A cultura da cana-de-açúcar, pelo alto consumo de água e de nutrientes, além da destinação industrial, apresenta características ideais para o recebimento de efluente de estações de tratamento de esgoto (EETE) sob a forma de irrigação. Esta prática tem como objetivo a reciclagem de nutrientes e de água, o incremento da produtividade e a economia de fertilizantes, de terra arável e de água potável. Apesar das múltiplas vantagens ambientais, não é desprovida de riscos, e este trabalho teve como objetivos avaliar a dinâmica de nutrientes no sistema solo-planta de canavial irrigado com efluente de esgoto tratado em dois ciclos consecutivos da cana-soca e a influência do aporte de nutrientes e outros elementos via efluente sobre a nutrição mineral da canade- açúcar. Foram aplicadas lâminas de irrigação com o esgoto tratado entre 0 (sem irrigação) e 200 % da exigência de água pela cultura, em gotejamento subsuperficial. Foram avaliados os aportes de nutrientes e outros elementos pelo efluente, os efeitos na composição nutricional da planta e da fração trocável do solo e o desempenho quantitativo e qualitativo da cultura. Concluiu-se que o efluente pode fornecer até 163 kg ha-1 de N; 14 kg ha-1 P; 145 kg ha-1 de K; 80 kg ha-1 de Ca; 28 kg ha-1 de Mg; 207 kg ha-1 de S; 0,45 kg ha-1 de B; 0,07 kg ha-1 de Cu; 0,25 kg ha-1 de Fe e 0,18 kg ha-1 de Mn, sendo fonte potencial de nutrientes à cultura da cana-de-açúcar, principalmente N, Ca e S, precisando de complementação mineral de P, K, Mg e micronutrientes. O estado nutricional da cultura, avaliado pela diagnose foliar melhorou para N, Mg, S e Cu no segundo ano avaliado. A folha +1 foi mais sensível às alterações de disponibilidade de nutrientes. A presença de elementos no efluente que podem potencialmente provocar degradação nas propriedades físicas do solo, tal como o sódio, contaminação de águas subterrâneas, como o nitrogênio, ou ainda tóxicos, como cromo e cobre, exige monitoramento constante da área agrícola que recebe este resíduo. Neste trabalho de curto prazo, estes elementos não representaram problemas. A irrigação com EETE proporcionou aumento do desempenho vegetativo da cultura e um ganho de produtividade na cana-de-açúcar de até 19,84 e 40,47 Mg ha-1, na primeira e na segunda socas, respectivamente. A qualidade industrial da cana-de-açúcar não foi alterada significativamente pela irrigação com EETE. Este trabalho mostrou que a irrigação com EETE é exequível, possui potencial econômico e seria uma solução possível para parte da demanda agrícola de água e dos problemas de poluição dos corpos dágua naturais. / Sugarcane cultivation, due to the high water and nutrients consumption, besides the industrial utilization, has ideal characteristics for receiving sewage treatment plant effluent (STPE) as irrigation. This practice aims to recycle nutrients and water, increasing productivity and decreasing the use of fertilizers, agricultural land and potable water. Despite the many environmental benefits, it has risks, and this study aimed to evaluate the dynamics of nutrients in the soil-sugarcane plant system irrigated with treated sewage effluent in two consecutive sugarcane ratoon cycles and the influence of nutrient and other elements added as effluent on the sugarcane mineral nutrition. Irrigations with treated sewage were applied up to 200% of the crop water requirement by subsurface drip. Nutrient and other elements input by the effluent, its effect on plant nutritional composition, soil exchangeable fraction and the quantitative and qualitative sugarcane performance were evaluated. Effluent can provide up to 163 kg ha-1 N, 14 kg ha-1 P, 145 kg ha-1 K, 80 kg ha-1 Ca, 28 kg ha-1 Mg, 207 kg ha-1 S, 0.45 kg ha-1 B, 0.07 kg ha-1 Cu, 0.25 kg ha-1 Fe and 0.18 kg ha-1 Mn, being a potential source of N, Ca and S, needing additional P, K, Mg and micronutrients fertilization. Sugarcane nutritional status as assessed by foliar analysis was improved for N, Mg, S and Cu in the second ratoon evaluated. Top visible dewlap leaf was more sensitive to changes in the