Dissertations / Theses: 'Sewage sludge treatment'

1

Ng, Yue-hang. "Dewatering and treatment of sewage sludge before landfill /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14723232.

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2

Fong, Chun-yau. "Latest development in waterworks sludge treatment and disposal in Hong Kong /." [Hong Kong : University of Hong Kong], 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13498733.

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3

Ng, Yue-hang, and 伍宇鏗. "Dewatering and treatment of sewage sludge before landfill." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31253222.

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4

Martin, Garcia Ignacio. "Sludge free and energy neutral treatment of sewage." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6530.

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Anaerobic biological processes have been recognized as the most suitable pathway towards sustainable wastewater treatment due to the lower energy required and the lower amounts of biosolids generated when compared to conventional aerobic technologies. The difficulties experienced with the implementation of anaerobic reactors for the treatment of low strength wastewater at low temperatures are related to the deterioration of treatment capacity and effluent quality due to inefficient removal of colloidal matter and biomass washout. Membrane technology can overcome the limitation of anaerobic bioreactors since they retain not only solids but also colloidal and high molecular weight organics. This thesis explores the potential of anaerobic membrane bioreactors as core technology for mainstream wastewater treatment. The impacts of seed sludge, temperatures and bioreactors configuration on treatment efficiency and membrane performance as well as nutrient removal using ion exchange resins are investigated. Cont/d.

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5

Nordin, Andreas. "Heavy metal removal from sewage sludge by pyrolysis treatment." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-8807.

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Sewage sludge is the product from wastewater treatment that mostly is considered as a waste material. However, it contains several nutrients, especially phosphorus, potassium and nitrogen which are excellent fertilizers. The downside is the harmful content it also carries with pathogens, heavy metals and a variety of organic pollutants that in many cases have unknown effects on the ecosystem. A possible solution to this problem could be to pyrolyse the sewage sludge and by that decrease the levels of heavy metals and also render both pathogens and organic pollutants harmless. In this thesis project pyrolysis of dried sewage sludge has been evaluated at temperatures 650 750, 850 and 950 °C with addition of chlorine in the form of PVC and straw. An energy balance for pyrolysis and drying of dewatered sewage sludge has also been suggested. The results of the pyrolysis evaluation indicate that cadmium concentration can be reduced significantly with increasing temperature in the product char. But also other heavy metals like lead and zinc are affected at the higher temperatures evaluated. Mercury is completely removed from the char residue. The more latent volatile metals copper, chromium and nickel cannot be reduced to lower concentrations at these temperatures. They are instead enriched under these conditions. Chlorine addition to the sludge enhances the evaporation of all heavy metals but copper, nickel and chromium. The energy balance over the system indicates that the drying process requires more energy than is released from the sludge into the pyrolysis gases. The energy carried by the pyrolysis gases is however larger than what is required to drive the pyrolysis process.

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6

Tshivhunge, Azwiedziswi Sylvia. "Enzymology of activated sewage sludge during anaerobic treatment of wastewaters : identification, characterisation, isolation and partial purification of proteases." Thesis, Rhodes University, 2001. http://hdl.handle.net/10962/d1004072.

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During anaerobic digestion bacteria inside the digester require a carbon source for their growth and metabolism, sewage sludge was used as a carbon source in this study. The COD content was used to measure the disappearance of the substrate. COD content was reduced by 48.3% and 49% in the methanogenic and sulphidogenic bioreactors, respectively, while sulphate concentration was reduced by 40%, producing 70mg/L of hydrogen sulphide as the end product over the first 5-7 days. Sulphate (which is used as a terminal electron acceptor of sulphur reducing bacteria) has little or no effect on the sulphidogenic and methanogenic proteases. Sulphite and sulphide (the intermediate and end product of sulphate reduction) increased protease activity by 20% and 40%-80%, respectively. Maximum protease activity occurred on day 21 in the methanogenic reactor and on day 9 in the sulphidogenic reactor. The absorbance, which indicates the level of amino acid increased to 2 and 9 for methanogenic and sulphidogenic bioreactors, respectively. Proteases that were active during anaerobic digestion were associated with the pellet (organic particulate matter) of the sewage. These enzymes have an optimum activity at pH 10 and at temperature of 50°C. The proteases that were active at pH 5 and 7, had optimum temperatures at 30°C and 60°C, respectively. Due to their association with organic particulate matter, these enzymes were stable at their optimum temperatures for at least five hours at their respective pH. Inhibition by PMSF, TPCK and 1.10-phenanthroline suggested that proteases inside the anaerobic digester are a mixture of cysteine, serine and metalloproteases. At pH 5, however, EDTA appeared to enhance protease activity by 368% (three-fold). Acetic acid decreased protease activity by 21%, while both propionic and butyric acid at 200 mg/L cause total inhibition of protease activity while these acids at higher pH (where they exist as their corresponding salts) exerted little effect. Copper, iron and zinc inhibited protease activity by 85% at pH 5 with concentrations ranging between 200 and 600 mg/L. On the other hand, nickel, showed an increase in protease activity of nearly 250%. At pH 7 and 10, copper had no effect on protease activity while iron, nickel and zinc inhibited these enzymes by 20-40%. Proteases at pH 7 were extracted from the pellet by sonication, releasing 50% of the total enzymes into the solution. The enzymes were precipitated by ammonium sulphate precipitation, and further purified by ion exchange chromatography and gel filtration. Ion exchange chromatography revealed that most of the enzymes that hydrolyse proteins are negatively charged while gel filtration showed that their molecular weight is approximately 500 kDa.

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Wong, Tak Ian. "Numerical flow simulations of an egg-shaped anaerobic sludge digester in wastewater treatment /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202005%20WONG.

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8

Ozkan, Yucel Umay G. "Co-treatment Of Hazardous Compounds In Anaerobic Sewage Sludge Digesters." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609952/index.pdf.

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Xenobiotic compounds, which are exclusively man made, are produced in large quantities every year and released to the environment. Besides, anaerobic sludge digestion offers advantage in co-treatment of hazardous substances produced by the industry. The performance of the digesters can be monitored by modeling efforts. In this study, Anaerobic Digestion Model No.1 (ADM1) was calibrated, and validated for full-scale digester, lab-scale digester, and lab-scale digester seeded with totally different anaerobic biomass than that of full-scale digester. The model xenobiotic compound, a mono azo dye RO107, was co-treated with sewage sludge in an anaerobic digester. High removal efficiencies as 98% was found for azo dye at standard operating conditions of anaerobic digesters. The digester performance was not effected from azo dye or its reduction products. The dye reduction mechanism was modeled by biochemical mechanism due to unspecific enzymes and by chemical mechanism due to sulfide reduction. Some of the dye metabolites were suggested to be degraded by aerobic biotreatment. The anaerobic reduction metabolites of RO107 were identified as 2-(4-aminophenylsulfonyl) ethanol and 2,5-diamino-4-formamidobenzenesulfonic acid, and sulfanilic acid.

