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1
Sidhu, Jatinder. "Pathogen regrowth in composted biosolids." Thesis, Sidhu, Jatinder (2000) Pathogen regrowth in composted biosolids. PhD thesis, Murdoch University, 2000. https://researchrepository.murdoch.edu.au/id/eprint/52513/.
Full textAbstract:
Composting is commonly used as an effective means of stabilising wastewater biosolids and reducing pathogen concentrations to very low levels. However, under certain conditions enteric bacteria such as Salmonella and E. coli can regrow in previously composted biosolids and compost based soil amendments. Regrowth of Salmonella in composted biosolids can pose a potential threat to public health.
Pathogen regrowth in composted biosolids is affected by a number of factors, such as moisture content, bio-available nutrients, temperature and indigenous microorganisms. However, assessment of the bio-safety of composted biosolids on the basis of these parameters is very difficult and unreliable. Moreover regrowth of
pathogens in composted biosolids is unpredictable. The main aim of this study was to find out whether regrowth of pathogens in composted biosolids could be prevented or controlled. To accomplish this goal, the effect of composting and storage on survival and regrowth of Salmonella typhimurium was investigated. The role of bio-available nutrients and indigenous microorganisms in suppression of Salmonella regrowth was investigated in detail.
The results of this study suggest that a full-scale windrow composting process carried out in accordance with recommended guidelines (ARMCANZ) is effective in reducing Salmonella concentrations to below detection limit. However, Salmonella regrowth in stored biosolids after 26 weeks, coinciding with a rainfall after a dry spell was observed. This suggests that Salmonella can survive the composting process in low numbers and regrowth can take place in the presence of favourable growth conditions.
A pathogen regrowth potential test using antibiotic-resistant S. typhimurium was developed to evaluate the pathogen regrowth potential of composted biosolids. The regrowth potential test was found to be a very useful tool for laboratory investigation. However, further validation of the pathogen regrowth potential test is required, prior to its routine use for monitoring composted biosolids.
The antagonistic activity of indigenous microorganisms was found to be the most significant factor in suppression of S. typhimuriwn growth in composted biosolids. Rapid growth of seeded S. typhimurium, with a maximum population density of more than 108 MPN g-1, was observed in sterilised biosolids. Conversely, growth of S.typhimurium was suppressed in non-sterilised compost with a maximum population density of less than 103 MPN g-1. The inactivation rate of Salmonella was also found to be significantly greater in non-sterilised compost as compared to sterilised compost. Maximum inhibition of Salmonella growth was observed in biosolids that had been composting for two weeks.
The specific growth rate of Salmonella was found to have a strong negative correlation (-0.85) with the maturity of the compost. However, a decline in bioavailable nutrients was not sufficient to prevent regrowth of Salmonella in composted biosolids stored for two years. The role of bio-available nutrients (age. of compost) was non significant (P<_ 0.05) as compared to the role of indigenous microorganisms in inhibition of Salmonella regrowth.
The antagonistic effect of indigenous microorganisms towards Salmonella declined with the storage of compost. A strong negative correlation (-0.85) between the Salmonella inactivation rate and age of compost was observed. Salmonella inactivation rate was also found to be seven times higher in biosolids composting for two weeks as compared to compost stored for two years. Consequently, it can be concluded that all composted biosolids had a Salmonella regrowth potential. However, the presence of biologically active indigenous microflora significantly reduced this regrowth potential. As a result of a decline in the antagonistic activity of indigenous microflora with storage, a longer Salmonella survival time could be expected in stored compost as compared to freshly composted biosolids. Consequently, long term storage of compost is not recommended as this may lead to an increased pathogen regrowth potential and longer survival time.
The dilution-plate procedure adopted in this study showed that bacterial concentrations in compost declined by two log10 during storage for two years, whereas population of actinomycetes and fungi increased during the same period. Indigenous bacteria and actinomycetes isolated from composted biosolids of different maturity were screened for their role in the suppression of Salmonella regrowth. Some of the indigenous bacteria were found to suppress Salmonella growth by one to two log10 when Salmonella was seeded into stationary phase culture of indigenous bacteria. None of the isolated indigenous microorganisms produced secondary metabolites active against Salmonella.
Somatic Salmonella (SS) phages were found to survive in composted biosolids for up to two years. Growth of Salmonella was suppressed by one to two log10 in the presence of SS phages. It is possible that Salmonella growth suppression in compost is due to an intense competition for limited nutrients in the presence of biologically active indigenous microorganisms, with some anti-Salmonella activity from SS phages.
The results of this study suggest that prevention of pathogen regrowth in composted biosolids is difficult due to the availability of nutrients and limited control over environmental factors which influence the antagonistic activity of indigenous microorganisms. However, regrowth of pathogens in composted biosolids can be prevented if a biologically active population of indigenous microorganisms is maintained. It is possible that by preventing rapid drying of compost during maturation biological activity of indigenous microorganisms can be maintained. Covering of compost piles during maturation can preserve moisture and the effect of preserving moisture on the antagonistic activity of indigenous microorganisms should be investigated. Research should be carried out further to identify the indigenous microorganisms which suppress Salmonella regrowth. Additional research work should also be carried out to determine the mechanism of growth suppression. Resolving this issue could provide a better understanding of the antagonistic effect of indigenous microflora towards pathogenic bacteria in composted biosolids.
2
Artiola, Janick. "Biosolids Land Use in Arizona." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011. http://hdl.handle.net/10150/146291.
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Rios, Andrea. "DEWATERING OF BIOSOLIDS BY SODIUM FERRATE." Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2887.
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This study was conducted to evaluate the effectiveness of the liquid form of ferrate for dewatering of biosolids from wastewater treatment facilities. Two different ferrate products prepared using calcium hypochlorite and sodium hypochlorite were used. Samples of anaerobic digested sludge and waste activated sludge with solids content of 2.1% and 0.95 %, respectively were conditioned with both products to evaluate and compare their effectiveness. Centrifugation and filtration of the sludge after conditioning were used. For centrifugation the volume reduction and the turbidity of the supernatant after centrifugation were evaluated. For filtration, the Capillary Suction Time test was used. The optimum doses and conditions for dewatering of the sludge using ferrate were determined for each type of sludge. The centrifugation and filtration results were compared with those obtained for polymer doses currently used at the wastewater treatment plants where the samples were collected and with ferric coagulants as well. The results of this research indicated that optimum pH was 7.0. The time required to achieve mechanical equilibrium defined as the time at which the volume occupied by the solids was no more than one percent of the preceding reading was 1800 seconds for both types of sludge. The optimum rotational speeds were 800 and 2400 for waste activated sludge and anaerobic digested sludge, respectively. The optimum ferrate dose for anaerobic digested sludge for centrifugation and filtration was 5000 mg/l. For waste activated sludge a dose of 10 mg/l was found to be effective for filtration and centrifugation. The results indicated that the ferrate product prepared using calcium hypochlorite provides better results for the waste activated sludge than the ferrate prepared using sodium hypochlorite, while for anaerobic digested sludge no significant difference was observed. Finally, the results show that ferrate is a cost-effective alternative for the conditioning and disinfection of waste activated sludge, but not for the conditioning of anaerobic digested sludge.M.S.Env.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engineering
4
Fane, Sarah Elizabeth. "Control of E. coli in biosolids." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/11815.
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Achieving microbial compliance levels in biosolids storage is complicated by the unpredictable increase of Escherichia coli (E. coli), which serves as an important indicator for pathogen presence risk. Meeting required microbial specifications validates sludge treatment processes and ensures that a safe product is applied to agricultural land. Controlled indicator monitoring provides confidence for farmers, retailers and the food industry, safeguarding the sludge-to-land application route. Following mechanical dewatering biosolids products are stored before microbial compliance testing permits agricultural application. During storage, concentrations of E. coli bacteria can become elevated and prevent the product from meeting the conventional or enhanced levels of treatment outlined in The Safe Sludge Matrix guidelines. Literature research identified innate characteristics of sludge and ambient environmental parameters of storage which are factors likely to influence E. coli behaviour in stored biosolids. The research hypothesis tested whether E. coli growth and death in dewatered sewage sludge can be controlled by the modification of physical-chemical factors in the cake storage environment. Parameters including nutrient availability, temperature, moisture content and atmospheric influences were investigated through a series of laboratory-scale experiments. Controlled dewatering and the assessment of modified storage environments using traditional microbial plating and novel flow cytometry analysis have been performed. At an operational scale, pilot trials and up-scaled monitoring of the sludge storage environment have been conducted enabling verification of laboratory results. Understanding the dynamics of cell health within the sludge matrix in relation to nutrient availability has provided a valuable understanding of the mechanisms that may be affecting bacterial growth post-dewatering. The importance of elevated storage temperatures on E. coli death rates and results showing the benefits of a controlled atmosphere storage environment provide important considerations for utilities.
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Rance, Logan T. "Understanding Student Perceptions of Biosolids and Other Fertilizers in Central Ohio." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587657377716495.
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Ginige, Pushpa. "Decontamination of biosolids for land application : metals bioleaching and process impacts on the nutrient value of biosolids." Thesis, Queensland University of Technology, 1998.
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Gorgy, Tamer George Alexan. "Polybrominated diphenyl ethers in biosolids-amended soils." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/35020.
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Polybrominated diphenyl ethers (PBDEs) are added to many consumer products as flame retardants. Their hydrophobic characteristics and high n-octanol-water coefficients make them partition in organic media such us sludge and biosolids, by-products of wastewater treatment which are commonly applied to agricultural soils to promote crop growth or discarded in landfills. Biosolids-amended soils have been found to contain up to 7x10⁶ pg PBDEs/g dry weight, whereas leachates from biosolids and flame-retarded products in landfills, contained up to 4,000 pg PBDEs/litre. PBDEs in the environment could potentially cause serious health effects.
Research was conducted to determine the concentration and mobility of PBDEs in biosolids, biosolids-amended soil, and clay liners used to retain PBDEs. A field study investigated the degree of PBDE contamination due to the application of biosolids at an agricultural site near Kamloops and an agricultural field in Totem Field at the University of British Columbia in Vancouver. PBDEs were found to migrate downwards to depths of at least 0.85 m.
