Two shallow-placed low pressure distribution (LPD) systems were evaluated in soils that were marginally suited for a conventional on-site wastewater disposal system (OSWDS) because of low hydraulic conductivity and shallow depth of soil to bedrock. The soils used for this study were Edom (fine, illitic, mesic, Typic Hapludult) and Penn-Bucks soil (fine-loamy, mixed, mesic, ultic Hapludult). In the Edam soil, the LPD system was installed with four subsystem designs operating: a narrow trench design with a design loading rate of 17.5 Lpd/m², and three designs based on Virginia regulations with design loading rates of 9.0 Lpd/m², 4.5 Lpd/m², and 5.7 Lpd/m². In the Penn-Bucks soil, the LPD system was installed with three subsystem designs operating: a narrow trench design with a design loading rate of 30.6 Lpd/m², and two designs based on Virginia regulations with design loading rates of 14.3 Lpd/m², and 7.3 Lpd/m². The evaluation was conducted under different moisture and temperature conditions (summer of 1989, and the winter of 1990), and focused on the fate and transport below each system of two antibiotic resistant <i>Escherichia coli</i> strains and two host-specific bacteriophage strains. The potential loss of N0₃"-N through the biological process of denitrification was also examined. In the Edom soil, a narrow trench design, and designs based on the Virginia regulation all removed >99.9% of the bacterial and viral tracers during the summer of 1989, and >99% during the winter of 1990 throughout a 152 cm depth. The potential loss of N0₃"-N in the Edom soil by denitrification was estimated to be 38%. In the Penn-Bucks soil, the narrow trench design failed within six months of installation because the effluent loading rate was too high to permit infiltration through the silty clay loam soil, once biological clogging developed with the subsequent decrease in infiltrative capacity. The lower Virginia loading rate was mlore effective at microbial retention with >99.9% removal throughout a 114 cm depth in both the summer of 1989 and the winter of 1990. The normal Virginia loading rate removed> 99% of the bacterial and viral tracers throughout a 102 cm depth in both the summer of 1989 and the winter of 1990. The overall loss of N0₃"-N in the Penn-Bucks soil through denitrification was estimated at 67%. / Master of Science

Odorous gases such as hydrogen sulfide have long been associated with wastewater treatment plants, especially those with long forced mains which allow septic conditions to develop. With the encroachment of urban and suburban populations, many wastewater treatment plants are no longer located far enough from residential areas to prevent odor problems. This has lead to renewed efforts to develop odor control techniques. The application of high energy coronas as a means to oxidize odorous gases has been limited by the relatively small size of the corona region around a given charged wire, approximately 1 centimeter at an applied voltage of 35 kilovolts. Attempts to enlarge the effective corona region by spacing wires such that their coronas would overlap have failed due to corona extinction, the destructive interference of the electric fields surrounding adjacent charged wires. This study demonstrates that corona extinction can be avoided in a system of closely spaced wires flanked by grounded plates if the wires are energized individually instead of' simultaneously. By employing a rapid load-switching technique an essentially continuous corona sheet can be produced. A bench-scale device utilizing the rapid switching principle was constructed and its ability to remove odorous gases, including hydrogen sulfide, was demonstrated. The influence of parameters such as flowrate, inlet concentration, switching frequency, temperature, and humidity on removal efficiency was evaluated. / Ph. D. / incomplete_metadata

The nature of this problem divides itself into two parts, that is, a study of the old sewage plants in operation through the summer of 1947 and a study of the new plant put in operation during the fall of the same year.

published_or_final_version / Civil and Structural Engineering / Master / Master of Philosophy

Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.E.S.)--Evergreen State College, 2009. / Title from title screen (viewed 4/15/2010). Includes bibliographical references (leaves 63-67).

Thesis (M. Sc.)--University of Hong Kong, 1997. / Includes bibliographical references (leaf 84-86).