nutrients availability. The presence of elements in the effluent that can potentially cause degradation in soil physical properties, such as sodium, groundwater contamination, such as nitrogen, or toxic substances, such as chromium and copper, requires constant monitoring of the agricultural area that receives this residue. In these short-term experiments there were no such problems. The replacement of crop evapotranspiration by irrigation with STPE provided an increase in vegetative performance and a gain in productivity of the sugarcane by 19.84 and 40.47 Mg ha-1, in the first and in the second ratoon, respectively. Industrial quality of sugarcane was not significantly affected by irrigation with STPE. This study showed that irrigation with STPE is potentially feasible, has economic potential, and would be a possible solution to part of the agricultural water demand and natural water bodies pollution problems

O objetivo deste estudo foi avaliar a qualidade virológica da água de reúso produzida em uma das estações de tratamento de esgoto da cidade de São Paulo. Para tanto, foram coletadas concomitantemente 177 amostras de esgoto tratado (100L) e bruto (15L) e os vírus concentrados utilizando método Viradel-ultracentrifugação. Em seguida as amostras foram tratadas com Vertrel XF e os ácidos nucléicos extraídos para a detecção de adenovírus (HAdV), rotavírus (RV-A), norovírus e vírus da hepatite A (VHA). A detecção por PCR e/ou RT-PCR evidenciou RV-A (G1-G5), VHA e HAdV incluindo os da espécie F tanto no esgoto bruto quanto no tratado, no entanto norovírus não foram detectados em ambos os efluentes. A infectividade de RV-A e HAdV foi avaliada por cultivo celular e os rotavírus RV-A foram também quantificados por reação de imunoperoxidase direta. PCR em tempo real foi padronizada para quantificação de vírus não cultiváveis ou de difícil cultivo como os VHA. Com base nos resultados obtidos foi verificada a ocorrência e a distribuição anual de cada vírus nas águas de reúso. / The aim of the study was to evaluate the virological quality from one Sewage Treatment Plant in the state of São Paulo. From January/2005 to November/2006, 177 samples (15L) of raw sewage were collected at the entrance and another 177 (100L) at the end of treatment, twice a week. Viruses were concentrated by filtration through positively charged microporous filters, followed by ultracentrifugation. Virus concentrates were treated by using Vertrel-XF and the viral genomes extracted for detection of adenovirus (HAdV), rotavirus (RV-A), norovirus and hepatitis A virus (HAV). PCR and RT-PCR revealed RV-A (G1-G5), HAV and HAdV, including the enteric ones (species F) in sewage and treated wastewater samples. Norovirus was not detected in any samples. The infectivity of HAdV and RV-A was assayed by inoculating onto suitable cell line. Immunoperoxidase assay was used to calculate the rotavirus FFU/L in the samples. Real time-PCR was standardized for enumeration of non-cultivable virus. The occurrence and annual distribution of each virus in reuse water were analyzed.

Made available in DSpace on 2017-07-10T19:24:35Z (GMT). No. of bitstreams: 1 Rosimaldo Soncela.pdf: 1165359 bytes, checksum: 65125007d81deb1038c3d55926b33252 (MD5) Previous issue date: 2010-06-30 / The swine waste water (SWW) application in soil has become an alternative fertilizer for soil and used as a water reuse. However, special attention must be given to the amount of salt content in such water since succeeding applications can stimulate the saltishness process on soil, which can ask for an indispensable monitoring of salt content in soil. The time-domain reflectometry (TDR) allows for a continuous and simultaneous monitoring of water content and apparent electric conductivity on soil (AEC), in order to make feasible the indirect determination of electric conductivity of soil solution, which can estimate salt content in the soil. Nevertheless, there is a need to obtain and calibrate a model for each type of soil. Thus, this trial aimed at obtaining a volumetric humidity