Laboratory experiments determined leachability of PBDEs from biosolids. PBDEs sorbed on fine particles suspended in the leachate, allowing PBDEs to exceed their aqueous phase solubilities. Concentrations were much higher on ultra-fine than on fine particles. Leaching column tests demonstrated that PBDEs leached from biosolids-amended soils and migrated through the soils.
PBDEs in soils upgradient and downgradient of solid waste facilities in Northern Canada varied widely from location to location. There was evidence that PBDE contamination in Iqaluit is due to long-range atmospheric transport, whereas that found at Yellowknife is mainly from the solid waste facility. Laboratory experiments showed that sand-bentonite partially retained PBDEs. The hydraulic conductivity decreased with leaching, and then gradually increased. The decrease is attributed to swelling, whereas the increase is due to shrinkage of the clay interlayer, owing to the hydrophobicity of the permeant.
The research may be helpful in establishing regulations on land application of biosolids, regulating waste disposal and landfill design requirements.
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Massanet-Nicolau, Jaime. "Mesophilic fermentative hydrogen production from sewage biosolids." Thesis, University of South Wales, 2009. https://pure.southwales.ac.uk/en/studentthesis/mesophilic-fermentative-hydrogen-production-from-sewage-biosolids(45d910c7-f8d1-4c9d-bc46-ca0b80de8361).html.
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The increasing cost of fossil fuels, combined with concerns about their impact on our environment has led to a renewed interest in hydrogen as a clean, sustainable, alternative energy vector. Using sewage biosolids as the substrate for fermentative hydrogen production offers several advantages over the use of other biomass sources. It is available at little or no cost and is abundant, being produced wherever there are human settlements, with 1.3 million tonnes (dry solids) per year currently being produced in the U.K alone. This research demonstrated the feasibility of hydrogen production from sewage biosolids via anaerobic fermentation. To do this a number of issues specifically relating to the nature of sewage biosolids had to be addressed. Firstly, the solids content and rheology made automatic feeding difficult. The feedstock also contained high levels of indigenous microorganisms and a high ratio of insoluble to soluble carbohydrate. To address these challenges, a novel reactor design using wide bore tubing and computer controlled pumping equipment was successfully used to construct a working continuously fed bio-reactor. A combination of heat treatment at 70°C for one hour and pre-treatment with a commercially available food processing enzyme mixture was found to be the most efficient method of inactivating competing microorganisms and improving substrate quality. Hydrogen was successfully produced via batch fermentation of primary sewage biosolids which had undergone heat treatment and enzymatic digestion. When fermentation took place at pH 5.5 a peak hydrogen production rate of 3.75 cm3 min"1 was observed. At this pH the hydrogen yield was 0.37 mol H2 mol~ : carbohydrate, equivalent to 18.14 L H2 kg"1 dry solids. Fermentative hydrogen production from sewage biosolids was also demonstrated in a five litre, continuously fed bio-reactor for the first time. A comparison of different hydraulic retention times showed that hydrogen production was most stable at a HRT of 24 hours. A hydrogen producing fermenter was successfully linked to a methanogenic bio-reactor in a two stage digestion process.
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Vu, Tran Mai Anh. "Nutrient Mobility From Biosolids Land Application Sites." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/74.
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Three types of biosolids (lime-stabilized, aerobically digested, and anaerobically digested biosolids) were applied on 0.13-ha test plots on disturbed rangelands in Western Utah at rates of up to twenty times (20X) the estimated N-based agronomic rate. Soil samples at depths up to 1.5 m were collected and analyzed for nitrogen, phosphorus, regulated metals, pH, and electrical conductivity for up to two years after biosolids application. NH4-N at the soil surface (0.2 m) was primarily lost through ammonia volatilization and nitrification. This observation was consistent with reported increases in nitrate (NO3-N) concentrations found within the soil surface on the biosolids-amended sites. A nitrogen mass balance on the surface soil control volume indicated that the nitrogen residual field measurements were significantly higher than the nitrogen level estimated by accounting for nitrogen inputs (biosolids) and outputs (vegetative yield, nitrogen volatilization and nitrate leaching). Biosolids land application led to increases in vegetative growth and dry matter yield when compared to vegetation grown on control plots. Based on the Root Zone Water Quality Model (RZWQM), the model predicted NH4 and NO3 storage values at biosolids-amended sites were significantly different from the field data, which suggests that the model default and limited measured values were inappropriate for a non-irrigated rangeland landscape. The majority of total P and plant available P accumulation was found to occur primarily within the soil surface (0.2 m). Phosphorus soil residual measurements were higher than phosphorus accumulation based on a phosphorus mass balance at soil surface. The phosphorus leachability to ground water at the biosolids-amended treatment sites was low based on the molar ratio of ([P]/([Al]+[Fe])) and the potential formation of calcium phosphate (Ca3(PO4)2). Aerobically digested biosolids appeared to be the optimal biosolids type with regard to minimizing the adverse environmental effects of phosphorus based on the Phosphorus Site Index (PSI). Regulated metal concentrations (As, Cd, Cu, Pb, Mo, Ni, Se, and Zn) were well below the cumulative pollutant loading limits for biosolids-amended soils. Finally, nutrients as well as regulated heavy metals associated with biosolids land application to disturbed rangelands do not pose any significant threat to the environment.
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Stone, Peyton Franklin. "Evaluation of Biosolids for Use in Biodegradable Transplant Containers." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/75649.
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Sustainability practices are leading to the development and use of alternative products in the floriculture and wastewater industries, such as the use of biodegradable containers instead of plastic containers. The objective of this research was to evaluate the efficacy of using digested biosolids from a regional wastewater treatment plant as an ingredient in creating a biodegradable transplant biocontainer. The biosolids were tested for metals limits as specified by the U.S. EPA Part 503 Rule, and met the requirements for Class B. Multiple mixes of biosolids, fibers, starch, polymer, and natural glue were developed to provide overall pot stability and structural strength. Engineering tests, such as tensile strength, pH, and saturated paste tests, were conducted on the different mixes to determine the optimum strength that could be produced.
The top-performing biosolids mixes were used to make 10.2 cm (four-inch) pots that were compared in various ways to the market leaders, Peat Pots and standard plastic pots. A two-part mold was created on a 3D printer, which would allow for positive pressure to be used in forming the BioPots. Mixes were transferred to the lower half of the mold, the upper part was then plunged and fastened into the lower half, and then the mold with its mix was placed in an oven to dry. Laboratory germination bioassays were performed to test for the presence of phytotoxic compounds. Construction of BioPots for the lab-scale studies was tedious. Different methods (e.g., negative pressure systems) need to be investigated for use in producing the BioPots commercially.
Most of the BioPots survived the resiliency study. Leachate quality from the biocontainers was no worse than from the plastic containers. Some discoloration was observed on the biocontainers, but it was not due to algal/fungal growth. Growth of soybeans, marigolds, and romaine in the biocontainers was significantly better (e.g., increased height, leaf sizes, and weight) than in the plastic containers.Master of Science
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Zhang, Dian. "Effect of Process Intensification Techniques on Biosolids Management." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/97594.
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This study is aimed to provide comprehensive evaluation and mechanistic understanding of the impact of process intensification techniques applied in main and side stream wastewater treatment on biosolids management in terms of anaerobic digestion enhancement, dewaterability improvement, odor mitigation, as well as phosphorus and nitrogen removal. The first part of this study was conducted to understand the effect of anaerobic digester solids retention time (SRT) on odor emission from biosolids. A kinetic model and inhibitory studies showed the emission of methanethiol (MT), a representative odor compound, was primarily determined by the dynamic concurrence of MT production from amino acid and utilization by methanogens in the course of anaerobic digestion. MT emission pattern follows a bell-shape curve with SRT in anaerobic digesters. However, for digested and dewatered biosolids, SRT ranging from 15 to 50 days in anaerobic digesters demonstrated insignificant effect on the odor emission from biosolids. In contrast, the peak odor emission was found to exponentially increase with both shear intensity and polymer dose applied during dewatering.
The second part of this study investigated the impact of process intensification practices on sludge dewatering performance. The integration of high-rate activated sludge process and anaerobic digestion elevated the sludge orthophosphate level, leading to struvite scaling and dewaterability deterioration. Superior orthophosphate removal, significant improvement of sludge dewaterability, and favorable economics were achieved through sludge conditioning by cerium chloride.
Continuous flow aerobic granulation technology offered significant process intensification of mainstream treatment trains. However, its impact on biosolids management was not studied. This study showed that there was little dewaterability difference between aerobic granular sludge and activated sludge when polymer was not added. However, about 75% polymer saving and improved dewatering performance were observed with polymer addition. When subjected to high shear, a greater dewaterability deterioration was observed for granular sludge than activated sludge.
The last part of this study is focused on the impact of anaerobic digestion process intensification through thermal treatment including pre-pasteurization, thermophilic anaerobic digestion, temperature phased anaerobic digestion, and thermal hydrolysis pretreatment. Improved methane production, pathogen reduction, dewatering performance, and odor mitigation were observed with the involvement of these high-temperature processes. However, special cautions and measure should be taken during the start-up of these high rate processes as they are more liable to digester souring. In addition, the in-depth understanding of the mechanism of recalcitrant dissolved organic nitrogen formation during sludge thermal pretreatment was provided.Doctor of Philosophy
This study is aimed to provide comprehensive evaluation and mechanistic understanding of the impact of process intensification techniques applied in main and side stream wastewater treatment on biosolids management in terms of anaerobic digestion enhancement, dewaterability improvement, odor mitigation, as well as phosphorus and nitrogen removal. The first part of this study was conducted to understand the effect of anaerobic digester solids retention time (SRT) on odor emission from biosolids. A kinetic model and inhibitory studies showed the emission of methanethiol (MT), a representative odor compound, was primarily determined by the dynamic concurrence of MT production from amino acid and utilization by methanogens in the course of anaerobic digestion. MT emission pattern follows a bell-shape curve with SRT in anaerobic digesters. However, for digested and dewatered biosolids, SRT ranging from 15 to 50 days in anaerobic digesters demonstrated insignificant effect on the odor emission from biosolids. In contrast, the peak odor emission was found to exponentially increase with both shear intensity and polymer dose applied during dewatering. The second part of this study investigated the impact of process intensification practices on sludge dewatering performance. The integration of high-rate activated sludge process and anaerobic digestion elevated the sludge orthophosphate level, leading to struvite scaling and dewaterability deterioration. Superior orthophosphate removal, significant improvement of sludge dewaterability, and favorable economics were achieved through sludge conditioning by cerium chloride. Continuous flow aerobic granulation technology offered significant process intensification of mainstream treatment trains. However, its impact on biosolids management was not studied. This study showed that there was little dewaterability difference between aerobic granular sludge and activated sludge when polymer was not added. However, about 75% polymer saving and improved dewatering performance were observed with polymer addition. When subjected to high shear, a greater dewaterability deterioration was observed for granular sludge than activated sludge. The last part of this study is focused on the impact of anaerobic digestion process intensification through thermal treatment including pre-pasteurization, thermophilic anaerobic digestion, temperature phased anaerobic digestion, and thermal hydrolysis pretreatment. Improved methane production, pathogen reduction, dewatering performance, and odor mitigation were observed with the involvement of these high-temperature processes. However, special cautions and measure should be taken during the start-up of these high rate processes as they are more liable to digester souring. In addition, the in-depth understanding of the mechanism of recalcitrant dissolved organic nitrogen formation during sludge thermal pretreatment was provided.