M. Tech. (Chemical Engineering) / The usual target of an upgrading process using membrane is to produce a retentate stream, the product, with high CH4 concentration. This work presents a simulation of two possible membrane configurations, single stage without recycle (SSWR) and double stage with permeate recycle (DSPR), of an existing operational biogas upgrading plant. The simulation was conducted using ChemCAD and AlmeeSoft gas permeation software to investigate the performance of the configurations on product purity, recovery and required compressor power with a view to determine the optimal operational conditions for maximising the concentration of CH4 and its recovery. Thereafter, an economic assessment on the optimal configuration was conducted to determine the gas processing cost (GPC), the profitability of producing biomethane and cost-benefit of utilising biomethane as a vehicular fuel. The simulation was validated against plant data with a maximum percentage error of 2.64%. Increasing CO2 in feed reduced product recovery and purity. Increasing feed pressure and selectivity increased product recovery and purity up to the pressure limit of the membrane module. Increasing feed flow rate increased product recovery but reduces purity. In both configurations, increasing CO2 in the feed and increasing feed pressure increased the GPC. However, increasing feed flow rate reduced the GPC. The overall performance of DSPR configuration was much higher due to increased trans-membrane area available for separation. At optimal conditions, a product purity of 91% and 96% CH4 recovery was achieved from the initial plant result of 87.2% product purity and 91.16% CH4 recovery. The total compression duty was 141 kW. The GPC was $0.46/m3 of biomethane. The cumulative discounted NPV, IRR and BCR for producing biomethane was R15,240,343, 22.41% and 2.05 respectively, with a break-even in the 5th year after plant start-up considering a prime lending rate at 9%. Using CBG instead of gasoline saves 34% of annual fuel cost with a payback period of one year and three months for the cost of retrofitting the vehicle.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: A severely polluted industrial effluent is generated by the local gelatinmanufacturing industry. Due to increasingly stringent restrictions on discharge qualities enforced by the National Water Act of 1998 and National Environmental Management Act of 1998, as well as increasing trade-effluent charges implemented via the Local Municipal Bylaws, the industry is compelled to consider a system to pre-treat the polluted effluent. A study was undertaken to examine the viability of anaerobic treatment of the gelatin-manufacturing effluent, since the anaerobic digestion technology is well recognised for the high success rate in the treatment of high-strength, complex wastewaters. Various laboratory and pilot-scale studies were done, using different hybrid Upflow Anaerobic Sludge Blanket (UASB) and contact designs. Two mesophilic laboratory-scale hybrid UASB digester designs, fitted with polyethylene (AD-1) and polyurethane (AD-2), performed well at a hydraulic retention time (HRT) of 1.0 d. Chemical oxygen demand (COD) removal efficiencies of up to 90% (avg. 53%) for AD-1 and 83% (avg. 60%) for AD-2 at organic loading rates (OLR) of 9.56 and 4.62 kg COD.m-3.d-1, respectively, were obtained. High sulphate (S04) removal efficiencies of up to 96% (avg. 86%) for AD-1 and 98% (avg. 82%) for AD-2 were also achieved, respectively. A maximum total solid (TS) removal of 65% (avg. 25%) for AD-1 and 62% (avg. 28%) for AD-2 was reported. An average methane content of 80% (AD-1) and 79% (AD-2) with average methane yields per COD removed of 2.19 and 1.86 m3. kg CODremoved.df-o1r AD-1 and AD-2 were found, respectively. When the same digesters (AD-1 and AD-2) were combined in a muItiphase series configuration, a total COD removal efficiency of up to 97% (avg. 80%) at an OLR of 8.32 kg COD.m-3.d-1,was achieved. Excellent total S04 removals of 96% (avg. 69%) were accomplished. Up to 82% TS (avg. 29%) was also removed during this study and the biogas consisted of 89% methane (avg. 79%). For this multi-phase combination up to 92% volatile fatty acids (VFA) (avg. 48%) were removed, indicating possible selective phase separation of the respective fatty acid producing/utilising bacterial populations. The use of a laboratory-scale UASB bioreactor with recirculation, resulted in COD removal efficiencies of up to 96% (avg. 51%) at an HRT of 3.0 d, and 95% (avg. 54%) at a HRT of 1.0 d. Low performances were generally found, with average S04 and TS removals of 59% (max. 97%) and 26% (max. 67%), respectively at an HRT of 1.0 d. The biogas production was very low throughout the study (0.05 - 0.63 I,d-1 ). A pilot-scale UASB reactor (300 I) was constructed and performed satisfactory with a 58% average COD removal and maximum of 96%. S04 and TS removals up to 96% (avg. 44%) and 93% (avg. 63%), respectively, were obtained. The methane content of the biogas was 85%. The pilot-scale studies were conducted under actual field conditions, where various shock and organic loads had to be absorbed by the system. The pilot-scale contact