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Assessment of the prevalence of virulent Eschericia coli strains in the final effluents of wastewater treatment plants in the Eastern Cape Province of South AfricaOsode, Augustina Nwabuje January 2010 (has links)
Escherichia coli (E. coli) is a common inhabitant of surface waters in the developed and developing worlds. The majority of E. coli cells present in water are not particularly pathogenic to humans; however, there are some present in small proportion that possess virulence genes that allow them to colonize the digestive tract. Pathogenic E. coli causes acute and chronic diarrheal diseases, especially among children in developing countries and in travelers in these locales. The present study, conducted between August 2007 and July 2008, investigated the prevalence and distribution of virulent E. coli strains as either free or attached cells in the final effluents of three wastewater treatment plants located in the Eastern Cape Province of South Africa and its impact on the physico-chemical quality of the receiving water body. The wastewater treatment plants are located in urban (East Bank Reclamation Works, East London), peri-urban (Dimbaza Sewage Treatment Works) and in rural area (Alice Sewage Treatment Works). The effluent quality of the treatment plants were acceptable with respect to pH (6.9-7.8), temperature (13.8-22.0 °C), dissolved oxygen (DO) (4.9-7.8 mg/L), salinity (0.12-0.17 psu), total dissolved solids (TDS) (119-162 mg/ L) and nitrite concentration (0.1-0.4 mg/l). The other xii physicochemical parameters that did not comply with regulated standards include the following: phosphate (0.1-4.0 mg/L); chemical oxygen demand (COD) (5-211 mg/L); electrical conductivity (EC) (237-325 μS/cm) and Turbidity (7.7-62.7 NTU). Results suggest that eutrophication is intensified in the vicinity of the effluent discharge points, where phosphate and nitrate were found in high concentrations. Presumptive E. coli was isolated from the effluent samples by culture-based methods and confirmed using Polymerase Chain Reaction (PCR) techniques. Antibiogram assay was also carried out using standard in vitro methods on Mueller Hinton agar. The viable counts of presumptive E. coli for the effluent samples associated with 180 μm plankton size ranged between 0 – 4.30 × 101 cfu/ml in Dimbaza, 0 – 3.88 × 101 cfu/ml in Alice and 0 – 8.00 × 101 cfu/ml in East London. In the 60 μm plankton size category E. coli densities ranged between 0 and 4.2 × 101 cfu/ml in Dimbaza, 0 and 2.13 × 101 cfu/ml in Alice and 0 and 8.75 × 101 cfu/ml in East London. Whereas in the 20 μm plankton size category presumptive E. coli density varied from 0 to 5.0 × 101 cfu/ml in Dimbaza, 0 to 3.75 × 101 cfu/ml in Alice and 0 to 9.0 × 101 cfu/ml in East London. The free-living presumptive E. coli density ranged between 0 and 3.13 × 101 cfu/ml in Dimbaza, between 0 and 8.0 × 101 cfu/ml in Alice and between 0 and 9.5 × 101 cfu/ml in East London. Molecular analysis successfully amplified target genes (fliCH7, rfbEO157, ial and aap) which are characteristic of pathogenic E. coli strains. The PCR assays using uidA-specific primer confirmed that a genetic region homologous in size to the E. coli uidA structural gene, including the regulatory region, was present in 3 of the E. coli isolates from Alice, 10 from Dimbaza and 8 from East London. Of the 3 E. coli isolates from Alice, 1 (33.3%) was positive for the fliCH7 genes and 3 was positive for rfbEO157 genes. Out of the 10 isolates from Dimbaza, 4 were xiii positive for fliCH7 genes, 6 were positive for the rfbEO157 genes and 1 was positive for the aap genes; and of the 8 isolates from East London, 1 was positive for fliCH7 genes, 2 were for the rfbEO157 genes, 6 were positive for the ial genes. Antimicrobial susceptibility profile revealed that all of the E. coli strains isolated from the effluent water samples were resistant (R) to linezolid, polymyxin B, penicillin G and sulfamethoxazole. The E. coli isolates from Dimbaza (9/10) and East London (8/8) respectively were resistant to erythromycin. All the isolates were found to be susceptible (S) to amikacin, ceftazidime, ciprofloxacin, colistin sulphate, ceftriaxone, cefotaxime, cefuroxime, ertapenem, gatifloxacin, gentamycin, imidazole, kanamycin, meropenem, moxifloxacin, neomycin, netilmicin, norfloxacin and tobramycin. The findings of this study revealed that the Alice wastewater treatment plant was the most efficient as it produced the final effluent with the least pathogenic E. coli followed by the Dimbaza wastewater treatment plant. In addition, the findings showed that the wastewater treatment plant effluents are a veritable source of pathogenic E. coli in the Eastern Cape Province watershed. We suggest that to maximize public health protection, treated wastewater effluent quality should be diligently monitored pursuant to ensuring high quality of final effluents.
