Integrating ultrafiltration (UF) membranes in lieu of traditional media filters within conventional surface water coagulation-flocculation-sedimentation processes is growing in popularity. UF systems are able to produce low turbidity filtered water that meets newer drinking water standards. For typical drinking water applications, UF membranes require periodic chemically enhanced backwashes (CEBs) to maintain production; and citric acid is a common chemical used for this purpose. Problems may arise when the backwash recycle stream from a citric acid CEB is blended with raw water entering the coagulation basin, a common practice for conventional surface water plants. Citric acid is a chelating agent capable of forming complexes that interfere with alum or ferric chloride coagulation. Interference with coagulation negatively affects settled water quality. Acetic acid was investigated as a potential substitute for citric acid in CEB applications. A jar testing study was conducted to compare the impacts of both citric acid and acetic acid on the effectiveness of aluminum sulfate (alum) and ferric chloride coagulants. Citric acid was found to adversely affect coagulation at lower acid to coagulant (A/C) molar ratios than acetic acid, and a coagulation interference threshold was identified for both acids based on settled water turbidity goals recommended by the U.S. Environmental Protection Agency (EPA). Pilot testing was conducted to assess the viability of acetic acid as a UF CEB chemical. Acetic acid CEBs maintained pilot performance in combination with sodium hypochlorite CEBs for filtering a raw California surface water. It is believed that this is the first ultrafiltration membrane process application of acetic acid CEBs for municipal potable water production in the United States.

Background: Access to safe water and sanitation are universal need and basic human right, but the provision of quality water and improved sanitation remains a challenge in many African countries including Ethiopia. Objectives: The study investigated drinking water quality, sanitation-hygiene practices and the potential of Moringa stenopetala seed powder for the purification of water in Bale Zone, Southeast Ethiopia. Methodology: A community-based cross-sectional study was conducted among 422 randomly selected households in Robe and Ginnir Towns. Data were collected by interviewer-administered structured questionnaires from June 2012 to August 2013. An observation checklist was used to observe the sanitary condition of water sources. A total of 71 water samples were collected using sterile glass bottles in accordance with the standard method of American Public Health Association APHA. The physicochemical and bacteriological water quality analyses were done in Addis Ababa Environmental protection and Oromia water and Energy laboratories. The efficiency of Moringa stenopetala seed powder for removal of turbidity, hardness, and nitrate was evaluated. Data were analyzed SPSS Version 21.0 for the window. Descriptive analysis was done for appropriate variables. Logistic regression was used to identify the factors associated with under-five diarrhea. The results were presented using adjusted odds ratio and P-value of < 0.05 was used to declare significance association. Results: From the total sample, 401 respondents participated making a response rate of 95%. More than one third (37.9%) of the respondents were found to use pipe water. Two hundred and eighty (69.8%) of households wash storage containers before refilling and 325 (81%) of households were using separate containers for water storage. Two hundred seventy (67.3%) of the households had pit latrine. Prevalence of childhood diarrhea was found to be 50.1%. From the logistic regression model, those households having access to clean water source are 68% less likely to have under-five diarrhea, the households having clean storage of drinking water are 45% less likely to have under-five diarrhea in their home, and those households having poor latrine sanitation are 68% more likely to have under-five diarrhea in their home. Seed powder of 200mg/l Moringa stenopetala reduced the Nitrate concentration doses from 5.49mg/l to 8.18mg/l, a 75mg/l was reduced the turbidity from 4.49NTU to 1.07 NTU. A total hardness of 427 was reduced by 7.8% after treatment with powder seed of Moringa stenopetala. Conclusion: Prevalence of childhood diarrhea was high and it is associated with lack of access to a clean water source, poor sanitation of drinking water storage and latrine. Prevalence of open field defecation was remarkably high. The iron content of drinking water was above the range of World Health Organization standards. Moringa stenopetala seed powder has efficiency in the reduction of total and faecal coliform, turbidity, hardness and nitrate level in drinking water Recommendation: Health education on water handling, sanitation and low-cost effective water treatment methods like