calibration model for a typical Distroferric Red Latosol, as well as studying this technique viability to indirectly determine the electrical conductivity in a soil solution using an empiric equation for the TDR Trase 6050X1 devise. Calibration was performed under laboratory conditions, with deformed samples of the studied soil, conditioned in columns, with a 0.0078 m3 volume. TDR hand-made probes, with three 0.20m-long shafts, were vertically installed in the soil columns, five probes per column, totaling 16 columns. The weighing answers were obtained by digital scales and daily readings with the TDR equipment. To indirectly determine soil solution electric conductivity, deformed and saturated samples were used and saturated with SWW at 0, 10, 20, 40, 60, and 80 liters with a soil volume of 0.0225 m3. The SWW was evaporated so that saturated soil got completely dry and sieved in a 2 mm sieve to obtain the air dried fine soil (ADFS). The volumes of dried soils were conditioned in three columns to characterize T0, T1, T2, T3, T4 and T5 treatments. The same procedure was carried out for probes calibration. At that moment, four probes were installed by column, totaling 18 columns. The empirical model to estimate the volumetric soil humidity under study showed an adequate degree of determination. At last, It was possible to establish an empirical model that connected AEC recorded by the TDR equipment and electrical conductivity of saturated soil sample (ECss), making possible the use of this technique on soil salinity estimation. / A aplicação de águas residuárias de suinocultura (ARS) no solo vem sendo uma alternativa como forma de adubação e reúso de água. Entretanto, atenção especial deve ser dada à quantidade de sais contidos nessas águas, uma vez que aplicações sucessivas podem favorecer o processo de salinização do solo, tornando-se necessário um monitoramento do teor de sais no solo. A reflectometria no domínio do tempo (TDR) possibilita o monitoramento simultâneo e contínuo do teor de água e da condutividade elétrica aparente do solo (CEa) a fim de viabilizar a determinação indireta da condutividade elétrica da solução do solo, a qual possibilita a estimativa do teor de sais no solo. Porém, há necessidade de obtenção e calibração de um modelo para cada tipo de solo. Desta forma, o objetivo deste trabalho foi obter um modelo de calibração de umidade volumétrica para um Latossolo Vermelho Distroférrico Típico, bem como estudar a viabilidade da técnica na determinação indireta da condutividade elétrica da solução do solo por meio de uma equação empírica para o equipamento TDR Trase 6050X1. A calibração foi realizada em condições de laboratório, utilizando amostras deformadas do solo em estudo, acondicionadas em colunas com volume de 0,0078 m3. As sondas fabricadas artesanalmente da TDR com três hastes e 0,20 m de comprimento foram instaladas verticalmente nas colunas de solo, em um total de cinco sondas por coluna, totalizando 16 colunas. Realizaram-se as pesagens com balança digital e leituras diárias com o equipamento TDR. Para a determinação indireta da condutividade elétrica da solução do solo, foram utilizadas amostras deformadas, as quais foram saturadas com ARS nas taxas de 0, 10, 20, 40, 60 e 80 litros por um volume de 0,0225 m3 de solo. Deixou-se que a ARS evaporasse até que o solo saturado secasse totalmente, peneirado em peneira de 2 mm para formar Terra Fina Seca ao Ar (TFSA). Os volumes de solos secos foram acondicionados em três colunas, caracterizando-se os tratamentos T0, T1, T2, T3, T4 e T5. O mesmo processo ocorreu para a calibração das sondas. Nesta etapa, foram instaladas quatro sondas por coluna totalizando 18 colunas. O modelo empírico para estimativa da umidade volumétrica do solo em estudo apresentou suficiente grau de determinação. Foi possível estabelecer um modelo empírico que relacionou a condutividade elétrica aparente do solo (CETDR) e a condutividade elétrica do extrato saturado do solo (CEes) para viabilizar o uso da técnica na estimativa da salinidade do solo.