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9

Bauer, Torben. "Can new treatment combinations make sewage sludge management more sustainable?" Licentiate thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-84162.

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Treated sewage sludge is often reused as a fertilizer but several European countries are phasing out this option due to concerns about harmful substances in the sludge. Valuables in the sludge should still be recycled so the removal of the pollutants is necessary. The technology in sewage sludge treatment remained nearly unchanged in the past century. Adapting traditional treatments and combining them with upcoming ones can be a way to separate substances in sewage sludge. This work discusses examples of how treatment methods can be combined and which potential these treatment combinations may have. New tools for system analyses need to be developed to allow the integration and adaption of treatments into existing infrastructure.

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Tsang, Wai Lik. "Performance of sulfate reduction, autotrophic denitrification, and nitrification integrated process (SANI process) for saline sewage treatment /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202007%20TSANG.

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11

Haseltine, Michael H. "The effect of inert biomass support media on activated sludge treatment of a high-strength industrial wastewater." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-12052009-020051/.

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12

Fong, Chun-yau, and 方鎮猷. "Latest development in waterworks sludge treatment and disposal in HongKong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B3125259X.

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13

Cumbie, William E. "Effects of storage on water treatment plant sludges." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45542.

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The effects of in-basin storage of sludge on the iron, manganese, and TOC removal of water treatment plant (WTP) clarifiers and on the dewatering characteristics of sludge were examined. The use of chlorine dioxide as a preoxidant to retard observed detrimental effects was also investigated.

Sludge samples that were stored over a period of 120 days were found to release up to ten times the original supernatant concentration of iron and manganese from the sludge into the overlying supernatant liquor when sludge redox potential values decreased below +100 mV. Organic carbon also increased in the supernatant but to a lesser extent. Sludge dewatering characteristics as measured by specific resistance and capillary suction time were found to improve when sludge redox potential readings remained over 100 mV but varied greatly when readings were below this level.

Field monitoring and sampling of the clarifiers at Lee Hall WTP and Harwood's Mill WTP from April to July showed that the removal efficiencies of the clarifiers was not related to in-basin sludge storage. This conflicted with a later portion of the study and was thought to be due to the lack of standardized sampling techniques.

The final phase of the investigation dealt with the use of chlorine dioxide to retard the negative effects of in-basin storage of sludge. Sludge accumulation in clarifiers resulted in decreased iron and manganese removal efficiencies when chlorine dioxide was not used. Addition of chlorine dioxide improved the iron and manganese removal efficiencies of the clarifiers. Sludge dewatering characteristics were found to improve with the use of chlorine dioxide as a preoxidant.

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14

O'Palko, Brian A. "The use of a microbubble dispersion to enhance a dissolved air flotation system in a wastewater treatment sludge media." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10222009-125034/.

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15

Ek, Anders. "Ultrasonic treatment of sewage sludge in order to increase biogas yields." Thesis, Linköping University, Department of Water and Environmental Studies, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4581.

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Biogas, a mixture of methane and carbon dioxide, is produced in the anaerobic digestion of sewage sludge. After anaerobic digestion, the digested sludge is often allowed to degas for one or two days. This gas is seldom utilised, but if the degassing could be accelerated, utilisation would be easier. Ultrasound can be used as a pretreatment method for waste activated sludge. It has a disintegrating effect on the sludge and causes lysis of bacteria in the sludge. It also speeds up the hydrolysis; the limiting step of anaerobic digestion of waste activated sludge. Ultrasound can be used to degas waterbased liquids. Ultrasonic degassing of sewage sludge has not been examined previously. The present study aims to investigate the effect of ultrasound on waste activated sludge as well as the potential of ultrasound to speed up the degassing of digested sludge. A semi-continuous, lab-scale digestion experiment was performed with four reactors: two receiving untreated sludge and two receiving treated sludge. The effect of the sonicator was 420 W and the treatment time was 6 min, which corresponds to an energy input of 8.4 kWh/m³. Total solids (TS) of the waste activated sludge was ~3.5 %. The ultrasonic treatment caused an increase in gas production of 13 %. There was no difference in methane content. The concentration of filterable chemical oxygen demand (fCOD) increased 375 %, or from 2.8 % to 11 % of total COD. In terms of energy loss/gain the increase in gas production resulted in a loss of 2.7 kWh/m³, i.e. more energy is needed to treat the sludge than the potential energy of the increased gas production. However, if the sludge is thickened to a TS >5 %, a net energy gain should be reached. The effect of ultrasound on the degassing of digested sludge was examined in three barrels. The degassing was measured with and without circulation as well as with ultrasonic treatment. The digested sludge had a gas emission rate of 115 L/(m³ day). No direct burst of gas occurred due to ultrasonic treatment. Over two days more gas was emitted from the barrel equipped with ultrasound, probably due to an induced post-digestion. Thus, ultrasonic pretreatment of waste activated sludge increases the biogas yield. It is inconclusive, whether ultrasonic treatment of digested sludge effects the degassing or not.

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16

Cheng, Yingchao. "Behavior and Control of Mercury in Sewage Sludge Thermal Treatment Process." Doctoral thesis, Kyoto University, 2020. http://hdl.handle.net/2433/253266.

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京都大学
0048
新制・課程博士
博士(工学)
甲第22430号
工博第4691号
新制||工||1732(附属図書館)
京都大学大学院工学研究科都市環境工学専攻
(主査)教授高岡昌輝, 教授米田稔, 准教授大下和徹
学位規則第4条第1項該当
Doctor of Philosophy (Engineering)
Kyoto University
DFAM

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17

Sharma, Keshab Raj. "High rate wastewater treatment using aerobic upflow sludge blanket (AUSB) with external oxygenation /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202003%20SHARMA.

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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.

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18

Mostafa, Ahmed Mohamed Khaled. "Effect of sludge treatment processes on ASCARIS destruction for safe utilisation of sewage sludge in Egypt." Thesis, University of Newcastle Upon Tyne, 2000. http://hdl.handle.net/10443/532.