Using Moringa stenopetala seed should be practiced at the household level. / Environmental Sciences / Ph. D. (Environmental Science)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A mandioca (Manihot esculenta) é a terceira cultura mais importante do país na alimentação básica da população. A produção de farinha de mandioca gera um efluente denominado manipueira que contem elevada quantidade de matéria orgânica e cianeto. O objetivo deste trabalho foi investigar a remoção da demanda química de oxigênio (DQO), turbidez e cianeto da manipueira por tratamentos físico-químico e biológico. No tratamento físico-químico por coagulação-floculação, três planejamentos fatoriais completos foram realizados para investigar os fatores: pH, tanino e o polímero sintético auxiliar da floculação (Polipan) sobre as variáveis respostas: DQO, turbidez e cianeto. A eficiência máxima de remoção de DQO foi 91 % a pH 8,0, na presença de tanino 1,0 mL/L e Polipan 0,030 ppm. A maior remoção de turbidez (75 %) foi determinada a pH 8 e tanino 0,8 mL/L, na ausência do Polipan para diminuir os custos do tratamento. Nessas condições, a redução máxima de cianeto foi de 12 %. Nos tratamentos biológicos aeróbios durante 48 h, as eficiências máximas de redução de DQO 88 % e de turbidez 69 % foram determinadas na presença de consórcio microbiano 20 % v/v, cloreto de amônio 5 - 6 % e a pH 8,0. Para os tratamentos físico-químico e biológico, os resultados obtidos mostram que o pH 8 foi fator chave para remoção de compostos orgânicos e do cianeto da manipueira. Os tratamentos da manipueira por coagulação-floculação e por consórcio microbiano diminuem a carga orgânica desse efluente antes de ser lançado nos recursos hídricos / Cassava (Manihot esculenta) is the third most important crop in the basic food of the Brazilian population. The production of cassava flour generates an effluent, called manipueira, containing high organic matter and cyanide. The objective of this study was to investigate the removal of chemical oxygen demand (COD), turbidity and cyanide from cassava wastewater by physical-chemical and biological treatments. In the physicalchemical treatment by coagulation-flocculation, three full factorial designs were carried out to investigate the factors: pH, tannin concentration and the flocculation polymer (Polipan) concentration on the response variables: COD, turbidity and cyanide. The maximum efficiency for COD removal was 91 % at pH 8.0 in the presence of tannin 1.0 mL/L and Polipan 0.030 ppm. The highest removal of turbidity (75 %) was determined at pH 8 and tannin 0.8 mL/L in the absence of Polipan to reduce the costs of treatment. Under these conditions, the maximum removal of cyanide was 12 %. In the aerobic biological treatment for 48 h, the maximum efficiencies for COD reduction of 88 % and for turbidity reduction of 69 % were determined in the presence of the microbial consortium 20 % v/v, ammonium chloride 5 6 % and at pH 8.0. For the treatments, physical-chemical and biological, the results show that pH 8 is a key factor for removal of organic compounds and cyanide from cassava wastewater. The treatments of the manipueira by coagulation-flocculation and by microbial consortium decrease the pollution of this effluent before being launched in the water resources

Made available in DSpace on 2017-06-01T18:20:28Z (GMT). No. of bitstreams: 1 dissertacao_roberto.pdf: 771972 bytes, checksum: 84b4fdd96e095e36234f411eb7d531d5 (MD5) Previous issue date: 2010-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cassava (Manihot esculenta) is the third most important crop in the basic food of the Brazilian population. The production of cassava flour generates an effluent, called manipueira , containing high organic matter and cyanide. The objective of this study was to investigate the removal of chemical oxygen demand (COD), turbidity and cyanide from cassava wastewater by physical-chemical and biological treatments. In the physicalchemical treatment by coagulation-flocculation, three full factorial designs were carried out to investigate the factors: pH, tannin concentration and the flocculation polymer (Polipan) concentration on the response variables: COD, turbidity and cyanide. The maximum efficiency for COD removal was 91 % at pH 8.0 in the presence of tannin 1.0 mL/L and Polipan 0.030 ppm. The highest removal of turbidity (75 %) was determined at pH 8 and tannin 0.8 mL/L in the absence of Polipan to reduce the costs of treatment. Under these conditions, the maximum removal of cyanide was 12 %. In the aerobic biological treatment for 48 h, the maximum efficiencies for COD reduction of 88 % and for turbidity reduction of 69 % were determined in the presence of the microbial consortium 20 % v/v, ammonium chloride 5 6 % and at pH 8.0. For the treatments, physical-chemical and biological, the results show that pH 8 is a key factor for removal of organic compounds and cyanide from cassava wastewater. The treatments