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Alvarez-Campos, Odiney Maria. "Assessment of Exceptional Quality Biosolids for Urban Agriculture." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/88745.
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Biosolids have been used as soil conditioners and fertilizers in agriculture and mine land reclamation, but application of Exceptional Quality (EQ) biosolids to rehabilitate anthropogenic soils for urban agriculture is recent and requires greater study to ensure their appropriate use. The objectives were: 1) to quantify plant available nitrogen (PAN) of new EQ biosolids in a greenhouse bioassay; 2) to quantify PAN of EQ biosolids applied to an urban degraded subsoil via tall fescue N fertilizer equivalency, and compare field results to laboratory tests; 3) to investigate EQ biosolids and inorganic fertilizer effects on urban soil properties, vegetable yields, and potential N and phosphorus (P) loss. Biosolids evaluated were products of thermal hydrolysis plus anaerobic digestion (BLOOM), blending with woody mulch (BM) and sand/sawdust (BSS), composting (LBC), and heat-drying (OCB). Organic N mineralization of new blended biosolids products ranged between 20-25% in the greenhouse bioassay. Products BLOOM, BM, and OCB had the highest organic N mineralization as estimated by the 7-day anaerobic incubation, and this test and soil nitrate-N had the highest correlations with tall fescue N uptake (r=0.49 and r=0.505, respectively). We conducted a two-year field study with four growing seasons (fall 2016-2017 and summer 2017-2018) in an urban disturbed subsoil where EQ biosolids were applied seasonally at agronomic N rates, and yearly at reclamation rates (5x agronomic N). Cabbage yields were greater with reclamation rates (~3.0 kg m-2) and bell pepper yields were greater with BLOOM reclamation rate (~1.0 kg m-2) than with the inorganic fertilizer (1.0 kg m-2 and 0.2 kg m-2, respectively) during second year growing seasons. Soil carbon (C) accumulation (%C remaining in the soil) two years after biosolids additions ranged between 37 to 84%. Soil N availability and mineralization were limited most likely due to lack of residual soil C and N, and high clay content. Nitrogen leaching losses from reclamation rates were not greater than agronomic N rates. Leachate P was below detection during most of the experiment. Despite limiting soil conditions, biosolids amendment at reclamation rates showed greatest potential to increase vegetable yield and improve soil properties after two years of application, while not impairing water quality.Doctor of Philosophy
Exceptional Quality (EQ) biosolids are by-products of wastewater treatment plants that have been processed to destroy pathogens, reduce attraction by disease-spreading organisms (e.g. flies, mosquitoes, rodents, etc.), and limit heavy metal concentrations. These characteristics make EQ biosolids safe for use by home gardeners for growing food crops. There is limited information on optimal recommended rates at which these products should be applied to urban gardens. The purpose of our research was to determine optimum application rates of EQ biosolids to urban gardens based on their essential plant nutrient (esp., nitrogen and phosphorus) availability. We learned that the EQ biosolids we studied are less concentrated in plant available nitrogen and phosphorus than biosolids applied to conventional agricultural fields. This is because we diluted our biosolids with sawdust, sand, and woody mulch to facilitate their storage, handling, and ease of application. We learned that high EQ biosolids application rates reduce soil compaction and increase essential plant nutrient availability and crop yields for agriculture practiced in urban soils. The high application rates of EQ biosolids accomplished such soil-improving and yield-increasing benefits without impairing local water quality.
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Rigby, Hannah. "Quantifying the Agronomic Value of Biosolids and Biowastes." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/4268.
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Predicting N release in agricultural soils amended with organic residuals is essential to ensure there are sufficient nutrients for crops, and minimal losses to the environment. Factors such as moisture, temperature, soil type and organic residuals type may affect the amount of mineralised nutrients. Information is required to describe microbial N immobilisation in biosolids-amended soil, which may vary between soil types influencing extent and rate of nutrient release. Industrial biowastes are increasingly being used as soil amendments as a diversion from landfill disposal; these materials result from a diverse range of processes and vary greatly in physical and chemical characteristics. There is little published or advisory information regarding their agronomic benefit, therefore research is required to quantify their fertiliser value. The aims of this research were to quantify mineralisation of N, and investigate other agronomic benefits of biosolids and biowastes, and to investigate microbial biomass N (MBN) dynamics, with the aim of improving fertiliser guidelines. A field trial was established at the Imperial College field station in Wye, Kent, in spring 2005, to investigate N transformations in contrasting soil types amended with conventional and enhanced treated biosolids. Analysis of MBN in biosolids-amended soil indicated that there were differences in N immobilisation processes in soils of differing fertility status, with greater immobilisation observed in the lower fertility soil in some cases. Despite initial differences in rate of mineralisation and nitrification, overall extent of N release was similar in both soils. A programme of field trials was established at Imperial College Silwood Park campus in 2006-2007 to quantify the agronomic value of a range of industrial biowastes. Biowastes from the vegetable, meat and dairy industries and from aerobic and anaerobic digestion plants were investigated. Yield response and N offtake of perennial ryegrass to biowastes, at five rates of application, in comparison to mineral N fertiliser, was used to calculate the replacement N fertiliser value. The results of a laboratory incubation experiment, to investigate MBN and mineral N in biowastes-amended soil, demonstrated lower recoveries of N in fine textured soil with low stability waste. Denitrification was suspected as the potential mechanism for this observation. Interactions between soil type and biowaste type on N availability, and the implications for gaseous N losses to the environment from biowastes-amended soils require further research.
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Castro, del Campo Nohelia. "Survival of Enteric Bacteria and Viruses in Biosolids." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195414.
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In the developed world most of domestic sewage is treated by the activated sludge process, which results in large volumes of sludge or biosolids being produced. This results in millions of tons of biosolids produced each year in the United States, which must either be disposed of or recycled in some manner. Land application is seen as the most economical and beneficial way of handling biosolids. Although the United States Environmental Protection Agency supports and regulates the land application of biosolids, more research is needed to ensure its safe.The Appendix study A assessed the potential of Salmonella regrowth in Class A biosolids pellets and compost after land application. No Salmonella growth occurred in any of the soil/biosolids mixtures regardless of inoculum size or moisture content. While regrowth of Salmonella in biosolids may occur under saturated conditions it does not occur after Class A biosolid land application at typical agronomic rates. The Appendix B study evaluated the sensitivity of BGM and PLC/PRF/5 cell lines for detection of viruses as well as the occurrence and concentration of adenoviruses. The PLC/PRF/5 cell line was more sensitive for the detection of adenovirus and other enteroviruses in raw and Class B biosolids. The Appendix C study determined the potential of regrowth of Salmonella typhimurium in vermicompost and Class A biosolids alone and after addition to soil. In summary, no regrowth of Salmonella was observed, and the die-off of Salmonella was not different in soil, biosolids or vermicompost.
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Gul-e-Hina, Ms. "Regrowth of bacterial pathogen indicators in electro- dewatered biosolids." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107904.