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Two different types of sludges from two popular sewage treatment systems were used in this study; namely, anaerobic pond sludge from a wastewater stabilisation pond system and filter pressed primary sludge from a primary sewage treatment plant. Under Egyptian conditions, Ascaris eggs represent the main health concern for sludge application on land and, accordingly, the effect of sand drying beds and a passive composting system (using agricultural wastes as bulking agents and cement dust as an additive to the sludge) were studied in terms of the inactivation of Ascaris eggs. From the characterisation and assessment of the anaerobic pond sludge from the Mit Mazah wastewater stabilisation pond system, it has been concluded that the sludge was well digested and free of viable Ascaris eggs. Consequently, this sludge is considered to be safe for land application, after appropriate dewatering. For the purposes of the study, anaerobic pond sludge was seeded with Ascaris vitilorum eggs (cattle ascarid). Within 30 days of dewatering on sand drying beds during the winter season (October and November), the Ascaris eggs were found to be inactivated only in the top layers, where the average solids content was approximately 85%. By the end of the two month drying period, the middle and bottom layers of sludge on the drying beds contained an average solids content of 74% to 77% and 72 to 73%, respectively, yet viable Ascaris eggs were still detected. During a second sludge application during the winter season (December and January), unfavourable weather conditions prevailed and, by the end of the 60 days drying period, total solids content averaged 54% in the top layer of sludge. The middle and bottom layers had an average total solids content of 49% and 44%, respectively. Throughout the winter drying period, all samples collected were positive for viable Ascaris eggs throughout the full depth of sludge. However, during the summer season, samples collected from the drying beds after 17 days of drying did not contain viable Ascaris eggs in the top sludge layers, where the solids content ranged from 74% to 63%. After one month of summer drying, no viable Ascaris eggs were detected throughout the entire depth of sludge on the drying beds and the lowest solids content recorded was 80% for the bottom layers. From this study, it can be concluded that, during the wet season in Egypt, drying beds were not efficient in destroying Ascaris eggs throughout the entire sludge depth. During the summer season, Ascaris eggs can be inactivated much more rapidly, compared to the winter season. Desiccation does not seem to be the only factor influencing the destruction of Ascaris eggs, with sludge temperature, solar radiation intensity and exposure time being possible major factors. By comparing the composting of filter pressed primary sludge in passive and windrow piles (used as control piles), it has been proved that the passive composting system is much more efficient in maintaining regular high temperatures in the composting mixture for a much longer duration (additional 10 days), due to the favourable aerobic conditions. Moreover, passive composting preserves the nitrogen content through the naturally controlled internal temperature, less need for turning and lower loss of moisture. By the end of the composting process, the total nitrogen content for the passive and windrow piles was a gain of 17.5% and a loss of 0.7%, respectively, while the ammoniacal nitrogen content in the product was 1109 mg/l and 837 m/l, respectively. From the hygienic point of view, passive composting technology proved to be much more effective in inactivating Ascaris eggs present in the primary sludge, compared to the windrow pile system. Viable Ascaris eggs were not detected after 30 days of composting using the passive system, compared with 60 days of composting for the windrow pile. Industrial cement dust as an additive and agricultural wastes (from fennel and basil production) were incorporated with sludge to form a range of composing mixtures. From the sludge/cement dust composting piles with agricultural wastes as bulking agent, it can be concluded that more than 35% concentration of cement dust was unfavourable for the decomposition process, due to the high pH and high temperature levels attained as a result of the effect of cement dust and dehydration of the organic matter. Moreover, loss of nitrogen was very high, due to the release of ammonia, encouraged by the high pH and high temperature in the composting mixture. The passive composting system was very efficient in naturally controlling the internal temperature in all the sludge/cement dust piles with bulking agent. Excessive heat was released to the atmosphere through the chimney effect created by the circulation of air through the perforated pipes and upwards into the pile. Internal temperatures for even the piles with the highest proportion of cement dust did not exceed 73°C. Inactivation of Ascaris eggs was achieved after only 15 days of composting for all the different cement dust concentrations, mainly due to the influence of high pH and high temperature levels for long periods but may also be due to the high release of ammonia gas. The passive composting of sludge amended with 30% cement dust without bulking agent was inefficient for both the decomposition process and inactivation of Ascaris eggs. No biological activity was taking place during the two months fermentation stage, due to the prevailing anaerobic conditions (lack of air voids and high moisture content) By considering all the different parameters for evaluating a treated compost, including the stability, maturity, nutrient content, heavy metals content and viable Ascaris eggs content for the sludge/cement dust piles with bulking agent, it can be concluded that more than 30% cement dust concentration would be unfavourable, according to the relatively high loss of nitrogen. More than 35% cement dust concentration is certainly unfavourable, mainly as a result of the delay of the decomposition process, the elongation of the composting period and the high loss of nitrogen content. There is no need to separate out the agricultural waste bulking materials after composting because they are organic in nature. Likewise, there is no need to consider separating out the cement dust, as the physicochemical analysis of the final sludge/cement compost with bulking materials showed its suitability for adding to agricultural land as an amendment. In conclusion, sand bed drying is considered to be a suitable process for dewatering of anaerobic stabilisation pond sludge in Egypt and, for extended periods between pond desludging of the order of 6 years, the dewatered sludge will be suitable for direct application to agricultural land. Passive composting is an appropriate technique for preparation of Egyptian filter pressed primary sludge for safe application to agricultural land. Cement dust additions of less than 30% concentration, to the composting mixture in a passive composting system produces sanitised and mature compost. The potential for co-disposal of agricultural wastes and cement kiln dust as bulking agents and additive, respectively, with sewage sludge in the production of compost, is very promising to produce a safe and beneficial outcome to the community.

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19

Gostick, Nicholas Andrew. "A study of the effect of substrate composition on the settlement of activated sludge." Thesis, Cranfield University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305386.

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20

Enongene, Godlove Nkwelle. "The enzymology of enhanced hydrolysis within the biosulphidogenic recycling sludge bed reactor (RSBR)." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1015744.

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The hydrolysis of complex organic heteropolymers contained in municipal wastewater to simpler monomers by extracellular hydrolytic enzymes is generally considered the rate-limiting step of the biodegradation process. Previous studies of the Recycling Sludge Bed Reactor (RSBR) revealed that the hydrolysis of complex particulate organics, such as those contained in primary sludge (PS), was enhanced under anaerobic biosulphidogenic conditions. Although the mechanism was not fully understood, it appeared to involve the interaction of sulfide and sludge flocs. The current study was conducted using a 3500 ml laboratory-scale RSBR fed sieved PS at a loading rate of 0.5 kg COD/m³.day and an initial chemical oxygen demand (COD) to sulfate ratio (COD:SO₄) of 1:1. There was no significant accumulation of undigested sludge in the reactor over the 60-day experimental period and the quantity of SO₄ reduced indicated that the yield of soluble products from PS was at least as high as those reported previously for this system (> 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.