Made available in DSpace on 2017-05-12T14:47:58Z (GMT). No. of bitstreams: 1 Rosimaldo Soncela.pdf: 1165359 bytes, checksum: 65125007d81deb1038c3d55926b33252 (MD5) Previous issue date: 2010-06-30 / The swine waste water (SWW) application in soil has become an alternative fertilizer for soil and used as a water reuse. However, special attention must be given to the amount of salt content in such water since succeeding applications can stimulate the saltishness process on soil, which can ask for an indispensable monitoring of salt content in soil. The time-domain reflectometry (TDR) allows for a continuous and simultaneous monitoring of water content and apparent electric conductivity on soil (AEC), in order to make feasible the indirect determination of electric conductivity of soil solution, which can estimate salt content in the soil. Nevertheless, there is a need to obtain and calibrate a model for each type of soil. Thus, this trial aimed at obtaining a volumetric humidity calibration model for a typical Distroferric Red Latosol, as well as studying this technique viability to indirectly determine the electrical conductivity in a soil solution using an empiric equation for the TDR Trase 6050X1 devise. Calibration was performed under laboratory conditions, with deformed samples of the studied soil, conditioned in columns, with a 0.0078 m3 volume. TDR hand-made probes, with three 0.20m-long shafts, were vertically installed in the soil columns, five probes per column, totaling 16 columns. The weighing answers were obtained by digital scales and daily readings with the TDR equipment. To indirectly determine soil solution electric conductivity, deformed and saturated samples were used and saturated with SWW at 0, 10, 20, 40, 60, and 80 liters with a soil volume of 0.0225 m3. The SWW was evaporated so that saturated soil got completely dry and sieved in a 2 mm sieve to obtain the air dried fine soil (ADFS). The volumes of dried soils were conditioned in three columns to characterize T0, T1, T2, T3, T4 and T5 treatments. The same procedure was carried out for probes calibration. At that moment, four probes were installed by column, totaling 18 columns. The empirical model to estimate the volumetric soil humidity under study showed an adequate degree of determination. At last, It was possible to establish an empirical model that connected AEC recorded by the TDR equipment and electrical conductivity of saturated soil sample (ECss), making possible the use of this technique on soil salinity estimation. / A aplicação de águas residuárias de suinocultura (ARS) no solo vem sendo uma alternativa como forma de adubação e reúso de água. Entretanto, atenção especial deve ser dada à quantidade de sais contidos nessas águas, uma vez que aplicações sucessivas podem favorecer o processo de salinização do solo, tornando-se necessário um monitoramento do teor de sais no solo. A reflectometria no domínio do tempo (TDR) possibilita o monitoramento simultâneo e contínuo do teor de água e da condutividade elétrica aparente do solo (CEa) a fim de viabilizar a determinação indireta da condutividade elétrica da solução do solo, a qual possibilita a estimativa do teor de sais no solo. Porém, há necessidade de obtenção e calibração de um modelo para cada tipo de solo. Desta forma, o objetivo deste trabalho foi obter um modelo de calibração de umidade volumétrica para um Latossolo Vermelho Distroférrico Típico, bem como estudar a viabilidade da técnica na determinação indireta da condutividade elétrica da solução do solo por meio de uma equação empírica para o equipamento TDR Trase 6050X1. A calibração foi realizada em condições de laboratório, utilizando amostras deformadas do solo em estudo, acondicionadas em colunas com volume de 0,0078 m3. As sondas fabricadas artesanalmente da TDR com três hastes e 0,20 m de comprimento foram instaladas verticalmente nas colunas de solo, em um total de cinco sondas por coluna, totalizando 16 colunas. Realizaram-se as pesagens com balança digital e leituras diárias com o equipamento TDR. Para a determinação indireta da condutividade elétrica da solução do solo, foram utilizadas amostras deformadas, as quais foram saturadas com ARS nas taxas de 0, 10, 20, 40, 60 e 80 litros por um volume de 0,0225 m3 de solo. Deixou-se que a ARS evaporasse até que o solo saturado secasse totalmente, peneirado em peneira de 2 mm para formar Terra Fina Seca ao Ar (TFSA). Os volumes de solos secos foram acondicionados em três colunas, caracterizando-se os tratamentos T0, T1, T2, T3, T4 e T5. O mesmo processo ocorreu para a calibração das sondas. Nesta etapa, foram instaladas quatro sondas por coluna totalizando 18 colunas. O modelo empírico para estimativa da umidade volumétrica do solo em estudo apresentou suficiente grau de determinação. Foi possível estabelecer um modelo empírico que relacionou a condutividade elétrica aparente do solo (CETDR) e a condutividade elétrica do extrato saturado do solo (CEes) para viabilizar o uso da técnica na estimativa da salinidade do solo.

