Segui questo link per vedere altri tipi di pubblicazioni sul tema: Sewage sludge.
Articoli di riviste sul tema "Sewage sludge"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 articoli di riviste per l'attività di ricerca sul tema "Sewage sludge".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.
1
da Silva, Paulo Henrique Müller, Fabio Poggiani e Jean Paul Laclau. "Applying Sewage Sludge toEucalyptus grandisPlantations: Effects on Biomass Production and Nutrient Cycling through Litterfall". Applied and Environmental Soil Science 2011 (2011): 1–11. http://dx.doi.org/10.1155/2011/710614.
Testo completoAbstract (sommario):
In most Brazilian cities sewage sludge is dumped into sanitary landfills, even though its use in forest plantations as a fertilizer and soil conditioner might be an interesting option. Sewage sludge applications might reduce the amounts of mineral fertilizers needed to sustain the productivity on infertile tropical soils. However, sewage sludge must be applied with care to crops to avoid soil and water pollution. The aim of our study was to assess the effects of dry and wet sewage sludges on the growth and nutrient cycling ofEucalyptus grandisplantations established on the most common soil type for Brazilian eucalypt plantations. Biomass production and nutrient cycling were studied over a 36-month period in a complete randomized block design. Four experimental treatments were compared: wet sewage sludge, dry sludge, mineral fertilizer, and no fertilizer applications. The two types of sludges as well as mineral fertilizer increased significantly the biomass ofEucalyptustrees. Wood biomass productions 36 months after planting were similar in the sewage sludge and mineral fertilization treatments (about 80 tons ha−1) and 86% higher than in the control treatment. Sewage sludge application also affected positively leaf litter production and significantly increased nutrient transfer among the components of the ecosystem.
2
Facchini, Francesco, Giovanni Mummolo e Micaela Vitti. "Scenario Analysis for Selecting Sewage Sludge-to-Energy/Matter Recovery Processes". Energies 14, n. 2 (6 gennaio 2021): 276. http://dx.doi.org/10.3390/en14020276.
Testo completoAbstract (sommario):
The sewage sludges are the byproducts of the wastewater treatment. The new perspective of the wastewater value chain points to a sustainable circular economy approach, where the residual solid material produced by sewage sludge treatments is a resource rather than a waste. A sewage sludge treatment system consists of five main phases; each of them can be performed by different alternative processes. Each process is characterized by its capability to recover energy and/or matter. In this paper, a state of the art of the sludge-to-energy and sludge-to-matter treatments is provided. Then, a scenario analysis is developed to identify suitable sewage sludge treatments plants that best fit the quality and flowrate of sewage sludge to be processed while meeting technological and economic constraints. Based on the scientific literature findings and experts’ opinions, the authors identify a set of reference initial scenarios and the corresponding best treatments’ selection for configuring sewage sludge treatment plants. The scenario analysis reveals a useful reference technical framework when circular economy goals are pursued. The results achieved in all scenarios ensure the potential recovery of matter and/or energy from sewage sludges processes.
3
Tiwari, Soni, Prabhash Kumar Pandey, Ranjan Singh, Ajad Patel, Laxmi Kant Pandey, Femina Sobin, Neeraj Khare et al. "Detoxification of Sewage Sludge by Natural Attenuation and its Application as a Fertilizer-A Review". International Journal of Current Microbiology and Applied Sciences 12, n. 4 (10 aprile 2023): 71–85. http://dx.doi.org/10.20546/ijcmas.2023.1204.008.
Testo completoAbstract (sommario):
Sewage sludge generated from the waste-water treatment systems can play an essential role as fertilizers in the agriculture system. Sewage sludges have hazardous toxic materials; therefore, their application is minimal. Proper dumping of sludge produced via waste-water treatment plants (WWTP) has been categorized as severe ecological trouble and a feasible option to be used in farming formerly sewage sludge is affluent in natural substance and nutrients. On the other hand, sewage sludge contains various toxic agents therefore special attention is required for its application in farming to evade any harm to the organisms as well as to the environment. Controlled and well monitored process of natural attenuation (biological, physical, and chemical processes) which is a part of the environment can detoxify the toxic substances present in the sewage sludges. This review will lead the readers towards the assessment of different processes used for the decontaminating sewage sludge naturally.
4
Arrobas, Margarida, Ramily Meneses, Andressa Gribler Gusmão, Julieta Moreira da Silva, Carlos Manuel Correia e Manuel Ângelo Rodrigues. "Nitrogen-Rich Sewage Sludge Mineralized Quickly, Improving Lettuce Nutrition and Yield, with Reduced Risk of Heavy Metal Contamination of Soil and Plant Tissues". Agronomy 14, n. 5 (27 aprile 2024): 924. http://dx.doi.org/10.3390/agronomy14050924.
Testo completoAbstract (sommario):
Sewage sludge should primarily find use in agriculture, reducing the quantity directed towards alternative disposal methods like incineration or deposition in municipal landfills. This study evaluated the agronomic value and the risk of soil and plant tissue contamination with heavy metals in sewage sludge obtained from two wastewater treatment plants (WWTP). The experiment was arranged as a 2 × 5 factorial (two sewage sludges, five sanitation treatments), involving lettuce cultivation in pots over two growing cycles. The two sewage sludges were sourced from the WWTPs of Gelfa and Viana do Castelo and underwent five sanitation and stabilization treatments (40% and 20% calcium oxide, 40% and 20% calcium hydroxide, and untreated sewage sludge). The Gelfa sewage sludge, characterized by a higher initial nitrogen (N) concentration, resulted in greater dry-matter yield (DMY) (12.4 and 8.6 g plant−1 for the first and second growing cycles, respectively) compared to that from Viana do Castelo (11.0 and 8.1 g plant−1), with N release likely being a major factor influencing crop productivity. The high N concentration and the low carbon (C)/N ratio of sewage sludge led to rapid mineralization of the organic substrate, which additionally led to a higher release of other important nutrients, such as phosphorus (P) and boron (B), making them available for plant uptake. Alkalizing treatments further stimulated sewage sludge mineralization, increasing soil pH and exchangeable calcium (Ca), thereby enhancing Ca availability for plants, and indicating a preference for use in acidic soils. Cationic micronutrients were minimally affected by the sewage sludge and their treatments. The concentrations of heavy metals in the sewage sludge, soils, and lettuce tissues were all below internationally established threshold limits. This study highlighted the high fertilizing value of these sewage sludges, supplying N, P, and B to plants, while demonstrating a low risk of environmental contamination with heavy metals. Nevertheless, the safe use of sewage sludge by farmers depends on monitoring other risks, such as toxic organic compounds, which were not evaluated in this study.
5
Cheng, H. F., S. Y. Chen e J. G. Lin. "Hazardous organic matters in municipal sewage sludge in Taiwan". Water Science and Technology 44, n. 10 (1 novembre 2001): 65–70. http://dx.doi.org/10.2166/wst.2001.0582.
Testo completoAbstract (sommario):
Application of municipal sewage sludge to agricultural land has attracted significant attention in recent years because it conserves abundant nutrients and hydrocarbons that can be used as a soil amendment. The presence of hazardous organic matters (HOMs) in sewage sludge limits the feasibility of reuse of sewage sludge. The purpose of this study was to investigate the types and the concentrations of HOMs in municipal sewage sludge in Taiwan. An efficient SFE/GC/MS method was used to determine HOMs in sludge samples. The results indicated that di-(2-ethylhexyl) phthalate (DEHP) was persistently found in both aerobically and anaerobically digested sludges. 4-nonylphenol (4-NP) was only found in anaerobically digested sludges. Both DEHP and 4-NP have been characterized as endocrine disrupting chemicals (EDCs) or environmental endorine disruptors (EEDs). It suggested that sludges containing high levels of DEHP and 4-NP need further treatment and reduction of possible impacts on the environment before their reuse as soil fertilizers.
6
Samson, K. A., e G. A. Ekama. "An assessment of sewage sludge stability with a specific oxygen utilization rate (SOUR) test method". Water Science and Technology 42, n. 9 (1 novembre 2000): 37–40. http://dx.doi.org/10.2166/wst.2000.0165.
Testo completoAbstract (sommario):
Sewage sludge treatment systems are intended to stabilize the sludge so that its disposal or reuse can be environmentally acceptable. However, stabilized sludges may still contain residual biodegradable organic matter that can be environmentally a nuisance. This paper presents a specific oxygen utilization rate [SOUR, mgO2/(gVSS·h)] batch reactor test method to quantify the residual biodegradable organic matter content of the treated (stabilized) sewage sludges. The results of the study, in which 37 SOUR batch tests were done on 10 different sewage sludges, show that the SOUR, when determined over a prolonged period (4 to 5 days), gives an indirect measure of sludge stability defined as the % soluble and particulate residual biodegradable organics in the sludge; to determine % sludge stability, it is necessary to simulate the experimental SOUR data by means of a general activated sludge model. The % sludge stability obtained for the 10 different sludges, taking due account of their soluble and particulate constituents, was consistent with that expected from the stabilization treatment systems to which the sludges were subjected.