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Bocken, Stephan. "D.O. control and O.U.R. estimation in the activated sludge process." Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/22156.

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22

Betmal, Salim Mohamed. "The fate of bacterial enteric pathogens during enhanced treatment of sewage sludge." Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406879.

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Lawson, Lilian. "Microscopic Investigation of Filamentous Microorganisms in Activated Sludge Process for Sewage Treatment." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231524.

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Hammarby Sjöstadsverk is a pilot plant operated by IVL Swedish Environmental Research Institute and Royal Institute of Technology (KTH) which treats municipal wastewater. Different processes are used of which one is a Sequential Batch Reactor (SBR) with activated sludge process. The activated sludge process is an effective biological municipal wastewater treatment process. Foaming and floating sludge is a significant problem for municipal wastewater treatment plants globally, that appears from time to time and a full understanding of the process causing this phenomenon is still not available. The problem can have multiple causes such as imbalance of microorganisms, nutrients, toxicity, pH, DO, temperature, denitrification, nitrification etc. The scope of this thesis project is to find out which microorganism’s cause foaming and bulking and how to control it. For this investigation, the Hammarby Sjöstadsverk pilot wastewater treatment plant in Stockholm was utilized. The laboratory facilities at KTH were used during thesis work. Laboratory methods were used to cultivate and isolate filamentous organisms from foam, sludge and inlet wastewater samples to investigate by microscopy and see which microorganisms exist in the activated sludge process were performed. General cultivation media for bacteria and fungi were used for culturing microorganisms. Isolation of some filamentous forms was based on colony morphology on an agar plate and microscopy. Microscopic observation of foam and isolates were performed, comparing cell morphology with literature studies. The sludge showed very few types of protozoa. The isolated and cultivated samples were fungi, yeast-like fungi and bacteria. The organisms are most likely the reason for foaming and bulking. Other reasons were also investigated by comparing retrieved data from IVL with literature studies; the process levels such as pH, DO, temperature and nutrients proved to be low or varying. The reason to why fungi and yeast-like microorganisms habitate in the basin depend on a low pH level average of 6.7. A method for effective settling is to withstand a cutting-pump to the container. This was tested during this project and resulted in increased levels of floating sludge during a period of time. Hence this is not a recommended treatment solution. Suggested treatment methods for further studies are to introduce protozoa to treat foaming and bulking, or by raising the pH and DO. This has not been covered within this project.
Hammarby Sjöstadsverk är en testanläggning som drivs av IVL Svenska Miljöinstitutet och KTH som består av ett avloppsreningsverk i pilotskala. Verket behandlar kommunalt avloppsvatten i en Sekvenserad Batch Reaktor (SBR) med aktiv slam processen. Den aktiva slamprocessen är en effektiv biologisk reningsmetod av avloppsvatten. Skumning och flytslam är ett stort problem för avloppsreningsverk globalt sett. Orsaken till dessa problem kan vara många, som t.ex. obalans av mikroorganismer, näringsämnen, toxicitet, pH, löst syre, temperatur, denitrifikation, nitrifikation osv. Målet med projektet är att ta reda på vilka organismer orsakar skumning och flytslam hos Hammarby Sjöstadsverk i Stockholm. Vad som orsakar dessa samt vilka kontrollmetoder som fungerar mot skumning och flytslam. Under projektet användes laboratoriet på KTH campus för att kultivera och isolera filamentösa organismer för att undersöka dessa under mikroskop och även se vilka mikroorganismer faktiskt existerar i skummet och flytslammet. Ympning av bakterier och fungi användes med hjälp av media. Isolering av vissa filamentösa organismer baserades på dess morfologi på agar plattor. Mikroskopiska observationer av skummet och isoleringar utvärderades och jämfördes med relevant litteratur om cellmorfologi. Resultaten av isolaten var fungi, jäst-liknande fungi och bakterier. Organismerna är mest sannolikt anledningen till skumning och flytslam. Andra anledningar så som datajämförelser med litteraturstudier visade att processens parametrar så som pH, löst syre, temperatur och näringsämnen visades vara låga eller varierande. Anledningen till att exempelvis fungi och jäst-liknande organismer trivdes berodde på låga pH nivåer som i snitt var 6.7. En föreslagen metod för att gynna sedimentering är att inte använda en skärpump till bassängen. Detta testades under projektets gång och resulterade under en period i ökade nivåer av flytslam. Därmed är denna metod inte att föredra. Ett förslag till en biologisk metod introduceras med att tillföra protozoer för att behandla skumning och flytslam, eller att höja pH och löst syre i bassängen. Detta har dock inte undersökts inom ramen för detta projekt.

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24

Carliell-Marquet, Cynthia. "The effect of phosphorus enrichment on fractionation of metals and phosphorus in anaerobically digested sludge." Thesis, Loughborough University, 2000. https://dspace.lboro.ac.uk/2134/17074.

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In designated nutrient-sensitive areas, phosphorus must be removed from sewage before it is discharged to the receiving water body. Phosphorus-rich sludge is generated, which is usually digested anaerobically prior to disposal. This research investigated the effect of phosphorus enrichment on metal and phosphorus fractionation in anaerobically digested sludge. The use of two complementary sequential chemical extraction procedures to measure phosphorus and metal fractionation, was a key focus of the research. The fractionation procedures were tested by sequentially extracting inorganic compounds (phosphates, sulphides and carbonates) which showed that the operationally defined metal and phosphorus fractions were not always representative of precise metal phases. Species were tentatively assigned to metal and phosphorus fractions using model compound results. Laboratory-scale batch anaerobic digestion experiments were performed, in which model compounds were used to simulate conditions of soluble and insoluble phosphorus enrichment. Soluble phosphorus at concentrations of 500 mg/l or greater was found to retard volatile solids removal and methane production in the laboratory digesters. Soluble phosphorus enrichment facilitated precipitation of calcium, magnesium and manganese but increased trace metal solubility, particularly that of chromium. Enrichment of digesters with Na2HP04 and MgCb caused struvite to precipitate in digesters containing 1000 mg/l of additional phosphorus. FeP04 enrichment of digested sludge showed that ferric iron was reduced to ferrous iron, releasing soluble phosphorus into the digester. Most of the phosphorus was reprecipitated as ferrous phosphate, causing co-precipitation of magnesium, manganese and cobalt. By contrast, A1P04 added to the digesters was stable in the sludge. Full-scale CPR sludge digestion (Fe2(S04)3 dosing) caused soluble phosphorus in the digester to decrease below 0.05 mg/l. Phosphorus remained associated with iron in the sludge fraction but soluble calcium and magnesium concentrations in the full-scale digester increased as a result of CPR sludge digestion. Comparison of laboratory and full-scale results showed that the fate of iron-precipitated phosphorus in digested sludge was primarily dependent pn the molar ratio of Fe:P in the sludge. Full-scale BPR sludge digestion showed high concentrations of soluble phosphorus in the digester and some struvite precipitation, although phosphorus was precipitated primarily as calcium phosphate, as was found to occur in the laboratory digesters simulating BPR sludge digestion.

