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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

An investigation into the cyanobacteria and related cyanotoxins in the Vaalkop dam and Vaalkop Treatment Plant, Rustenburg

Bezuidenhout, Nelanie 24 July 2013 (has links)
M.Sc. (Environmental Management) / In South Africa, there are practically no freshwater lakes. Therefore, exploitable water supplies are confined to rivers, artificial lakes behind dams, and groundwater. The many demands for water, and the erratic flow of most South African rivers, have led to the creation of artificial lakes and dams, i.e. impoundments on all the major rivers, in order to stabilise flow and therefore guarantee annual water supply. Cyanobacterial bloom formation in freshwater sources, such as rivers, lakes, dams and reservoirs are known to occur throughout the world. In South Africa, the occurrence of cyanobacteria has also been recorded with the best known being the bloom of the hyper-eutrophic Hartbeespoort Dam. In South Africa specifically, cyanobacteria are mostly seasonally driven. Species that are known to cause bloom formation are Microcystis sp., Anabaena sp., Oscillatoria sp. and Cylindrospermopsis sp. These species are known to produce cyanotoxins that cause health problems in animals and humans, but also produce taste and odour problems in drinking water, if not treated effectively. In most cases where cyanobacteria blooms have been known to occur, it also enters source water for drinking water purification plants. Because source water containing cyanobacteria and the effect it has on the consumer, environment and animals, it is thus important to identify the dominant algae species. Cyanotoxin drinking water guidelines must be developed and implemented and a management plan for the Water Treatment Plant must be produced, to ensure that the risk of human exposure to the cyanotoxins are minimised. The present study focuses on the Vaalkop Dam from which raw water is abstracted and treated by the Magalies Water Vaalkop Water Treatment Plant (MWVWTP) to produce potable water. The source water abstracted from the Vaalkop Dam can contain high numbers of cyanobacteria as well as cyanotoxins that must be removed by the MWVWTP during potable water purification to ensure compliance to water quality standards. The overall objective of the study is to investigate the occurrence of cyanobacteria and cyanotoxins in the Vaalkop Dam at the point where the source water is abstracted for drinking water purification.
72

Condicionamento químico de lodo de estação de tratamento de água com monitoramento através de potencial redox / Chemical conditioning of sludge from a water treatment plant with monitoring through redox potential

