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Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2005. / The thesis reports the investigation of various distillery processes and wastewater streams. The aim was to evaluate the processes and thereafter design interventions for improved wastewater treatment at the respective distilleries. An integrated environmental approach was adopted based on the principle that prevention of pollution is the preferred option and end-of-pipe treatment the least favoured option. As such, feed material to the processes was studied to determine whether some of the components that are not required in the distillation process could in fact be removed prior to entering the system. The results indicate that organic constituents such as phenol and tartaric acid could be removed using physico-chemical and biological treatment methods. The treatment of effluent was studied using an Upflow Anaerobic Sludge Blanket (UASB) set-up to determine the reduction in Chemical Oxygen Demand (COD) in the wastewater. Thereafter the UASB treated effluent was exposed to aeration for further treatment. Summary of conclusions • Pretreatment of wine feed material with calcium hydroxide is effective in removal of 98% tartaric acid, 30% COD and a total phenol content of 57%. • Bio-augmentation results showed that the soil inoculum was the most effective treatment method with reductions of 61% COD at a temperature of 30°C, tartaric acid removal of 98% at the same temperature and 25% reduction in total phenol at 26°C. • UASB was effective with soil inoculum and removed approximately 90% of COD although operational problems were experienced and hindered the operation of the plant. • Aeration of UASB effluent further reduced the COD by a further 60% with a total COD reduction of 96% after both UASB and aeration treatment. • Effective reduction of total phosphorus by 70% and the total phenol content by 80% was achieved by UASB treatment followed by aeration.

Using the 1990, 1994 and 1998 Congressional mid-term elections, this study looks at whether the type of primary system in a person's state has an effect on whether or not that person will vote in the general election. The five types of primary systems (closed, semi-closed, semiopen, open and blanket) are explained as well as traditional factors for likelihood of voting. It is hypothesized that the more closed the primary system, the less likely a person is to vote. Data analysis shows that when significant, living in an open primary state does significantly increase the likelihood that a person will vote. However, primary type was significant in only six of the nine models studied here.

Este trabalho apresenta e discute os resultados obtidos na operação de um reator anaeróbico com manta de lodo (UASB) de 10,5 L, alimentado continuamente com substrato sintético (DQO = 2000 mg/L) e submetido ao aumento progressivo da concentração de sulfato (de 25 a 10000 mg \'SO IND.4\'POT.2-\'/L). A vazão de 16 L/dia, corresponde ao tempo de detenção hidráulico (e) de 15,6 h foi mantida constante durante os 10 meses do experimento. O monitoramento da operação do reator incluiu a determinação dos principais parâmetros do processo, visando detectar a inibição da metanogênese pelas bactérias redutoras de sulfato (BRS) que competem, com as metanogênicas, pelos mesmos substratos. Constatou-se estimulação do processo até a concentração de 400 mg \'SO IND.4\'POT.2-\'/L, a partir da qual ocorreram sequencias de quedas de eficiência seguidas de recuperação do reator, mantendo sempre a eficiência média de remoção de DQO acima de 80%. Embora a atividade metanogênica tenha sido parcialmente afetada, os balanços de \'SO IND.4\'POT.2-\' mostraram que a redução do sulfato não foi o principal responsável pela inibição ocorrida. / This thesis presents and discuss the results obtained during the operation of a 10.5 L upflow sludge blanket reactor, continuously fed with synthetic substrate (COD = 2,000 mg/L), which was subjected to step-increase of sulfate concentrations ranging from 25 to 10,000 mg \'SO IND.4\'POT.2-\'/L. The flow-rate of 16 L/d corresponding to a hydraulic detention of 15.6 h, was kept constant throughout the 10 months of experimentation. Operation monitoring included the determination of the main process parameters, aiming to detected the inhibition of lhe methanogenesis by the sulfate reducing bacteria (SRB) which autocompete the methanogens in the presence of common substrates. Stimulation effects were obseved up to the sulfate concentration of the 400 mg.\'SO IND.4\'POT.2-\'/L. Further on, sequences of falls of efficiency followed by restoration of the reactor performance defined the behavior pattern of the reactor, which maintained an average COD removal efficiency higher than 80%. Although the methanogenic activity has been parcially affected, \'SO IND.4\'POT2-\' balances showed that the sulfate reduction activity was not the main process responsible for such inhibition.

Magister Artium - MA (History) / The aim of this mini-thesis is to interrogate an incident that happened in Lesotho in 1982, where the South African Defence Force (SADF) invaded the capital, Maseru, under the guise of searching for ANC operatives and killed 42 people thirty of whom were South Africans, while the remaining 12 were Basotho citizens. A particular concern is how traumatic events are represented by witnesses, how they remember or, rather talk, about the event, and the secrets and silences which may arise. A lack of literature on this period of Lesotho's history and the Raid itself has necessitated a wider engagement with Raid as it is the first raid that involved the SADF, perpetrated in Lesotho. The first chapter draws out and highlights the complicated relationships between Lesotho and South Africa and their respective main opposition political parties, namely, the Basotho Congress Party and the overall South African liberation movements including the African National Congress and the Pan Africanist Congress. This brings me to conclude that the 1982 Maseru Raid and subsequent ones took place on the back of a period that was burdened with gross human rights violations in Lesotho and, this can be argued to explain why the Raid is not particularly spoken about.