7
Chu, C. W., C. S. Poon e R. Y. H. Cheung. "Characterization of raw sludge, chemically modified sludge and anaerobically digested sludge in Hong Kong". Water Science and Technology 38, n. 2 (1 luglio 1998): 25–32. http://dx.doi.org/10.2166/wst.1998.0095.
Testo completoAbstract (sommario):
Chemically Enhanced Primary Treatment (CEPT) or Chemically Assisted Primary Sedimentation (CAPS) is being employed at the new sewage work on Stonecutters Island as part of the Strategic Sewage Disposal Scheme (SSDS) in Hong Kong. CAPS involves the use of chemical coagulants (such as lime or ferric chloride) to induce coagulation or flocculation and let these finely-divided particles form large aggregates (floc) so that they can settle out within a reasonable period of time. In this study, five sludge samples collected from different sewage treatment plants in Hong Kong were physically and chemically characterized. They were chemically modified sludge from Stonecutters Island (CAPS) raw sludge from Tai Po and Yuen Long Sewage Treatment Plant (STP) (rTP & rYL) and anaerobically digested sludge from Tai Po and Yuen Long STP (dTP & dYL). It was found that CAPS sludge was better than other 4 sludge samples in terms of settleability and dewaterability. CAPS sludge contained significant higher amounts (p<0.01) of extractable compounds than other sludges (except NO3− for dTP, NH4+ and PO43− for dYL). The concentration of total N and P in CAPS sludge were significantly higher (p<0.01) than other sludges (except dYL). The concentrations of total Cu, Pb, Ni, Cd, Cr and K in the CAPS sludge were also significantly higher (p<0.01) than other sludge samples. Most of the metals (Cr, Pb, Cr and Zn) in CAPS sludge were associated with the organically-bounded phase. It is concluded that there are significant differences in both physical and chemical properties between the chemically modified sludge and biological treated sludges.
8
Rio, S., C. Faur-Brasquet, L. Le Coq, D. Lecomte e P. Le Cloirec. "Preparation and characterization of activated carbon from sewage sludge: carbonization step". Water Science and Technology 49, n. 1 (1 gennaio 2004): 139–46. http://dx.doi.org/10.2166/wst.2004.0041.
Testo completoAbstract (sommario):
Sewage sludges produced from wastewater treatment plants continue to create environmental problems in terms of volume and method of valorization. Thermal treatment of sewage sludge is considered as an attractive method in reducing sludge volume which at the same time produces reusable by-products. This paper deals with the first step of activated carbon production from sewage sludge, the carbonization step. Experiments are carried out on viscous liquid sludge and limed sludge by varying carbonization temperature and heating rate. The results show that carbonized residue properties are interesting for activated carbon production.
9
Meunier, N., R. D. Tyagi e J. F. Blais. "Traitement acide pour la stabilisation des boues d'épuration". Canadian Journal of Civil Engineering 23, n. 1 (1 febbraio 1996): 76–85. http://dx.doi.org/10.1139/l96-008.
Testo completoAbstract (sommario):
Chemical stabilization of sewage sludge is one of the most researched alternative to conventional biological digestion. The present research was therefore dedicated to studying a new acid treatment process for residual sludge from wastewater treatment, both industrial and municipal. This study demonstrated that sludge acidification (pH = 2.0–2.5) with sulphuric acid brings about a very rapid hydrolysis and mineralization of organic matter of the biomass that causes a significant reduction in sludge solids. This simple and efficient process of acidification for a partial digestion of different types of municipal (primary, secondary, and mixed) and industrial (pulp and paper) sludges could be integrated into the actual chain of treatment and stabilization of sewage sludges. Key words: sewage sludge, stabilization, digestion, acid treatment, sulphuric acid.
10
Hu, Mian Hao, e Ju Hong Yuan. "Heavy Metal Speciation of Sewage Sludge and its Phytotoxic Effects on the Germination of Three Plant Species". Advanced Materials Research 347-353 (ottobre 2011): 1022–30. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.1022.
Testo completoAbstract (sommario):
The environmental impact of sewage sludges depends on the availability and phytotoxicity of their heavy metal. The influence of representative sludges (industrial sludge and municipal sludge) on the availability of heavy metals, and their effects on seed germination were compared. The total heavy metal concentrations were below the maximum permitted for land applied waste and the differences among them were small. The DTPA-extracted metal concentrations were significant different. The sum of all the fractions in the slugdes was close to the total metal content as determined by extraction with aqua regia. In addition, there were significant differences in the chemical forms of the heavy metals (Hg, Ni, As, Cd, Cu, Cr, Zn, Pb) by the sequential extraction system. The two different sludges also affected seed germination and root elongation in different ways. The most serious adverse effects were caused by the municipal sewage sludge extract.
11
Morera, M. T., J. C. Echeverría e J. J. Garrido. "Mobility of heavy metals in soils amended with sewage sludge". Canadian Journal of Soil Science 81, n. 4 (1 agosto 2001): 405–14. http://dx.doi.org/10.4141/s00-043.
Testo completoAbstract (sommario):
Sewage sludges added to arable land can improve soil fertility and physical properties. However, the concentrations of heavy metals commonly found in sludges limits their application to soil. The purpose of this paper is to evaluate the mobility of heavy metals (Cd, Cu, Ni, Pb and Zn) in four soils amended with different rates (0, 80, 60 and 320 t ha–1) of anaerobically stabilized urban sewage sludge. Total metal content in the sewage sludge was Zn >> Cu > Pb > Ni >> Cd. Sludge, soils and sludge-soil mixtures were fractionated by the Tessier sequential extraction procedure. The fractions extracted by H2O2/HNO3 and NH2OH.HCl were the most abundant pools for metals under study. The apparent mobility of metals in the sludge was Zn ≈ Cd ≈ Ni > Pb > Cu. The addition of sewage sludge in soils increased the percentages of metal extracted in non-residual fractions. ANOVA showed that the most significant increases were those of Zn, followed by Cu and Pb; there were no statistical differences (P < 0.05) for Ni and Cd. Exchangeable Zn from sludge was immobilized in basic soils. The other trace metals showed no fraction redistribution. The soils and sludge-treated soil samples were also extracted with EDTA and DTPA. Extraction with EDTA was more sensitive to soil type, whereas extraction with DTPA showed wider variation with metals. Both chelates seemed to be more effective to assess the mobility of metals added with the sludges at low concentrations than the Tessier’s chemical partitioning. Key words: Soils, sewage sludge, heavy metals, mobility
12
Hiraishi, Akira, Yoko Ueda e Junko Ishihara. "Quinone Profiling of Bacterial Communities in Natural and Synthetic Sewage Activated Sludge for Enhanced Phosphate Removal". Applied and Environmental Microbiology 64, n. 3 (1 marzo 1998): 992–98. http://dx.doi.org/10.1128/aem.64.3.992-998.1998.
Testo completoAbstract (sommario):
ABSTRACT Respiratory quinones were used as biomarkers to study bacterial community structures in activated sludge reactors used for enhanced biological phosphate removal (EBPR). We compared the quinone profiles of EBPR sludges and standard sludges, of natural sewage and synthetic sewage, and of plant scale and laboratory scale systems. Ubiquinone (Q) and menaquinone (MK) components were detected in all sludges tested at molar MK/Q ratios of 0.455 to 0.981. The differences in MK/Q ratios were much larger when we compared different wastewater sludges (i.e., raw sewage and synthetic sewage) than when we compared sludges from the EBPR and standard processes or plant scale and laboratory scale systems. In all sludges tested a Q with eight isoprene units (Q-8) was the most abundant quinone. In the MK fraction, either tetrahydrogenated MK-8 or MK-7 was the predominant type, and there was also a significant proportion of MK-6 to MK-8 in most cases. A numerical cluster analysis of the profiles showed that the sludges tested fell into two major clusters; one included all raw sewage sludges, and the other consisted of all synthetic sewage sludges, independent of the operational mode and scale of the reactors and the phosphate accumulation. These data suggested that Q-8-containing species belonging to the classProteobacteria (i.e., species belonging to the beta subclass) were the major constituents of the bacterial populations in the EBPR sludge, as well as in standard activated sludge. Members of the class Actinobacteria (gram-positive bacteria with high DNA G+C contents) were the second most abundant group in both types of sludge. The bacterial community structures in activated sludge processes may be affected more by the nature of the influent wastewater than by the introduction of an anaerobic stage into the process or by the scale of the reactors.