Haak, Wando 18 August 2018 (has links)
Orientador: Ricardo de Lima Isaac / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-18T11:03:55Z (GMT). No. of bitstreams: 1 Haak_Wando_M.pdf: 4830827 bytes, checksum: 311caf27f5b5da6d03f6312ef08d15bc (MD5) Previous issue date: 2011 / Resumo: Estações de tratamento de água (ETA) geram resíduos durante o processo de potabilização da água bruta. Esse resíduo onera as companhias de saneamento, no que tange o tratamento e disposição final. O tratamento do lodo é constituído de processos de separação sólido-líquido, cuja eficiência - quanto à maximização do teor de sólidos da torta (lodo desaguado) e melhor qualidade da água recuperada no processo - é dependente do adequado condicionamento químico, em geral obtido pela ação de polímeros. A super- dosagem ou a sub-dosagem desse produto ocasiona perda de qualidade, tanto da torta, quanto da água eliminada. Este trabalho tem como objetivo verificar através de estudo de bancada, a viabilidade técnica e econômica do condicionamento químico na adequação de processo de tratamento de lodo de ETA, visando melhor desempenho na fase de desaguamento, tendo em vista a disposição final dos resíduos gerados durante o tratamento. Foram relacionadas medidas de potencial redox com controle de dosagem e consumo de polímero catiônico de alto e muito alto peso molecular, de baixa, média e alta densidade de carga e polímero aniônico de alto peso molecular, com baixa e média densidade de carga, com e sem oxidação química com cloro e permanganato de potássio. Na investigação experimental os resultados referentes ao tempo de filtração, indicaram os polímeros catiônicos de alto peso molecular, de baixa e média e alta carga como sendo mais eficientes. Para valores de potencial redox entre -57mV e 75mV, os polímeros catiônicos, em sua maioria, apresentaram consumos de 6,0 a 10,0 (kg/tms), em lodo não oxidado. A oxidação do lodo com permanganato de potássio ou cloro para valores entre -11mV e +11mV foi significativa, com redução da dosagem de polímeros catiônicos para valores de 4,0 a 7,0 (kg/tms), proporcionando economia de 30%. Considerando-se as correlações encontradas, tendo em mãos, sondas confiáveis de pH e potencial redox, é possível automatizar um determinado sistema de dosagem para oxidação do lodo / Abstract: Water treatment plants (WTP) generate waste during the process of potabilization of raw water. This residue burdens the sanitation companies, with regard to treatment and final disposal. The sludge treatment process consists of solid-liquid separation, whose efficiency - as to maximize the solids cake (dewatered sludge) and better quality of the reclaimed water in the process - is dependent on proper chemical conditioning, usually obtained by action of polymers. Over dosage or under dosage of those products causes loss of quality of both, cake and eliminated water. The aim of this work is to verify the technical and economical feasibility of the chemical conditioning at the fitting of sludge treatment process at a WTP, through work bench study, aiming at better performance during the dewatering, looking at the treatment final discharge of residues. Measures of redox-controlled dispensing were related to consumption of cationic polymer of high and very high molecular weight, of low, medium and high charge density and anionic polymer of high molecular weight, of low and medium charge density, with and without chemical oxidation with chlorine and potassium permanganate. At the primary investigation of percolating time, the cationic polymers of high molecular weight with low, medium and high charge, proved to be more efficient. For potential redox values between -57mV and 75mV, most of the cationic polymers consumed from 6.0 to 10.0 (kg/tms), in non-oxidized sludge. There was a significant oxidation of sludge with potassium permanganate or chlorine for values between -11 and +11mV, reducing the dosage of cationic polymers to values from 4.0 to 7.0 (kg/tms), providing a 30% economy. Taking into account the correlations found, using reliable pH and redox potential probes, it is possible to automate a system of dosage for the sludge oxidation / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil
73

Preparation of poly (vinylindene fluoride-co-hexafluoriproylene) composite membranes for treatment of water hardness

Ramollo, Khaleke Veronicah January 2022 (has links)
Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2022 / Calcium and magnesium are two dominant species that contribute to water hardness. The aim of this study was to develop a poly (vinylidene fluoride-co hexafluoropropylene) (PVDF-HFP) composite membrane for treatment of water hardness. The synthesis of PVDF-HFP composite membranes was confirmed by X ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The concentrations of the hardness causing agents in both the simulated and real hard water samples were investigated in batch studies wherein parameters such as pH, contact time, temperature, and adsorbent were optimised. The maximum adsorption efficiency of 56 and 45 mg/g (evaluated by Langmuir isotherm) for Ca(II) and Mg(II) ions were obtained. These were achieved at an optimum pH of 7 and adsorption dosage of 0.5 mg/L using the 3% PVDF-HFP/cellulose acetate (CA) and 1% nitrogen doped multiwalled carbon nanotubes (N-MWCNTs)/CA composite membranes respectively. The adsorption kinetics and isotherm models were all consistent with the pseudo-second order and Freundlich isotherm models for all the membranes suggesting that the sorption process met heterogeneous adsorption. Furthermore, the thermodynamic parameters indicated that the adsorption is physical and endothermic in nature. Reusability studies showed that all the PVDF-HFP based membranes can be recycled at least 3 times and for Ca(II) ions an adsorption loss of only 0.35 % was recorded while using a 3% PVDF-HFP/CA composite membrane. These results were further confirmed by XRD, TGA and inductively coupled plasma mass (ICP-MS) spectrometry. Thus, the findings from this study have shown that the PVDF-HFP based membranes could provide valuable material for hardness removal to acceptable level.
74

