions for all operating conditions. Evaluating the results from these two experiments may suggest that a microbial population shift occurred between 16 and 19 mg/l of dissolved CO2 concentration. These dissolved CO2 concentrations represent pH values of 7.1 and 7.0, respectively, and were compared to experimentation conducted at a pH of 7.0. Though the pH difference is minor, in combination with the elevated dissolved CO2 concentration, a microbial shift was hypothesized.
Microbial samples were collected from the designed experiment that optimized dissolved CO2 concentration (5, 10 and 15 mg/l) and pH (6.5, 7.0, 7.5 and 8.0). These samples were evaluated using Fluorescence in situ hybridizations (FISH) to determine the population density of common ammonium oxidizing bacteria (AOB) (Nitrosomonas and Nitrosospira) and nitrite oxidizing bacteria (NOB) Nitrobacter and Nitrospirae). The dominant AOB and NOB microbes were found to be Nitrosomonas and Nitrospirae.
These results suggest that increased nitrification rates can be achieved by incorporating appropriate controls in a wastewater treatment plant (WWTP). With higher nitrification rates, lower nitrogen values can be obtained which will reduce the WWTP effluent nitrogen concentration. Conversely, these increased nitrification rates can also reduce the volume of an aeration basin given similar effluent nitrogen concentrations.
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Enetjärn, Albin. "Temporal och spatial variation för pH och relaterade parametrar i Bastuån, Jämtland." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-153162.
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Anthropogenic emissions of acidifying substances, mainly sulfur dioxide, during the second half of the 20th century caused a widespread acidification of many European freshwater environments. Even relatively remote areas, such as inland northern Sweden, experienced reduced pH-values, much due to low buffering capacity in the environment. Extensive liming has taken place in Sweden over the past fifty years to counteract negative effects on limnic ecosystems. Despite a general increase in pH over the last decades, problems with acidification still occur. However, this can be hard to separate from natural acidity due to a large landscape variability. This study aims at describing the temporal and spatial variation of pH and pH-related parameters in Bastuån, a 46 km2 watershed in Jämtland, Sweden, which is being investigated for future liming measures. Existing water chemistry data sets were analyzed and extended with an additional field study, sampling the twelve largest tributaries to Bastuån. Results show that pronounced high and low pH values has become increasingly rare while the average is basically unchanged between 1999 and 2017. Low pH is mainly associated with high discharge during snowmelt or rain events. Anthropogenic SO42- concentrations seems to contribute relatively little to pH-depressions while organic acids plays a more important role. Large water chemical variations in the tributaries indicate that several different biological and physical properties within the watershed regulates pH. However, any credible function that can predict pH using such properties remains to be found.
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Timoumi, Asma. "Study of the dynamics of physiological and metabolic responses of Yarrowia lipolytica to environmental physico-chemical perturbations." Thesis, Toulouse, INSA, 2017. http://www.theses.fr/2017ISAT0009/document.
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En raison des capacités de mélange limitantes, des hétérogénéités au sein des bioréacteurs se produisent régulièrement lors de l’extrapolation à l’échelle industrielle. En conséquence, les microorganismes circulant au sein de ces bioréacteurs sont continuellement exposés à des gradients locaux au niveau des paramètres fondamentaux du procédé tel que le pH, la température, la concentration en substrat et en oxygène dissous. Ces fluctuations micro-environnementales peuvent affecter la croissance, le métabolisme et la morphologie des cellules, en fonction de la nature, de l’intensité, de la durée et/ou de la fréquence de la perturbation rencontrée. L’objectif de ce travail est l’étude quantitative de l’impact des fluctuations de pH et d’oxygène dissous sur le comportement dynamique de Yarrowia lipolytica, une levure avec un potentiel biotechnologique prometteur, aussi bien aux niveaux morphologique que métabolique. Pour répondre à cet objectif, des cultures en bioréacteur en conditions d’environnement contrôlé ont été mises en œuvre afin d’établir un lien de causalité directe entre la perturbation et la réponse observée. L’implémentation de deux modes de cultures différents (batch et chemostat) a permis de caractériser le comportement dynamique des populations cellulaires dans des états physiologiques différents: En mode continu, toutes les cellules sont dans le