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25

Li, Bing, and 李炳. "Occurrence, transformation and fate of antibiotics in municipal wastewater treatment plants." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46591102.

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26

Li, Yun, and 李贇. "Formation and stability of aerobic granular sludge in biological wastewater treatment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/197519.

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Aerobic sludge granulation is a new technology that has been developed for biological wastewater treatment. Compared with conventional activated sludge, aerobic granules allow better sludge-water separation and a higher biomass concentration. However, the mechanism of the transformation from sludge flocs to granular sludge under the aerobic condition is still unclear. Deterioration of aerobic granules in long-term operation is also a concern for its scale-up application. The present study was conducted to investigate the crucial factors for aerobic granulation and its underlying mechanism. In addition, the stability of aerobic granules under unfavorable conditions and the recovery of deteriorated granules in bioreactors were also studied. For formation of aerobic granules, gelation-facilitated biofilm growth was proposed as a new mechanism for the granulation process. Simulation of granule formation was performed in a well-controlled chemical system to provide an experimental proof for the proposed aerobic granulation theory. Granule formation was achieved in a particle suspension with latex microspheres for bacterial cells and alginate and peptone for extracellular polymeric substances (EPS), together with the cation addition and floc discharge. In the mixture with the dosing of alginate and a small amount of peptone, artificial gels and granules could be well formed, and the artificial granules share the similar micro-structure as the aerobic bacterial granules. However, as the dose of peptone increased, gels were not formed and only large particle flocs were produced. The formation of artificial granules proves that effective EPS interactions with cations and the subsequent gelation are crucial to aerobic granulation in bioreactors. In relation to granulation, the effect of the substrate feeding pattern on the microbial yield was tested. The results show that the bioreactor with a more frequent substrate feeding interval had a lower sludge yield than the reactor (0.45 vs. 0.55) with a less frequent feeding. The sludge fed less frequently was able to store more substrates as intracellular substances, resulting in more biomass growth. Moreover, a long feeding interval would force the biomass into the feast-famine regime, which was found to enhance microbial growth and granulation, producing granules with a compact and stable structure. For the stability of aerobic granules, various factors that would been countered in biological wastewater treatment were experimented. The results show that granules deteriorated in structure under unfavorable conditions, such as a low solution pH (pH~6.0), a high loading rate, and feed of starch instead of glucose into the bioreactors. In some deterioration cases, filamentous bacterial growth became more dominant and the granules became loose and fluffy flocs. Compared to mature granules, fresh granules were less stable and more vulnerable to the unfavorable conditions. As the granules deteriorated in structure, their surface roughness values increased considerably from 35 or less to more than 230. Under a favorable condition with a feed of sodium acetate, the deteriorated granules could be recovered in some reactors. However, deterioration of the granules caused by filamentous growth at a low pH or high loading rate could hardly be recovered.
published_or_final_version
Civil Engineering
Master
Master of Philosophy

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27

Kidby, David W. "Biogas hydrogen as an indicator of digester instability in anaerobic sewage sludge digesters." Thesis, University of Essex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280473.

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28

Buali, A. M. "Isolation and characterization of filamentous bacteria from activated sludge and their growth under feast/fast regimes." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234686.

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29

Olofsson, Ulrika. "Removal processes in sewage treatment plants : Sludge quality and treatment efficiency of structurally diverse organic compounds." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-51315.

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Large and ever-increasing numbers of chemicals, including large quantities of a broad spectrum of organic compounds are used in modern society. More than 30 000 of the more than 100 000 chemical substances registered in the EU are estimated to be daily used, of which many will be discharged into the waste-streams handled by municipal sewage treatment plants (STPs). The main objective of the work underlying this thesis was to improve understanding of the relationships between the characteristics of sewage contaminants and their sewage treatment efficiency. Further objectives were to examine the relationships between socio-economic uses of chemicals and sludge quality, and the effects of regulatory actions on sludge quality. The quality of the sewage sludge and the levels and distribution patterns of the sludge contaminants, both within and between the STPs, seem to remain quite constant over time. The overall findings indicate that the levels of contaminants in sewage sludge seem to be largely independent of the location, size and treatment techniques applied at the STPs, and generally, of the types of human activity connected to them. The total and relative concentrations of the sludge contaminants were found to be fairly constant on a dry weight basis, with some exceptions, indicating that the pollutants originate from broad usage and diffuse dispersion rather than (industrial) point sources. The proportion of cyclic methylsiloxanes recovered in sludge seems to strongly depend on their vapour pressure, which decreases with the number of siloxane units. The higher water solubility and biodegradability of organophosphorus flame retardants and plasticizers than polybrominated diphenyl ethers (PBDEs) were also reflected in lower percentages (relative to their national use) found in sludge. Significant time-trends in levels of a-third of the sludge contaminants included in the annual national measurement program were detected over a period of seven years. The levels of compounds displaying significant time-trends generally decreased following declines in the quantities used nationally. However, a quarter of these compounds showed increasing trends, of which the linear methylsiloxanes followed the same trend as used quantities. The decaBDE was also found to be increasing in sludge, probably as a result of the phase-out of pentaBDE and octaBDE. The results indicate that the STP removal efficiency of anthropogenic substances, in Sweden, is generally good and that STPs, at least those in cold climates, do not efficiently remove certain polar contaminants. A non-targeted screening (by use of environmetrics and GCxGC-TOFMS) was performed and found to fulfil the objective to assess the STP removal efficiency, with emphasis to systematically analyse which compound classes that are not efficiently removed using the current STP technology. Many polar aromatic compounds were identified to be poorly removed. The acquired data on levels, profiles and variations in sludge contaminants (sludge quality) extend both the available information and understanding of the degree and nature of sludge contamination, which should help attempts to track changes in its contaminants and revisions, if necessary, of guideline values. This thesis also contributes to improve the knowledge base for the development of future STP technologies, and that archived sewage sludge can be used in retrospective analysis of new and emerging pollutants.

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30

Stevens, Karen B. "Investigation of the microbial populations in the activated sludge of the Hoechst-Celanese wastewater treatment plant." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-01242009-063441/.