Orientador: Roberto Alves Oliveira / Resumo: A co-digestão de água residuária da bovinocultura leiteira (ARBL) e água residuária do beneficiamento do café (ARC) em reatores anaeróbios de fluxo ascendente com manta de lodos (UASB, R1 e R2), em série, é inédita e importante para o desenvolvimento dos setores envolvidos. Foram utilizadas proporções de 100:0; 85:15, 70:30 e 50:50 de ARBL:ARC no afluente dos reatores UASB e aplicados tempo de detenção hidráulica (TDH) de 2 (R1) e 4 (R2) dias. Isto proporcionou cargas orgânicas volumétricas (COV) de 11,9 (valor médio obtido nos testes 1 e 2, sem adição de ARC); 12,9 (teste 3); 14,0 (teste 4) e 21,3 (teste 5) g DQOtotal (L d)-1 no R1. As maiores produções volumétricas de metano, de até 0,89 L CH4 (L reator d)-1 foram obtidas com COV de 14,0 g DQO (L d)-1. As concentrações médias de fenóis totais no afluente variaram entre 6 e 132 mg L-1 e as eficiências médias de remoção nos reatores UASB, em dois estágios, foram de 35 a 52% com concentração de 50 mg L-1 para efluente do R2 após adição de ARC que contém elevadas concentrações de fenóis totais e apresentam toxicidade ao tratamento anaeróbio podendo afetar a estabilidade do processo. O sistema foi eficiente para remoção de ovos de helmintos. Os Domínios Bacteria e Archaea, as Ordens Methanobacteriales, Methanomicrobiales e Methanosarcinales e as Famílias Methanosaetaceae e Methanosarcinaceae se apresentaram de forma sincrônica e equilibrada na co-digestão anaeróbia dos resíduos estudados. / Abstract: The co-digestion of dairy manure wastewater (DMW) and coffee processing wastewater (CPW) in up flow anaerobic sludge blanket (UASB, R1 and R2) in series is unprecedented and important for the development of the sectors involved. Proportions of 100: 0; 85:15, 70:30 and 50:50 DMW:CPW were used in the UASB reactors influent and applied hydraulic retention time (HRT) of 2 (R1) and 4 (R2) days. This provided organic loading rate (OLR) of 11.9 (mean value obtained in tests 1 and 2, without addition of CPW); 12.9 (test 3); 14.0 (test 4) and 21.3 (test 5) g CODtotal (L d) -1 on R1. The highest volumetric methane yields of up to 0.89 L CH4 (L reactor d) -1 were obtained with OLR of 14.0 g COD (L d) -1. The mean concentrations of total phenols in the affluent ranged from 6-132 mg L-1 and the mean removal efficiencies in two-stage UASB reactors were 35-52% with 50 mg L-1 concentration for R2 effluent after addition of ARC containing high concentrations of total phenols and toxicity to anaerobic treatment may affect process stability. The system was efficient for removal of helminth eggs. The Bacteria and Archaea Domains, the Methanobacteriales, Methanomicrobiales and Methanosarcinales Orders, and the Methanosaetaceae and Methanosarcinaceae families were presented in a synchronic and balanced manner in the anaerobic co-digestion of the residues studied. / Mestre

Whey permeate was anaerobically digested in laboratory scale upflow anaerobic sludge blanket reactors. Nine hydraulic retention times between 5 and 0.2 days were examined with a fixed influent concentration of 10.6 ± 0.2 g COD/L. Chemical oxygen demand removal efficiency ranged from 99.0 to 18.9% and maximum production rate of methane gas was 2.67 L/L/day at a hydraulic loading rate of 12.97 kg COD/m3/day. About 70% of the chemical oxygen demand removed was converted to methane. Both the nonlinear least square method with 95% confidence interval and linear regression were used to evaluate kinetic coefficients. The maximum substrate utilization rate, k, and half saturation coefficient, KL, were determined to be 1.269 ± 0.163 Kg COD/kg VSS/day and 1.000 ± 0.179 kg COD/kg VSS/day. The yield coefficient, Y, and biomass decay rate coefficient, Kd, were also determined to be 0.160 ± 0.012 kg VSS/kg COD and 0.027 ± 0.004 day-1, respectively.