13
Dokulilová, Tereza, Tomáš Vítěz, Jan Chovanec, Robert Rouš, Monika Vítězová e Ivan Kushkevych. "Primary and Activated Sludge Biogas Production: Effect of Temperature". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 66, n. 1 (2018): 23–28. http://dx.doi.org/10.11118/actaun201866010023.
Testo completoAbstract (sommario):
Sewage sludge management is a problem of growing importance. Anaerobic sewage sludge stabilization is commonly used technology, where organic matter contained in primary and activated sewage sludge is converted into biogas, so both, pollution control and energy recovery can be achieved. The paper deals with the effect of process temperature (36 °C, 42 °C and 50 °C) on biogas production and quality during anaerobic stabilization of primary and activated sewage sludge generated during purifying process in low‑loaded activated sludge process. Primary and activated sewage sludge samples were taken at the wastewater treatment plant Brno, Czech Republic. The characteristics of sludges (dry matter and organic dry matter content, pH, conductivity, redox potential) were dermined. Biogas production and quality was measured using 3 anaerobic systems, each of 8 batch anaerobic fermenters, at the 3 different temperature conditions 36 °C, 42 °C and 50 °C. Hydraulic retention time was 20 days. Hypothesis, which predicts that the fermentation of primary and activated sludge provides dissimilar methane quantity and quality under different temperature conditions (36 °C, 42 °C and 50 °C), was partially confirmed. Temperature 42 °C significantly increased biogas production from primary sewage sludge (by 60 % in comparison with production at 36 °C). For activated sewage sludge samples no significant influence of temperature on the biogas production was observed.
14
Zere Taskin, Sinem, e Ugur Bilgili. "Using Sewage Sludge as Alternative Fertilizer: Effects on Turf Performance of Perennial Ryegrass". Sustainability 15, n. 18 (12 settembre 2023): 13597. http://dx.doi.org/10.3390/su151813597.
Testo completoAbstract (sommario):
Two years of research were carried out to evaluate the effects of various sewage sludge and nitrogen doses on the turf performance of perennial ryegrass (Lolium perenne L.) under Mediterranean-type climatic conditions. Four nitrogen sources (NS) [NS1: ammonium nitrate (26%), NS2: Bursa City’s wastewater treatment plant’s waste, NS3: biogas production plant reactor waste, and NS4: food processing and canning factory’s sludge waste] were used in the research. Four different nitrogen doses (0.0, 2.0, 4.0, and 6.0 g m−2) were applied. The sewage sludges were analyzed before the start of the research. It was determined that the heavy metal concentrations were below the limit values, and the plant nutrient content was high. Turfgrass color and quality observations were taken in the study, and turfgrass clipping yield was determined. The 4.0 g m−2 nitrogen dose provided acceptable turf color and quality values among the sewage sludges. NS4 showed the best turf performance among the sewage sludges. Despite increased turf color and quality values, sewage sludge produced a low clipping yield. Food processing and canning factories’ sewage sludges can be alternatives to a nitrogen source.
15
Stürmer, Bernhard, e Melanie Waltner. "Best Available Technology for P-Recycling from Sewage Sludge—An Overview of Sewage Sludge Composting in Austria". Recycling 6, n. 4 (17 dicembre 2021): 82. http://dx.doi.org/10.3390/recycling6040082.
Testo completoAbstract (sommario):
In order to close the phosphorus cycle in the long term, efficient recycling processes are necessary to ensure that this critical nutrient can be returned to arable land. Sewage sludge recycling is of particular importance due to the relatively high phosphorus content of sewage sludge. In this article, the current recycling paths of Austrian sewage sludge are highlighted, focusing on the advantages and limitations of sewage sludge composting. In addition to nutrient contents, pollutant loads were also analyzed in order to also discuss the limitations of this recycling pathway. Therefore, data from Austrian composting plants with focus on sewage sludge are used. The results show that the currently relevant pollutants (heavy metals) are predominantly below the limits prescribed for recycling and spreading on arable land. However, in order to decide on a recycling path at an early stage, a pollutant monitoring system must be in place. Due to pollution, mono-incineration with subsequent phosphorus recovery is also currently being discussed in Austria. Mono-incineration can represent an important component of sewage sludge disposal, because some sewage sludges are not suitable for composting due to potential environmental hazards. Therefore, it is important that evidence-based limit values and measures for the reduction in pollutants for input sources are determined.
16
Ostojski, Arkadiusz. "Elementary analysis and energetic potential of the municipal sewage sludges from the Gdańsk and Kościerzyna WWTPs". E3S Web of Conferences 26 (2018): 00004. http://dx.doi.org/10.1051/e3sconf/20182600004.
Testo completoAbstract (sommario):
This paper aims to present municipal sewage sludge (MSS) elementary analysis and energetic potential based on measurement of heat of combustion (higher heating value HHV) and calculation of calorific values (lower heating value LHV). The analysis takes into the consideration water content in sewage sludge, at different utilization stages, in wastewater treatment plants in Gdańsk Wschód and Kościerzyna – Pomeranian Voivodeship. The study yielded the following results (in % dry matter): ash 19÷31 %, C - 31÷36 %, H - 5÷6 %, N - 4÷6 %, O - 28÷32 %, S – 1 %. Calorific value of stabilized sludges in Gdańsk was on average 13.8÷15 MJ/kg. In case of sludges not undergoing digestion from Kościerzyna WWTP, the calorific value was at the level of 17.5 MJ/kg. Thus, sewage sludges are good energy carriers. High water content though is the problem, as it lowers the useful effect of heat. There is no alternative for thermal sewage sludge neutralization, which is in conformity with valid Polish National Waste Management Plan (KPGO 2022).
17
Balík, J., P. Tlustoš, J. Száková, D. Pavlíková e J. Černý. "The accumulation of zinc in oat grown in soils treated by incubated sewage sludge with peat and straw". Plant, Soil and Environment 48, No. 12 (22 dicembre 2011): 548–55. http://dx.doi.org/10.17221/4411-pse.
Testo completoAbstract (sommario):
The effect of addition of treated sewage sludge on the accumulation of Zn in plants was tested in pot experiment. The additions of eight months preincubated sewage sludge at temperature of 20°C under aerobic and anaerobic conditions with addition of peat and straw were tested. Two different combinations were designed: first consisted of 50% sludge + 35% peat and 15% straw, and second was made of 50% sludge + 5% peat and 45% straw (expressed as dry matter). Three different soils Chernozems, Luvisols, and Fluvisols and three sludges were tested in the experiment. Oat (cv. Pan) was planted as experimental crop. All treatments were fertilized by NPK. Green biomass of oat was harvested and analyzed. At treatments with addition of both composted sludges pH dropped down causing higher mobility of Zn in sewage sludge. Oat grown in these treatments contained higher amount of Zn compared to untreated soils. The application of anaerobically treated sludge led to increased Zn content in biomass compared to aerobically incubated one. Predominant effect on Zn accumulation in plants was determined by tested soil. The highest content was determined in plants grown on Fluvisols. The biomass yield was more affected by source of sewage sludge than by the soil type used. Treatments amended by anaerobically incubated sludge showed tendency to higher biomass production due to their higher content of nitrogen and carbon.
18
Winter, P., e S. C. Duckham. "Analaysis of volatile odour compounds in digested sewage sludge and aged sewage sludge cake". Water Science and Technology 41, n. 6 (1 marzo 2000): 73–80. http://dx.doi.org/10.2166/wst.2000.0095.
Testo completoAbstract (sommario):
A number of malodorous compounds were identified in digested sludge and the corresponding sludge cakes. The major components included a number of sulfides. The levels of these compounds were monitored in order to investigate the influence of the sludge treatment process and length of cake storage on the malodour of treated sewage sludge. Two sewage treatment works (STWs) were surveyed. One of the works (Site B) produced very malodorous sludge cake, whilst the other produced a much less odorous cake (Site A). The analysis consisted of purge and trap sampling of liquefied samples followed by gas chromatography-mass spectrometry (GC-MS). Afteran initial screening of samples, by full mass scan GC-MS analysis, targetcompounds were identified for quantification. Sulfide levels inthe majority of the liquid digested sludges were significantly lower than that in sludge cakes. Large differences in the level of sulfides were found in stockpiled sludge cakes. The majority of malodorous sludge cakes had higher sulfide levels than less odorous sludge cakes. The most abundant compounds were dimethylsulfide, dimethyldisulfide and dimethyltrisulfide. Thehighest sulfide levels were found during the first month of stockpiling. Whenthe odour threshold concentration of these compounds was taken into account and odour unit values were calculated, dimethyltrisulfide was found to have a proportionally greater impact on odour than any of the other compounds studied. The use of sulfide levels as indicators of malodour formation and possible strategies for reducing odour in stockpiled sludge cake are discussed.