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31

Jiwani, Ashifa. "Influence of plant operating conditions on the dewaterability of surplus activated sludge." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243950.

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32

Saktaywin, Wilasinee. "Development of advanced sewage treatment process with excess sludge reduction and phosphorus recovery." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144545.

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33

Russo, Stephen Leonard. "Anaerobic treatment of a paper plant effluent." Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/21988.

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The objective of this study was to investigate the anaerobic biological treatment of an organic-bearing wastewater from a particular paper manufacturing process at laboratory scale. The process produces paper by re-pulping waste paper. Effluent from the process has a Chemical Oxygen Demand (COD) concentration of approximately 4500 mg/l with a sulphate content of approximately 300 mg SO₄²⁻/l. The upflow anaerobic sludge bed (UASB) reactor was selected for the study. Important information derived from the laboratory treatability study was: (l) the extent of COD removal possible; (2) the effluent quality; (3) the maximum COD leading rate (kgCOD/m³ reactor/day) which can be achieved while maintaining reasonable COD removal, and the influence on loading rate of temperature: (4) the nature of the sludge produced in the reactor with particular reference to the extent of pelletisation: and (5) the effect of reactor effluent recycling on alkalinity requirements.

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34

Oyekola, Oluwaseun Oyekanmi. "The enzymology of sludge solubilisation under biosulphidogenic conditions : isolation, characterisation and partial purification of endoglucanases." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1003980.

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Endoglucanases play an important function in cellulose hydrolysis and catalyse the initial attack on the polymer by randomly hydrolysing the β-1,4 glucosidic bonds within the amorphous regions of cellulose chains. Cellulolytic bacteria have been isolated and characterised from the sewage sludge and the activation of several hydrolytic enzymes under biosulphidogenic conditions of sewage hydrolysis has been reported. The aims of this study were to: identify, induce production, locate and isolate, characterise (physicochemical and kinetic) and purify endoglucanases from anaerobic biosulphidogenic sludge. The endoglucanase activities were shown to be associated with the pellet particulate matter and exhibited a pH optimum of 6 and temperature optimum of 50 °C. The enzymes were thermally more stable when immobilised to the floc matrix of the sludge than when they were released into the aqueous solution via sonication. For both immobilised and released enzymes, sulphate was slightly inhibitory; activity was reduced to 84 % and 77.5 % of the initial activity at sulphate concentrations between 200 and 1000 mg/l, respectively. Sulphite was stimulatory to the immobilised enzymes between 200 and 1000 mg/l. Sulphide stimulated the activities of the immobilised endoglucanases, but inhibited activities of the soluble enzymes above 200 mg/l. The enzyme fraction did not hydrolyse avicel (a crystalline substrate), indicating the absence of any exocellulase activity. For CMC (carboxymethylcellulose) and HEC (hydroxylethylcellulose) the enzyme had K_m,app_ values of 4 and 5.1 mg/ml respectively and V_max,app_ values of 0.297 and 0.185 μmol/min/ml respectively. Divalent ions (Cu²⁺, Ni²⁺ and Zn²⁺) proved to be inhibitory while Fe²⁺, Mg²⁺ and Ca²⁺ stimulated the enzyme at concentrations between 200 and 1000 mg/l. All the volatile fatty acids studied (acetic acid, butyric acid, propionic acid and valeric acid) inhibited the enzymes, with acetic acid eliciting the highest degree of inhibition. Sonication released ~74.9 % of the total enzyme activities into solution and this was partially purified by PEG 20 000 concentration followed by DEAE-Cellulose ion exchange chromatography, which resulted in an appreciable purity as measured by the purification factor, 25.4 fold.

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35

Kunderu, Phanindra Kumar V. "Analysis of aging effects and effectiveness of dewatering treatment methods on acid mine drainage sludge." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3805.

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Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xiii, 127 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 108-113).

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36

Riley, S. A. "An investigation into the role of hydrogen during the anaerobic digestion of domestic sewage sludge." Thesis, University of Essex, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384502.

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37

Dulin, Betsy Ennis. "Relating treatment process decisions to sludge management concerns at water plants." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/101273.

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In this study, the effects of organics removal efficiency, oxidant dose, and alum dose on aluminum hydroxide sludge characteristics were assessed. In order to maintain control over operating parameters, a continuous-flow laboratory-scale plant was operated in the laboratory with daily monitoring of pH, as well as influent and effluent turbidity, total organic carbon, and color. Sludge thickening and dewatering characteristics were found to worsen when increasing amounts of organic matter were incorporated into the sludge floe matrix. Sludge properties improved with increases in oxidant dose and decreases in alum dose and alum/influent turbidity ratio. Changes in coagulation mechanism from sweep to charge neutralization were hypothesized to be partially responsible for changes in sludge properties caused by changing alum dose. Improvements in thickening and dewatering characteristics were found to be heavily dependent upon increases in sludge floe density, as well as decreases in aggregate water content.
M.S.

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38

Lessard, Paul. "Operational water quality management : control of stormwater discharges." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47538.

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39

Sui, Peng Zhe. "Behavior of Metals in the Advanced Sewage Treatment Process with Excess Sludge Reduction and Phosphorus Recovery." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/131884.

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40

徐浩光 and Ho-kwong Chui. "Effect of substrate on the performance an sludge characteristics of UASB reactors." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B31233533.

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The Best PhD Thesis in the Faculties of Dentistry, Engineering, Medicine and Science (University of Hong Kong), Li Ka Shing Prize,1993-1995
published_or_final_version
Civil and Structural Engineering
Doctoral
Doctor of Philosophy

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41

Kaschula, Wendy A. "The effect of alternative detergent builders on the nutrient removal activated sludge sewage treatment process." Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/8454.

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Includes bibliography.
Phosphate is an essential nutrient for photosynthetic plant growth. However if over-supplied in a water body, it leads to excessive algal growth, a condition is termed eutrophication. Eutrophication is not only unsightly, but renders the water less usable. Most of the highly eutrophied water bodies with a high phosphorus load still receive up to 90 of their phosphorus input from effluents discharged by sewage treatment works (Pretorius, 1983). The phosphorus content of domestic sewage originates from two main sources, namely human waste {±60) and detergents {±40) (Heynike and Wiechers, 1986). There is an argument for a ban on phosphate in detergents to reduce the phosphate load on sewage treatment plants and thereby limit phosphate discharges via treated municipal effluent. The removal of phosphate from detergent formulations has been an effective way in many countries of reducing the phosphorous load to receiving waters. In South Africa, detergent manufacturers are anticipating consumer pressure to reformulate their detergent products to eliminate phosphate. The two possible replacements for phosphates are zeolite 4A and high surface area {HSA) calcite. High surface area (SA) calcite is not yet being used as a detergent builder, but is being seriously considered as a potential replacement for phosphate in South African detergent formulations.