One of the greatest challenges facing the nuclear power industry is the final disposition of nuclear waste. To meet the needs of the nuclear power industry, a new fuel assembly design, called DUPLEX, has been developed which provides higher fuel burnups, burns transuranic waste while reducing minor actinides, reduces the long term radiotoxicity of spent nuclear fuel, and was developed for use in current light water reactors. The DUPLEX design considered in this thesis is based on a seed and blanket unit (SBU) configuration, where the seed region contains standard UO2 fuel, and the blanket region contains an inert matrix (Pu,Np,Am)O2-MgO-ZrO2 fuel. The research efforts of this thesis are first to consider the higher burnup effects on DUPLEX assembly thermal-hydraulic performance and thermal safety margin over the assembly’s expected operational lifetime. In order to accomplish this, an existing burnup-dependent thermal-hydraulic methodology for conventional homogeneous fuel assemblies has been updated to meet the modeling needs specific to SBU-type assemblies. The developed framework dramatically expands the capabilities of the latest thermal-hydraulic evaluation framework such that the most promising and unique DUPLEX fuel design can be evaluated. As part of this updated methodology, the posed DUPLEX design is evaluated with respect to the minimum departure from nucleate boiling ratio, peak fuel temperatures for both regions, and the peak cladding temperatures, under ANS Condition I, II, and III transient events with the thermal-hydraulic code VIPRE-01. Due to difficulty in the fabrication and handling of minor actinide dioxides, documented thermal conductivity values for the considered IMF design are unavailable. In order to develop a representative thermal conductivity model for use in VIPRE-01, an extensive literature survey on the thermal conductivity of (Pu,Np,Am)O2-MgO-ZrO2 component materials and a comprehensive review of combinatory models was performed. Using the updated methodology, VIPRE-01 is used to perform steady-state and transient thermal hydraulic analyses for the DUPLEX fuel assembly. During loss-of-flow accident scenarios, the DUPLEX design is shown to meet imposed safety criteria. However, using the most conservative thermal conductivity modeling approach for (Pu,Np,Am)O2-MgO-ZrO2, the blanket region fuel temperatures remain only slightly below the design limit.

Wastewater recycling and reuse is an important issue in the coming years due to the increasing water demand and the decreasing water supply. MBR (membrane bioreactor) technology has become an important pretreatment technology for reclaiming treated effluent from, for example, domestic, dyestuff, and pharmaceutical wastewater plants. However, variations in wastewater flow rate and polluted materials can be a great influence to the performance of MBR. The applications of MBR to the treatment of various industrial wastewaters are worthy of further investigation. The present study investigated performances of MBR for treating wastewaters from a tannery plant and an industrial park. In addition, a pilot-scale UASB (upflow anaerobic sludge blanket) reactor was used for the pretreatment of the tannery plant wastewater for COD (chemical oxygen demand) removal. Results from tannery wastewater treatment indicate that using effluent from the activated sludge ponds of plant A as an influent to the pilot MBR, COD and SS (suspended solids) of the MBR filtrates could always be kept at <100 and <30 mg/L, respectively. Both COD and SS of the filtrates meet effluent regulations of <160 and <30 mg/L, respectively. The operation conditions were HRT (hydraulic retention time) = 12.2-20.4 hr, flux = 4.92-8.17 L/m2.hr, and MLSS (mixed liquor suspended solids) = 5,060-37,800 mg/L. Because the effluent had high TDS (total dissolved solids) contents of 8,700-9,700 mg/L resulted from chloride and sulfate ions, the permissible operational fluxes (4.92-8.17 L/m2.hr) were far below the normal ones (20-30 L/m2.hr). Experiments from the UASB test indicate that on an average 70% of the influent COD (2,200 mg/L) could be removed. Wastewater plant for the industrial park had influent and effluent COD of 93-144 and 11-65 mg/L, respectively. By the MBR with EBRT of 2.16-12.2 hr, flux of 5.0-28 L/m2.hr, and MLSS of 1,550 mg/L, the filtrates had COD of 11-81 mg/L. In addition, COD of the MBR filtrates could be decreased from 77 to 20-40 mg/L after supplementation of PAC (powdered activated carbon) at a concentration of 500 mg/L, and a clearer filtrate was obtained. After 30 days of operation, COD of the filtrates could be maintained at 30-48 mg/L. Regular addition of PAC to the MBR reactor is necessary for keeping the effluent quality to meet the reuse requirements.

Esta dissertação apresenta a metodologia para o Projeto de Engenharia de Reatores Anaeróbios de Fluxo Ascendente com Manta de Lodo para tratamento de esgoto sanitário. A metodologia desenvolvida apresenta os parâmetros de cálculo e os condicionamentos técnicos físicos envolvidos no projeto e construção da unidade de tratamento. O trabalho contém uma proposta de protocolo para o projeto, construção e operação do Reator UASB. / This disquisition presents a methodology for the Project of Anaerobic Reactors Engineering of Sludge Blanket for sanitary sewage treatment. The methodology developed presents the calculus parameters and physic technical involved in the project and construction in the treatment unit. The work contains a protocol propose for the project, construction and operation of UASB Reactor.