Predictive Modeling Of Sulfide Removal In Tray Aerators

Faborode, Jumoke O. 01 January 2010 (has links)
Hydrogen sulfide is commonly found in many Florida potable groundwater supplies. Removing sulfur species, particularly hydrogen sulfide is important because if left untreated, sulfide can impact finished water quality, corrosivity, create undesirable taste and odor, and oxidize to form visible turbidity and color. This document presents the results of a study designed to investigate the removal efficiencies of a variety of tray aerators in Central Florida in order to develop a predictive mathematical model that could be used to determine tray effectiveness for sulfide removal. A literature review was performed that indicated there was limited information regarding the removal of hydrogen sulfide using conventional tray aerators, and no information regarding the removal of total sulfide from tray aerators. There was significantly more information available in the literature regarding the usefulness of sulfide removal technologies from water supplies. Consequently, the lack of literature regarding sulfide removal using tray aerators suggested that there was a need for additional research focused on sulfide removal from water flowing thru tray aerators. Several water purveyors that relied on tray aerators as a part of their water treatment operations were contacted and requested to participate in the study; three water purveyors agreed to allow the University of Central Florida (UCF) to enter their secured sites to collect samples and conduct this study. The three facilities included the UCF‘s water treatment plant located in Orlando and situated in eastern Orange County, the City of Lake Hamilton‘s water treatment plant located in west-central Polk County, and the Sarasota-Verna water treatment plant located in western Sarasota County. An experimental plan was developed and field sampling protocols were implemented to evaluate sulfide removal in commonly used tray aerators at the three drinking water treatment facilities. Total iv sulfide concentrations passing through the trays were determined in the field at each site using a standard iodometric analytical technique. In addition, other water quality parameters collected included dissolved oxygen, pH, temperature, conductivity, turbidity, alkalinity, hardness, total dissolved solids and total suspended solids; these samples were collected and analyzed either in the field or at the UCF laboratory. A first-order empirical model was developed that predicted sulfide removal in tray aerators. The model‘s constant was evaluated with respect to the water‘s proton concentration [H + ], the tray aerator‘s surface area, and hydraulic flow rate thru the trays. The selected model took the form of Cn=C0 (10-kn ) where Cn is the sulfide remaining after aeration in mg/L, C0 is the sulfide entering the distribution tray in mg/L, n is the number of tray stages in the aerator, and . From the empirical model, it was shown that sulfide removal was negatively impacted as the proton concentration (H+ ) decreased, and flow increased. Conversely, it was observed that increased sulfide removal occurred as the available tray aerator surface area increased. The combined parameters of proton concentration, flow rate, and area were statistically evaluated and used to develop an empirical constant that could be used in a first order model to predict sulfide removal in tray aerators. Using a site-specific derived experimental (empirical) constant, a water purveyor could use the developed model from this work to accurately predict sulfide removal in a tray aerator by simply measuring the total sulfide content in any raw groundwater supply and then providing the desired number of tray stages available for treatment.
75

Capacity building through sustainable operations and maintenance : the Zeerust wastewater treatment

Coetzer, Casper 12 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Providing basic access to water and sanitation is critical for poverty alleviation and stimulating economic growth, but at the same time it is putting a huge strain on South Africa’s existing economic infrastructure. Local governments allow their existing wastewater infrastructure to deteriorate to the extent that it no longer functions according to its design, and then apply for capital funding for refurbishment. Capital investment alone will not provide a sustainable solution to meet the increased demand on the ageing wastewater infrastructure, since local governments do not have the financial means and technical capacity to adequately maintain and operate their infrastructure. A paradigm shift is required to develop alternative and innovative business models to ensure a sustainable solution providing continued and consistent capacity as a basis for further expansion. Public-private partnerships (PPP) could provide a feasible solution towards building a sustainable technical capacity at local governments. Engaging the private sector must however not be aimed towards access to private sector finance, but rather the improvement in operational efficiency and increased level in service. Obtaining private sector finances will be the wrong focus for engaging in PPP undertakings in South Africa. Private operation must be combined with public financing. The design-build-operate (DBO) model with public financing would be highly viable. Such an arrangement will hold no financial risk to the private sector entity with revenue collection strictly remaining a local government function. The DBO method of delivery (with public funding) will be an effective way to realize cost savings, achieve efficiencies in construction and operation, utilize expertise, and most importantly, for skills transfers and capacity building at local government level. Ultimate sustainability will only be achieved once local government is able to raise the majority of its own funds for operation and maintenance through tariffs and other instruments, including some towards capital redemption. Grant funding must make provision for maintenance and operation of all capital funded projects. All shareholders must join forces in lobbying this concept at the highest political echelons because in terms of Section 154 of the Bill of Rights, national and provincial governments have a duty towards local governments to support and strengthen their capacity, to effectively perform their functions.
76