Thesis (MSc. Agriculture (Soil Science)) -- University of Limpopo, 2019 / Global shortage of fresh quality water has led to the use of treated wastewater in arid and semi-arid regions. Although, the treated wastewater has proven to be the best solution in ameliorating pressures brought by water shortage, it contains toxic heavy metals, some in high concentrations that could possibly pose health risks and degrade soil quality. Therefore, the objectives of the study were to determine the vertical and horizontal distribution of bioavailable heavy metals on virgin, cultivated and fallowed fields and to investigate the bioremediation abilities of selected soil microbes on non-essential heavy metals in cultivated and fallowed soils following irrigation with treated wastewater at University of Limpopo (UL) Experimental Farm. Three fields, namely, virgin field (VF), cultivated field (CF) and fallowed field (FF), each being 6.4 ha, were each divided into 40 equal grids, equivalent to 40 m × 40 m, which were used in vertical assessment of heavy metals. Soil profiles were established inside each grid and soil samples collected at 0-20; 20-40 and 40-60 cm soil depth for further laboratory analysis. The soil samples were analyzed for basic soil physico-chemicals, namely, particle size distribution, soil pH (H20 and KCl), electrical conductivity (EC), reduction potential (Eh), organic carbon (OC) and cation exchange capacity (CEC). Five essential heavy metals namely zinc (Zn), iron (Fe), copper (Cu), cobalt (Co), manganese (Mn) and five non-essential heavy metals, namely, arsenic (As), chromium (Cr), lead (Pb), aluminium (Al), and cadmium (Cd), were also extracted from the soil samples. Heavy metal resistant Gram-negative (–) and Gram-positive (+) bacteria were isolated from the soil and identified as Providencia rettgeri (–), Enterobacter cloacae (–), Bacillus cereus (+) and Arthrobacter aurescens (+). xix The isolated bacteria were cultured and inoculated in heavy metal-contaminated soils and incubated for 12 weeks to bioremediate the non-essential heavy metals. Results obtained suggested that the treatments had no significant (P ≤ 0.05) effects on vertical distribution of all the essential and non-essential heavy metals among the three fields. However, on average Co was above the permissible level at 53 mg/kg in CF at 0-20 cm and although all the other essential heavy metals increased, they were still within the permissible levels. The concentration of As was also above the permissible levels in CF with an average concentration of 4.30 mg/kg. Cadmium levels were also above the permissible levels in CF with an average concentration of 1.146 mg/kg in CF and this increased by 0.46 units from VF which had an average value of 1 mg/kg. However, fallowing reduced Cd to 0.51 mg/kg which was below or within the expected limits in soil previously irrigated with treated waste water. Gram-positive bacteria reduced more concentrations of non-essential heavy metals separately and combined, especially in the fallowed field. Irrigation with treated wastewater has shown to have both negative and positive effects on the concentration of essential and non-essential heavy metals in cultivated and fallowed fields. Bioremediation coupled with fallowing has been proven to be the best solution in ameliorating heavy metal toxicity while naturally improving the quality of the soil. / National Research Foundation (NRF)

No description available.

There is an urgent need for wastewater treatment plants (WWTPs) to adapt to a rise in water and energy demands, prolonged periods of drought, climate variability, and resource scarcity. As population increases, minimizing the carbon and energy footprints of wastewater treatment, while properly managing nutrients is crucial to improving the sustainability WWTPs. Integrated resource recovery can mitigate the environmental impact of wastewater treatment systems; however, the mitigation potential depends on various factors such as treatment technology, resource recovery strategy, and system size. Amidst these challenges, this research seeks to investigate the environmental sustainability of wastewater treatment plants (WWTPs) integrating resource recovery (e.g., water reuse, energy recovery and nutrient recycling) in different contexts (developing versus developed world) and at different scales (household, community, and city). The over-arching hypothesis guiding this research is that: Context and scale impact the environmental sustainability of WWTPs integrated with resource recovery. Three major research tasks were designed to contribute to a greater understanding of the environmental sustainability of resource recovery integrated with wastewater treatment systems. They include a framework development task (Chapter 2), scale assessment task (Chapter 3), and context assessment task (Chapter 4). The framework development task includes a critical review of literature and models used to design a framework to assess the environmental sustainability of wastewater treatment and integrated resource recovery strategies. Most studies used life cycle assessment (LCA) to assess these systems. LCA is a quantitative tool, which estimates the environmental impact of a system over its lifetime. Based on this review, a comprehensive system boundary was selected to assess the life cycle impacts of collection, treatment, and distribution over the construction and operation and maintenance life stages. Additionally, resource recovery offsets associated with water reuse, energy recovery, and nutrient recycling are considered. The framework’s life cycle inventory includes material production and delivery, equipment operation, energy production, sludge disposal, direct greenhouse gas (GHG) emissions, and