même état physiologique et se multiplient à la même vitesse de croissance, tandis que des sous-populations de levures dans des états physiologiques distincts peuvent cohabiter dans les cultures en mode batch. Un effort important a été consacré au développement et validation des méthodes pour une quantification rigoureuse des évolutions morphologiques de Y. lipolytica à l’échelle de la population. Le comportement macroscopique de la levure a été caractérisé par l’évaluation des dynamiques de croissance, la viabilité, les vitesses de consommation du glucose et d’oxygène, ainsi que les vitesses de production d’acide organique et de dioxyde de carbone. Trois techniques, à savoir la cytométrie en flux (CYT), la morpho-granulométrie (MG) et la diffraction dynamique de la lumière (DLS) ont été employé pour la quantification du phénomène d’élongation. Les résultats obtenus démontrent qu’il n’y a pas d’effet significatif des fluctuations de pH et d’oxygène dissous sur le comportement macroscopique (vitesses spécifiques, rendements, viabilité) de la levure. Néanmoins, une transition micellaire a été induite en réponse aux deux facteurs de stress (pH and pO2) seulement en conditions d’excès de glucose, suggérant ainsi un impact de la concentration résiduelle de glucose sur la régulation de dimorphisme chez Y. lipolytica. Le contrôle et la régulation de la concentration de glucose dans le milieu peut contribuer à une meilleure maitrise des changements morphologiques de Y. lipolytica en réponse à des stimuli de l’environnementDue to limited mixing capacities, heterogeneities regularly occur when scaling-up bioreactors for large-scale production. Microbial cultures are continuously exposed to local gradients in fundamental process parameters such as substrate, pH, temperature and dissolved oxygen DO concentration. These micro-environmental fluctuations may have detrimental effects on cellular growth, metabolism and morphology, depending on the nature, intensity, duration and/or frequency of the fluctuations encountered. The aim of this study was to investigate the impact of pH and DO fluctuations on the dynamic behavior of Yarrowia lipolytica, a microorganism with a promising biotechnological potential, at both morphological and metabolic levels. For this purpose, batch and continuous cultivations modes were preferentially adopted, as it enabled respectively, the study of the stress response of yeast populations growing at their maximum specific rate, and at various controlled specific growth rates in physiological steady-states. In addition, an important effort was devoted to the development and validation of morphological methods in order to acquire quantitative characterization of the response dynamics at the population scale. The macroscopic behavior of Y. lipolytica was assessed through examining the patterns of growth, viability, glucose uptake, oxygen consumption, organic acid and carbon dioxide production rates. Changes in the yeast morphology were characterized at the cell population level by means of flow cytometry, morphogranulometry and diffraction light scattering techniques. The results reflected no significant effect of pH and DO fluctuations on the macroscopic behavior (specific rates, yields, viability) of the yeast. Nevertheless, mycelial growth was induced upon exposure to both stressors, only in glucose-excess environments, suggesting therefore an impact of glucose levels on the regulation of dimorphic transition in Y. lipolytica. Controlling residual glucose concentrations in Y. lipolytica fermentations may contribute to a better monitoring of its morphological changes in response to environmental stimuli. Such data would help to optimize bioprocess performances at the industrial scale since it alleviates physico-chemical impacts due to filamentous cells
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Valentine, Vecorena Rominna E. "Arsenic Analysis: Comparative Arsenic Groundwater Concentration in Relation to Soil and Vegetation." CSUSB ScholarWorks, 2016. https://scholarworks.lib.csusb.edu/etd/279.
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Arsenic (As) is a toxic semi-metallic element found in groundwater, soils, and plants. Natural and anthropogenic sources contribute to the distribution of arsenic in the environment. Arsenic’s toxic and mobile behavior is associated with its speciation ability. There are two types of arsenic available to the environment, inorganic and organic arsenic. Of the two, inorganic arsenic is more toxic to humans and more mobile in the environment. Two inorganic compounds responsible for arsenic contamination are trivalent arsenite, As (III), and pentavalent arsenate, As (V). Trivalent arsenate is considered to be more soluble, toxic, and mobile than pentavalent arsenate. Arsenic’s absorptive properties in plant cells and ability to attach to minerals causing secondary contamination are due to environmental factors such as pH, redox potential, and solubility.