Abordagem sistêmica do sistema de tratamento de água de Registro, São Paulo, com ênfase na avaliação do impacto do descarte dos resíduos na bacia hidrográfica do Rio Ribeira de Iguape / Sistemic approach of water treatment plant of Registro, São Paulo, focusing the evaluation of the impact of the discharge of solid residues in Ribeira de Iguape River Basin

Reis, Edson Luís Tocaia dos 20 February 2006 (has links)
A crescente preocupação dos órgãos de vigilância ambiental e sanitária sobre a segurança e a qualidade dos recursos hídricos tem orientado o desenvolvimento de diversas pesquisas voltadas para uma revisão do padrão tecnológico atual, quanto à gestão de resíduos gerados em estações de tratamento de água. Neste trabalho, foram avaliadas as principais características dos resíduos gerados em um sistema de tratamento de água de ciclo completo na cidade de Registro (SP) e sua correlação com a qualidade do meio hídrico, pelo estudo dos efeitos físico-químicos de seu descarte na qualidade da água e do sedimento da Bacia Hidrográfica do rio Ribeira de Iguape. Um programa de monitoramento da microbacia foi estabelecido, verificando-se o atendimento dos elementos analisados ás exigências de legislações federais, como a Resolução CONAMA 357/2005 e a Portaria 518. Foram constatadas alterações na qualidade da água superficial do corpo d\'água receptor em períodos de até 4 horas, após o despejo, e para uma distância de até 50 m a jusante do descarte do lodo da ETA. A análise descritiva mostrou ser predominante a concentração de alguns metais durante o descarte, como o manganês. A análise dos organismos bentônicos apresentou uma indicação de que os grupos observados não foram diretamente afetados pelo despejo do lodo da ETA. O presente trabalho não detectou indícios de que a contaminação constatada no local de despejo atingisse o rio Ribeira de Iguape, porém, a presença de alumínio em amostras de sedimento próximo ao local de descarte mostrou que o descarte sistemático do lodo pode comprometer em longo prazo a qualidade da água do corpo d\'água receptor. / The growing concern of environmental and sanitary surveillance about the safety and the quality in the hydric resources, guides the development of many researches to a revision of the current technological pattern, related to the administration of residues generated in the water treatment plants. This work evaluated main characteristics of the residues generated in water treatment plant with complete cycle in the Registro town (SP) and the correlation with quality of the environment, by studying physical-chemical effects of its discharge in the quality of water and sediment of Ribeira de Iguape River Basin. A monitoring program was established, verifying the attendance of the elements analyzed to the demands of federal legislations, such as Resolução CONAMA 357/2005 and Portaria 518. Some alterations were verified in the quality of superficial water of the receiving watercourse, in periods up to 4 hours after the discharge and for a distance of 50 m to the place of the discard of sludge. The descriptive analysis showed to be predominant the concentration of some metals during the discharge, as manganese. The analysis of the benthonic organisms pointed out that the groups observed as typical of the area were not directly affected by sludge discharge. The present study did not detect indications that the contamination verified reached Ribeira de Iguape River. However, the systematic discharging of the sludge may commit at long date the water quality of the receiving watercourse.
77