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Étude de la dégradation de molécules organiques complexant des radionucléides par l’utilisation de Procédés d’Oxydation Avancée / Study of the degradation of organic molecules complexing radionuclides by the use of Advanced Oxidation ProcessesRekab, Kamal 23 September 2014 (has links)
Ce travail s'inscrit dans le cadre d'un possible traitement des effluents de Très Faibles Activités (TFA). Parmi ces effluents, certains contiennent du 60Co qui est complexé à des composés organiques tels que l'acide éthylènediaminetétraacétique (EDTA) limitant alors les traitements existants par des méthodes conventionnelles. Ce travail de thèse porte sur l'évaluation de l'efficacité de Procédés d'Oxydation Avancée (UV/H2O2 et UV/TiO2) en vue de dégrader l'EDTA pour libérer le 60Co et ainsi le piéger (par précipitation et/ou adsorption sur des matrices minérales). En effet, l'étude d'adsorption a mis en évidence la capacité du TiO2 à adsorber le cobalt lorsqu'il n'est pas complexé. La précipitation totale du cobalt est quant à elle possible à pH 10 mais peut être réalisée dès pH 9 en présence d'irradiation UV-C. Le flux photonique émis par la lampe a été déterminé par actinométrie chimique et par la méthode de Keitz qui ont données des résultats similaires. L'efficacité des différents procédés pour dégrader l'EDTA et le complexe Co-EDTA a été étudiée en considérant l'influence de plusieurs paramètres (pH, mode d'agitation, type de catalyseur, concentration en H2O2...). Dans leurs conditions optimales, les procédés UV/TiO2 et UV/H2O2 permettent de dégrader et de minéraliser efficacement l'EDTA (composés azotés essentiellement minéralisés en ammonium). Après dégradation du complexe Co-EDTA, il est alors possible de récupérer la totalité du cobalt par adsorption sur le TiO2 et/ou par précipitation. Les procédés ont ensuite été appliqués à un effluent nucléaire contenant du 60Co complexés à des composés organiques. Les POA ont permis d'améliorer de manière significative les facteurs de décontamination en comparaison des méthodes de traitement conventionnelles / This work is part of a possible treatment of effluents of Very Low Level (VLL). Some of these effluents contain 60Co which is complexed with organic compounds such as ethylenediaminetetraacetic acid (EDTA), which limits existing treatments by conventional methods. This PhD work focuses on the evaluation of the efficiency of Advanced Oxidation Processes (UV / H2O2 and UV / TiO2) in order to degrade EDTA to release 60Co and thus trap it (by precipitation and / or adsorption on mineral matrices). Indeed, the adsorption study has demonstrated the ability of TiO2 to adsorb cobalt when it is not complexed. The total precipitation of cobalt is possible at pH 10 but can be performed at pH 9 in the presence of UV-C irradiation. The photon flux emitted by the lamp was determined by chemical actinometry and by the Keitz method which gave similar results. The effectiveness of the various processes to degrade EDTA and the Co-EDTA complex was studied by considering the influence of several parameters (pH, agitation mode, type of catalyst, H2O2 concentration, etc.). Under their optimal conditions, the UV / TiO2 and UV / H2O2 processes can effectively degrade and mineralize EDTA (nitrogen compounds that are essentially mineralized to ammonium). After degradation of the Co-EDTA complex, it is then possible to recover all the cobalt by adsorption on TiO2 and / or by precipitation. The processes were then applied to a nuclear effluent containing 60Co complexed with organic compounds. POAs have significantly improved decontamination factors compared to conventional treatment methods
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Sorption et transport réactif d'ions dans des monolithes de silice fonctionnalisés aux hexacyanoferrates pour le traitement d'effluents radioactifs / Sorption and reactive transport of ions in HCF-functionalized silica monolith for radioactive effluent treatmentCabaud, Clément 26 September 2019 (has links)