configuration (300 I) did not perform satisfactory as a result of continuous blockages experienced in the feed and recirculation lines. Maximum COD, S04, VFA and TS removal efficiencies of 41% (avg. 27%), 62% (avg. 41%), 64% (avg. 27%) and 39% (avg. 21%), respectively, were obtained. The results of all the studies indicated acceptable COD removals with increasing OLR's. Indications of the presence of active methanogenic and sulphate-reducing bacterial populations were apparent throughout the studies. One possibility for the successful start-up and commissioning of the anaerobic reactors was the use of a well-adjusted biomass, which consisted of highly selected and adapted microbial consortium for the specific gelatinmanufacturing effluent. It was clear from this study that gelatin-manufacturing effluent can be treated successfully, especially with the use of the UASB design. A welldefined data base was constructed which could be of great value for further upscaling to a full-scale digester. / AFRIKAANSE OPSOMMING: 'n Hoogs besoedelde industriele uitvloeisel word gegenereer deur die plaaslike gelatien-vervaardigings industrie. As gevolg van toenemende streng beperkings op die kwaliteit van uitvloeisels wat bepaal word deur die Nasionale Water Wet van 1998 en Nasionale Omgewings Bestuurs Wet van 1998, asook toenemende munisipale heffings wat geimplementeer word via Plaaslike Munisipale Wette, word die industrie verplig om die uitvloeisel vooraf te behandel. 'n Studie is onderneem om die lewensvatbaarheid van anaërobe behandeling van gelatien-vervaardigings uitvloeisel te ondersoek, aangesien anaërobe verterings tegnologie alombekend is vir die goeie sukses behaal in die behandeling van hoë-sterkte, komplekse uitvloeisels. Verskeie laboratorium- en loods-skaal studies is gedoen, met verskillende hibried Opvloei Anaërobe Slykkombers (OAS) en kontak ontwerpe. Goeie werksverrigting was verkry by 'n hidroliese retensie tyd (HRT) van 1.0 d met twee mesofiliese laboratorium-skaal hibried OAS verteerder ontwerpe wat uitgevoer was met poli-etileen (AD-1) en poli-uretaan (AD-2) materiaal. Chemiese suurstof behoefte (CSB) verwyderings van so hoog as 90% (gem. 53%) vir AD-1 en 83% (gem. 60%) vir AD-2 by organiese ladingstempo's (OLT) van 9.56 en 4.62 kg CSB.m-3.d-1,was onderskeidelik verkry. Hoë sulfaat (S04) verwyderings van tot 96% (gem. 86%) vir AD-1 en 98% (gem. 82%) vir AD-2 was ook onderskeidelik verkry. 'n Maksimum totale vaste stof (TVS) verwydering van 65% (gem. 25%) vir AD-1 en 62% (gem. 28%) vir AD-2 is gerapporteer. 'n Gemiddelde metaan inhoud van 80% (AD-1) en 79% (AD-2) met 'n gemiddelde metaan opbrengs per CSB verwyder van 2.19 en 1.86 m3.kg CSBverwyder.dv-i1r AD-1 en AD-2, was onderskeidelik gevind. Met die aanwending van dieselfde twee verteerders (AD-1 en AD-2) in 'n series gekoppelde multi-fase konfigurasie, is 'n totale CSB verwydering so hoog as 97% (gem. 80%) verkry by 'n OLT van 8.32 kg CSB.m-3.d-1. Uitstekende totale S04 verwydering van 96% (gem. 69%) is behaal. Tot 82% TVS (gem. 29%) was vewyder gedurende die studie en die biogas het uit 89% metaan (gem. 79%) bestaan. Vir die multi-fase kombinasie is 'n maksimum van 92% vlugtige vetsure (WS) (gem. 48%) verwyder, wat dui op die moontlike skeiding van selektiewe fases van die onderskeie vetsuur produserende/verbruiker bakteriële populasies. CSB verwydering van tot 96% (gem. 51%) by 'n HRT van 3.0 d en 95% (gem. 54%) met 'n HRT van 1.0 d was verkry, tydens die gebruik van In laboratorium-skaal OAS bioreaktor met hersirkulasie. Lae werksverrigting was oor die algemeen waargeneem, met gemiddelde S04 en TVS verwyderings van 59% (maks. 97%) en 26% (maks. 67%) by In HRT van 1.0 d. Die biogas produksie was baie laag gedurende die studie (0.05 - 0.63 I,d-\ In Loods-skaal OAS verteerder was opgerig en bevredigende resultate was verkry met In gemiddeld van 58% CSB verwydering en maksimum van 96%. S04 en TVS verwyderings so hoog as 96% (gem. 44%) en 93% (gem. 63%) is onderskeidelik verkry. Die metaan inhoud van die biogas was 85%. Die loods-skaal studie was uitgevoer gedurende ware veld kondisies, waartydens verskeie skok en organiese ladings deur die sisteem geabsorbeer is. Die loods-skaal kontak konfigurasie (300 I) het nie bevredigende resultate getoon nie, as gevolg van voortdurende blokkasies wat ondervind is in die toevoer en hersirkulasie pype. Maksimum CSB, S04, WS en TVS verwyderings van 41% (gem. 27%), 62% (gem. 41%), 64% (gem. 27%) en 39% (gem. 21%) was onderskeidelik verkry. Die resultate van al die studies het aanvaarbare CSB verwydering aangedui by toenemende OLT's. Indikasies van aktiewe metanogene en sulfaat-reduserende bakteriële populasies was ook teenwoordig gedurende die studies. Die suksesvolle aansit-prosedure en begin van die anaërobe verteerders kan toegeskryf word aan die gebruik van In goed aangepaste biomassa, wat uit hoogs selektiewe en aangepaste mikrobiese populasies vir die spesifieke uitvloeisel bestaan. Hierdie studie het getoon dat gelatien-vervaardigings uitvloeisel suksesvol met die OAS ontwerp behandel kan word. In Goed gedefinieerde data basis kan voorsien word, wat van groot waarde sal wees vir verdere opgradering na In volskaalse verteerder.