Evaluation of some pharmaceutical and personal care products and pesticide residues in selected wastewater treatment plants and receiving watersheds in Eastern Cape, South Africa

Ademoyegun, Olufemi Temitope January 2017 (has links)
Emerging organic contaminants (EOCs) have been the focus of global environmental research for over three decades. EOCs have caused widespread concern due to their extensive use. As EOCs were designed to correct, enhance or protect a specific physiological, their target effects in humans and/or farm stocks are relatively well known and documented. However, there is limited knowledge about their unintended effects in the environment. To address the occurrence, distribution and fate of EOCs in the environment, efficient and reliable analytical methods are needed. The relatively low concentration, high polarity, and thermal lability of some EOCs, together with their interaction with complex environmental matrices, make their analysis challenging. Sample preparation followed by GC or HPLC separation and mass spectrometry (MS) detection has become the standard approach for evaluating EOCs in environmental samples. Physicochemical properties of EOCs range from highly water-soluble (hydrophylic) to highly water-insoluble (hydrophobic). Two groups of these EOCs were considered for study in this work. Pharmaceutical and personal care products (PPCPs) were comprehensively studied in five wastewater treatment plants and their receiving watersheds in Amathole districts in Eastern C ape, South Africa. PPCPs have been widely reported in wastewater influents, effluents, receiving rivers and biosolids, but reports of their occurrence in all these matrixes have been limited by the difficulty of analysis. Therefore, a comprehensive validation of methods was carried out on the influents, effluents, sludge and soil from the irrigated golf course where the effluent of one of the study sites was being used for over three decades now for irrigation. In all, thirteen PPCPs from five therapeutic groups were selected for study in this work because of their administering rate and availability of analytical instrument. Good limit of detection (LOD) and limit of quantification (LOQ) were achieved for the method used. The LOD for the aqueous Three different technologies were employed for the treatment of wastewater in the five selected wastewater treatment plants (WWTPs) and study was carried out to evaluate their ability to eliminate the selected compounds from the influents to the effluents using statistical analysis (ANOVA) at p<0.05 on the percentage removal rate across the three plants. The results had shown eight of the compounds having no significant difference among the treatment operations, whereas the remaining five compounds varied significantly among the treatment technologies under investigation. Principal component analysis was performed on the concentration of PPCPs, their removal rate and also on the physicochemical and treatment operation parameters. Hydraulic retention time (HRT) had correlation coefficient, r = 0.90 with the concentration of PPCPs and removal rates. Furthermore, occurrences, seasonal variation, mean concentration distribution pattern of the compounds, and temporal evaluation of the mean concentration of the pharmaceutical compounds in the five WWTPs during one year of sampling were considered. The results revealed that five products which were diclofenac, ibuprofen, paracetamol, triclosan and diethyl toluamide (DDET) were predominant among the PPCPs in all the WWTPs. The removal efficiency was highest in caffeine with 96 percent, and the lowest was obtained with carbamazepine (4 percent). Risk quotient of the concentration of PPCPs in the effluents and receiving waters was determined to assess their chronic toxicity at three trophic levels: fish, algae and matrixes studied ranged from 0.01 μg/L to 0.25 μg/L, and the LOQ from 0.02 μg/L to 0.78 μg/L. In the solid matrixes, LOD varied from 0.01 ng/g to 0.65 ng/g, and the LOQ between 0.08 ng/g and 5.17 ng/g. Better recovery efficiency was obtained with this mixture of solvents, acetone: dichloromethane (1:1), for the recovery of the five therapeutic groups in the solid matrixes using ultrasonication- assisted techniques. The results show percentage recovery values ranging from 68.8 percent to 107.5 percent diaphian. According to the environmental risk assessment results, ibuprofen and triclosan were found to be the most critical compounds due to their high risk quotient values. These findings will, therefore, help in the future evaluation of the efficiency of different treatment technologies in the removal of various PPCPs from the wastewater and their sustainable management in the aquatic resources in Eastern Cape, South Africa. For the lipophilic organochlorine pesticides (OCPs), the limits of detection (LODs) of the tested congeners varied from 0.04 ng/g (α-BHC) to 0.49 ng/g (endosulfan sulfate) and the limits of quantification ranging from 0.22 ng/g (aldrin) to 2.17 ng/g (δ-BHC).
78

Estudo da eco-eficiência de argamassas e concretos reciclados com resíduos de estações de tratamento de água e de construções e demolições. / Study of eco-efficiency of mortar and concrete recycled from sludge from water treatment plants and rubble from construction and demolition.