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Land application of biosolids from activated sludge wastewater treatment plant (WWTP) is an attractive disposal solution. However, to be land applied in the US and Canada, biosolids need to meet specific pathogen loads regulations at the time of land application (i.e., not immediately after treatment). This study examined bacterial regrowth potential after electro-dewatering of biosolids. During a 8-min typical electro-dewatering treatment performed in the laboratory or a control heat treatment, Escherichia coli and fecal coliform (FC) counts were reduced to below the detection limit. After treatment, the extent of E. coli and FC regrowth was assessed by incubating the biosolids in aerobic or anaerobic conditions. After aerobic incubation, FC and E. coli counts stabilized between 107-109 MPN/g-dry solids in all biosolids samples irrespective of treatments (electro-dewatering, heat-treatment and no treatment) despite different levels of pH and dryness. Total aerobic counts also stabilized between 107-109 CFU/g-dry solids after four days of incubation. Finally, stable FC and E. coli counts at the end of incubation of samples prepared by belt filter press during winter were 1 log lower than in samples prepared by centrifuge press during the summer. Although similar trends about the effects of dewatering processes were reported in the literature, it is not be possible to conclude because seasonal factors are confounded with process factors. After anaerobic incubation, E. coli and FC counts in electro-dewatered biosolids stabilized 1 log lower than their respective counts in heat-treated or not treated biosolids (107-108 vs 108-109 MPN/g-dry solids, respectively). This difference was not changed when electro-dewatering filtrate was added back into the electro-dewatered biosolids. At WWTP, biosolids are typically stored as large piles. It is therefore likely that a major portion of piles is anaerobic, and that storage (hence regrowth) takes place under anaerobic condition. This study suggests that the electro-dewatered biosolids would exhibit a lower level of regrowth than other biosolids. Microbial counts observed in this study would not allow land application of these biosolids after 7-day storage because the lowest counts observed for electro-dewatered biosolids under anaerobic conditions were just above the requirements for the US-EPA Class B (FC counts above106 MPN/g-dry solids). However, these results suggest that this technology could be improved such that biosolids could meet land application regulations even after extended storage periods.L'épandage de biosolides provenant des usines de traitement d'eaux usées par boues activées est une solution d'élimination intéressante. Toutefois, pour être épandues aux États-Unis et au Canada, les biosolides doivent répondre à des réglementations visant à limiter la quantité d'organismes pathogènes au moment de l'épandage (et non pas immédiatement après le traitement). Cette étude a examiné le potentiel de repousse bactérienne après électro-déshydratation des biosolides. Lors d'un traitement d'électro-déshydratation typique de 8 minutes effectué dans un laboratoire ou un traitement thermique de contrôle, le compte total d'Escherichia coli et de coliformes fécaux (CF) étaient en deca de la limite de détection. Après le traitement, l'étendue de la repousse de E. coli et de CF a été évaluée par incubation des biosolides dans des conditions aérobies ou anaérobies.Après une incubation aérobie, les comptes de CF et E. coli se sont stabilisés entre 107 à 109 NPP / g matières solides sèches dans tous les échantillons de biosolides, indépendamment des traitements (électro-déshydratation, traitement thermique et aucun traitement), malgré les différents niveaux de pH et de sécheresse. Les comptes aérobies totaux se sont également stabilisé entre 107 à 109 UFC / g de matières solides sèches, après quatre jours d'incubation. Enfin, le compte de FC et E. coli à la fin de l'incubation des échantillons préparés par des presses à filtres à bande au cours de l'hiver ont été 1 log inférieure à celle des échantillons préparés par des presses centrifugeuses pendant l'été. Bien que des tendances similaires sur les effets des procédés de déshydratation aient été rapportées dans la littérature, il n'est pas possible de conclure puisque les facteurs saisonniers sont confondus avec les facteurs de procédés. Après une incubation anaérobie, les comptes de E. coli et de CF dans les biosolides électro-déshydratées étaient 1 log inférieure aux compte respectif dans les biosolides traités thermiquement ou non traités (107-108 vs 108-109 NPP / g matières solides sèches, respectivement). Cette différence n'a pas été modifiée lorsque le filtrat d'électro-déshydratation a été rajouté dans le biosolides électro-déshydratées. A l'usine de traitement des eaux usées, les biosolides sont généralement stockés sous forme de monticule. Il est donc probable que la majeure partie des monticules soit anaérobie, et que le stockage (et donc la repousse) se déroule dans des conditions anaérobies. Cette étude suggère que les biosolides électro-déshydratées présentent un niveau inférieur de repousse des indicateurs pathogènes bactériens que d'autres biosolides. L'énumération microbienne observée dans cette étude ne permettrait pas l'épandage de ces biosolides après 7 jours d'entreposage, parce que même les énumérations les plus basses demeurent au-dessus des exigences pour le US-EPA classe B (FC > 106 NPP / g matières solides sèches). Toutefois, ces résultats suggèrent que cette technologie pourrait être améliorée de telle sorte que les biosolides peuvent respecter les règlements d'application sur les terres arables, même après des périodes d'entreposage étendues.
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Fields-Johnson, Christopher Warren. "Biochar in Land Reclamation, Biosolids Applications and Prescribed Fires." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/83401.
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Biochar is a form of stable organic carbon whose application to soils has the potential to sequester large amounts of atmospheric CO2 while improving the physical, chemical and biological properties of soil. However, the optimal rates and methods of biochar application are unknown for many situations. Three experiments were performed to test methods of biochar application to soils as a stand-alone amendment, in combination with biosolids as a complementary amendment and in-situ through controlled landscape burning. The first was a greenhouse pot study, which involved combining biochar with spoil from an Appalachian surface coal mine to grow trees. Biochar combined with mine soil produced a much higher growth rate for trees, and pure biochar helped tree root growth, suggesting that it might be useful as a broadcasted amendment, as a nursery growing medium or as a backfill in tree planting holes. The second experiment explored methods to combine biochar and biosolids materials to form a granular product. Combining biochar and biosolids before applications reduced windborne losses of biochar as well as the nutrient leachate produced by the biosolids. Drum rolling was found to work best for producing aggregate granules. Wetting pure biochar to 100% gravimetric water content before applications reduced windborne losses from over 50% to under 5% as compared to when it was applied as a dry product. A series of controlled burns were conducted in the third experiment to determine the ideal range of meteorological conditions to produce the highest possible biochar yields in-situ. Relative humidity, forest litter moisture and ambient temperature were found to be the governing factors over the tonnage of biochar produced. Up to 3.0 Mg Ha-1 of biochar were produced under ideal conditions by controlled burning. Repeated high-yielding burns have the potential accumulate large amounts of biochar in the soil to improve soil properties.Ph. D.
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Li, Jinling. "Effects of Biosolids on Carbon Sequestration and Nitrogen Cycling." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/49585.
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Land application of biosolids has been demonstrated to improve nutrient availability (mainly N and P) and improve organic matter in soils, but the effects of biosolids on C sequestration and N cycling in the Mid-Atlantic region is not well understood. The objectives were: 1) to investigate soil C sequestration at sites with a long-term history of biosolids either in repeated application or single large application; 2) to characterize and compare soil C chemistry using advanced 13C nuclear magnetic resonance (NMR) and C (1s) near edge x-ray absorption fine structure (NEXAFS) spectroscopic techniques; and 3) to compare biosolids types and tillage practices on short-term N availability in the Coastal Plain soils. Biosolids led to C accumulation in the soil surface (< 15 cm) after long-time application in both Piedmont and Coastal Plain soils. The C saturation phenomenon occurred in Coastal Plain soils, thus additional soil C accumulation was not achieved by increasing C inputs from biosolids to the Coastal Plain. Soil organic C from profiles in the field sites was not different at depths below the plow layer (15-60 cm). The quantitative NMR analyses concluded that O-alkyl C was the dominant form in the particulate organic matter (POM), followed by aromatic C, alkyl C, COO/N-C=O, aromatic C-O, OCH3 / NCH and ketones and aldehydes. The aliphatic C and aromatic C were enriched but the O-alkyl C was decreased in the biosolids-amended soils. The changes indicated that the biosolids-derived soil C was more decomposed and, thus, more stable than the control. The NEXAFS spectra showed that O-alkyl C was the dominant form in the POM extracted from biosolids-amended soils, followed by aromatic C, alkyl C, carboxylic C and phenolic C groups. These results were similar to those from NMR analysis. The regression and correlation analyses of C functional groups in the POM between NEXAFS and NMR indicated that both techniques had good sensitivity for the characterization of C from biosolids-amended soils. To evaluate short-term biosolids N availability, a three-year field study to investigate the effects of lime-stabilized (LS) and anaerobically digested (AD) biosolids on N availability in a corn-soybean rotation under conventional tillage and no-tillage practices was set up in 2009-2011. Results showed that both LS and AD biosolids increased spring soil nitrate N, plant tissue N at silking, post-season corn stalk nitrate N, grain yield, and soil total N by the end of the growing season. The same factors used to calculate plant available N for incorporated biosolids can be used on biosolids applied to no-till systems in coarse-textured soils. All these results indicated that the application of biosolids affects the long-term quantification and qualification of soil organic C and also improve short-term N availability in the Mid-Atlantic region.Ph. D.
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Sahakij, Prawat. "Multiobjective optimization models for distributing biosolids to reuse fields." College Park, Md. : University of Maryland, 2008. http://hdl.handle.net/1903/7851.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2008.Thesis research directed by: Dept. of Civil and Environmental Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Vilalai, Sirapong. "Statistical odor prediction models for supporting biosolids odor management." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8805.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2008.Thesis research directed by: Dept. of Civil and Environmental Engineering Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Wang, Junbo. "Smouldering combustion of biosolids from wastewater treatment plants (WWTPs)." Thesis, Wang, Junbo (2017) Smouldering combustion of biosolids from wastewater treatment plants (WWTPs). Honours thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/40482/.
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The management of biosolids, the major by-product from wastewater treatment plants (WWTPs), exists as a main global challenge which takes up most of WWTP operating costs. Self-sustaining smouldering is a new method for organic waste treatment, where the waste (i.e., biosolids) is destroyed in an energy efficient way after mixing it with porous medium (i.e., sand). Column experiments, utilising biosolids generated from a WWTP, were used to detect whether smouldering combustion was able to be utilized for biosolids treatment or not. According to the peak tempertures of thermocouples obtained from the experiments, it can be identified whether the smouldering reactions are self-sustaining (SS) or non-self-sustaining (NSS). In addition, the average front velocity (AFV) can be calculated then. In this study, Self-sustaining Treatment for Active Remediation applied ex-situ (STARx) refers to the commercial technology which utilizes smouldering combustion to destroy organic wastes (i.e., biosolids). An economic consideration would be completed to estimate the expected payback period and cost savings for considering STARx as a biosolids treatment retrofit in a large WWTP in Australia. The cost savings and payback period concerning replacing either landfill or incineration were considered as these are the most popular disposals for biosolids treatment. Finally, it is obtained that STARx is a good option to be employed in the WWTPs which have employed typical disposal methods (e.g., landfill and incineration) for recent decades.
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Purusottam, Rudra Narayan. "Towards improved sensitivity of solid-state NMR experiments in biosolids." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066213/document.