nutrients discharged to the environment. Process-based LCA is used to evaluate major environmental impact categories, including global impacts (e.g., carbon footprint, embodied energy) and local impacts (e.g., eutrophication potential). This is followed by an interpretation of results using sensitivity or uncertainty analysis. The scale assessment task investigates how scale impacts the environmental sustainability of three wastewater treatment systems integrated with resource recovery in a U.S. context. Household, community, and city scale systems using mechanized technologies applicable to a developed world setting were investigated. The household system was found to have the highest environmental impacts due high electricity usage for treatment and distribution, methane emissions from the septic tank, and high nutrient discharges. Consequently, the life cycle impacts of passive nutrient reduction systems with low energy usage at the household level merit further investigation. The community scale system highlights trade-offs between global impacts (e.g., embodied energy and carbon footprint) and local impacts (e.g., eutrophication potential) where low nutrient pollution can be achieved at the cost of a high embodied energy and carbon footprint. The city scale system had the lowest global impacts due to economies of scale and the benefits of integrating all three forms of resource recovery: Energy recovery, water reuse, and nutrient recycling. Integrating these three strategies at the city scale led to a 49% energy offset, which mitigates the carbon footprint associated with water reuse. The context assessment task investigates how context impacts the environmental sustainability of selected community scale systems in both Bolivia and the United States. In this task, rural developing world and urban developed world wastewater management solutions with resource recovery strategies are compared. Less mechanized treatment technologies used in rural Bolivia were found to have a lower carbon footprint and embodied energy than highly mechanized technologies used in urban United States. However, the U.S. community system had a lower eutrophication potential than the Bolivia systems, highlighting trade-offs between global and local impacts. Furthermore, collection and direct methane emissions had more important energy and carbon implications in Bolivia, whereas treatment electricity was dominant for the U.S. community system. Water reuse offsets of embodied energy and carbon footprint were higher for the U.S community system, because high quality potable water is replaced instead of river water. In contrast, water reuse offsets of eutrophication potential were high for the Bolivia systems, highlighting the importance of matching treatment level to end-use application. One of the Bolivia systems benefits from the integration of water, energy, and nutrient recovery leading to beneficial offsets of both global and local impacts. This research can potentially lead to transformative thinking on the appropriate scale of WWTPs with integrated resource recovery, while highlighting that context lead to changes in the dominant contributors to environmental impact, appropriate technologies, and mitigation strategies.

Centralized infrastructure (CI) is difficult to sustain with limited water and fossil fuel resources because CI withdraws 100% of water demand from the environment as an open-loop system and electricity is consumed to transport and treat water and wastewater while demand is increasing. Hybrid infrastructure (HI) is proposed to combine CI with decentralized alternatives such as low impact development (LID) technologies (i.e., xeriscaping, rain gardens, and rainwater harvesting) or greywater reclamation systems with membrane bioreactors (MBRs). Water, wastewater, and stormwater systems in the City of Atlanta (COA) were regarded as CI. HI was compared to CI using life cycle environmental impacts measured by water reuse index (WRI) and life cycle assessment (LCA) scores. WRI is a ratio of water withdrawal to sustainable water resources of wastewater (i.e., return flow) and stormwater discharge, which presents water stress level (e.g., 0.2 ~ 0.4: medium-high level). LCA score is determined as % of annual world average environmental damage per capita. As stormwater runoff, water demand, greywater generation, rainwater harvesting, etc. vary depending on land use and population density, feasibility of decentralized alternatives was evaluated in eleven residential communities. Five single-family residential communities were designated as between R-1 of 16 people/10 acres and R-5 of 169 people/10 acres and six multi-family residential communities were designated as between RG-1 of 148 people/10 acres and RG-6 of 5,808 people/10 acres. HI with LID technologies reduced WRI of COA that relies on CI from 0.45 to 0.12. HI reduced the LCA scores of CI with combined sewer system (CSS) by between 1% for RG-6 and 68% for R-1 and the LCA scores of CI with separate sewer system (SSS) by between 0% for RG-6 and 18% for R-1. As population density increases for the multi-family residential communities, harvested rainwater decreases and a small amount of water demand is satisfied. Consequently, it has a negligible impact on the LCA scores in RG-6. HI with greywater reclamation system reduced WRI of COA from 0.45 to 0.35. HI resulted in the LCA scores greater as compared to CI in the five single-family communities and RG-1, RG-2, and RG-3 because of the electricity consumption of small-scale MBR. However, the electricity consumption per kgal decreases with increasing MBR treatment capacity and the LCA scores were reduced by 5% for RG-4, 15% for RG-5, and 21% for RG-6. The MBR treatment capacity of RG-4 is 15.6 kgal/day.