19
Wang, Jie, Yan Li Yi, Feng De Tang, Xiang Rui Pang, Zhong Lin Chen, Li Man Peng, Xiao Yang Zhou e Chun Lu Yang. "Effects of Composted Sewage Sludge on the Enzyme Activities in the Aeolian Sandy Soil". Advanced Materials Research 518-523 (maggio 2012): 3341–44. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.3341.
Testo completoAbstract (sommario):
A field experiment was conducted to investigate the effects of composted sewage sludge’s application on the dynamics change of enzyme activities in aeolian sandy soil. The composted sewage sludge was applied to the soil at 0,2,5,10,15,20 and 25 t·ha-1 respectively. The effects of various sewage sludge dosages on the soil’s enzyme activities were evaluated by measuring urease,sucrase,neutral phosphatase and catalase at different time intervals of 15,50,80,110 and 150 days after the addition of sewage sludge to the soil.The results showed that the urease,sucrase,neutral phosphatase and catalase activities increased to varying degrees as the sewage sludge dosages added to the soil increased. And the four enzyme activities were affected by the sampling time significantly,the urease and sucrase activities reached their maximum values in 50 days,and neutral phosphatase and catalase activities reached their maximum values in 80 days.The results also showed that the application of sewage sludge had positive effects on improving the aeolian sandy soil’s fertility.
20
Basta, Nicholas T. "Sewage sludge". Field Crops Research 44, n. 1 (novembre 1995): 51–52. http://dx.doi.org/10.1016/0378-4290(95)90081-0.
Testo completo
21
Iticescu, Catalina, Puiu-Lucian Georgescu, Maxim Arseni, Adrian Rosu, Mihaela Timofti, Gabriel Carp e Lucian-Ionel Cioca. "Optimal Solutions for the Use of Sewage Sludge on Agricultural Lands". Water 13, n. 5 (24 febbraio 2021): 585. http://dx.doi.org/10.3390/w13050585.
Testo completoAbstract (sommario):
The use of sewage sludge in agriculture decreases the pressure on landfills. In Romania, massive investments have been made in wastewater treatment stations, which have resulted in the accumulation of important quantities of sewage sludge. The presence of these sewage sludges coincides with large areas of degraded agricultural land. The aim of the present article is to identify the best technological combinations meant to solve these problems simultaneously. Adapting the quality and parameters of the sludge to the specificity of the land solves the possible compatibility problems, thus reducing the impact on the environment. The physico-chemical characteristics of the fermented sludge were monitored and optimal solutions for their treatment were suggested so as to allow that the sludge could be used in agriculture according to the characteristics of the soils. The content of heavy metals in the sewage sludge was closely monitored because the use of sewage sludge as a fertilizer does not allow for any increases in the concentrations of these in soils. The article identifies those agricultural areas which are suitable for the use of sludge, as well as ways of correcting some parameters (e.g., pH), which allow the improvement of soil quality and obtained higher agricultural production.
22
Stachowicz, Feliks, Beata Pawłowska e Marta Wójcik. "HYDROMETALLURGICAL METHOD OF SELECTED MET-ALS RECOVERY FROM SEWAGE SLUDGE ASHES". Acta Metallurgica Slovaca 23, n. 4 (4 dicembre 2017): 296. http://dx.doi.org/10.12776/ams.v23i4.991.
Testo completoAbstract (sommario):
<p class="Metallographymaintext"><em>With the increasing number of new residents attached to the sewerage system, the amount of generated sewage sludge is systematically growing. In line with the restriction placed on landfill waste with a calorific value above 6 MJ/kg introduced on 1 January 2016, the most popular sewage sludge utilization methods are thermal processes and agricultural use. In recent years, there has been increased interest in using thermal sewage sludge utilization methods. The major problem associated with sludge combustion is the enormous amount of by-products, particularly ashes. </em><em>Due to the specific characteristics, it is necessary to develop new sewage sludge ashes utilization methods in line with economic, law and environmental requirements. </em><em>Sewage sludge ashes are rich in valuable metals, particularly in zinc, copper and iron. As utilization methods of sewage sludge ashes do not guarantee the metals recovery until now, metals are lost irretrievably. This article presents hydrometallurgical methods of metals recovery from sewage sludge ashes with the use of acid leaching. The aforementioned propositions are beneficial from the economical and environmental point of view because they prevent valuable metals from waste. Additionally, the whole undertaking could contribute to the popularization of sustainable development.</em></p>
23
Hoffmann, Gaston, Daniel Schingnitz e Bernd Bilitewski. "Comparing different methods of analysing sewage sludge, dewatered sewage sludge and sewage sludge ash". Desalination 250, n. 1 (gennaio 2010): 399–403. http://dx.doi.org/10.1016/j.desal.2009.09.064.
Testo completo
24
Stoll, U., e K. Parameswaran. "Treatment and disposal of domestic sewage sludge and nightsoil sludge for Bangkok". Water Science and Technology 34, n. 11 (1 dicembre 1996): 209–17. http://dx.doi.org/10.2166/wst.1996.0282.
Testo completoAbstract (sommario):
In the recent past, treatment and disposal of sewage sludge has become an expensive and environmentally sensitive problem in western countries. It is becoming a growing problem worldwide with its focus on the megacities in the newly developed countries, since sludge production will continue to increase as new sewage treatment plants are built and environmental quality standards become more stringent. With some traditional disposal routes coming under pressure, the challenge facing the wastewater treatment authorities is to find cost-effective and environmentally sound solutions whilst responding to increasing public awareness. This paper describes the development of a plan for integrated management of municipal sludges (sewage sludge, nightsoil/septage sludge) which has high security for medium-and long-term sludge utilization and disposal as the goal. It concludes that incineration and agricultural use should be implemented and operated in parallel as first priority options.
25
Dregulo, A. M. "A STUDY OF HEAVY METAL COMPOSITIONS AND PHOSPHATES IN POLYMER SUBSTANCES OF THE ACTIVATED SLUDGE BIOMASS". Water and Ecology 25, n. 3 (2020): 8–13. http://dx.doi.org/10.23968/2305-3488.2020.25.3.8-13.
Testo completoAbstract (sommario):
Introduction. Heavy metals discharged with wastewater can lead to a toxic effect on the microbiocenosis of activated sludge and significantly decrease the degree of wastewater treatment, which dictates the need for a more detailed study and search for ways to detoxify activated sludge at the recycling stage and, at the same time, solve the problems of the neutralization of sewage sludge for safe soil disposal. To ensure the adequacy of the approach to the choice of the methodology for the neutralization of sludge, including sewage sludge, it is necessary to perform compositional analysis of their organic fractions and heavy metal compositions. Methods. To determine the quantitative content of organic components in activated sludge, a sample of sludge was dried to an air-dry state and then subjected to separation into fractions using a method based on the different solubility of compounds with the use of different solvents. Then, extractants were added step by step to the weighted samples of sewage sludge weighing about 2 g each (in a volume 20 times greater than the weight of the weighted sample (40 ml)). Results. The results of the study show that polysaccharides are the dominant form of the organic fraction (polymers) in sewage sludge. Most heavy metals were identified in acidic polysaccharides, humic-like acids and lipids. Significant concentrations of phosphates were observed for the same components of polymer substances in the biomass of activated sludges. Conclusion. The products of extraction of polymer substances of the activated sludge biomass and the content of heavy metals in them may indicate the biosorption of heavy metals by zoogleal accumulations (having a polysaccharide structure) of activated sludges in aeration tanks during biological treatment. Therefore, extracellular biopolymers can be a “target” in the development of targeted technologies for the neutralization of activated sludges.
26
Cheng, H. F., S. Y. Chen e J. G. Lin. "Biodegradation of di-(2-ethylhexyl) phthalate in sewage sludge". Water Science and Technology 41, n. 12 (1 giugno 2000): 1–6. http://dx.doi.org/10.2166/wst.2000.0227.
Testo completoAbstract (sommario):
Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer in the production of polyvinyl chloride to impart flexibility to the product. Because of its mutagenicity and carcinogenicity, the presence of DEHP in sludge limits the application of sludge as a soil fertilizer. In this study, sludges were collected from three sewage treatment plants and thirteen wastewater treatment plants of different industries in Taiwan. A supercritical fluid extraction (SFE) was first established as an effective method for determining the concentration of DEHP in sludge. Laboratory-scale land-simulated experiments were performed to investigate the biodegradation of DEHP in sludge under various conditions (moisture, temperature, sunlight and ventilation). DEHP was found in aerobically and anaerobically digested sludges and their values significantly exceeded the restricted concentration of DEHP for sludge land application. DEHP was found to degrade in sludge under the conditions of good ventilation, sufficient sunlight and proper moisture. The indigenous microorganisms in the sludge appeared to dominate the biodegradation of DEHP in sludge. However about 70% of DEHP remained in sludge after 189 d indicating that DEHP is persistent in the environment.