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RMN à l'état solide est devenue un outil de premier plan pour la caractérisation morphologique, structurale et dynamique de protéines microcristallines, de matériaux polymères, synthétiques ou naturels, de petites molécules d’intérêt pharmaceutique ou des minéraux. Les progrès dans la compréhension de la structure et de la dynamique des systèmes moléculaires à l’état solide sont très fortement dépendants des méthodologies mises en œuvre dans leurs études. Cette thèse s’inscrit dans cette optique en portant l’effort principal sur certains aspects méthodologiques de la RMN à l’état solide, avec comme objectif de développer des nouvelles approches ou améliorer les méthodes déjà utilisées et ceci afin d’extraire de façon optimale des informations spécifiques sur le système de spins étudié. Les études fondamentales de systèmes solides d’intérêt biologique, la mise au point de nouvelles méthodologies ainsi qu’une analyse méthodologique approfondie forment l’essentiel de cette thèse ayant pour le dénominateur commun une amélioration de la sensibilité des expériences RMN à l’état solide. Le mémoire de thèse présente dans sa première partie de nouvelles approches dans les études structurales et dynamiques des protéines microcristallines, membranaires et fibrillaires ainsi qu’une étude dynamique et conformationnelle des chaines phospholipidiques dans les liposomes. La deuxième partie est essentiellement concentrée sur une analyse détaillée de certains aspects méthodologiques de la RMN du solide en relation avec le découplage dipolaire hétéronucléaire, indispensable dans l’obtention des spectres de haute résolutionNMR in the solid state has become a major tool for morphological characterization, structural and dynamic microcrystalline proteins, polymers, synthetic or natural materials, small molecules of pharmaceutical interest or minerals. Progress in understanding the structure and dynamics of molecular systems in the solid state are very heavily dependent on methodologies implemented in their studies. This thesis in this context carrying the main effort on certain methodological aspects of NMR in the solid state, with the goal of developing new approaches and improve the methods already used and in order to extract optimum specific information on the spin system under study. The fundamental studies of solid biologically relevant systems, the development of new methodologies and a thorough methodological analysis form the core of this thesis with the common denominator for an improvement of the sensitivity of NMR experiments in solid state. The thesis presents the first part of new approaches in structural and dynamic studies microcrystalline proteins, membrane and fibrillar and a dynamic study and conformational channels in phospholipid liposomes. The second part is mainly concentrated on a detailed analysis of some methodological aspects of solid state NMR related heteronuclear dipolar decoupling essential in obtaining high resolution spectra
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Beyene, Mulubrhan. "The feasibility of biosolids composting for the City of Winnipeg." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ32054.pdf.
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Seth, Rajesh. "Biological conversion of metal-laden sludge to sulphur enhanced biosolids." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0013/NQ35317.pdf.
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Liu, Chunhe. "Pathogen inactivation in biosolids with lime and fly ash addition." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0028/MQ51743.pdf.
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Kennedy, Alison M. "Nitrogen availability for grapevines in a papermill biosolids amended soil." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58347.pdf.
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Banaitis, Michael R. "Biogeochemical Response of a Northeastern Forest Ecosystem to Biosolids Amendments." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/BanaitisMR2007.pdf.
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Grabau, Matthew. "Solar Drying to Reduce Pathogens In Biosolids In Arid Regions." Thesis, Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1341%5F1%5Fm.pdf&type=application/pdf.
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Dursun, Derya. "Gel-like behavior of biosolids in conditioning and dewatering processes." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 260 p, 2007. http://proquest.umi.com/pqdweb?did=1362540141&sid=7&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Vilalai, Sirapong. "Forecasting odor levels for biosolids product based on ambient conditions." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/128.
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Thesis (M.S.) -- University of Maryland, College Park, 2004.Thesis research directed by: Dept. of Civil and Environmental Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Mehdizadeh, Seyedeh Neda. "Enhancement of Kelowna's biosolids to energy conversion with thermal pretreatments." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43563.
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Enayet, Samia. "Evaluation of odour abatement causes following electro-dewatering of biosolids." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123224.
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Biosolids being recycled to the land for agriculture is not only cost-effective for municipalities but it is also beneficial to the environment. To protect public and environmental health, however, land application of biosolids is regulated for concentrations of pathogens and chemical contaminants, and for production of odours. Electro-dewatering (ED) of residual biosolids from wastewater treatment is a newly commercialized technology which can produce a drier biosolids cake compared to other advanced dewatering technologies. Additionally, it has been demonstrated that ED inactivates pathogen indicators below the detection limit and reduces the regrowth potential. In the current study, using olfactometry and headspace gas chromatography - mass spectrometry (GC/MS), reduced production of odours during storage of dewatered biosolids was documented, and possible mechanisms leading to this reduction were examined.The study compared centrifuged secondary biosolids as the untreated sample control with the same biosolids that had been either electro-dewatered for 10 min or simply heat-treated for 10 min as a secondary control. These samples were incubated at room temperature under anaerobic conditions. Qualitative analysis of the head space by a trained olfactometric panel showed that ED biosolids possessed lower perceived odour concentrations when characterized by detection threshold and recognition threshold compared to the untreated and the heat-treated biosolids (detection thresholds were 13,000 for ED biosolids, 25,000 for untreated biosolids, and 18,000 for heat-treated biosolids). Quantitative analysis by GC/MS of reduced sulphur compounds (methanethiol, dimethyl sulphide and dimethyl disulphide) showed relatively high concentrations for the untreated and heat treated samples, but these compounds remained below the detection limit (78 ppmv for methanethiol, 59 ppmv for dimethyl sulphide and 8 ppmv for dimethyl disulphide) for the ED samples during 14 days of anaerobic incubation. To investigate the reason for the lower odour production by ED biosolids, several factors were examined: (1) the lower pH of the electro-dewatered biosolids (pH 4.5-4.8 vs. pH 6.8-7.5 for the untreated and heat-treated biosolids), (2) the removal of odour precursors by ED, (3) the production of inhibitory compounds during ED. The low pH hypothesis was tested by increasing the pH of the ED biosolids to the level found in the untreated biosolids before anaerobic incubation. Increasing the pH of ED biosolids led to an increase in methanethiol generation. This suggests that lowering the pH of biosolids is one of the main factors causing the abatement of odour production by ED. The removal of odour precursor hypothesis was tested by adding back the filtrate extracted by ED. As the filtrate had a very high pH of 12.8, which also changed the pH of the ED biosolids, the filtrate pH was manipulated such that the pH of the resulting biosolids would be either ~4.5 or ~7. As in the pH-specific experiments, methanethiol emissions were not detected for all samples with a low pH, whereas methanethiol emissions from the high pH samples were increased in the ED biosolids with added filtrate. These methanethiol emissions were above those of the untreated, ED biosolids without filtrate and the heat-treated biosolids. These final results indicate that the dominant factor responsible for reduced odours in ED biosolids is the low pH, but that the removal of precursors may also contribute to lowering odour production. Once these factors were taken into account, there was no clear evidence that ED produced inhibitory compounds. Finally, these experiments confirmed that bacterial pathogen indicators did not regrow under the conditions tested. Therefore, it can be concluded that, under the conditions tested, ED achieved irreversible inactivation of pathogen indicator organisms and reduced odour production by lowering the pH.L'électro-déshydratation (ED) des biosolides résiduels découlant du traitement des eaux usées est une technologie nouvellement commercialisée qui peut produire des biosolides plus secs que d'autres technologies de déshydratation avancées. Dans l'étude présentée dans ce mémoire, la réduction de la production d'odeurs durant l'entreposage des biosolides déshydratés a été documentée et les mécanismes possibles conduisant à cette réduction ont été examinés en utilisant l'olfactométrie et la spectrométrie de masse (GC/MS) en phase gazeuse de l'espace de tête. L'étude a comparé des biosolides secondaires centrifugés en tant que contrôle (échantillons non traité) avec les mêmes biosolides qui avaient été soit électro-déshydratées pendant 10 min, soit simplement traité à la chaleur pendant 10 min comme un contrôle secondaire. L'analyse qualitative de l'espace gazeux au-dessus des échantillons par un panel olfactométrique a montré que les biosolides électro-déshydratés produisaient des concentrations perçus d'odeurs inférieure selon les seuils de détection et de reconnaissance des odeurs par rapport aux échantillons non traités ou traités à la chaleur (seuils de détection étaient 13 000 pour les biosolides électro-déshydratés, 25 000 pour les biosolides non traités, et 18 000 pour les biosolides traités à la chaleur). L'analyse de GC/MS des composés soufrés réduits (méthanethiol, sulfure de diméthyle et le disulfure de diméthyle) a montré des concentrations relativement élevées pour les échantillons non traités et traités à la chaleur, mais ces composés sont restés sous la limite de détection pour les échantillons électro-déshydratés et incubés en anaérobie pendant 14 jours.Pour determiner la cause de la réduction de la production d'odeur par les biosolides électro-déshydratés, plusieurs hypothèses ont été émises: (1) le pH inférieur des biosolides électro-déshydratée (pH 4,5-4,8 vs pH 6.8 à 7.5 pour les biosolides non-traités et traités thermiquement), (2) l'élimination des précurseurs d'odeur par le processus d'électro-déshydratation, (3) la production de composés inhibiteurs au cours de l'électro-déshydratation. L'hypothèse d'un pH faible a été testée en augmentant le pH des biosolides électro-déshydratées au niveau des biosolides non traitées avant l'incubation anaérobie. L'augmentation du pH des boues électro-déshydratées a conduit à une augmentation de la production méthanethiol. Ceci suggère que l'abaissement du pH des boues est l'un des principaux facteurs responsables de la réduction de la production d'odeur par électro- déshydratation. L'hypothèse de la suppression du précurseur d'odeur a été testée en rajoutant le filtrat extrait par l'électro-déshydratation. Comme le filtrat présente un pH très élevé (12.8), le filtrat pH a été manipulé de telle sorte que le pH des biosolides résultant serait soit de ~ 4.5 ou de ~ 7. Comme dans les expériences spécifiques au pH, les émissions de méthanethiol n'ont pas été détectées pour les échantillons dont le pH était bas, alors que les émissions méthanethiol à partir des échantillons à pH élevé ont augmentés dans les biosolides électro-déshydratées avec filtrat ajoutée. Ces émissions de méthanethiol étaient supérieures à ceux des biosolides électro-déshydratées sans filtrat, des biosolids non traités et des biosolides traités à la chaleur. Ces derniers résultats indiquent que le facteur dominant responsable de la réduction des odeurs dans les biosolides électro-déshydratées est le faible pH, mais que l'élimination des précurseurs peut également contribuer à réduire la production d'odeurs. Une fois que ces facteurs eurent été pris en compte, il n'y avait pas de preuve claire que l'électro-déshydratation produit des composés inhibiteurs. Par conséquent, on peut conclure que, dans les conditions testées, l'électro-déshydratation atteint une inactivation irréversible d'organisme indicateur d'agent pathogène et a réduit la production d'odeur par abaissement du pH.
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McGinley, Susan. "Biosolids Safe for Land Application: Study Shows Absence of Pathogens." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/622216.