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42

Katugampalage, Lalith Gamini Perera Usanee Uyasatian. "Utilization of sludge from Biyagama common wastewater treatment plant as fertilizer and soil conditioner in Sri Lanka /." Abstract, 2007. http://mulinet3.li.mahidol.ac.th/thesis/2550/cd399/4837460.pdf.

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43

Chen, Tong. "Anaerobic treatment of benzoate- and phenol- containing wastewaters /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17590607.

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44

Trahern, Patti Gremillion. "A comparative study of freeze-thaw processes for conditioning wastewater and water treatment sludges." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/53845.

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This research effort involved the application of indirect- and direct-contact, freeze-thaw conditioning techniques for improving the dewatering characteristics of both wastewater and water treatment sludges. Sludges tested included waste activated sludge, primary sewage sludge, waste activated/primary sewage sludge mixtures and alum sludge. The direct-freeze methods examined were the use of a secondary refrigerant (butane) evaporated in the sludge and the use of gas hydrate or clathrate formation by addition of Freon 12 under appropriate temperature and pressure conditions. Sludges were also frozen solid using indirect freezing methods, thawed and tested for comparative purposes. Particle size distribution and floc density measurements were used to determine changes in particle characteristics; specific resistance values and dewatered dry solids concentration were used to assess dewatering characteristics. Results of direct- and indirect-contact, freeze-thaw conditioning were compared to the effects of polymer conditioning. The results indicated that direct-freeze methods do not appear technically or economically competitive with currently accepted conditioning methods. The superior results obtained with the indirect-contact, freeze-thaw process when compared to the direct-contact processes suggested that the extent and rate of freezing may greatly influence the particle characteristics of the conditioned sludge, and thus its dewatering characteristics.
Ph. D.

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45

Chandra, Sanjay. "Evaluation of oxygen uptake rate as an activated sludge process control parameter." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/101173.

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A debate currently exists concerning whether or not oxygen uptake rate is a valid control parameter for monitoring the activated sludge process. A laboratory study was conducted to attempt to shed light on the controversy. Two bench-scale reactors were operated at steady state and under shock load. Oxygen uptake rate (OUR) was measured with the BOD bottle technique and with an on-line respirometer. The reliability of the results obtained from the BOD bottle technique was also of interest. No relationship could be deduced between effluent quality and oxygen uptake rate thereby suggesting that the latter would not be useful as a control parameter. As was concluded from the shock load data, the oxygen uptake rate varies very inconsistently at high organic loadings. It was found that the BOD bottle technique completely failed at very high organic loadings and gave meaningless results. The on-line respirometer, in spite of its high sensitivity, gave more realistic and consistent results.
M.S.

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46

Shah, Anal Shirish. "The effect of fixed film pretreatment on activated sludge stability during the treatment of cellulose acetate wastewater." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-05092009-040748/.

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47

Hamon, Jeff Richard. "The effect of treatment process variations on the thickening and dewatering characteristics of water plant sludges." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/94459.

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The effects of coagulation pH and influent turbidity on aluminum and ferric hydroxide sludge macro-and micro-properties were investigated. To reduce the number of variables, sludges were produced under specific operating conditions in a 400 L/day continuous-flow pilot-plant. The effluent turbidity was monitored to evaluate process modifications. Sludge thickening and dewatering characteristics improved with reductions in the coagulation pH, increases in the influent turbidity levels, and/or reductions in the coagulant dose/influent turbidity ratio. Sludge floc/ aggregate density was the dominant sludge micro-property; sludges with superior thickening and dewatering characteristics were composed of higher density flocs/aggregates. A trade-off appeared to exist between improved sludge characteristics and effluent quality; however, verification will require additional research.
M.S.

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48

Williams, Yasheemah. "Treatment of poultry slaughterhouse wastewater using an expanded granular sludge bed anaerobic digester coupled with anoxic/aerobic hybrid side stream ultrafiltration membrane bioreactor." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2758.

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Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2017.
For more than a decade, poultry product consumption increased in developed and developing countries, with more than 470 new slaughterhouses being constructed in South Africa (SA). Customer demand for poultry products resulted in a rapidly growing poultry industry, with consequential increases in the quantity of organic solid and liquid waste being produced from the poultry slaughterhouses. Annually, the productivity and profitability within the livestock production sector has increased, an evaluation based on the number of slaughtered and sold animals. Potable water is required for these animals, resulting in the generation of high strength wastewaters. Instantaneous disposal of such wastewaters into the environment is concerning as it results in odour and the spreading of diseases in local rivers and freshwater sources. The generated poultry slaughterhouse wastewater (PSW) contains a high quantity of biodegradable organic, suspended and colloidal matter in the form of proteins, fats, oil and grease (FOG), protein from meat, blood, skin, and feathers, resulting in high Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), which can contribute to environmental deterioration if not treated adequately before discharge. On average, PSW contains a high concentration of BOD, COD, nitrogen, pathogenic and non-pathogenic viruses, bacteria and parasites, including their eggs. These characteristics make PSW highly polluted with a large quantity of bird carcass debris including FOG. Due to the high concentration of organic matter and suspended solids in the wastewater, it is necessary to pre-treat the PSW prior to sequential anaerobic treatment. Most of the contaminants present in the PSW can be reduced by means of numerous treatment steps, i.e. physical, chemical and biological treatment. For this study, biological treatment methods, physical separation methods, and a membrane bioreactor system, were used to treat PSW. The biological treatment methods used were an anaerobic digester (AD) followed by a single stage nitrification/denitrification reactor and then a third stage in which an ultrafiltration (UF) and Microfiltration (MF) membrane bioreactor (MBR) was used. The AD used was an Expanded Granular sludge Bed Reactor (EGSB) as anaerobic digestion is one of the most effective biological wastewater treatment methods used, as it reduces the organic matter to even produce biogas as a renewable energy source. The basis of anaerobic treatment method relies on suitable bacteria cultivated in the absence of dissolved oxygen, facilitating decomposition of organic matter into a renewable source such as biogas. Similarly, biological nitrification/denitrification processes for the removal of total nitrogen (TN) in wastewater has become one of the most commonly used processes within the wastewater treatment sector. Nitrification and denitrification processes can be performed by some microorganisms within the wastewater in Wastewater Treatment Plants (WWTPs) The PSW used was collected at different times from a local poultry slaughterhouse in the Western Cape (South Africa) and stored in a refrigerator at 4°C until it was fed to the first stage of the treatment which was the EGSB. Before being fed to the EGSB, the PSW was filtered with a sieve to remove feathers and agglomerated FOG to avoid clogging of the tubing. The EGSB was inoculated with 0.747 L anaerobic granular sludge, had a working volume of 2.7 L, an inner diameter of 0.065 m and a height of 0.872 m respectively. Ceramic marbles with an average diameter of 0.0157m were placed at the bottom of the bioreactor as packing for the underdrain and to maintain the granular sludge within the heated section of the bioreactor. The EGSB was fed with three types of PSW: 50% (v/v), 70% (v/v), which was diluted with distilled water. Thereafter once the system stabilised the reactor was fed with undiluted PSW (100%). Each dilution was operated at different Hydraulic Retention Times (HRTs) and Organic Loading Rates (OLRs), with average HRTs used being 62.5, 57.5 and 49.65 h. Furthermore, the average OLRs were 1, 2 and 3 g tCOD/L.day respectively. The performance of the EGSB was determined using tCOD, Total Suspended Solids (TSS) and FOG, with overall averaged removal rates for these constituents being 69%, 98% and 92% respectively. The highest tCOD removal of 93 % (optimal efficiency) was obtained at an average HRT of 57.5 h with a corresponding average OLR of 2 g tCOD/L.day.