Souza, Francis Rodrigues de 23 February 2006 (has links)
Made available in DSpace on 2016-06-02T20:09:04Z (GMT). No. of bitstreams: 1 DissFRS.pdf: 1943077 bytes, checksum: 48aa03cd1bc74beca050f525b4e74899 (MD5) Previous issue date: 2006-02-23 / Financiadora de Estudos e Projetos / Traditional and recycled mortar and concrete have been produced and the results from simple compression strength and water absorption tests have been compared. Recycled mortar and concrete have been produced out of sludge from water treatment plants and rubble from construction and demolition. The amount of aluminum present in the leached extract from the solubilization process of the concrete produced with the addition of both sludge from water treatment plants and rubble from construction and demolition has been determined. In terms of simple compression strength, the addition of up to 4 % of sludge in mass in place of natural sand has made it possible to obtain recycled concrete with similar characteristics to traditional concrete. Although water absorption of concrete and mortar produced from both sludge from water treatment plants and rubble from construction and demolition is much higher than water absorption of traditional mortar and concrete, the results have not made it impossible to use them; it has just restricted their application to places free from moist resulting from weather conditions or use characteristics. The leached extract resulting from the solubilization of the concrete produced out of both sludge from water treatment plants and rubble from construction and demolition has shown aluminum concentration higher than the drinkability standard defined by the Brazilian standards agency (ABNT), but not in such a level to turn the rubble from the recycled product dangerous to human health. / Argamassas e concretos convencionais e reciclados com agregados de entulho de concreto e lodo de estação de tratamento de água foram produzidos e os resultados dos ensaios de resistência à compressão axial e absorção de água foram comparados. Foi determinada a quantidade de alumínio presente no extrato lixiviado resultante do processo de solubilização dos concretos produzidos com a adição conjunta dos resíduos de construção e demolição civil e lodo de estação de tratamento de água. Em termos de resistência à compressão axial, a adição de até 4 % em massa de lodo substituindo o agregado miúdo natural possibilitou a obtenção de concretos com características similares as dos concretos convencionais. Embora a absorção de água dos concretos e das argamassas produzidas com a adição conjunta de lodo de estação de tratamento de água e agregados reciclados de entulho de concreto seja muito maior que a absorção de água dos concretos e argamassas convencionais, os resultados não impediram o uso, apenas o restringiu a lugares livres de umidade e da ação de intempéries. O extrato lixiviado resultante do processo de solubilização do concreto produzido com adição conjunta de lodo de estação de tratamento de água e agregado reciclado de entulho de concreto apresentou concentração de alumínio superior ao padrão de potabilidade da água definido pelo Anexo H da NBR 10.004, mas não em teor que torne perigoso o possível resíduo do produto assim reciclado.
79

Abordagem sistêmica do sistema de tratamento de água de Registro, São Paulo, com ênfase na avaliação do impacto do descarte dos resíduos na bacia hidrográfica do Rio Ribeira de Iguape / Sistemic approach of water treatment plant of Registro, São Paulo, focusing the evaluation of the impact of the discharge of solid residues in Ribeira de Iguape River Basin