The current maximum contaminant level for arsenic in water is 10 µg/L (or ppb). Research on arsenic involving high concentrations already present in groundwater (>300ppb) are compared either with crops irrigated with such water or a human indicator (such as; hair, nails, blood, or urine) in order to determine exposure limits. In this current research, relationships between the area in the studies and the contaminated media (water, soil, vegetation) were tested to determine if arsenic in water was correlated with arsenic concentrations present in soil and vegetation. Commercially obtained ITS Quick Rapid Arsenic Test Kits were used to measure arsenic concentrations for the media tested. A method for analysis of arsenic in vegetation was developed, with an estimated 80% recovery. The pH and conductivity were also taken for water and soil samples as a means of correlative comparison. The development of faster and portable methods for arsenic concentration may provide means for predicting the relationship between all contaminated media. The purpose of the study was to determine the correlation between arsenic water concentration and pH for water, soil, or vegetation and whether it plays an overall role in the amount of arsenic present. As a result, water and soil pH played a significant role in the presence of arsenic in the water and vegetation, respectively. A moderate negative correlation between arsenic in water and water pH was discovered to have a Spearman’s rho value of -0.708 with a p ≤ 0.05. In addition, a significant negative correlation between soil pH and arsenic in vegetation was also discovered to have a Spearman’s rho of -0.628 at a p ≤ 0.05. Even though, pH was significantly correlated with arsenic concentrations in different media, there is evidence that pH plays a role also in the amount of arsenic available in the soil and vegetation. Further studies are recommended.
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Roland, David. "Impact of Growth Conditions, pH, and Suspension Time on Toxin Release from Microcystis Aeruginosa Upon Exposure to Potassium Permanganate." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1543922931806964.
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Lonergan, Sean P. "Macroinvertebrate community responses to acidification : isolating the effects of pH from other water chemistry variables." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68205.
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The effect of lake acidification was evaluated, in the field, in terms of its impact on both the structural and functional composition of the macrozoobenthic community. The littoral macrozoobenthic community and water chemistry of 45 Canadian Shield lakes was sampled. The water chemistry variables sampled included pH, total dissolved calcium, conductivity, and dissolved organic acid (measured as colour). Partial canonical correlation analysis and partial regression analysis were used to identify those components of the macrozoobenthic community that most directly reflected pH variability. This was done by first removing from the data that portion of the variability attributable to total dissolved calcium, conductivity, and dissolved organic acids. In addition, the spatial structure in the data was removed by identifying the geographic coordinates of the sampling sites.In general, the results presented here are not consistent with previous studies where the response of the macrozoobenthic community was related to pH without consideration of confounding covariables. Snails, leeches, mayflies and crayfish have all been cited for their sensitivity to acidification. The present study found these taxa to reflect, not pH variability, but rather attributes of water hardness. Similar results were found for both total zoobenthic biomass and functional feeding group abundance.
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Carter, Kimberly Anne. "Impacts of Salt and pH on the Phase Behavior of Sea Spray Aerosol Proxy Films." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534468159117872.
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Brenzinger, Kristof [Verfasser], and Gesche [Akademischer Betreuer] Braker. "Impact of changes in environmental parameters (pH and elevated CO2) on soil microbial communities involved in N-cycling / Kristof Brenzinger. Betreuer: Gesche Braker." Marburg : Philipps-Universität Marburg, 2015. http://d-nb.info/1080298436/34.
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Abarca, Betancourt Alberto Javier. "The Stability of Uranium-Bearing Precipitates Created as a Result of Ammonia Gas Injections in the Hanford Site Vadose Zone." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3359.
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Uranium (U) is a crucial contaminant in the Hanford Site. Remediation techniques to prevent contaminant migration of U located in the soils to other important water resources such as the Columbia River are of paramount importance. Given the location of the contaminant in the deep vadose zone, sequestration of U caused by ammonia (NH3) gas injections appears to be a feasible method to decrease U mobility in the contaminated subsurface via pH manipulation, ultimately converting aqueous U mobile phases to lower solubility precipitates that are stable in the natural environment. This study evaluated the stability of those U-bearing precipitates via preparation of artificial precipitates mimicking those that would be created after NH3 gas injections and sequential extractions experiment. Results showed that most of the U was recovered with the extracting solutions targeted to remove uranyl silicates and hard-to-extract U phases, suggesting that U present in the solid particles has strong bonds to the vadose zone sediments, causing the precipitates to be stable and therefore the remediation technology to be effective under the simulated conditions.