27
Öden, Muhammed Kamil, İrfan Özer e Bilgehan Yabgu Horasan. "Arıtma Çamurlarının Tarımsal Alanlarda Kullanım Örneklerinin Araştırılması". Turkish Journal of Agriculture - Food Science and Technology 7, n. 5 (21 maggio 2019): 743. http://dx.doi.org/10.24925/turjaf.v7i5.743-749.2400.
Testo completoAbstract (sommario):
Nowadays, due to some reasons, soil quality deteriorates, soil organic matter decreases, and plant growth is adversely affected such as damaging agricultural practices, unconscious pesticide and fertilizer use. There is also treatment sludge among the methods that will contribute to the soil. Sewage sludge, the inevitable by-product of municipal and other wastewater treatment plant operations, is a key issue in many countries due to its increasing volume and the impacts associated with its disposal. This environmentally hazardous treatment sludge can be significantly reduced by anaerobic digestion. However, the resulting gas and the residues from anaerobic digestion process need to be treated or stabilized. The use of sewage sludge in agriculture will provide both soil nutrient elements and waste sludge can be disposed with this application. Definitely, it is possible to evaluate the treatment sludges in many different areas. After cleaning the sludge from contaminants, it can be used as a good compost or soil improvement material. In this study, agricultural applications with sewage sludge were investigated.
28
Potapova, А. Yu, e O. A. Barkhatova. "Problems of Accumulation of Sewage Sludge on the Territory of Sewerage Treatment Plants". Bulletin of Irkutsk State University. Series Earth Sciences 48 (2024): 57–73. http://dx.doi.org/10.26516/2073-3402.2024.48.57.
Testo completoAbstract (sommario):
The work is devoted to the study of environmental problems associated with the impact of sewage sludge on environmental components and the problems of recycling a mixture of sludge on the territory of the STP. Sewage sludge can be harmful to the environment if we do not take proper steps to dispose and treat it. The main impact on the soil during the accumulation of sewage sludge on sludge deposits of sewage treatment plants is exerted by such heavy metals as copper, cadmium, nickel, manganese, lead, zinc. Heavy metals, coming from the soil into plants and transmitted through food chains, have a toxic effect on plants, animals and humans. Therefore, it is necessary to introduce modern technologies and equipment for effective wastewater treatment in order to reduce the amount of sludge formation and methods of its treatment to reduce the negative impact on the environment and human health. The purpose of the work is to analyze the processes of waste treatment “a mixture of sludge from mechanical and biological treatment of domestic and mixed wastewater” at a sewerage treatment plants in order to minimize the negative impact on the environment, using the example of Irkutsk. An analysis of literature sources was carried out as part of a study related to the problem of wastewater disposal. Possible methods of disposal in Russia include: burial, pyrolysis, incineration, use in construction and use as fertilizer. As a result of the analysis of sewage sludge treatment at the Irkutsk STP, it can be concluded that the current method of sludge treatment using sludge cards is ineffective and has a negative impact on the environment. Based on the considered methods of treating sewage sludge, the vitrification method can be accepted as optimal, which can solve the problem of treating sewage sludge at the Irkutsk STP.
29
Bwapwa, Joseph K. "Overview on Bioconversion of Domestic Wastewater Sewage Sludge into Green Energy: Biogas and Hydrogen". International Journal of Environmental Science and Development 12, n. 8 (2021): 232–41. http://dx.doi.org/10.18178/ijesd.2021.12.8.1345.
Testo completoAbstract (sommario):
Municipal wastewater treatment plants generate large amounts of sludge after a set of unit processes. The sewage sludge is an important resource for energy production because of its high level of biodegradability. Sewage sludges are generally made of non-toxic and biodegradable organic compounds mixed with a small fraction of non-toxic and toxic inorganic compounds having a very low biodegradability. The large fraction of biodegradable matter constitutes a pool for green/clean energy to be used for industrial and domestic applications. The generated energy can also be used in the wastewater treatment plant. Currently, fossil fuels are leading the energy world, however, they are being depleted and are considered to be among the main causes contributing to climate change and global warming. Domestic sewage sludge can be converted sustainably into bio-hydrogen and bio- methane. This conversion is achievable through anaerobic digestion, combustion, pyrolysis and gasification. With regard to the last three conversion processes, the organic and inorganic toxic compounds are eliminated. Production of biogas from sewage sludge is being undertaken worldwide on small, medium, and large scales. However, hydrogen production from sludge is still developing. There is an existence of substantial knowledge in this field, the production of hydrogen and biogas from sewage sludge is gaining interest. This study analyses various possibilities of sewage sludge conversion into clean energy. The analysis focuses on the technology strengths, weaknesses and gaps to be improved in future studies.
30
Paulsrud, Bjarne, e Kjell Terje Nedland. "Strategy for land application of sewage sludge in Norway". Water Science and Technology 36, n. 11 (1 dicembre 1997): 283–90. http://dx.doi.org/10.2166/wst.1997.0422.
Testo completoAbstract (sommario):
The Norwegian public health and environmental authorities have launched a regulation for sewage sludge handling and disposal aiming at increasing the amount of sludge to be utilised on land areas. The strategy for achieving this is to secure that only high quality sludge is being offered to agriculture and green areas; the two disposal routes acceptable for land application of sludge in Norway. Most sewage treatment plants have experienced a considerable reduction in sludge heavy metals content during the last 15-20 years and the major reason for this is believed to be the continuous control of industrial effluents discharged to the municipal sewerage system and the implementation of cleaner technologies in the industry. Health risks and odour nuisance from the sewage sludge will be almost eliminated by employing treatment processes with the main purpose of disinfection and stabilisation of the sludge.
31
Gouvea, Glaucia De Mello Cunha, Victor Ventura de Souza, Glaucio De Mello Cunha e Tatiana Da Silva Souza. "Effects of sewage sludge on the growth of coffea arabica seedlings and cell cycle of Allium cepa". Holos Environment 19, n. 4 (6 dicembre 2019): 657. http://dx.doi.org/10.14295/holos.v19i4.12357.
Testo completoAbstract (sommario):
Sewage sludge can contain toxic compounds and pathogens therefore it agronomic use must occur in a safer way to the population and environment. The objective of this study was to investigate the effects of substrates containing different proportions of sanitized sewage sludge in the growth of Coffea Arabica seedlings and to verify the cytogenotoxic potential of these substrates using the analysis of Allium cepa cell cycle. The substrate with the lowest proportion of sewage sludge (15%) was the one that obtained the greatest growth performance and did not present cytogenotoxic activity. Substrates with the highest concentrations of sanitized sewage sludge (30, 45 e 60%) were toxics. For coffee seedlings, all the growth variables decreased and the significant induction of aberrant meristematic cells in A. cepa was observed. However, the sewage toxicity was not related to the presence of metals, whose levels were within the maximum limits allowed by the Brazilian legislation, indicating that these biological tests are essential for the determination of the quality of sewages before their agricultural use.
32
Malczewska, Beata, Bartosz Jawecki e Sławomir Woźniak. "Zalety i wady kompostowania osadów ściekowych w porównaniu z termicznym ich spalaniem – studium przypadku". Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 26, n. 1 (14 aprile 2017): 125–35. http://dx.doi.org/10.22630/pniks.2017.26.1.11.
Testo completoAbstract (sommario):
New challenges for the territorial government in the field of urban sewage sludge oblige to limit it storage. Sewage sludge management is one of the most difficult environmental and economic problems. Therefore, it is important to choose the right technology for the sewage sludge disposal. The purpose of this article is an evaluation of applied disposal methods on sewage treatment sludge plant and comparison of this method (sewage sludge composting) with thermal transformation of sewage sludge. Study confi rms that, in the present case, the composting of sewage sludge is the most advantageous solution.
33
Lopes, Bruna C., Raíssa S. Figueiredo, Juliana C. Araújo e Antonio T. Matos. "Bacterial community dynamics in tropical soil after sewage sludge amendment". Water Science and Technology 82, n. 12 (3 novembre 2020): 2937–47. http://dx.doi.org/10.2166/wst.2020.523.