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Lu, Hung-Wei. "Evaluation of Solubilization with Thermal Hydrolysis Process of Municipal Biosolids." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64914.
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The increased demand for advanced sludge stabilization in wastewater treatment facilities over the past decade has led to the implementation of various pretreatment techniques prior to anaerobic digestion. In an attempt to reduce sludge volumes and improve sludge conditioning properties, the use of thermal hydrolysis process before anaerobic digestion has been adopted with an increase in solids destruction, COD removal, and methane gas. In this study, the evaluation of thermal hydrolysis process as a viable pretreatment strategy to anaerobic digestion has been conducted in order to assess its capacity for solids solubilization. Solubilization experiments were conducted at temperatures ranging from 130 to 170℃ and reaction times between 10 and 60 min. Anaerobic biogas production by thermally pre-treated sludge was carried out through a mesophilic anaerobic digester. The results showed that solids solubilization increased with increases in temperature and time, while temperatures above 160℃ for 30 min strongly affected the sludge characteristics. Ammonia production via deamination by thermal hydrolysis was less significant than protein solubilization at a temperature of 170℃. Both protein and carbohydrate solubilization were more dependent on temperature than reaction time. The enhancement of the biogas production was achieved with increases in temperature as pretreatment of 170℃ yielded 20% more biogas than at 130℃. However, it seems the enhancement was linked to the initial biodegradability of the sludge.Master of Science
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Lindelof, Kara L. "Contribution of Biosolids-derived Bioaerosols to the Airborne Microbial Population." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1302299544.
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Yamakawa, Isao. "Effects of aging on Leachate characteristics of Alkaline Stabilized Biosolids /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu148819244742797.
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Pritchard, Deborah L. "Phosphorus bioavailability from land-applied biosolids in south-western Australia /." Full text available, 2005. http://adt.curtin.edu.au/theses/available/adt-WCU20060811.140234.
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Snyder, Elizabeth Allene Hodges. "Fate, transport, and risk assessment of biosolids-borne triclocarban (TCC)." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024341.
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Pritchard, Deborah Leeanne. "Phosphorus bioavailability from land-applied biosolids in south-western Australia." Thesis, Curtin University, 2005. http://hdl.handle.net/20.500.11937/2380.
Full textAbstract:
The annual production of biosolids in the Perth region during the period of this study was approximately 13,800 t dry solids (DS), being supplied by three major wastewater treatment plants. Of this, 70% was typically used as a low-grade fertiliser in agriculture, representing an annual land use area of around 1,600 ha when spread between 5 and 7 t DS/ha. Loading rates of biosolids are typically based on the nitrogen (N) requirements of the crop to be grown, referred to as the N Limiting Biosolids Application Rate (NLBAR). A consequence of using the NLBAR to calculate loading rates is that phosphorus (P) is typically in excess of plant requirement. The resultant high loading rates of P are considered in the guidelines developed for the agricultural use of biosolids in Western Australia, but lack research data specific to local conditions and soil types. Regulatory changes throughout Australia and globally to protect the environment from wastewater pollution have created a need for more accountable and balanced nutrient data. Experiments presented in this thesis were undertaken to ascertain: the percentage relative effectiveness (RE) of biosolids as a source of plant available P compared with inorganic P fertiliser; loading rates to best supply P for optimum crop growth; P loading rates of risk to the environment; and the forms of P in local biosolids. Therefore, both the agronomic and environmental viewpoints were considered. Anaerobically digested and dewatered biosolids produced from Beenyup Wastewater Treatment Plant, Perth with a mean total P content of 2.97% dry weight basis (db) were used in a series of glasshouse, field and laboratory experiments. The biosolids were sequentially fractionated to identify the forms of P present and likewise in soil samples after applying biosolids or monocalcium phosphate (MCP).The biosolid P was predominantly inorganic (92%), and hence the organic fraction (8%) available for mineralisation at all times would be extremely low. The most common forms of biosolid P were water-soluble P and exchangeable inorganic P (66%), followed by bicarbonate extractable P (19%) and the remaining P as inorganic forms associated with Fe, Al and Ca (14%). Following the application of biosolids to a lateritic soil, the Fe and Al soil fractions sorbed large amounts of P, not unlike the distribution of P following the addition of MCP. Further investigation would be required to trace the cycling of biosolid P in the various soil pools. The growth response of wheat (Triticum aestivum L.) to increasing rates of biosolids and comparable rates of inorganic P as MCP, to a maximum of 150 mg P/kg soil was examined in the glasshouse. The percentage relative effectiveness (RE) of biosolids was calculated using fitted curve coefficients from the Mitscherlich equation: y = a (1-b exp–cx) for dry matter (DM) production and P uptake. The initial effectiveness of biosolid P was comparable to that of MCP with the percentage RE of biosolids averaging 106% for DM production of wheat shoots and 118% for shoot P uptake at 33 days after sowing (DAS) over three consecutive crops. The percentage residual value (RV) declined at similar rates for DM production in MCP and biosolids, decreasing to about 33% relative to freshly applied MCP in the second crop and to approximately 16% in the third crop. The effectiveness of biosolid P was reduced significantly compared with inorganic P when applied to a field site 80 km east of Perth (520 mm annual rainfall). An infertile lateritic podsolic soil, consistent with the glasshouse experiment and representative of a soil type typically used for the agricultural application of biosolids in Western Australia was used.Increasing rates of biosolids and comparable rates of triple superphosphate (TSP), to a maximum of 145 kg P/ha were applied to determine a P response curve. The percentage RE was calculated for seasonal DM production, final grain yield and P uptake in wheat followed by lupin (Lupinus angustifolius L.) rotation for the 2001 and 2002 growing seasons, respectively. In the first year of wheat, the RE for P uptake in biosolids compared with top-dressed TSP ranged from 33% to 55% over the season and by grain harvest was 67%. In the second year, and following incorporation with the disc plough at seeding, the RE for P uptake by lupins in biosolids averaged 79% over the growing season compared with top-dressed TSP, and by grain harvest the RE was 60%. The residual value (RV) of lupins at harvest in biosolids compared with freshly applied TSP was 47%. The non-uniform placement of biosolids (i.e. spatial heterogeneity) was primarily responsible for the decreased ability of plant roots to absorb P. The P was more effective where biosolids were finely dispersed throughout the soil, less so when roughly cultivated and least effective when placed on the soil surface without incorporation. The RE for grain harvest of wheat in the field decreased from 67% to 39% where biosolids were not incorporated (i.e. surface-applied). The RE could also be modified by factors such as soil moisture and N availability in the field, although it was possible to keep these variables constant in the glasshouse. Consequently, absolute values determined for the RE need to be treated judiciously. Calculations showed that typical loading rates of biosolids required to satisfy agronomic P requirements of wheat in Western Australia in the first season could vary from 0 to 8.1 t DS/ha, depending on soil factors such as the P Retention Index (PRI) and bicarbonate available P value.Loading rates of biosolids were inadequate for optimum P uptake by wheat at 5 t DS/ha (i.e. 145 kg P/ha) based on the NLBAR on high P sorbing soils with a low fertiliser history (i.e. PRI >15, Colwell bicarbonate extractable P <15 mg P/kg). On soils of PRI <2 mL/g however, biosolids applied at identical loading rates would result in high concentrations of available P. Further work on sites not P deficient would be necessary to validate these findings on farmed soils with a regular history of P fertiliser. The sieving of soil samples used in the field experiment to remove stones and coarse organic matter prior to chemical analysis inadvertently discarded biosolids particles >2 mm, and thus their was little relationship between soil bicarbonate extractable P and P uptake by plants in the field. The risk of P leaching in biosolids-amended soil was examined over a number of different soil types at comparable rates of P at 140 mg P/kg (as either biosolids or MCP) in a laboratory experiment. Given that biosolids are restricted on sites prone to water erosion, the study focussed on the movement of water-soluble P by leaching rather than by runoff of water-soluble P and particulate P. In general the percentage soluble reactive P recovered was lower in soils treated with biosolids than with MCP, as measured in leachate collected using a reverse soil leachate unit. This was particularly evident in acid washed sand with SRP measuring 14% for biosolids and 71% for MCP, respectively, although the differences were not as large in typical agricultural soils. Specific soil properties, such as the PRI, pH, organic carbon and reactive Fe content were negatively correlated to soluble reactive P in leachate and thus reduced the risk of P leaching in biosolids-amended soil.Conversely, the total P and bicarbonate extractable P status of the soils investigated were unreliable indicators as to the amount of P leached. On the basis of the experiments conducted, soils in Western Australia were categorised according to their ability to minimise P enrichment and provide P necessary for crop growth at loading rates determined by the NLBAR. Biosolids applied at the NLBAR to soils of PRI >2mL/g with reactive Fe >200 mg/kg were unlikely to necessitate P loading restrictions. Although specific to anaerobically digested biosolids cake applied to Western Australian soils, the results will be of relevance to any industry involved in the land application of biosolids, to prevent P contamination in water bodies and to make better use of P in crop production.
39
Pritchard, Deborah Leeanne. "Phosphorus bioavailability from land-applied biosolids in south-western Australia." Curtin University of Technology, Muresk Institute, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16492.