L’industrie du nucléaire produit de grandes quantités d’effluents radioactifs de sources diverses nécessitant des traitements spécifiques en fonction de leur composition chimique. Le césium 137 fait partie, avec le strontium 90, des radioéléments majoritairement présents dans ces effluents qui doivent être extraits le plus efficacement possible en produisant un minimum de déchets secondaires. Le traitement en colonne est parmi les procédés les plus adaptés pour ce type d’extraction sur support solide. Son principe repose sur la capacité de sorption du radioélément par des hexacyanoferrates (HCF) de cuivre, des échangeurs ioniques minéraux très sélectifs du césium. Des investigations sur les HCF ont permis de mettre en avant les modifications structurales intervenant lors de l’échange avec le césium, à l’origine de leur forte affinité pour cet ion. La fonctionnalisation des HCF sur des monolithes de silice à porosité hiérarchique a mis à profit les propriétés remarquables de ces supports pour une utilisation en colonne. Les cinétiques de sorption évaluées jusqu’aux concentrations traces ont montré une capture rapide du césium qui justifie l’intérêt de ce matériau pour un emploi en colonne. Par ailleurs, la compétitivité des monolithes fonctionnalisés par rapport à des lits particulaires a été démontrée. Ces matériaux ont enfin été mis en œuvre pour la décontamination simultanée du césium et du strontium par des mécanismes couplés d’échange d’ions et de coprécipitation du sulfate de baryum, rendue possible par la grande perméabilité des monolithes. Un modèle simplifié du transport réactif basé sur la morphologie du monolithe a été développé avec le code HYTEC en supposant un écoulement dispersif dans les canaux du squelette et la diffusion dans les parois du squelette et les agrégats de HCF. / The nuclear industry produces high amounts of contaminated water from various sources that require specific treatments depending on their chemical composition. Cesium-137 and strontium-90 are among the most abundant radionuclides in those effluents, which have to be removed as efficiently as possible in order to generate the lowest amount of waste. The column process is one of the most suitable processes to achieve this solid-phase extraction. Its principle is based on the sorption capacity of the radionuclide by copper hexacyanoferrates (HCF), highly cesium-selective mineral ion-exchangers. Investigations on HCF pointed out the structural effects of the cesium insertion within the crystal, which were linked to the high affinity of HCF for this ion. The functionalization of HCF on silica monolith with hierarchical pore structure was carried out in order to benefit the remarkable properties of these supports used as a column. Sorption kinetics evaluated down to trace concentrations have shown a fast capture of the cesium, which proves the interest of this material for a column process purpose. In addition, the performances of functionalized silica monolith have been highlighted in comparison with those made of particulate fixed beds. Finally, those materials were implemented for a simultaneous decontamination of cesium and strontium by a double extraction mechanism of ion exchange and coprecipitation of barium sulfate, allowed by the high permeability of the monolith. A simplified model of reactive transport was built with the HYTEC code, based on the actual morphology of the monolith. To do so, a dispersive flow in the macroporous intraskeletal channels and a diffusive flow inside the walls of the structure and the HCF aggregates were assumed.
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Waste disposal or discharge : a harmonised regulatory framework towards sustainable use / Catharina BosmanBosman, Catharina January 1999 (has links)
The discharge of waste into a water resource and its disposal on land can easily cause pollution,
especially of the water resource. However, it has long been accepted that these activities also
form an integral part of a holistic waste management strategy aimed at achieving sustainability.