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Buchanan, Catherine Lynn. "Method to evaluate plants and soils to optimize conditions for phytoremediation of copper." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1271788559.
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Szatkowska, Beata. "Performance and control of biofilm systems with partial nitritation and Anammox for supernatant treatment." Doctoral thesis, Stockholm : Mark- och vattenteknik, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4462.
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Prasetyo, Kuncoro Eko. "Contribution à l'étude de la récupération du mercure (Hg2+) par couplage complexation_ultrafiltration : utilisation du chitosane et de la PEI comme macroligands." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2005. http://tel.archives-ouvertes.fr/tel-00838057.
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Les propriétés complexantes de deux polymères, l'un d'origine biologique (le chitosane) l'autre synthétique (la polyethyleneimine, PEI), ont été mises à profit pour fixer des ions métalliques, au premier rang desquels le mercure. Le procédé de couplage complexation-ultrafiltration permet dans des conditions expérimentales optimisées, d'atteindre des taux de rétention supérieurs à 95 %. Si l'efficacité du chitosane est fortement contrôlée par le pH : rétention négligeable à pH inférieur à 4, et optimale à pH proche de 5,5 ; dans le cas de la PEI, l'influence du pH est moins marqué. La rétention du mercure a été testée dans des solutions binaires (Ni, Zn, Pb et Cu). Les deux macroligands montrent une nette préférence pour le mercure vis-à-vis de métaux tels que Zn, Ni et Pb. Le modèle de filtration sur gâteau se révèle logiquement le plus approprié pour modéliser le colmatage dans le cas de ces expériences menées sur une cellule d'ultrafiltration statique.
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Brzoska, Ryann Michelle. "The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH." Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1437753281.
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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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Juškevičiūtė, Aida. "Šalies ekologinių ūkių suformuotų agrofitocenozių vertinimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110601_112225-34602.
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Tyrimo tikslas - nustatyti ir įvertinti Lietuvoje ekologiškai ūkininkaujančių ir pagal rengiamą LR ŽŪM konkursą pretenduojančių tapti „Pažangiausias ekologiniais ūkiais“, dirvožemių turtingumą augalams prieinamomis maisto medžiagomis ir susiformavusių agrofitocenozių agrarinę būklę.
Tyrimo objektas – Lietuvos skirtingų regionų ekologinės gamybos ūkių, pretenduojančių tapti “ Pažangiausiais ekologiniais ūkiais“ dirvožemiai ir suformuotos agrofitocenozės.
Tyrimų metodika. 2007–2009 metais LR ŽŪM organizuoto konkurso metu renkant „Pažangiausius ekologinius ūkius“, iš ekologinių ūkių laukų buvo imami dirvožemio ėminiai ir atlikta agrocheminė dirvožemio analizė, taip pat nustatytas agrofitocenozių dominančių tankis ir segetinės floros kiekis.
Dirvožemio pH nustatytas potenciometriniu metodu, judrieji P2O5 ir K2O – Egnerio – Rimo – Domingo (A – L) metodo ištraukoje.
Agrofitocenozių įvertinimui pasirinktas ekspedicinių tyrimų analitinis metodas.
Tyrimo rezultatai. Atlikus tyrimus didžiausias judriojo kalio ir judriojo fosforo kiekis rastas Vakarų Lietuvos gamtinėje dirvožeminėje zonoje. Mažiausias kiekis – Baltijos aukštumų gamtinėje dirvožeminėje zonoje.
Judriuoju kaliu ir judriuoju fosforu turtingiausi Šiaulių, Telšių ir Tauragės apskričių ekologinių ūkių dirvožemiai.