Full textAbstract:
The annual production of biosolids in the Perth region during the period of this study was approximately 13,800 t dry solids (DS), being supplied by three major wastewater treatment plants. Of this, 70% was typically used as a low-grade fertiliser in agriculture, representing an annual land use area of around 1,600 ha when spread between 5 and 7 t DS/ha. Loading rates of biosolids are typically based on the nitrogen (N) requirements of the crop to be grown, referred to as the N Limiting Biosolids Application Rate (NLBAR). A consequence of using the NLBAR to calculate loading rates is that phosphorus (P) is typically in excess of plant requirement. The resultant high loading rates of P are considered in the guidelines developed for the agricultural use of biosolids in Western Australia, but lack research data specific to local conditions and soil types. Regulatory changes throughout Australia and globally to protect the environment from wastewater pollution have created a need for more accountable and balanced nutrient data. Experiments presented in this thesis were undertaken to ascertain: the percentage relative effectiveness (RE) of biosolids as a source of plant available P compared with inorganic P fertiliser; loading rates to best supply P for optimum crop growth; P loading rates of risk to the environment; and the forms of P in local biosolids. Therefore, both the agronomic and environmental viewpoints were considered. Anaerobically digested and dewatered biosolids produced from Beenyup Wastewater Treatment Plant, Perth with a mean total P content of 2.97% dry weight basis (db) were used in a series of glasshouse, field and laboratory experiments. The biosolids were sequentially fractionated to identify the forms of P present and likewise in soil samples after applying biosolids or monocalcium phosphate (MCP).The biosolid P was predominantly inorganic (92%), and hence the organic fraction (8%) available for mineralisation at all times would be extremely low. The most common forms of biosolid P were water-soluble P and exchangeable inorganic P (66%), followed by bicarbonate extractable P (19%) and the remaining P as inorganic forms associated with Fe, Al and Ca (14%). Following the application of biosolids to a lateritic soil, the Fe and Al soil fractions sorbed large amounts of P, not unlike the distribution of P following the addition of MCP. Further investigation would be required to trace the cycling of biosolid P in the various soil pools. The growth response of wheat (Triticum aestivum L.) to increasing rates of biosolids and comparable rates of inorganic P as MCP, to a maximum of 150 mg P/kg soil was examined in the glasshouse. The percentage relative effectiveness (RE) of biosolids was calculated using fitted curve coefficients from the Mitscherlich equation: y = a (1-b exp–cx) for dry matter (DM) production and P uptake. The initial effectiveness of biosolid P was comparable to that of MCP with the percentage RE of biosolids averaging 106% for DM production of wheat shoots and 118% for shoot P uptake at 33 days after sowing (DAS) over three consecutive crops. The percentage residual value (RV) declined at similar rates for DM production in MCP and biosolids, decreasing to about 33% relative to freshly applied MCP in the second crop and to approximately 16% in the third crop. The effectiveness of biosolid P was reduced significantly compared with inorganic P when applied to a field site 80 km east of Perth (520 mm annual rainfall). An infertile lateritic podsolic soil, consistent with the glasshouse experiment and representative of a soil type typically used for the agricultural application of biosolids in Western Australia was used.
Increasing rates of biosolids and comparable rates of triple superphosphate (TSP), to a maximum of 145 kg P/ha were applied to determine a P response curve. The percentage RE was calculated for seasonal DM production, final grain yield and P uptake in wheat followed by lupin (Lupinus angustifolius L.) rotation for the 2001 and 2002 growing seasons, respectively. In the first year of wheat, the RE for P uptake in biosolids compared with top-dressed TSP ranged from 33% to 55% over the season and by grain harvest was 67%. In the second year, and following incorporation with the disc plough at seeding, the RE for P uptake by lupins in biosolids averaged 79% over the growing season compared with top-dressed TSP, and by grain harvest the RE was 60%. The residual value (RV) of lupins at harvest in biosolids compared with freshly applied TSP was 47%. The non-uniform placement of biosolids (i.e. spatial heterogeneity) was primarily responsible for the decreased ability of plant roots to absorb P. The P was more effective where biosolids were finely dispersed throughout the soil, less so when roughly cultivated and least effective when placed on the soil surface without incorporation. The RE for grain harvest of wheat in the field decreased from 67% to 39% where biosolids were not incorporated (i.e. surface-applied). The RE could also be modified by factors such as soil moisture and N availability in the field, although it was possible to keep these variables constant in the glasshouse. Consequently, absolute values determined for the RE need to be treated judiciously. Calculations showed that typical loading rates of biosolids required to satisfy agronomic P requirements of wheat in Western Australia in the first season could vary from 0 to 8.1 t DS/ha, depending on soil factors such as the P Retention Index (PRI) and bicarbonate available P value.
Loading rates of biosolids were inadequate for optimum P uptake by wheat at 5 t DS/ha (i.e. 145 kg P/ha) based on the NLBAR on high P sorbing soils with a low fertiliser history (i.e. PRI >15, Colwell bicarbonate extractable P <15 mg P/kg). On soils of PRI <2 mL/g however, biosolids applied at identical loading rates would result in high concentrations of available P. Further work on sites not P deficient would be necessary to validate these findings on farmed soils with a regular history of P fertiliser. The sieving of soil samples used in the field experiment to remove stones and coarse organic matter prior to chemical analysis inadvertently discarded biosolids particles >2 mm, and thus their was little relationship between soil bicarbonate extractable P and P uptake by plants in the field. The risk of P leaching in biosolids-amended soil was examined over a number of different soil types at comparable rates of P at 140 mg P/kg (as either biosolids or MCP) in a laboratory experiment. Given that biosolids are restricted on sites prone to water erosion, the study focussed on the movement of water-soluble P by leaching rather than by runoff of water-soluble P and particulate P. In general the percentage soluble reactive P recovered was lower in soils treated with biosolids than with MCP, as measured in leachate collected using a reverse soil leachate unit. This was particularly evident in acid washed sand with SRP measuring 14% for biosolids and 71% for MCP, respectively, although the differences were not as large in typical agricultural soils. Specific soil properties, such as the PRI, pH, organic carbon and reactive Fe content were negatively correlated to soluble reactive P in leachate and thus reduced the risk of P leaching in biosolids-amended soil.
Conversely, the total P and bicarbonate extractable P status of the soils investigated were unreliable indicators as to the amount of P leached. On the basis of the experiments conducted, soils in Western Australia were categorised according to their ability to minimise P enrichment and provide P necessary for crop growth at loading rates determined by the NLBAR. Biosolids applied at the NLBAR to soils of PRI >2mL/g with reactive Fe >200 mg/kg were unlikely to necessitate P loading restrictions. Although specific to anaerobically digested biosolids cake applied to Western Australian soils, the results will be of relevance to any industry involved in the land application of biosolids, to prevent P contamination in water bodies and to make better use of P in crop production.
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Stine, Sarah G. "Enhancement of Municipal Wastewater Biosolids Drying through Interfacial Energy Modifying Amendments to Promote Uniform Agglomeration - Bench Scale Testing." Digital WPI, 2018. https://digitalcommons.wpi.edu/etd-theses/1269.
Full textAbstract:
Biosolids Drying is the process of producing a fertilizer product for beneficial reuse from solids produced during municipal wastewater treatment. The drying of biosolids involves the evaporation of water to stabilize the material and produce a product for beneficial use. Thermal energy needs to be transferred to the biosolids to evaporate the water and heat the solids. Energy can be provided by combustion of fuels, re-use of waste heat or solar radiation (WEF, 2014). The most common technology for biosolids drying in the United States utilizes rotary drum dryers. In these systems, fines and crushed oversized pellets produced during the drying system are mixed with dewatered biosolids upstream of the dryer to create a 55% - 65% dry biosolid in the form of pellets. Reducing the percentage of fines generated during the drying process can potentially reduce the amount of energy required for drying.
In earlier research completed by Zhang (2018) it was shown that energy modifying amendments, specifically cationic polyelectrolytes, can reduce the zeta potential of biosolids in solution and possibly promote aggregation of the fines. One of the tested amendments, polydiallyldimethylammonium chloride (PDADMAC), was also shown to increase the particle size of the biosolids in solution. In this work, a bench scale drying system was designed and developed to apply the polyelectrolyte amendments to biosolids during the mixing phase, and to gauge the impact on the pellet size distribution and the percentage of fines generated after drying. It was shown that PDADMAC, which is a high charge density cationic polyelectrolyte, had a measurable, though inconsistent, impact on pellet size when applied during the mixing phase. This work also highlights the varying characteristics of biosolids and the recycled biosolids produced during the drying process. Both PDADMAC, and polyallyamine, another cationic polyelectrolyte, when applied to biosolids during the mixing phase limited the increase in fines production as the mixing time was increased prior to drying.
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Van, der Waals Johan Hilgard. "Heavy metal extractability and plant bioavailability from two sacrificial biosolids soils as influenced by intensive liming." Thesis, University of Pretoria, 2005. http://hdl.handle.net/2263/27672.
Full textAbstract:
The influence of pH on metal extractability from two sacrificial soils that received large amounts of biosolids was studied in four separate trials. The soils (Soil 1: gravelly sandy loam; Soil 2: sandy clay loam) were collected from different water treatment plants in Gauteng. Both soils had undergone significant changes in physical (organic carbon content) and chemical characteristics (pH, metal and nutrient content) due to the prolonged disposal of biosolids. A preliminary pot trial was conducted where large quantities of lime were added to the soils. Results indicated that the soils had high pH buffer capacities due to low pH and high organic matter content. An unexpected increase in the metals extracted with NH4EDTA after intensive liming lead to the performing of three further trials to shed light on the phenomenon. In the second trial lime was added to the soils at four rates (0, 12, 24, 36 tons ha-1). An increase in most NH4EDTA extractable metals was found and this was correlated with increasing absorbance values (at 465 nm) of the extracting solutions (indicating increased extractability of organic matter). In the third trial limed (27 ton ha-1) and unlimed samples were incubated over a period of 20 weeks with regular sampling intervals. The NH4NO3 extractable metals decreased significantly in the lime treated soils but the NH4EDTA extractable metals generally increased. A fourth trial was conducted due to concern regarding the increased EDTA extractable metals after liming and a possible correlation with plant metal bioavailability. The soils were incubated in pots with four lime rates (0, 12, 24, and 36 ton ha-1) and wheat and spinach grown for two months. Although similar trends as for the previous trials were obtained in terms of metal extractability, plant metal content was best correlated with NH4NO3 extraction levels. The results indicate that liming is a safe option for sacrificial soils and that NH4NO3 extractable and plant metal levels decrease with liming. The use of EDTA in metal guidelines or in soil metal content studies is discouraged due to its increased metal extractability with liming and poor correlation with plant metal content.Thesis (PhD)--University of Pretoria, 2005.
Plant Production and Soil Science
Unrestricted
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Para, Eric George. "Coastal Sediment and Fish Biosolids Remediation Using a Microbial Fuel Cell." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/ParaEG2006.pdf.
Full text
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Dominguez, Sanchez Teodulo. "Reduction of Pathogens in Biosolids in Mexico Using Solar Drying Beds." Thesis, Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1383%5F1%5Fm.pdf&type=application/pdf.