The South African Constitution ensures a basic right to an environment that is not harmful to
human health and wellbeing, and states that pollution must be prevented, the environment must be
protected, and sustainable use of resources must be promoted, through "reasonable legislative
and other measures" .. The other measures that are currently used by the Department of Water
Affairs and Forestry to determine whether a waste disposal or discharge action is allowable, are
contained in the documents "Procedures to Assess Effluent Discharge Impacts" and "Minimum
Requirements for the Handling, Classification, and Disposal of Hazardous Waste". These
measures are evaluated to determine whether they are reasonable and effective in distinguishing
between sustainable use and pollution in terms of newly promulgated legislation aimed at
managing the environment and the water resource.
The criteria used for this evaluation are based on the principles of sustainability, the components of
risk analysis, and the scientific concepts and principles of waste discharge and disposal
management. Based on this evaluation, the shortcomings of current mechanisms are highlighted,
and their advantages are incorporated into a proposed integrated regulatory framework for an
assessment and decision-making approach based on risk harmonisation, which has various
advantageous applications, including:
• The identification of cleaner production alternatives;
• The identification of an appropriate medium of disposal or discharge (water or land);
• The selection of the Best Practical Environmental Option (BPEO) for treatment, disposal or
discharge methods;
• The licensing of sustainable waste disposal or discharge actions;
• The setting of charges for waste discharge activities;
• The prioritisation of regulatory intervention; and
• The rehabilitation of contaminated areas.
The findings of this investigation comprise the first step taken in South Africa towards the
harmonisation of assessment and decision-making approaches, which could have important
implications for integrated waste and environmental management in the future. / Thesis (M.Sc.)--Potchefstroom University for Christian Higher Education, 2000
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Waste disposal or discharge : a harmonised regulatory framework towards sustainable use / Catharina BosmanBosman, Catharina January 1999 (has links)
The discharge of waste into a water resource and its disposal on land can easily cause pollution,
especially of the water resource. However, it has long been accepted that these activities also
form an integral part of a holistic waste management strategy aimed at achieving sustainability.
The South African Constitution ensures a basic right to an environment that is not harmful to
human health and wellbeing, and states that pollution must be prevented, the environment must be
protected, and sustainable use of resources must be promoted, through "reasonable legislative
and other measures" .. The other measures that are currently used by the Department of Water
Affairs and Forestry to determine whether a waste disposal or discharge action is allowable, are
contained in the documents "Procedures to Assess Effluent Discharge Impacts" and "Minimum
Requirements for the Handling, Classification, and Disposal of Hazardous Waste". These
measures are evaluated to determine whether they are reasonable and effective in distinguishing
between sustainable use and pollution in terms of newly promulgated legislation aimed at
managing the environment and the water resource.
The criteria used for this evaluation are based on the principles of sustainability, the components of
risk analysis, and the scientific concepts and principles of waste discharge and disposal
management. Based on this evaluation, the shortcomings of current mechanisms are highlighted,
and their advantages are incorporated into a proposed integrated regulatory framework for an
assessment and decision-making approach based on risk harmonisation, which has various
advantageous applications, including:
• The identification of cleaner production alternatives;
• The identification of an appropriate medium of disposal or discharge (water or land);
• The selection of the Best Practical Environmental Option (BPEO) for treatment, disposal or
discharge methods;
• The licensing of sustainable waste disposal or discharge actions;
• The setting of charges for waste discharge activities;
• The prioritisation of regulatory intervention; and
• The rehabilitation of contaminated areas.
The findings of this investigation comprise the first step taken in South Africa towards the
harmonisation of assessment and decision-making approaches, which could have important
implications for integrated waste and environmental management in the future. / Thesis (M.Sc.)--Potchefstroom University for Christian Higher Education, 2000
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Characterisation of SAPPI SAICCOR pulp mill's effluent.Moodley, Brenda. January 2001 (has links)
SAPPI SAJCCOR, whose factory is situated south of Durban, South Africa, is one of the
few paper and pulp mills that uses the acid sulphite process with calcium and magnesium
bases to produce a high-grade cellulose pulp. Four streams of effluent, namely, the
calcium - spent liquor stream, the magnesium condensate stream and two streams from
the bleaching effluent are produced during this sulphite pulping process and they contain
a variety of organic compounds extracted from the wood. Characterisation of the effluent
was based on isolation using column chromatography and identification using NMR
techniques.