Humusu turtingiausi Vakarų Lietuvos gamtinės dirvožeminės zonos dirvožemiai
Mažiausias ekologinių ūkių agrofitocenozių dominantėse segetinės floros kiekis buvo Kauno, Panevėžio ir Tauragės apskrityse... [toliau žr. visą tekstą]The subject of research – to identify and evaluate the richness of soil in the nutrients suitable for plants and the agrarian state of the formed agrophytocenoses of the ecological farms of Lithuania and the candidates for the status of the Leading ecological farms under the competition organized by the Ministry of Agriculture of the Republic of Lithuania. The aim of the research. The soils and agrophytocenoses of the ecological farms of different regions of Lithuania seeking to become the Leading ecological farms. Methods of the research. In 2007–2009, during the competition for the name of the Leading ecological farms organized by the Ministry of Agriculture of the Republic of Lithuania, the soils of the fields of the ecological farms were sampled and undergone the agrochemical soil analysis. There also was determined the density of the agrophytocenoses and the amount of segetal flora. The soil pH was determined using the potentiometric method, the mobile P2O5 and K2O – using the Egner-Riem-Domingo method. The field analytical method was used to evaluate the agrophytocenoses. The results of the research. The tests showed that the area of natural soil of the western Lithuania contained the maximum amount of mobile potassium and mobile phosphorus. The minimum amount was found in the area of natural soil of Baltic Heights. The soils of the ecological farms of Šiauliai, Telšiai and Tauragė regions have the maximum content of mobile potassium and mobile... [to full text]
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Johansson, Elin, and Hoonk Jesper Ekström. "Phytoremediation using Lupinus mexicanus and biochar in arsenic contaminated soil an experimental study." Thesis, Linköpings universitet, Tema Miljöförändring, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-165896.
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Soil contamination is one of the main threats affecting food and water safety and ecosystem services on a global scale. Contamination of toxic inorganic and organic pollutants in soils and its remediation is closely related to the implementation of Sustainable Development Goals. With phytoremediation as a method and biochar as a tool, we used a common plant type Lupin Mexicanus to remediate soil from arsenic contamination further, we wanted to study how biochar affects the phytoremediation of contaminants. The combination of biochar made from reeds and L. mexicanus was in this study tested for its suitability for phytoremediation of arsenic (As) in soil. Seeds from L. mexicanus was grown in 18 different pots spiked with As (80 mg kg-1, dry weight) and different percentage of biochar amendment (0, 1, 2, 3, 4,5%). Two additional pots were planted with seeds but completely without any arsenic or biochar. The plants were grown for 5 weeks. The highest concentration in roots was 3094 mg kg-1 found in the pots with 2% biochar. The highest concentration of arsenic in the aerial parts was at a level of 168 mg kg-1 and found in the pots with 5 % biochar. L.mexicanus showed a potential of bioaccumulating arsenic from soil with a bioconcentration factor of 40,6 (2%) and 29,4 (5%), the concentration in leaves was 1-2 times higher compared to that in the soil. The results showed that biochar affected the translocation ratio and uptake of As in L. mexicanus, However, the biochar amended soil did not show anything major to the pH-value at these proportions (5% of biochar or less). This study was limited in explaining the mechanisms responsible for the increase in As uptake but shows a promising application for potential remediation of soils contaminated with high As levels.Markföroreningar och föroreningar har visat sig vara ett av de största hoten som påverkar mark- och ekosystemtjänster på global nivå. Arbetet med förebyggande av föroreningar i marken och reningsarbeten, såsom marksanering har en stark koppling till nästan alla mål för hållbar utveckling. Med fytoremediering som metod och biokol som medel använde vi växter för att extrahera arsenikförorening från jord. I ett försök att minska kunskapsklyftan kring hur biokol påverkar fytoremidering av föroreningar kombinerades dessa två. Kombinationen av biokol tillverkad av vass och L.mexicanus testades i denna studie för dess lämplighet för fytoremediering av As i jord. Frön från L.mexicanus odlades i 18 olika krukor spetsade med As (80 mg kg-1 torrsubstans) och i en variation av andelen biokol ändring (0,1,2,3,4,5%). Två ytterligare krukor planterades med frön men helt utan arsenik eller biokol. Dessa krukor fungerade som kontroll för att säkerställa grobarheten hos fröerna eller de förhållanden som växterna odlades i. Efter 5 veckor skördades växterna och den högsta koncentrationen av arsenik i rötter var på 3094 mg kg-1 och fanns i krukorna som hade 2% biokol. Den högsta koncentrationen av arsenik i plantdelar ovanjord var på 168 mg kg-1 och var i krukorna med 5% biokol. L. mexicanus visade sig kunna bioackumulera, och resultatet visade att bioconcentrations faktorn uppmätte 40,6 (2%) och 29,4 (5%), varav koncentrationen i löv och skälk var 1-2 gånger högre än vad som återfanns i jorden. Resultaten visade även att biokol påverkade translokeringsförhållandet och upptaget av arsenik i L. mexicanus, tillsättningen av biokol i jord gav inga stora förändringar i pH-värdet med tillsatt koncentration (5% av biokol eller mindre). Studien var begränsad i att förklara de mekanismer som är ansvarig för ökningen av As upptag men visar en lovande applikationspotential i arbetet med sanering av jordar från As.