Full text
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O'Shaughnessy, Susan Ann. "The Effects of Physical Stressors on Bacterial Inactivation Rates in Biosolids." Diss., Tucson, Ariz. : University of Arizona, 2006. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1673%5F1%5Fm.pdf&type=application/pdf.
Full text
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Yu, Ming Ming. "Co-gasification of biosolids with biomass in a bubbling fluidized bed." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44411.
Full textAbstract:
This thesis project studied the feasibility of co-gasification of biosolids with biomass
as a means of disposal with energy recovery. The kinetics and gasification
performance of biosolids and biomass mixtures were studied with a
thermogravimetric analyzer and a pilot scale bubbling fluidized bed, respectively.
From the kinetics study, it was found that biomass, such as switchgrass, could
catalyze the gasification reactions because the ash of switchgrass contained a high
proportion of potassium, which is considered as an excellent catalyst for gasification
processes. However, it was found that biosolids could also inhibit gasification. When
biosolids were mixed with biomass, the inhibition effect overwhelmed the catalytic
effect.
For the study of gasification performance, the impacts of biosolids proportion in the
fuel, bed temperature, and steam/fuel ratio on gasification performance were
investigated. As the biosolids proportion increased from 0 to 100%, syngas yield
decreased from 1.38 to 0.47 m³/kg, char conversion decreased from 81.7% to 35.5%,
tar content increased from 10.3 to 200 g/m³, and ammonia concentration increased
from 1660 to 19200 ppmv. A synergistic effect occurred at 25% biosolids. With
increasing biosolids proportion in the fuel, H₂ and CH₄ increased, CO decreased, and
CO₂ remained nearly constant in the syngas. As the steam/fuel ratio increased, the
concentrations of H₂ and CO₂ increased, while that of CO decreased in the syngas.
Decreasing the bed temperature from 825 to 728℃ did not affect syngas composition,
but decreased the syngas yield from 0.99 to 0.29 m³/kg
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Butler, Emma. "The fate and effects of triclosan in soils amended with biosolids." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7312.
Full textAbstract:
Many hydrophobic pollutants can be emitted to agricultural soils if sewage sludge is used as a fertiliser. The fate and effects of pollutants in such receiving environments are relatively poorly understood compared with our knowledge of chemical behaviour and impact in surface waters. One chemical of particular concern is triclosan because it has antimicrobial properties which could affect important soil functions. Triclosan is hydrophobic, which means it will sorb appreciably to organic solids and is not readily biodegradable. It is also used extensively in personal care products. These factors have prompted considerable attention in the literature with respect to its environmental profile. In recent years, this attention has shifted away from the water environment to terrestrial systems. This thesis bridges some of the knowledge gaps considering the fate (specifically mineralisation, primary degradation and the formation of bound residues) and the effects (to the soil function and phenotype) of triclosan in soils amended with biosolids. Cont/d.
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Denholm, Patricia Margaret. "Biodiversity, biosolids and bioindicators in Pinus radiata D. Don planted forests." Thesis, University of Canterbury. Forestry, 2003. http://hdl.handle.net/10092/6021.
Full textAbstract:
The global issue of biodiversity was addressed at a local level in this thesis, which examined the effects of a biosolids application programme on the diversity of soil and litter arthropods in Pinus radiata D. Don planted forests in mid Canterbury, New Zealand. A taxonomic inventory of selected sites not only added to the sparse records of entomological data for similar habitats across New Zealand, but also enabled the development of a predictive model for comparison and validation in forward research. Evidence was sought for biosolids-mediated effects in the field on (i) the functional diversity of the arthropod assemblage, (ii) Shannon-Wiener diversity (H') and (iii) an ecologically relevant, invertebrate bioindicator. This novel bioindicator, the larval cranefly Leptotarsus spp. (Diptera:Tipulidae) was further used in a laboratory manipulation in an attempt to quantify the ecological relationship between the genus and soil physical properties. It was then subject to chronic toxicology tests to explore the histological effects of dietary uptake of Cu and Zn. Damage to the gut tissues and a differential effect on the architecture of the fat bodies was shown by histochemistry and light micrography. This evidence providing Support for the "scope for growth" hypothesis, which suggests the allocation of energy to detoxification may impact on an organism's energy reserves, thus affecting growth and development. The larval cranefly Leptotarsus spp. is recommended as a pliable and responsive organism for chronic metal toxicity testing.
No support was found for the general hypothesis of a biosolid-mediated effect on arthropod functional diversity at the community level or on the diversity (H') of species. However, there was unequivocal evidence of a significant negative effect on the abundance of the larval cranefly Leptotarsus spp. in the field where dewatered biosolids are applied at rates beyond 400 kg N/ha. It was predicted that cranefly species with a brachypterous female would most likely be affected in forests receiving biosolids applications above 400 kg N/ha. The four cranefly species identified from the study sites were the sale representatives of the myceto/geophagic functional group. Although biosolids applications are likely to constrain both the local diversity and abundance of craneflies, the species redundancy hypothesis predicts ecological processes are unlikely to be affected. Laboratory manipulations failed to show linkage between cranefly larval abundance and their contribution to the generation of porous space in the soil, although these larvae are expected to mediate other soil-related processes, such as the redistribution of fungal inoculants.
Arthropod diversity under P. radiata is dominated by generalist species. Greater than 50% of the arthropods trapped were indigenous. The sampled forests clearly provide a refuge within the agricultural mosaic and contribute to the retention of local biodiversity. The trophic structure of the arthropod assemblage was dominated by predatory species. A positive relationship between species diversity (H') and the stage of development of a stand was best described by a logarithmic curve, indicating diversity (H') increased most rapidly during the first (approx.) 10 years of forest establishment. The suites of indicator species identified as significantly indicative of the P. radiata habitat are expected to simplify future assessment at the long-term monitoring sites by offering an investigative tool for the non-specialist.
This thesis provides information on the community structure of a highly modified habitat which is of interest to both entomologists and forest managers. As well as giving information on seasonal abundances in relation to trapping methodologies, it provides baseline data and predictive models useful for comparing long-term effects and suggests appropriate bioindicator species as tools for straightforward and cost-effective monitoring in the future. In practice, the main results demonstrated that although biosolids-mediated effects in the Pinus habitat were effectively quantified at the level of genus, forest managers can have a high level of confidence that a significant biosolids-mediated effect on invertebrate biodiversity at the community level is unlikely, at least in the short term, at advised rates of application.
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Pinapati, Kishore. "VARIATION OF GEOTECHNICAL STRENGTH PROPERTIES WITH AGE OF LANDFILLS ACCEPTING BIOSOLIDS." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3992.
Full textAbstract:
The solid portion of waste disposal, known as Municipal Solid Waste (MSW) can be landfilled. Landfilling has proved to be a safe, sanitary and economical method of disposal. A by-product from wastewater treatment plants called biosolids is sometimes co-disposed along with MSW in landfills. Recent work at the University of Central Florida has focused on the behavior of the mixture of MSW and biosolids. As an increased amount of waste accumulates in these landfills, it creates a new problem – the geotechnical stability of landfills. In current literature, classical geotechnical testing methods have been followed to find the strength properties of these landfill materials. Furthermore, geotechnical methods of slope stability analyses have been employed to determine the stability of landfill slopes. As these materials have a high organic content, their strength properties may potentially change with time because of the decay of the organic materials. In the present work, an attempt is made to monitor the change in the geotechnical strength properties of the landfill materials as a function of time. Direct shear tests used for soil testing, with some modifications, were performed on cured compost samples of MSW mixed with biosolids. Geotechnical strength properties of these cured samples were compared to those of an artificially prepared mixture of MSW and biosolids, from the published literature. In addition, direct shear tests are also performed to find the interface properties of a geonet with the cured samples to check the role of a geonet in reinforcing the landfill slopes. A slope stability analysis software SLOPE/W is used to analyze the stability of the landfills. Cohesion is observed to decrease with time while the friction angle increases with time. Stability (the factor of safety against failure) of landfill slopes increases with time due to increased effective stresses and increased friction angle, as the organic material decays. This may result in additional subsidence but an increase in the effective shear strength with time. Based on the interface test results and subsequent slope stability analyses, it is found that the inclusion of a geonet improves the slope stability of a landfill. This could be a potential benefit to the landfill as reinforcement if properly placed. Based on the slope stability analysis on landfills with different slopes, it is concluded that the slope stability of a landfill is improved by keeping the slopes less steep.M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering
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Youngquist, Caitlin Price. "Local biosolids compost| agricultural use, fate of antibiotics, and community engagement." Thesis, Washington State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3628900.
Full textAbstract:
We investigated the agricultural use of locally produced biosolids compost, the fate of the antibiotic ciprofloxacin during the composting process, community perceptions about biosolids, and sociological factors of community involvement in waste management research and decision-making.
Two biological assays were used to determine if the antibiotic ciprofloxacin selects for and amplifies ciprofloxacin-resistant bacteria during composting. A third biological assay measured the capacity of compost to adsorb ciprofloxacin from solution. Our results show that the ciprofloxacin had no selective effect on resistant populations of bacteria during composting and that the compost was capable of adsorbing and effectively neutralizing this antibiotic.
A two-year field trial was conducted to evaluate the potential of biosolids compost as a high-carbon soil amendment in local agriculture. Potatoes and small grains were grown with biosolids compost and/or synthetic fertilizer and effects on crop yield, soil fertility, and soil quality were measured. Biosolids compost increased potato tuber and grain yield in the second year, demonstrating cumulative effects of repeated compost applications. In this study, the value of biosolids compost was primarily as a source of nitrogen, plant available phosphorus, and soil organic matter.
A mail survey of 1,374 Skagit County households was conducted to gain insight into community perceptions about the use of biosolids in local agriculture, interest in using biosolids compost as a soil amendment, and desire to participate in local waste management decision-making processes. Mail survey results and participant observation were used to develop a case study of community involvement in waste management research and decision-making in the town of La Conner.
This project addressed challenges inherent in conducting research on a controversial topic while developing a new collaborative research model for the region. Scientists, public planners and biosolids managers may be able to build and improve upon what was learned here in their efforts to develop effective regional waste management solutions.
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McGinley, Susan. "Mine Tailings Restoration: Method Uses High Grade Biosolids to Revegetate Land." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/622232.
Full text