No description available.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisors: Steven K. Dentel and Pei C. Chiu, Dept. of Civil & Environmental Engineering. Includes bibliographical references.

Thesis (M. Sc.)(Microbiology)--University of Pretoria, 2005. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographic references (p.91-111).

Includes bibliographical references (p. 62-73).

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 170-181). Also available in electronic version. Access restricted to campus users.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

The application of municipal sewage biosolids to agricultural land is a common practice worldwide. Increasing attention is being directed at the presence of organic contaminants bound to the organic phase during wastewater treatment, which end up in the biosolids. The goal of this study was to investigate the decomposition of an alkaline-stabilized biosolid being used as an agricultural soil amendment containing unknown organic contaminants. A two year field trial and a 120 day laboratory soil incubation using increasing rates (0, 7, 14, 28, and 42 Mg ha-1) of an alkaline-stabilized biosolid (ASB) were set up to monitor biosolid decomposition and concentrations of selected contaminants over time. The seven contaminants selected for monitoring (p-cresol, indole, 4-t-octylphenol, phenanthrene, triclosan, carbamazepine, and benzo[a]pyrene) represent a wide range of physico-chemical properties and fall under several different chemical classes. The decomposition of ASB in soil was examined in the incubation study. Almost half of the CO2-C evolved from ASB amended soils occurred within the first 6 days, indicating that a relatively labile pool of carbon remains in ASB following the sewage treatment process. By day 121, between 71 to 78% of the total carbon added to soil had been evolved as CO2-C. A new model developed during this study to describe carbon mineralization, a first order plus logistic function (FLOG), performed better than other commonly used models. The method chosen to analyze organic contaminants in soil was only able to determine four out of seven compounds reliably, with recoveries greater than 50% for 4-t-octylphenol, phenanthrene, triclosan, and benzo[a]pyrene. In treated soils, only triclosan was able to be detected and quantified. Average triclosan concentration in the incubation study ranged from a high of 143 ng g-1 on day 3 to a low of 26 ng g-1 by day 121, representing an 81% decrease over a roughly 4 month period under idealized conditions. In the field, triclosan concentrations following a Fall biosolids application in Oct. 2008 increased to detectable levels (29 to 47 ng g-1) in all three plots measured in Nov. 2008, which remained elevated (29 to 66 ng g-1) over the winter period in two out of three plots when sampled in May 2009. Following the Spring application in June 2009, measured triclosan concentrations in July 2009 samples from these same two plots were lower than predicted (33 to 48 ng g-1) and eventually decreased to levels below the detection limit by the Oct. 2009 sampling.

In light of rising costs in fossil fuels and petroleum, as well as the strain on this largely non-renewable resource, the conversion of biomass, in this case waste biomass, to value-added products is becoming more attractive. In this study, municipal sewage sludge and biosolids were used to determine their potential for glucose recovery. This research focused on three pretreatment processes including drying/grinding, as well as acid and alkaline pretreatments, followed by acid hydrolysis on primary sludge, activated sludge and biosolids. After each pretreatment under specified conditions, the residues remaining from the sludges and biosolids underwent a 2 % H2SO4 acid hydrolysis at 120oC for 1 hr. Compared with activated sludge and biosolids, primary sludge was found to demonstrate the highest potential for glucose recovery in this study. Primary sludge with 1.0 N HCl pretreatment over a 24 hour contact period yielded the highest glucose conversion result as 5.67±0.24%. The best KOH pretreatment condition for primary sludge was a 0.5 N KOH concentration for a 0.5 hour contact period. However, no consistent glucose recovery trend as a function of reagent concentration or contact time was identified for any of the sludges or biosolids in this study. Drying and grinding were also found to efficiently improve the acid hydrolysis results. Fibre content analysis was also performed on the sludge and biomass feedstocks and their residues following pretreatment and acid hydrolysis during this study, to better understand the conversion of these waste biomass feedstock. The Van Soest methods for neutral-detergent, acid-detergent and acid insoluble lignin analysis and the Weende crude fibre analysis were applied to the sewage sludge and biosolids samples prior to and after acid hydrolysis to determine the fibre content including cellulose, hemicellulose and lignin. A modification to the Weende crude fibre analysis was introduced, where a centrifuge step was added prior to the second filtration after the alkaline digestion of the procedure to reduce filter clogging problems. The centrifuge modification effectively reduced the filtering time from one day to 30 minutes; however, there was an average loss of 46% in crude fibre with the addition of this centrifugation step. It was found that most of cellulose content in the feedstock samples was hydrolyzed to glucose after the acid hydrolysis process and most hemicellulose content was likely to have been solubilized and washed away during acid and alkaline pretreatments and acid hydrolysis. The lignin content did not appear to be affected by the pretreatments applied nor the acid hydrolysis. / Thesis (Master, Civil Engineering) -- Queen's University, 2008-07-25 16:10:42.518

The purpose of this study is to investigate the possibility of using the Bleached Kraft wastewater sludges as a sealant to a permeable soil structure which could contain these liquids. The sludges used are either self-contained in wastewater, produced from treatment processes, or from the addition of chemical coagulant to the wastewater. / The mechanisms of the sludge sealing phenomena which were investigated individually are divided into physical, physico-chemical, biophysical and bio-physico-chemical types of seals. Coarse sand #24 was found suitable for this sealing study as a particle size cut. Among the types of sealings studied, the bio-physical type of seals is the most effective. The physico-chemical type of seals is effective in the initial stage of sealing. The coefficient of the permeability is reduced from an average of 6.4 x 10('-2) cm/sec to 1.0 x 10('-6) cm/sec in a period of 24 hours, with a risk of leakage of less than 1% of the total effluent. / A long-term stability of using sludges as a liner to the wastewater pond has become a substantial issue. Alum was originally chosen as an effective coagulant for forming a layer of sludge for physico-chemical types of sealing. However, after the stability analyses, one finds that alum sludge is not a stable material under commonly-found hydrostatic pressures and high pH ranges. The results of the research shows that one of the alumino-silicate sludges is much more stable than that of alum sludge. The relatively stable alumino-silicate sludge was obtained from one of the coprecipitations of sodium-silicate and sodium aluminate in a BKME solution. / The economic impact of using alumino-silicate sludge is significant. The cost comparison study shows a cost ratio in the range of up to 1:10 as compared to conventional lining material. The results can be used for the implementation of field work in sludge sealing practice. In addition, this investigation could form an excellent foundation for further studies on other effluents with different parameters.