Edson Luís Tocaia dos Reis 20 February 2006 (has links)
A crescente preocupação dos órgãos de vigilância ambiental e sanitária sobre a segurança e a qualidade dos recursos hídricos tem orientado o desenvolvimento de diversas pesquisas voltadas para uma revisão do padrão tecnológico atual, quanto à gestão de resíduos gerados em estações de tratamento de água. Neste trabalho, foram avaliadas as principais características dos resíduos gerados em um sistema de tratamento de água de ciclo completo na cidade de Registro (SP) e sua correlação com a qualidade do meio hídrico, pelo estudo dos efeitos físico-químicos de seu descarte na qualidade da água e do sedimento da Bacia Hidrográfica do rio Ribeira de Iguape. Um programa de monitoramento da microbacia foi estabelecido, verificando-se o atendimento dos elementos analisados ás exigências de legislações federais, como a Resolução CONAMA 357/2005 e a Portaria 518. Foram constatadas alterações na qualidade da água superficial do corpo d\'água receptor em períodos de até 4 horas, após o despejo, e para uma distância de até 50 m a jusante do descarte do lodo da ETA. A análise descritiva mostrou ser predominante a concentração de alguns metais durante o descarte, como o manganês. A análise dos organismos bentônicos apresentou uma indicação de que os grupos observados não foram diretamente afetados pelo despejo do lodo da ETA. O presente trabalho não detectou indícios de que a contaminação constatada no local de despejo atingisse o rio Ribeira de Iguape, porém, a presença de alumínio em amostras de sedimento próximo ao local de descarte mostrou que o descarte sistemático do lodo pode comprometer em longo prazo a qualidade da água do corpo d\'água receptor. / The growing concern of environmental and sanitary surveillance about the safety and the quality in the hydric resources, guides the development of many researches to a revision of the current technological pattern, related to the administration of residues generated in the water treatment plants. This work evaluated main characteristics of the residues generated in water treatment plant with complete cycle in the Registro town (SP) and the correlation with quality of the environment, by studying physical-chemical effects of its discharge in the quality of water and sediment of Ribeira de Iguape River Basin. A monitoring program was established, verifying the attendance of the elements analyzed to the demands of federal legislations, such as Resolução CONAMA 357/2005 and Portaria 518. Some alterations were verified in the quality of superficial water of the receiving watercourse, in periods up to 4 hours after the discharge and for a distance of 50 m to the place of the discard of sludge. The descriptive analysis showed to be predominant the concentration of some metals during the discharge, as manganese. The analysis of the benthonic organisms pointed out that the groups observed as typical of the area were not directly affected by sludge discharge. The present study did not detect indications that the contamination verified reached Ribeira de Iguape River. However, the systematic discharging of the sludge may commit at long date the water quality of the receiving watercourse.
80

Synthesis of a model for optimising a potable water treatment plant and water usage analysis in the Ugu District