of the manipueira by coagulation-flocculation and by microbial consortium decrease the pollution of this effluent before being launched in the water resources / A mandioca (Manihot esculenta) é a terceira cultura mais importante do país na alimentação básica da população. A produção de farinha de mandioca gera um efluente denominado manipueira que contem elevada quantidade de matéria orgânica e cianeto. O objetivo deste trabalho foi investigar a remoção da demanda química de oxigênio (DQO), turbidez e cianeto da manipueira por tratamentos físico-químico e biológico. No tratamento físico-químico por coagulação-floculação, três planejamentos fatoriais completos foram realizados para investigar os fatores: pH, tanino e o polímero sintético auxiliar da floculação (Polipan) sobre as variáveis respostas: DQO, turbidez e cianeto. A eficiência máxima de remoção de DQO foi 91 % a pH 8,0, na presença de tanino 1,0 mL/L e Polipan 0,030 ppm. A maior remoção de turbidez (75 %) foi determinada a pH 8 e tanino 0,8 mL/L, na ausência do Polipan para diminuir os custos do tratamento. Nessas condições, a redução máxima de cianeto foi de 12 %. Nos tratamentos biológicos aeróbios durante 48 h, as eficiências máximas de redução de DQO 88 % e de turbidez 69 % foram determinadas na presença de consórcio microbiano 20 % v/v, cloreto de amônio 5 - 6 % e a pH 8,0. Para os tratamentos físico-químico e biológico, os resultados obtidos mostram que o pH 8 foi fator chave para remoção de compostos orgânicos e do cianeto da manipueira. Os tratamentos da manipueira por coagulação-floculação e por consórcio microbiano diminuem a carga orgânica desse efluente antes de ser lançado nos recursos hídricos

Submitted in fulfillment of the requirements of the Degree of Master of Technology: Chemistry, Durban University of Technology, 2014. / This project arose out the need for a simple method to analyse NOM on a routine basis. Water samples were obtained from the Vaal dam, which is one of the dams used by a hydroelectric power station. Analysis was preceded by separation of NOM into the humic and non-humic portions. The humic portion was separated into two fractions by employing a non-ionic resin (DAX-8) to separate humic acid from fulvic acid. High performance size exclusion chromatography (HPSEC), equipped with an Ultraviolet( UV) detector and an Evaporative Light Scattering (ELS) detector connected in series, was used to obtain molecular weight distribution information and the concentration levels of the two acids. Mixed standards of polyethylene oxide/glycol were employed to calibrate the selected column. Suwanee River humic acid standard was used as a certified reference material. The molecular weight distributions (MWDs) of the isolated fractions of humic and fulvic acids were determined with ELSD detection as weight-average (Mw), number-average (Mn) and polydispersity (ρ) of individual NOM fractions. The Mw/Mn ratio was found to be less than 1.5 in all the fractions, indicating that they have a low and narrow size fraction. An increase in Mn and Mw values, with increasing wavelength for all three humic substances (HS) examined was observed. The HS, isolated from the dam water, was found to be about the same molecular weight as the International Humic Acid Standard (IIHSS). For the fulvic acid standard, the molecular weight was estimated to be around 7500 Da. Characterization of NOM was done to assist in the identification of the species present in the water. FTIR-ATR was used to as a characterization tool to identify the functional groups in the structure of the humic and fulvic acid respectively present in the Vaal Dam. Analysis of the infrared (IR) spectra indicated that the humic acids of the Vaal dam have phenolic hydroxyl groups, hydroxyl groups, conjugated double bond of aromatic family (C=C), and free carboxyl groups. The isolation method has proved to be applicable and reliable for dam water samples and showed to successfully separate the humic substances from water and further separate the humic substances into its hydrophobic acids, namely, humic and fulvic acids. It can be concluded that the Eskom Vaal dam composes of humic substance which shows that the technique alone gives a very good indication of the characteristics of water. The HPSEC method used, equipped with UV and ELSD was able to identify the molecular weight range of NOM present in source water as it confirmed that the Eskom Vaal dam contains humic substances as humic acid and fulvic acid and these pose a health concern as they can form disinfectant byproducts in the course of water treatment with chemicals. FTIR characterization was successful as important functional groups were clearly assigned. Lastly, the use of the TOC and DOC values to calculate SUVA was also a good tool to indicate the organic content in water. It is recommended to use larger amounts of water must be processed to obtain useful quantities of the humic and fulvic acid fractions.

Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: The objective of this research was to obtain clean drinkable water from treated sewage effluent by using a solar-powered distillation cycle. Technologies and concepts were borrowed from the solar desalination industry to propose a unique circular distillation cell design. From the design, a specific mathematical correlation was developed to predict the distillate mass flow rate by using only evaporation and condensation temperature as inputs. This model was incorporated into a simulation model built using Transient System Simulation software. Long-term simulations were carried out to determine the operating capabilities of the design. A prototype was successfully constructed and operated. Experimental results indicated good agreement with the mass flow rate mathematical correlation. Water quality levels were tested against the South African National Standard 241 national drinking water quality standard. Four quality parameters are outside acceptable levels. Evidence suggested that acceptable quality levels could be reached. The circular distillation cell design is a major contribution made by this research. Another contribution is the simulation model capable of predicting an output for different locations. Finally, the proposed prototype is potentially a very valuable device contributing towards the reduction of consumer demand in terms of water and energy as well as the household load on the wastewater treatment system. / AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om te beskryf hoe behandelde rioolwater deur middel van ’n son aangedrewe distillasiesisteem gesuiwer kan word om drinkbare water as eindproduk te lewer. Die nodige tegnologieë en konsepte is oorgeneem uit kommersiële sonaangedrewe ontsoutingsisteme om met ’n unieke ontwerp voorendag te kom wat uit ’n sirkelvormige natuurlike konveksie distillasiesel bestaan. Met behulp van hierdie ontwerp is ’n wiskundige korrelasie ontwikkel om die gesuiwerde water se massavloei te bepaal. Slegs die verdampings- en kondensasietemperature word as insetwaardes gebruik om die massavloei te bereken. ’n Simulasiemodel is met behulp van die Transient System Simulation programmatuur gebou. Die wiskundige korrelasie is by die simulasiemodel geïnkorporeer om langtermynsimulasies te kan uitvoer. Voorts is ’n demonstrasiemodel suksesvol gebou en aangedryf. Eksperimentele resultate toon goeie ooreenstemming met die simulasieresultate. Die gesuiwerde water se gehalte is met die nationale SANS 241 drinkwaterstandaard as maatstaf getoets. Slegs vier gehalteparameters val buite die aanvaarbare vlakke, hoewel dit blyk dat hierdie elemente wel tot aanvaarbare vlakke verlaag kan word. Hierdie navorsing se grootstet bydrae is die ontwerp van die unieke sirkelvormige distillasiesel. ’n Bykomende bydra is die aanpasbaarheid van die simulasiemodel sodat dit produksievermoë op verskillende plekke kan voorspel. Die demonstrasiemodel is ’n potensieel waardevolle ontwerp wat kan bydra tot die verlaging in verbruikersaanvraag na water en energie. ’n Ontwerp van hierdie aard kan die las wat huishoudings op suiweringaanlegte vir rioolwater plaas, verlig.

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.

M.Tech. (Civil Engineering) / This study presents work on the design and construction of three dual-chamber microbial fuel cells (MFCs) using a sandwich separator electrode assembly (SSEA) and membrane cathode assembly (MCA) for the dual purposes of energy generation from domestic wastewater and wastewater treatment. MFC1 was designed using an improvised SSEA technique (i.e. a separator electrode membrane electrode configuration, SEMEC) by gluing a sandwich of anode, membrane and a mesh current collector cathode to an anode chamber made from a polyethylene wide-mouth bottle. The reactor was filled with 1500 mL of domestic wastewater and operated on a long fed-batch mode with a residence time of 3 weeks. The reactor was inoculated with a mixed culture of bacteria present in the wastewater stream. The aim was to study the impact of wastewater COD concentration on power generation and wastewater treatment efficiency. For MFC2 and MFC 3, cathodes were constructed using the MCA technique consisting of a membrane and a mesh current collector cathode, with the anode electrode at the opposite side of stacked Perspex sections used for the anode chamber. The impact of electrode material on current production was examined in this study. For MFC2 a mesh current collector treated with polytetrafluoroethylene (PTFE) and activated carbon (AC) functioned as the cathode, while the MFC3 cathode was an uncatalyzed mesh current collector. The two reactors were both filled with 350 mL of domestic wastewater...

A study has been conducted for the qualitative and Quantitative analysis of chlorinated organic compounds in water. The study included the adaptation of Amberlite XAD macroreticular resin techniques for the concentration of municipal wastewater samples, followed by GC/MS analysis. A new analytical method was developed for the determination of volatile halogenated organics using liquid-liquid extraction and electron capture gas chromatography. And, a computer program was written which searches raw GC/MS computer files for halogen-containing organic compounds.