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49

Karius, Ralf. "Developing an integrated concept for sewage sludge treatment and disposal from municipal wastewater treatment systems in (peri-)urban areas in Vietnam." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-71141.

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The study took place in Vietnam at Hanoi University of Science in the framework of the DAAD (German Academic Exchange Service) – “An advancement of the German-Vietnamese University partnerships”. The research has been supported by the program: “Wastewater and Solid Waste Management in Provincial Centers” and belongs to its technical component. The present diploma thesis elaborates the current situation of sewage sludge management in Vietnam and is dealing with sludge characteristics from both domestic sewage treatment facilities and septic tanks. During the research, different treatment components and treatment facilities have been analyzed to carry out a comprehensive survey of sewage sludge types. In this thesis, a guideline (draft) was developed as a main result, which can be helpful to bridge the legislative gap for sewage sludge re-use in Vietnam. In conclusion, an integrated concept has been developed, which recommends the application of selected proceeding elements to treat sewage sludge and the further utilization of re-useable materials in agriculture in a controlled and environmentally-safe manner
Die Diplomarbeit wurde im Rahmen des Deutsch-Vietnamesischem Auslandsaustauschprogramms an der „Hanoi University of Science“ verfasst. Dieses Vorhaben wurde unterstützt von dem DAAD (Deutschen Akademischen Austausch Dienst), und ist im technischem Bereich des Programms “Wastewater and Solid Waste Management in Provincial Centers“ einzugliedern. Die vorstehende Diplomarbeit beschäftigt sich mit dem aktuellen Klärschlammmanagement in Vietnam und liefert dabei detaillierte Resultate zu verschiedenen Klarschlammtypen aus kommunalen Abwasserbehandlungsanlagen. Bei den Untersuchungen wurden verschiedene Abwasser- und Klärschlammbehandlungsanlagen untersucht, um einen Überblick zu den gebräuchlichen Behandlungsmethoden in Vietnam zu erarbeiten. Zusätzlich wurden die institutionellen und rechtlichen Rahmenbedingungen überprüft. Der Entwurf einer Verordnung zur Verwertung von Klärschlamm in der Landwirtschaft wurde vorgelegt, um eine bestehende rechtliche Lücke in Vietnam zu schließen. Mit dieser Arbeit wurde ein integriertes Konzept entwickelt, welches mittels verschiedene verfahrenstechnische Elemente den Klärschlamm behandelt und darauffolgend das verwertbare Material in ausgewählten landwirtschaftlichen Flächen in einer kontrollierten und umweltschonenden Weise verwertet

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50

Mlambo, Patricia Zanele. "Exploring the fertiliser potential of biosolids from algae integrated wastewater treatment systems." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013342.

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High rate algae oxidation ponds (HRAOP) for domestic wastewater treatment generate biosolids that are predominantly microalgae. Consequently, HRAOP biosolids are enriched with minerals, amino acids, nutrients and possibly contain plant growth regulator (PGR)-like substances, which makes HRAOP biosolids attractive as fertiliser or PGR. This study investigated HRAOP biosolids as a starting material for a natural, cost-effective and readily-available eco-friendly organic fertiliser and/or PGRs. Various HRAOP extract formulations were prepared and their effect on plant growth and development was evaluated using selected bioassays. Initial screening included assessing the effect on change in specific leaf area, radish cotyledon expansion as an indicator of PGR-like activity, and seed germination index (GI). More detailed studies on fertiliser efficacy and PGR-like activity utilised bean (Phaseolus vulgaris) and tomato (Solanum lycopersicum) plants. Combined effects of sonicated (S) and 40% v/v methanol (M) extract (5:1 SM) had impressive plant responses, comparable to Hoagland solution (HS). Other potentially fertiliser formulations included 0.5% M, 1% M, 2.5% S and 5% S formulations. The 5:1 SM and 5% S showed greater PGR-like activity, promoting cotyledon expansion by 459 ± 0.02% and 362 ± 0.01%, respectively. GI data showed that none of the formulations negatively impacted germination. Further investigation showed that the 5% S formulation increased leaf length, width and area by 6.69 ± 0.24, 6.21 ± 0.2 mm and 41.55 ± 0.2 mm². All formulated fertiliser extracts had no adverse effect on chlorophyll content and plant nutrient balance as indicated by C:N (8-10:1) ratio. In addition, plants appeared to actively mobilise nutrients to regions where needed as evidenced by a shift in shoot: root ratio depending on C, N and water availability. Furthermore, 5% S caused a 75% increase in tomato productivity and had no effect on bean productivity. Whereas, 5:1 SM and 1% M formulation improved bean pod production by 33.3% and 11%, respectively but did not affect tomato production. Harvest index (HI) however indicated a 3% reduction in tomato productivity with 5:1 SM and little or no enhancement in bean productivity with both 5:1 SM and 5% S treatments. Bean plants treated with 5:1 SM and 5% S produced larger fruits, which could be an indication of the presence of a PGR effect. Overall, HRAOP biosolids extracts prepared and investigated in this study demonstrated both fertiliser characteristics and PGR-like activity with performances comparable and in some cases exceeding that of commercial products. However additional research is needed to confirm presence of PGR-like activities and fertiliser efficacy.

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