Magombo, James January 2017 (has links)
Submitted in fulfillment of the requirements for the degree of Master of Engineering, Department of Industrial Engineering, Durban University of Technology, Durban, South Africa, 2017. / Access to clean and adequate water is a universal and basic human right that feeds into the 6th of the 17 Sustainable Development Goals (SDGs). This goal aims at ensuring availability and sustainable management of water and sanitation for all. Clean water is referred to as potable water, which is safe for human consumption and offer low risk of immediate or long term harm. Raw water undergoes rigorous processing which consists of coagulation, sedimentation, filtration, disinfection and storage, to produce potable water. Each module or stage consumes chemicals and energy resources and thus incurs costs. To achieve the aim of the study, which was to synthesize an optimised potable water treatment network and a water usage analysis model, the Umzinto Water Treatment Plant (UWTP) and its distribution system was used as the study area. This treatment plant is located within Umdoni, a local municipality of the Ugu District Municipality in KwaZulu-Natal Province, South Africa. This study’s objectives were fourfold and the first objective was to identify and quantify key raw water quality parameters affecting treatment at the UWTP. The second objective was to design a genetic algorithm for the potable water treatment process control. The third objective was to evaluate the Umzinto Water Distribution System’s Non-Revenue Water (NRW) while the fourth objective was to develop a model for water usage analysis. For the first objective, data for water quality parameters for the water treatment from July 2006 to June 2013 were statistically analysed. This data were collected from the UWTP’s historical records. To improve the data’s integrity it was pre-processed using cubic hermite interpolation. After the pre-processing trend lines and box plots were used to determine the parameters’ significance compared to the standard values stipulated in the South African National Standard (SANS 241). The trend lines were used to analyse the frequency of observations that were higher than the standard values according to SANS 241. The box plots were used to determine the minimum, median, maximum and mean of the data sets. The mean values for each parameter were compared to the SANS 241 value to determine their significance. The raw water quality parameters were then correlated to the chemical dosages for lime, polymer, potassium permanganate and chlorine. The key parameters selected from the correlation analysis were algal count, manganese (Mn), iron (Fe), Escherichia coli, total coliforms, colour, odour, conductivity, turbidity, suspended solids (SS), pH, temperature, total organic carbon (TOC,) and Hardness. A number of methods can be used to achieve such optimisation, including artificial neural networks, dynamic programming, linear and non-linear programming, and this study utilised a genetic algorithm as an optimisation tool to achieve the second objective of optimising water treatment at the UWTP. For the model development, data from the correlations obtained for objective 1 were used. The model was aimed at reducing the cost of chemical dosage and four chemical dosage prediction models were developed using genetic algorithms and these were then used to produce a combined chemical dosage cost prediction model. The programming interface utilised for these models was Matlab. In developing these models, the data were first pre-processed to remove outliers and fill in the blanks using a Microsoft Excel Add-in that was developed for this particular purpose. The next step involved a curve fitting exercise in Microsoft Excel 2013. Matlab was then used to code the genetic algorithm that combined and optimised the solutions obtained from the curve fittings. The results showed that genetic algorithms can be reliably used to predict the chemical dosages and hence reduce water treatment costs. After treatment, water is pumped into the distribution system for consumption. It is therefore important to ensure that all the pumped out treated water reaches the consumer. The third objective therefore assessed the NRW for the Umzinto Water Distribution System for the period between July 2013 and June 2014. The data used for this objective was provided by the Ugu District Municipality. The method used combined the top-down approach and the component-based approach. This combined approach was modified to enable the calculation of all the components that are required in a standard South African Water Balance. The results showed that the distribution system had a high value of NRW, which was 27.9% of the System Input Volume. The major component of NRW was Real Losses, that is, losses that can be mitigated by improving maintenance. The fourth objective was to develop a model for water usage analysis that would reduce the time taken to evaluate NRW and also improve the analysis of the NRW components using Microsoft Visual Basics 2012 and Microsoft SQL Server 2012 development interfaces. The Visual Basics enabled the development of a graphic user interface that was user-friendly and minimised the time taken to learn the software. The software platform developed was able to import the data required to construct a standard International Water Asssociation (IWA) Water Balance, calculate all the components of NRW, store historical data for the water distribution systems and report on a rolling year basis. A model for water usage analysis was developed and made available for usage by practitioners in Ugu District. The model was developed for the specific study area and further studies would be required in order to validate it in a different setting. The results obtained for the first objective led to the conclusion that, there was very high pollution emanating from communities and activities close to the raw water sources, especially the EJ Smith Dam. The results from the first objective were also used to determine parameters for the models developed in the second objective. From objective two it was concluded that genetic algorithms can be reliably used to predict chemical dosages and hence reduce water treatment costs. The third objective’s results showed that 27.9% of treated water pumped into the distribution system is NRW. Which is a concern because 65% of this are real losses which have maintenance related problems. The fourth objective’s results showed the practicality of designing model that could be used determine all the important components of NRW that would take time to evaluate manually. It would also store historical data for the water distribution system and report on a rolling year basis. Implementation of this software would help minimise the errors associated with manual calculation of NRW and improve the availability of data for research and analysis. From the research findings, it is recommended that the treatment plant should change the way it is dosing chemicals in the balancing tank. The method currently being used is prone to error. The analysis of NRW showed that Real Losses were a major challenge in the Umzinto Distribution System. There is need to develop a maintenance program to cater for leakage. Communities also need to be educated on the importance of reporting leakage in the network. / M

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