A range of constituents, such as lignans and lignin - type precursors, a trilerpenoid and
fatty acids were isolated and identified. X-ray diffraction was used to identify an
inorganic residue obtained from the calcium - spent liquor stream and gas
chromatography/mass spectrometry was used to identify a wax residue. which builds up
in the process. In addition to this, the carbohydrate content of the four streams of effluent
was detennined using UV/visiblc spectroscopy. / Thesis (M.Sc.)-University of Natal, Durban, 2001.
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The qualitative and quantitative evaluation of estrogen and estrogen-mimicking substances in the South African water environment / Liesl van der MerweVan der Merwe, Liesl January 1998 (has links)
Recently some chemicals has been accused of mimicking the female hormone
estrogen. The mode of action is termed estrogen-mimicking, because of the effects
that is produced by these chemicals. Playing canary in a coal mine, wildlife was the
first to indicate that something was wrong. Reproductive abnormalities such as
abnormal sperm, reduced sperm production, cryptorchidism (undescended testes).
abnormal hormone levels – particularly high estrogen ratios to that of testosterone.
infertility, and genital abnormalities were all evidence that something in the
environment was affecting the reproductive status of these animals. Also in humans
instances like rising cases of infertility, abnormal sperm conditions and cases of
breast cancer raised an increased concern about the potential disruptive effects of
these substances on the human existence. After investigations were conducted, it
was found that substances which enhance the quality of life like some detergents,
agricultural products, additives to plastic, dyestuffs, paint components and
pharmaceuticals to name but a few, all caused an abnormal reproductive status as
seen in animals. The aims of this study were not to focus on the effect of these
substances, but rather to identify estrogen and estrogen - mimics in the South
African environment and to evaluate their presence in the water environment
qualitatively and quantitatively with the most suitable analytical methods. Estrogen -
mimics such as nonylphenol. o'p' and p'p' DDE, o'p' DDD, lindane, atrazine and the
PCB's : Arochlor 1254 & Arochlor 1260 were found to contaminate the environment.
The drinking water tested of the PWV area indicated that the water was free of these
substances, and thus indicated a present safe situation. / Thesis (MSc (Farmaseutika))--PU for CHE, 1998
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Toxicity and biodegradability assays for hazardous landfill leachate and textile size effluentsRakgotho, Thabisile January 2005 (has links)
Submitted in fulfillment of the academic requirements for the Degree of Master of Technology: Biotechnology, Durban Institute of Technology, 2005. / The cumulative effects of pollution have led to increased public concern, which is resulting in strict legislation on the discharge of wastes in whatever state they are present, i.e. solid, liquid or gas. Currently, in South Africa, effluents with a high organic load are sent to landfills or marine outfall because the cost of discharge to sewer is prohibitive. In regions where there is a net surplus of rainfall, landfill sites have the potential to pollute the groundwater due to saturated soil conditions. Therefore, many landfill sites should not receive liquid effluents. If liquid wastes are disposed onto landfills, then an alternate sink is required for the treatment of the high volumes of leachate that are generated. These concentrated effluents could then be treated by biological, chemical or physical methods to reduce the pollution load in the natural water resources. In this study, anaerobic digestion has been identified as one of the biological processes that can be applied to treat high-strength or toxic organic liquid effluents, since a survey conducted by Sacks (1997) indicated that many anaerobic digesters in the KwaZulu-Natal region have spare capacity. However before high strength industrial wastes can be treated in existing anaerobic digesters, their impact on the digestion process, i.e. their toxicity and biodegradability under anaerobic conditions, needs to be determined. During this project, several high-strength or toxic industrial effluents were tested to assess their toxicity and biodegradability under anaerobic conditions. These include three synthetic textile size effluents from the textile industry (Textile effluent 1, 2, and 3) and three hazardous landfillieachates (Holfontein, Shongweni and Aloes). In addition, the components of a textile effluent, i.e., starch and wax, were tested to determine which / M
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The Potential Impacts of the Nogales International Wastewater Treatment Plant on the Santa Cruz RiverLaBrie, Holli, LaBrie, Holli January 2016 (has links)