Testo completoAbstract (sommario):
Abstract Although the widespread use of sewage sludge in developing countries is common, little is known about how sludge disposal can affect the microbial composition and diversity of tropical soils. We evaluated the effects of the sewage sludges of two types of anaerobic digestors differing, by the biological treatment they have undergone (uplow anaerobic sludge blanket and activated sludge digester), and two different disposal methods (surface and incorporated) on tropical soils. Samples were taken from topsoil (0–10 cm) and analyzed by amplifying the 16S rRNA genes to study the microbial community, and physicochemical analysis was performed concomitantly. The results indicated that, in general, sewage sludge amendment (SSA) significantly changed the tropical soil bacterial community by the sludge type and by application method. Moreover, the redundancy analysis diagram indicates that changes in soil chemical parameters over time due to SSA resulted in changes in the bacterial community's composition, increasing the population responsible for recycling nutrients in the soil.
34
Netzer, Corinna, e Terese Løvås. "Chemical Model for Thermal Treatment of Sewage Sludge". ChemEngineering 6, n. 1 (7 febbraio 2022): 16. http://dx.doi.org/10.3390/chemengineering6010016.
Testo completoAbstract (sommario):
Sewage sludge is here studied as a valuable source for processing or energy conversation thanks to its high nutrition and energy content. However, various origins of the wastewater, different water cleaning technologies, and seasonal and regional dependencies lead to the high variability of the sewage sludge properties. In thermal treatment units, that is, incineration, gasification and pyrolysis, sewage sludge serves as feedstock or fuel, hence a proper characterization and a mathematical description of the sewage sludge are required to estimate product streams and to formulate numerical simulations and optimization methods. The presented work introduces a surrogate concept that allows replication of sewage sludge’s ultimate composition, moisture, and ash content. The surrogate approach aims to model the decomposition of any sewage sludge sample, opposite to the established determination of kinetic rates for individual samples. Based on chemical solid surrogate species and corresponding reaction mechanisms, the thermal decomposition path is described. Sewage sludge is represented by a combination of lignocellulosic species, proteins, sugars, lipids, and representative inorganic species. The devolatilization and heterogeneous reactions are formulated such that they can be used together with a detailed gas-phase model, including tar oxidation and emission models for nitrogen and sulfur oxides, recently proposed by the authors. The developed chemical model is applied using a zero-dimensional gasification reactor in order to model weight loss within the thermogravimetric analysis, pyrolysis, gasification and combustion conditions. Weight loss, the composition of product gases, and emission release (nitrogen and sulfur oxides) are captured well by the model. The flexible surrogate approach allows us to represent various sewage sludge samples.
35
Yasuda, Yasuhiro. "Sewage Sludge Utilization Technology in Tokyo". Water Science and Technology 23, n. 10-12 (1 maggio 1991): 1743–52. http://dx.doi.org/10.2166/wst.1991.0629.
Testo completoAbstract (sommario):
With increasing sewage sludge produced in Tokyo, it has become difficult to acquire land for sewage sludge disposal. To solve this problem, efforts have been made to develop sewage sludge utilization technologies. Five technologies have already been developed; conversion of sewage sludge to compost, conversion of sewage sludge to fuel, producing artificial lightweight aggregate from ashes, press burning of incineration ashes, and conversion of sewage sludge to melted slag. The present paper describes these utilization technologies.
36
Hawrylik, Eliza, e Andrzej Butarewicz. "Toxicity assessment of sewage sludge from municipal sewage treatment plants". Ekonomia i Środowisko - Economics and Environment 82, n. 3 (26 ottobre 2022): 257–68. http://dx.doi.org/10.34659/eis.2022.82.3.491.
Testo completoAbstract (sommario):
The aim of this study was to assess the toxicity of sewage sludge from the municipal sewage treatment plant in Bialystok. Raw sewage, sewage sludge from the primary settling tank, activated sludge, sludge before the fermentation chamber, recirculated sludge and sewage sludge after fermentation and dehydration on press were tested. The Microtox Model 500 kit using Aliivibrio fischeri luminescent bacteria was used for the toxicity analyzes. The EC50 index (indicating the concentration of toxic substances resulting in a 50% reduction in the intensity of luminescence of the bacterial strains used) converted into the TUa toxicity units was adopted as the value describing the toxicity of the tested media. The obtained results showed high and very high ecotoxicity of raw sewage and sewage sludge from the primary settling tank, sludge in front of the fermentation chamber and after fermentation and dehydration in the press. The use of tests determining the toxicity of sewage flowing into the sewage treatment plant and sewage sludge generated at various stages of the treatment process allows to detect the danger associated with the uncontrolled discharge of toxic substances into the sewage system.
37
Seghezzo, L., C. M. Cuevas, A. P. Trupiano, R. G. Guerra, S. M. González, G. Zeeman e G. Lettinga. "Stability and activity of anaerobic sludge from UASB reactors treating sewage in subtropical regions". Water Science and Technology 54, n. 2 (1 luglio 2006): 223–29. http://dx.doi.org/10.2166/wst.2006.509.
Testo completoAbstract (sommario):
The production of small amounts of well-stabilized biological sludge is one of the main advantages of upflow anaerobic sludge bed (UASB) reactors over aerobic wastewater treatment systems. In this work, sludge produced in three pilot-scale UASB reactors used to treat sewage under subtropical conditions was assessed for both stability and specific methanogenic activity. Stability of primary sludge from settling tanks and digested sludge from conventional sludge digesters was also measured for comparison purposes. Kinetic parameters like the hydrolysis rate constant and the decay rate constant were calculated. High stability was observed in sludge from UASB reactors. Methanogenic activity in anaerobic sludges was relatively low, probably due to the low organic matter concentration in influent sewage. Knowledge on sludge growth rate, stability, and activity might be very useful to optimize sludge management activities in full-scale UASB reactors.
38
Hiraoka, M. "Advanced sludge thermal processes in Japan". Water Science and Technology 30, n. 8 (1 ottobre 1994): 139–48. http://dx.doi.org/10.2166/wst.1994.0398.
Testo completoAbstract (sommario):
As a result of the spread of sewerage systems, the management of growing quantities of sewage sludge is becoming an urgent need. As the method of sludge management, thermal processes have mostly been applied to the treatment and disposal of sewage sludge in Japan, because of the difficulty of finding final disposal sites. This paper describes the progress of thermal processing technologies, especially focusing on drying-incineration process systems and melting-slag recycling process systems.
39
Tatarus, Alina, Diana Puiu, Roxana Scutariu, Marius Simion, Marcela Antoaneta Niculescu e Toma Galaon. "PCB congeners occurrence in sewage sludge from municipal wastewater treatment plants in Romania". SIMI 2019, SIMI 2019 (20 settembre 2019): 310–17. http://dx.doi.org/10.21698/simi.2019.fp39.
Testo completoAbstract (sommario):
Sewage sludges originating from waste water treatment plants (WWTP) act as a sink for various contaminants including polychlorinated biphenyls (PCBs). The fate of organochlorine compounds in sewage sludge is shaped by their physical-chemical properties and by environmental conditions. The high persistence of polychlorobiphenyls (PCBs) in sewage sludge is given by an extremely reduced degradation rate which varies from months to years (the half-life of PCB 28 is 10.9 years, and PCB 52, 11.2 years). Due to their increased hydrophobicity, these carcinogenic compounds can be easily uptake by plants and transferred to the food chain. The present study investigated the occurrence of these seven PCB congeners in sewage sludge sampled from municipal waste water treatment plants from different geographical areas in Romania for a two-year period (2018 and 2019). For the analyzed PCB congeners a database was created concerning their occurrence levels in sewage sludge from these WWTPs. A total number of 62 sewage sludge samples were collected from different WWTPs between 2018-2019 and analyzed for PCB congener content using a validated GC-ECD method according to SR EN 16167/2013. In all the samples that were analyzed in this study the sum of PCB congeners was situated below the maximum allowable concentration (MAC = 0.8 mg/kg d.w.) stated by the Order 708/2004.
40
Abbas, Ahmed Mahmoud, Sameh K. Abd-Elmabod, Soad M. El-Ashry, Wagdi Saber Soliman, Noha El-Tayeh e Jesus M. Castillo. "Capability of the Invasive Tree Prosopis glandulosa Torr. to Remediate Soil Treated with Sewage Sludge". Sustainability 11, n. 9 (13 maggio 2019): 2711. http://dx.doi.org/10.3390/su11092711.