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Thomson, C. C. "Rootstock and canopy density effects on grape berry composition : organic acid composition, potassium content and pH." Lincoln University, 2006. http://hdl.handle.net/10182/772.
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The influence of rootstock and canopy density on grape berry composition was investigated over the summer of 2003-2004 on a commercial vineyard at Waipara, North Canterbury. This experiment was designed to investigate the influence of rootstock and canopy density on the acid composition, potassium (K) content and final pH of harvested fruit (Pinot Noir AM 10/5 Lincoln Selection). The trial block consisted of eight rootstocks laid out to an 8 x 8 latin square, each plot consisting of five vines of the same rootstock. Two canopy treatments were overlaid the block (down whole rows, assigned randomly, four rows to each treatment); one treatment allowed to grow naturally, in the other treatment the canopy was thinned removing double burst shoots and laterals. The bunch numbers were adjusted in the Unthinned canopy treatment (UCT) to match the Thinned canopy treatment (TCT). Information was gathered to assess: the canopy size and density (Pinot Quadrat Leaf Layer and Percent Gaps and canopy porosity), the plant yield (and berry size, berries per cluster, cluster weight, clusters per plant), plant K levels at flowering and veraison (from petioles and leaf blades) and berry composition at harvest (soluble solids (as brix), K, titratable acidity (TA), tartaric acid concentration, malic acid concentration and pH). The trial area was non-irrigated on clay loam soils and viticultural management was to best commercial practice. It was found that although rootstock influenced the levels of K in the plant and in the juice at harvest, the level of K in the juice did not influence pH in this experiment (range of rootstock juice K: 808 ppm to 928 ppm, l.s.d. = 75 ppm). The level of tartaric acid concentration in the juice was found to be the dominant influence on the level of pH in this experiment (rootstock pH range: 3.21 to 3.39, l.s.d. = 0.05). The juice concentration of tartaric acid was influenced by both rootstock (rootstock range 4.0 to 4.7 g/L, l.s.d = 0.4) and canopy density (UCT = 4.1, TCT = 4.7, l.s.d. = 0.4), decreased shading positively increasing the level of tartaric acid. The malic acid concentration in the juice was positively influenced by increasing canopy density (UCT = 4.7 g/L, TCT = 4.1 g/L, l.s.d = 0.4) and this played a minor role in the determination of pH in this experiment; an influence of rootstock on the level of malic acid concentration was found. The malic acid concentration strongly influenced the determination of TA (UCT = 11.0 g/L, TCT = 10.2 g/L, l.s.d = 0.5); tartaric acid concentration had a minor influence on the recorded TA. Attempts to characterise the influence of rootstock on malic acid, tartaric acid and pH were inconclusive. Rootstock was found to influence the canopy variables measured in this experiment and the recorded average plant yield. Crosses of Vitis rupestris were found to exhibit the most canopy vigour and those derived from Vitis berlandieri and Vitis riparia the least. The Canopy treatment did not show an influence over yield but the rootstock was found to influence plant yield, through the numbers of berries set in a cluster and the final harvest cluster weight. The influence of rootstock on pH may be described by the influence it exerts on canopy growth and yield but this was thought unlikely. Further research is required to describe the nature of the rootstock influence on K, malic acid, tartaric acid and pH.
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Schnürer, Ylva. "Influence of soil properties and organic pesticides om soil microbial metabolism /." Umeå : Dept. of Forest Ecology, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/2006118.pdf.
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