The Nogales International Wastewater Treatment Plant releases treated wastewater from both Nogales, Arizona and Nogales, Sonora, Mexico into the Santa Cruz River. In recent years, the discharged effluent has contained high levels of cadmium and nickel, which exceed the plant's permit standards. Due to the industrial demographic of the region, outdated infrastructure, and differences in sampling schedules of multiple organizations, the treatment facility and the treated effluent is an important area of study. To understand how the treated effluent is affecting the river, data were compiled from existing water quality databases and flow reports from 2008 to 2015. To address how flow quantity has changed during drought periods, effluent flows were compared to historical flood data produced by the USGS. To evaluate water quality issues, water quality reports produced by the International Boundary and Water Commission were examined for past exceedances of constituents. According to flow volumes reported at the U.S.-Mexico border, the majority of the effluent was produced in Nogales, Sonora. Results showed that spikes in effluent flow corresponded with rainfall events. Results also show that rainfall influences the flow volumes from Nogales, Arizona, but there is little impact to flow volumes from Mexico. Although the quality of the effluent generally meets the permitted standards, exceedances did occur. The potential impact of such exceedances on stream water quality was evaluated using measured and simulated data. Although outreach to stakeholders across the border and updated infrastructure has improved the quality of water in the river, there are still many areas to improve upon, including sampling and monitoring schedules. To identify opportunities for improvement, further studies should examine the specific fate of each contaminant present in the effluent.
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Effect of chemical oxygen demand on the ability of some cover crops to prevent mineral accumulation in a sandy vineyard soil irrigated with augmented winery wastewaterOchse, Charles Henry January 2015 (has links)
Thesis (MTech (Agriculture))--Cape Peninsula University of Technology. / During the past years government regulations concerning winery effluent became stricter to protect the environment. Wineries are continually improving wastewater management and finding appropriate ways to reduce cellar effluent. Due to water scarcity in South Africa, it could be a huge advantage if winery effluent could be used as irrigation water for vineyards. If the industry can re-use the untreated wastewater, it will not only save a huge amount of irrigation water, but it will also be able to get rid of the vast amount of cellar effluent.
Grape production plays a major role in agriculture worldwide. The world production of grapes worldwide in 2013 was 751 MgL. South Africa is the 9th biggest wine producer in the world with 10 X 10HL of wine.
In the earlier years of wine production in South Africa, the small volumes of winery wastewater did not have a negative impact on the environment but with the increased volumes over the last years, the possibility of contamination of the soil and the environment has increased. Government decided to regulate the irrigation of cellar effluent with the National Water Act of 1998 as approved by the Department of Water Affairs (DWAF).
There are different ways to get rid of cellar effluent. One successful way is by constructed wetlands where plants are used to break down minerals which could be detrimental to the environment. This is a successful way to get rid of cellar effluent but could take up to six weeks before the mineral contents can be broken down by the plants. Another way is to use bio-reactors to break down the contents of the cellar effluent, but this is expensive.
Wastewater consists of important nutrients needed for plant growth such as macro-nutrients like N, P, K and micro-nutrients like Fe, Zn, Mn and Cu and a substantial amount of organic matter. If cellar water, just like domestic wastewater is used for irrigation the farmer can save water when he uses less fertiliser, because of the high nutrient content in the cellar effluent.
If cover crops such as oats (Avena sativa L. cv. Pallinup) in winter and pearl millet (Pennisetum glaucum (L.) R. Br.) in summer can be used to remove excess cations, as well as unwanted chemicals such as toxic metals from the soil, it may result in effluent water with a higher chemical oxygen demand (COD) level than the current legal limitations that can be used to irrigate the vineyard. The aim of this project was, therefore, to determine the ability of oat and pearl millet cover crop to remove excess minerals from the soil irrigated with augmented water at different COD levels, without a negative effect on growth and yield of the vineyard or wine quality. Field trials were carried out in a Cabernet Sauvignon/99 Richter vineyard established on a sandy soil at the Goudini Cellar near Rawsonville.
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