Testo completoAbstract (sommario):
Sewage sludge improves agricultural soil and plant growth, but there are hazards associated with its use, including high metal(loid) contents. An experimental study was conducted under greenhouse conditions to examine the effects of sewage sludge on growth of the invasive tree Prosopis glandulosa, as well as to determine its phytoremediation capacity. Plants were established and grown for seven months along a gradient of sewage sludge content. Plant traits, soil properties, and plant and soil concentrations of N, P, K, Cd, Pb, Cu, Ni, Zn, Cr, Co, As, and Fe were recorded. The addition of sewage sludge led to a significant decrease in soil pH, and Ni, Co, and As concentrations, as well as an increase in soil organic matter and the concentrations of N, P, Cu, Zn, and Cr. Increasing sewage sludge content in the growth medium raised the total uptake of most metals by P. glandulosa plants due to higher biomass accumulation (taller plants with more leaves) and higher metal concentrations in the plant tissues. P. glandulosa concentrated more Cd, Pb, Cu, Zn, and Fe in its below-ground biomass (BGB) than in its above-ground biomass (AGB). P. glandulosa concentrated Ni, Co, and As in both BGB and AGB. P. glandulosa has potential as a biotool for the phytoremediation of sewage sludges and sewage-amended soils in arid and semi-arid environments, with a potential accumulation capability for As in plant leaves.
41
ALHAFEZ, Livia, Nicoleta MUNTEAN, Edward MUNTEAN e Dumitru RISTOIU. "Polycyclic Aromatic Hydrocarbons in Sewage Sludge from Cluj-Napoca Wastewater Treatment Plant". Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture 70, n. 2 (25 novembre 2013): 387–89. http://dx.doi.org/10.15835/buasvmcn-agr:9760.
Testo completoAbstract (sommario):
Polycyclic aromatic hydrocarbons (PAHs) are organic compounds widely distributed in the environment. In the present work, concentrations of these organic compounds in sludge samples from Cluj-Napoca wastewater treatment plant are reported. The objective was to investigate PAHs in sludge from wastewater treatment plant and to assess their potential for land application. Primary sludge, fermented sludge, fermented concentrated sludge, anaerobic-digested dehydrated sludge and rejection water samples were collected monthly from December 2012. Ultrasonic assisted extraction with hexane was used, being followed by filtration and concentration to dryness in a rotary evaporator; the obtained residue was redisolved in acetonitrile. High performance liquid chromatographic analysis was achieved using an Agilent 1100 system consisting in a solvent degasser, a quaternary pumping system, an autosampler, a column oven, a diode-array detector and a fluorescence detector. Separations were accomplished using an Envirosep PP column with acetonitrile:water as mobile phase (45:55 v/v). Detection limit was 0.001 ïg/ kg, with good linearities for all PAHs, with correlation coefficients higher than 0.998. PAHs with four rings appeared to be the primary components in most of the tested sludge samples, the highest concentration levels being in anaerobic-digested dehydrated sludge samples. The obtained results can be helpful for the regional policy makers to make proper decisions on treating the increasing amount of sewage sludge, to provide practical reference for establishing threshold values of PAHs for land application of sludge, knowing that the practice of recycling sewage sludge onto agricultural lands poses an additional risk of soil contamination with PAHs.
42
Pereira, Alex Borges, Antonio José Vinha Zanuncio, Amélia Guimarães Carvalho, Angélica de Cassia Oliveira Carneiro, Vinícius Resende de Castro, Ana Marcia Macedo Ladeira Carvalho, Olivia Pereira Lopes et al. "Sustainable Solid Biofuel Production: Transforming Sewage Sludge and Pinus sp. Sawdust into Resources for the Circular Economy". Sustainability 16, n. 11 (27 maggio 2024): 4554. http://dx.doi.org/10.3390/su16114554.
Testo completoAbstract (sommario):
The lack of adequate sanitation in Brazil overloads the health system and causes deaths. The utilization of sewage sludge hinders advancements in water treatment. This study aimed to assess the feasibility of producing briquettes by blending sewage sludge with Pinus sp. sawdust. The sewage sludge was sourced from a water treatment facility, while the Pinus sp. sawdust was obtained from a sawmill. Elemental analysis, proximate analysis, and calorific value were evaluated for both biomasses. Briquettes were manufactured using a hydraulic press, varying the proportion of sewage sludge from 0% to 95%, followed by thermogravimetric analysis. Pinus sp. sawdust exhibited higher carbon, oxygen, and hydrogen content, whereas sewage sludge contained more nitrogen and sulfur. The sawdust had greater fixed carbon content, volatile matter, and calorific value, while the sewage sludge had higher ash content. Samples with higher sewage sludge content showed better thermal resistance, with 100% sewage sludge retaining 63.3% mass after exposure to 950 °C. Briquettes with higher sewage sludge content had increased energy density. Considering the elevated nitrogen, sulfur, and ash content, sewage sludge should be limited to 5% in briquette production with Pinus sp. sawdust. This research underscores a significant avenue for sewage sludge utilization and sustainable bioenergy production.
43
Zhu, Puli, Xiaoyun Li, Jing Feng, Rui Zhang, Hui Bai, Duo Bu, Zeng Dan, Wei Li e Xuebin Lu. "Short-Chain Fatty Acids Production from Anaerobic Fermentation of Sewage Sludge: The Effect of Higher Levels Polyaluminium Chloride". International Journal of Environmental Research and Public Health 19, n. 5 (28 febbraio 2022): 2806. http://dx.doi.org/10.3390/ijerph19052806.
Testo completoAbstract (sommario):
With the annual increase in the sludge production in China’s sewage treatment plants, the problem of sewage sludge treatment and disposal is becoming more and more serious. Anaerobic fermentation can convert complex organic matter in sewage sludge into short-chain fatty acid, hydrogen, methane and other resources and is an effective method for sewage sludge treatment and disposal. At the same time, sewage sludge often contains flocculants, which will inevitably affect the effect of anaerobic fermentation. As a high-performance flocculant, polyaluminum chloride (PAC) is widely used in wastewater treatment and sewage sludge dewatering processes. Previous studies indicated that lower levels of PAC inhibit the effect of the anaerobic fermentation process of sewage sludge; on the other hand, it is necessary to understand the effects of higher levels of PAC in anaerobically fermented sewage sludge. The results showed that higher levels (0.2–1 g Al/g total solids (TS)) of PAC could promote acid production from anaerobically fermented sewage sludge. Moreover, mechanism studies suggest that higher levels (0.2–1 g Al/g total solids (TS)) of PAC caused excessive adsorption of the charge on the surface of the sewage sludge colloid and reversed the charge. The sewage sludge colloid was stabilized again, which increases the concentration of soluble proteins, polysaccharides, and soluble extracellular polymers (S-EPS) in the fermentation broth, thereby improving the anaerobically fermented sewage sludge efficiency. The results provided from this study may act as technical reference and guidance for the engineering application of sewage sludge anaerobic fermentation.
44
Mason, C. A., A. Häner e G. Hamer. "Aerobic Thermophilic Waste Sludge Treatment". Water Science and Technology 25, n. 1 (1 gennaio 1992): 113–18. http://dx.doi.org/10.2166/wst.1992.0017.
Testo completoAbstract (sommario):
The expansion in both industrial and municipal wastewater treatment in recent years has resulted in a major increase in the quantities of by-product sludge produced and has exacerbated problems of waste sludge treatment and/or disposal. The traditional method for waste sewage sludge treatment is anaerobic mesophilic digestion for sludges that are to be disposed of on agricultural land. Other disposal methods for untreated sludges include incineration, an option receiving increased interest, and ocean dumping, an option that is environmentally incompatable and used much less frequently today compared with 10 years ago. Sewage sludge can be considered to be a resource as far as its mineral nutrient composition is concerned. However, this resource cannot be exploited in agriculture because sludges are inevitably contaminated with noxious chemicals that partition into the sludge during either primary or secondary wastewater treatment. In the case sewage sludge, pathogenic and potentially pathogenic organisms are also present unless such contaminants are removed during treatment. Traditional mesophilic treatment under anaerobic conditions does not remove either noxious chemicals such as detergent residues or pathogenic organisms to a satisfactory degree. During the past decade, autothermal aerobic thermophilic pretreatment processes have been introduced as a complementary sludge treatment stage. Such aerobic pretreatment processes allow both the biodegradation of chemicals that are recalcitrant to anaerobic treatment and the thermal inactivation of pathogenic organisms. However, their introduction as a total treatment process for sludges is inhibited by their relatively poor conversion efficiencies as far as mineralization is concerned. In this contribution the biodegradation bacteria under aerobic thermophilic conditions will be described and discussed and concepts for biomass yield coefficient reduction that could enhance aerobic thermophilic sludge treatment process effectiveness will be introduced.
45
Evers, P., F. Schmitt, D. R. Albrecht e N. Jardin. "The Ruhrverband sewage sludge disposal concept in the conflict between European and German standards and regulations". Water Science and Technology 52, n. 10-11 (1 novembre 2005): 247–53. http://dx.doi.org/10.2166/wst.2005.0700.