Thesis (M.Sc. (Zoology)) --University of Limpopo, 2014 / Contamination of aquatic ecosystems by agricultural and mining activities, as well as by industrial discharges and urbanization in the catchment of the South African river systems has been the cause of increasing public concern. These activities may result in water pollution. One such river is the Olifants River System in Mpumalanga and Limpopo provinces which is highly impacted. The main aim of the study was to assess the impact of the water and sediment quality on the health of Clarias gariepinus and Labeo rosae and human risk when the fish is consumed at the Phalaborwa Barrage in the Lower Olifants River, Limpopo Province. This was achieved by assessing the water and sediment quality of the barrage at the three sampling sites; assessing the condition of the fish and the fish parasites by applying the fish HAI (Health Assessment Index) and PI (Parasite Index); determining the bioaccumulation of selected metals in the muscle tissue of the two fish species; and to determine the Human health risk factor upon consumption of fish contaminated with metals at the barrage. Ten fish from each fish species were collected seasonally at each site using gill nets of different mesh sizes. Standards methods were followed when testing selected water and sediment constituents. For water quality sampling, the water samples were collected over four seasons (autumn, winter, spring and summer) at three sites (inflow, wall and below wall) from April 2010 to January 2011. Sediment samples were also collected using a Friedlinger mudgrab (225cm3) at the three sites during winter and summer. Fish hosts were examined for mobile ectoparasites, weighed and measured. Blood samples were drawn and skin smears were made. Fish were killed, dissected and all external and internal organs were examined as prescribed in the fish health assessment index. The condition factor was determined for each fish population. All parasites were collected, fixed and preserved using standard methods. The highest water temperature (28.5 ºC) was in spring and lowest in winter (18 ºC). Overall pH was in an alkaline condition as it ranged from 7.4 to 8.7. Most water quality parameters were recorded at higher concentration in spring which includes; water temperature, pH, conductivity, salinity, TDS, alkalinity, and turbidity. Major ions (cations and anions) recorded were all within the TWQR. Sulphates concentrations were all within the TWQR. Calcium concentration levels exceeded the typical concentration limit in spring but the levels were still within the TWQR for domestic use. Nutrients levels (nitrate, nitrite, sulphate) were very low which indicate oligotrophic conditions. Highest total nitrogen was recorded in spring which is an indicative of eutrophic conditions. Highest phosphorous concentrations were recorded in winter, spring and summer which are an indicative of eutrophic conditions. Noticeable elevated levels were recorded at the inflow in summer which is an indicative of hypertrophic conditions. The results of the metals concentrations analysed demonstrated that metals within the barrage are present in trace amounts in the water. Analysis of the metal concentrations in water, sediment and fish muscle tissue revealed that the sediment contained the highest concentrations of metals followed by fish tissue and then the water. Metals that were detected in the water column includes; aluminium, antimony, arsenic, barium, boron, iron, manganese, selenium, strontium and tin. Metals that were detected at concentrations above the TWQR for aquatic ecosystem were; aluminium, antimony and selenium. Arsenic, cadmium and chromium were recorded at concentrations above the detection limit as suggested by CCME. Zinc concentrations were recorded at levels below suggested detection limit. Aluminium, barium, boron, cadmium, chromium, manganese, selenium and strontium were all detected at elevated levels in water and above the TWQR. Among the metals recorded in the water column, significant seasonal variations in concentration were found for aluminium, barium, boron, lead selenium and strontium whereas only boron showed a significant variation between sites. In comparison to the metals concentrations accumulated in the muscle tissue of both fish species. It was noted that C.gariepinus accumulated more metals than L. rosae; however L. rosae accumulated more metals at elevated concentrations than C. gariepinus. The metals that were accumulated at elevated levels in C. gariepinus were barium, boron, zinc and selenium. In L. rosae, iron, aluminium, strontium, titanium, vanadium and arsenic accumulated at elevated levels. All these metals pose a high risk to fish and human’s health. The highest population HAI was recorded in summer for both fish species. The lowest HAI value was recorded in autumn for both fish species. Although a high HAI population value was recorded higher in summer for both fish species, in general both fish species from the barrage were in a normal condition. A high number of ectoparasites were recorded in L. rosae than in C. gariepinus while high numbers of endoparasites were recorded in C. gariepinus than L. rosae. The dominating ectoparasites for both species were from the class monogenea. Although the prevalence for Contracaecum sp. in C. gariepinus was 100% in all season, it did not influence the condition of the host. None of the parasites identified from both fish species neither reached alarmingly infection levels nor caused any visible damage to the host. In conclusion, the water quality at the Phalaborwa Barrage is slightly polluted based on the water quality parameter(phosphorous) presence and recorded of some metals at the inflow that were recorded at elevated levels above the TWQR. Further recommendations are refereed such as extension of this study to all tributaries and to include other fish species in addition to constant monitoring of the impoundment.