Thesis (MPhil)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: This study undertakes a scientific investigation into the social and environmental problems encountered by the Oshiwana Penduka informal settlement as a result of the lack of a proper sanitation system. This informal settlement is located on the periphery of the municipal boundaries of the town of Mariental in Southern Namibia, about 270 kilometres south of the capital, Windhoek. The unique problem faced by the settlement is the absence of sanitation facilities or sewage system as a method of solid waste management. Needless to say, the informal settlement is characterized by overcrowding, poor sanitation, lack of housing, unemployment and poverty. From the literature review, it became clear that inadequate water supply and sanitation posed serious implications to the physical environment and human health. The literature also reveals that these core challenges are propagated by the continual influx of people to urban areas and the re-birth of irregular settlements. In light of the above, the problem statements to be addressed are the following, namely: what is the impact of the absence of a proper and sustainable sanitation system on the inhabitants of the Oshiwana Penduka informal settlement and what can be done by the Mariental Municipality to address the concerns raised? The key research methods applied for this study entails individual semi-structured questionnaires and key informant groups. The answers to the interviewed questions are highlighted in chapter four and the interpretation of the research findings are constituted in the latter chapter. The hypothesis was proven false and the new model of thinking generated is suggesting that the prevailing social and environmental problems are caused by the absence of toilet facilities. It is evident to note from the study results that the negative social impact, which is being attributed by inadequate sanitation in the informal settlement, is severe and lethal to human health. In order to prove the hypothesis, data has been collected at household levels from the informal settlers. Despite the survey results which support the conventional water borne sanitation as the most preferred sanitation system, vacuum system as an ecological sanitation technology is recommended for this informal settlement. This particular sanitation system works on the principle of enhancing water conservation, recycling, reduction of health, and promotes environmental integrity. / AFRIKAANSE OPSOMMING: Hierdie studie onderneem ʼn wetenskaplike ondersoek na die sosiale en omgewingsprobleme, wat ondervind word deur die Oshiwana Penduka informele nedersetting en die gebrek aan ʼn behoorlike sanitasie stelsel. Hierdie betrokke informele nedersetting is geleë aan die buitewyke van die munisipale grense van die dorp Mariental. Die dorp Mariental is geleë in die suidelike deel van Namibië, ongeveer 270 km suid van die hoofstad Windhoek. Die unieke problem wat hierdie nedersetting ondervind is die afwesigheid van sanitasie fasiliteite of ʼn rioolstelsel wat ʼn soliede metode van goeie rioolbeheer is. Hierdie nedersetting word gekenmerk deur oorbevolking, swak sanitasie, gebrek aan behuising, werkloosheid en armoede. Vanuit die literatuurstudie, het dit aan die lig gekom dat onvoldoende water toevoer en sanitasie ernstige implikasies vir die fisiese omgewing en die menslike gesondheid inhou. Die literatuur het ook aan die lig gebring dat hierdie basiese probleme vererger word deur die aanhoudende invloei van mense na die stedelike gebiede. In die lig van bogenoemde, is die probleemstelling wat aangespreek moet word, soos volg: wat is die gevolge van ʼn gebrek aan ʼn behoorlike en volhoubare sanitasiestelsel vir die inwoners van die informele nedersetting en wat kan die Mariental Munisipaliteit doen om hierdie problem aan te spreek? Die navorsingsmetode wat aangewend word bevat individuele semi- gestruktureerde vraelyste en sleutel fokusgroepe. Die antwoorde op die onderhoudsvraelyste word vervat in hoofstuk vier en die vertolking van die navorsingsbevinding word in die daaropvolgende hoofstuk aangebied. Die hipoteses was verkeerd bewys en die alternatief wat gegenereer is, stel voor dat die bestaande sosiale en omgewingsprobleme veroorsaak word deur die afwesigheid van toilet fasiliteite. Ten spyte van die navorsingsresultate, wat ʼn watersanitasiestelsel as die meeste verkose stelsel ondersteun, word ʼn suigstelsel as ekologiese volhoubare tegnologie vir hierdie informele nedersetting aanbeveel. Hierdie betrokke sanitasiestelsel toon verskeie voordele, onder andere bewaring van water, vermindering van gesondheidsprobleme en die bevordering van omgewingsvolhoubaarheid.