Testo completoAbstract (sommario):
The Ruhrverband, acting as a water association responsible for integrated water resources management within the entire natural river basin of the Ruhr, operates a network of 83 wastewater treatment plants (WWTPs) and connected sludge disposal facilities. According to German regulations, the disposal of sewage sludge containing more than 5% of organic dry solids will be prohibited as of 1 June 2005. In Germany, the only future alternative to incineration will be the agricultural utilization of sludge. However, this way of sludge disposal is presently the subject of critical discussions in Germany because of the organic and inorganic toxic substances, which may be contained in sewage sludge, despite the fact that very stringent standards are to be met by agricultural uses. On the other hand, application of sewage sludge to agricultural land is explicitly supported by the European Sewage Sludge Directive 86/278/EEC. In the face of this controversial situation the Ruhrverband has initiated, in 2000, the development of a comprehensive and sustainable sludge and waste disposal concept for all wastewater facilities it operates in the entire Ruhr River Basin. The concept includes de-central sludge digestion and dewatering and subsequent transport to two central sludge incineration plants. It is expected that in future not more than 5% of all sludges produced in Ruhrverband's WWTPs will be used in agriculture. That means, the major part of 95% will have to be incinerated.
46
Abu-Kaddourah, Z., A. Idris, M. J. Noor e F. R. Ahmadun. "Effects of high temperature melting on the porosity and microstructure of slags from domestic sewage sludge". Water Science and Technology 41, n. 8 (1 aprile 2000): 99–105. http://dx.doi.org/10.2166/wst.2000.0148.
Testo completoAbstract (sommario):
Sewage treatment plant sludges continue to pose great problems in terms of volume, odour and method of disposal. Thermal treatment of sewage sludge is considered as an attractive method in reducing sludge volume, which at the same time produces reusable by-products. Studies on high temperature melting of sewage sludge, above 1200°C, show promising results where by stable and inert by-products are produced. This paper presents a part of a big project on thermal treatment of sewage sludge, carried out in University of Putra Malaysia, this part highlights the changes in the microstructure of domestic sewage sludge when subjected to different meltingprocedures; heating temperature, cooling rate, and holding time. The heating temperatures ranged between 1250°C–550°C, and the rate of cooling was between 2.5°C–10°C per minute. Using XRD analyses, itwas found that the melted slags were amorphous despite the different melting procedures applied. The SEM microphotographs indicated that some crystallization had occurred under the melting procedures; 1350°C with a cooling rate of 5°C per minute and a holding time of 45 minutes, 1400°C with a cooling rate of 2.5°C per minute and holding time of 45 minutes, and 1400°C with a cooling rate of 5°C per minute and without holding time.
47
Kodom, Piyabalo, Antonio J. Aragón-Barroso, Edem K. Koledzi, Kwamivi Segbeaya, Jesús González-López e Francisco Osorio. "Microwave Treatment of Three Different Types of Sewage Sludge Based on Their Solar Drying Exposure Time: Effect on Microorganisms, Water Content and Agronomic Aspects". Water 16, n. 2 (18 gennaio 2024): 321. http://dx.doi.org/10.3390/w16020321.
Testo completoAbstract (sommario):
This study aimed to treat sewage sludge through microwave irradiation at a laboratory scale. The objective was to investigate the effect of microwave irradiation on microorganisms, water content, organic matter, and agronomic nutrients present in sewage sludge. Three types of sewage sludges obtained from a full-scale wastewater treatment plant were considered: Sludge A (raw sludge), Sludge B (subjected to 15 days of solar exposure, achieving 48% dryness), and Sludge C (exposed to solar conditions and left open to the air for 23 months, reaching 94% dryness). These diverse sludges were exposed to microwave irradiation at various power levels (analysed variables: ε (Watts/g), θ (°C), T (min)). The specific exposure powers and temperature levels for the water reduction analysis were: 555, 955, 1355, and 1500 Watts/g and 55, 75, 95, and 105 °C, respectively. On the other hand, microbiological and agronomic nutrient analyses were conducted at 75 °C–1355 W and 95 °C–1355 W. After microwave exposure experiments, the results demonstrated the high effectiveness of microwave technology in eradicating indicator microorganisms of faecal contamination and reducing sludge volume while not affecting trace elements of significant agricultural value. The reduction in Escherichia Coli revealed that 4 min of irradiation was necessary to completely eliminate it to 0 ulog, indicating a 100% reduction, in Sludge A. In Sludges B and C, an additional 1 min was needed under conditions of 75 °C and 1355 W for a mass of 50 g. Moreover, Sludge A (46.27 × 105 or 4.80 ulog of dry matter), Sludge B (1.29 × 106 or 6.11 ulog of dry matter), and Sludge C (8.77 × 104 or 4.94 ulog of dry matter) were heavily contaminated with faecal coliforms. It took 6 min to reduce faecal coliforms to below the detection threshold.
48
Przydatek, Grzegorz, e Aldona Katarzyna Wota. "Analysis of the comprehensive management of sewage sludge in Poland". Journal of Material Cycles and Waste Management 22, n. 1 (31 ottobre 2019): 80–88. http://dx.doi.org/10.1007/s10163-019-00937-y.
Testo completoAbstract (sommario):
Abstract The methods of sewage sludge management in Poland have largely been determined by the legal requirements related to the Poland’s membership in the European Union. Since 1st January 2016, sewage sludge landfilling is prohibited. It must be emphasised that legal changes regarding wastewater management, along with the systematic increase in the volume of produced sludge, entail the necessity to change the existing method of sewage sludge management. This paper contains an analysis of solutions for management of sewage sludge produced in Poland over the period of 8 years. The goal of the work was an assessment of comprehensive management of sewage sludge produced in Poland from 2009 to 2016. Despite the decrease in the agricultural use of sewage sludge, their average share of 32% was the highest among other forms of sewage sludge management in Poland. Another form, related with the final stage of sewage sludge management, concerned its thermal processing. It was treated as a promising method, with a 19% increase over the analysed period. An optimal solution should be found to ensure safe management of sewage sludge.
49
Hsiao, P. C., e S. L. Lo. "Extractability and fractionation of heavy metals in chemically treated sewage sludges". Water Science and Technology 44, n. 10 (1 novembre 2001): 91–94. http://dx.doi.org/10.2166/wst.2001.0590.
Testo completoAbstract (sommario):
Four chemically treated sludges, lime-treated (LS), lime/sodium silicate-treated (LSS), cement-treated (CS), and cement/sodium silicate-treated (CSS) were produced form the chemical treatment of aerobic digested sewage sludge cake, using lime, cement, and sodium silicate as additives. Ex tractability and fractionation of the heavy metals (Cu, Pb, Cr, and Zn) in these products and untreated sludge (S) were investigated using sequential extraction, single extraction, and 13C cross-polarization magic angle spinning nuclear magnetic resonance analysis (13C-NMR). These approaches revealed that chemical treatment of sewage sludge makes sludge Cu, Pb, and Cr more extractable. It was attributed to the irreversible dissolution of a portion of organics at very high pH during chemical treatment of sludge. The enhanced extraction of some metals having higher affinity to organics, e.g. Cu and Pb, from the chemically treated sludges was due to their complexion with the above soluble organics.
50
Gamache, M., J. F. Blais, R. D. Tyagi e N. Meunier. "Microflore hétérotrophe impliquée dans le procédé simultané de biolixiviation des métaux et de digestion des boues d'épuration". Canadian Journal of Civil Engineering 28, n. 1 (1 febbraio 2001): 158–74. http://dx.doi.org/10.1139/l00-110.
Testo completoAbstract (sommario):
Until now, some microbiological studies have made it possible to highlight the role and identification of certain chimiolithotroph microorganisms directly involved in the simultaneous sewage sludge digestion and metal leaching (SSDML process). Moreover, some other studies have established the performance of the SSDML process for the destruction of pathogens. However, until now no study has been carried out to define the equilibrium of the heterotrophic microbial populations during the sludge acidification occurring during the operation of the SSDML process. Hence, the SSDML process was studied in batch and continuous mode employing different types of sludges (Communauté Urbaine de Québec (CUQ)-East primary sludge, Beauceville secondary sludge, and mixture of primary and secondary Valcartier sludge). The equilibrium of heterotrophic microbial populations was investigated along with sludge acidification and solids degradation. The results obtained during the SSDML process on different sludges showed a decrease followed by the destruction of a majority of heterotrophic bacterial species found in fresh sludges. The isolation and characterization of different microbial species showed that only two types of microorganisms persisted: the yeast Blastoschizomyces capitatus and an unidentified fungus.Key words: sewage sludge, simultanous bioleaching and digestion, heterotrophic bacteria, Blastoschizomyces capitatus, fungi.