Water is precious, particularly in South Australia, the driest State in Australia, with over 80% of its land area receiving less than 250mm of rainfall per year. Security of water supply has always played a critical role in the economic and social development of South Australia, and will continue to do so while dependency on water from the River Murray is so high and there is competition over this from states and for different uses – municipal, irrigation, industry, and the environment. The drive towards sustainable development has evolved to attenuate overconsumption of the world’s natural resources of which water is a key element. Provision of reliable water supplies to regional South Australia has always presented challenges, given the vast distances involved and the limited number of natural water sources. Despite these, a majority of South Australians enjoy the benefit of a reliable and safe water supply, adequate waste disposal system, good community health and high standard of living. A challenge remains to determine the sustainability of current major water pipe transfer systems from remote resources to small communities. There may be scope for managing existing water supplies more effectively and further developing local water harvesting and reuse solutions to minimise the need for more significant infrastructure investment. This study investigates the challenges and opportunities for extending development of non-potable (secondary) water supply schemes in South Australian towns. These schemes will conserve the State’s freshwater resources. The primary focus of this study is harnessing stormwater runoff and treated effluent generated by normal township development to supplement higher quality public water for uses such as irrigation of public areas and sporting fields in country areas. Water harvesting and reuse is not likely to occur due to some technological breakthrough but through application of known technology and the adoption of water conscious ethics by society. However, it is a sensible reality for the South Australian climate, particularly when coupled with appropriate conservation and suitable landscaping practices. Thus, the major theme of this study is information sharing since if people are familiar with and understand the concepts then more communities may be encouraged to develop their resources. Water reuse has proven to be a beneficial strategy for addressing stormwater runoff and wastewater disposal problems and alleviating localised water supply problems for several South Australian towns and communities. The existing projects demonstrate both the strong community-based and innovative approach to water resources management in this state. They are inherently simple in form, and can often be assembled with readily available materials by people with a basic understanding of plumbing and construction skills (locally available). The potential for localised water harvesting and reuse in South Australian towns is generally limited to single purpose communal non-potable systems. Further, it is likely to only be sustainable in rural communities willing to make a commitment to its long term, proper operation and maintenance, or they could endanger public health. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283773 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Civil and Environmental Engineering, 2007

Les eaux grises (EG) peuvent être considérées comme une ressource alternative à l’eau potable et peuvent donc être réutilisées, par exemple, pour l'arrosage d'espaces verts pour lequel une qualité ''eau destinée à la consommation humaine'' ne semble pas nécessaire. Toutefois la présence de microorganismes pathogènes et de composés organiques peut entraîner des risques sanitaires et environnementaux. Il est donc nécessaire de traiter ces EG avant de les réutiliser et caractériser les risques liés à leur recyclage, jusqu'à présent peu connus. Pour répondre à ces objectifs, la démarche a consisté à caractériser les EG afin de choisir un traitement adapté. Le procédé biologique retenu est un réacteur à lit fluidisé aérobie. Son optimisation a été basée sur l’étude de son comportement hydrodynamique et sur la cinétique de biodégradation des EG. Ses performances épuratoires ont également été déterminées. La qualité des EG traitées produites atteint les objectifs attendus par la réglementation française pour l'irrigation d'espaces verts avec des eaux usées traitées. En effet, la DCO et les MES obtenues dans l'effluent traité sont respectivement de 26 mg O2.L-1 et 5,6 mg.L-1. Le réacteur a permis de traiter 144 L.j-1 d'EG durant 16 mois. Trois parcelles de pelouse ont été irriguées respectivement par des EG brutes, des EG traitées et par de l’eau potable. Contrairement à la parcelle irriguée par les EG brutes, l'analyse de risques n'a montré aucune différence significative entre celle irriguée par les EG traitées et celle irriguée par l'eau potable. Ces travaux démontrent que les EG traitées produites dans cette étude peuvent être employées pour l’irrigation d’espaces verts. / A level of water quality intended for human consumption does not seem necessary for domestic uses such as irrigation of green spaces. Alternative water supplies like the use of greywater (GW) can thus be considered. However, GW contains pathogenic microorganisms and organic compounds which can cause environmental and health risks. As the risks related to recycling are unknown, GW treatment is necessary before reusing. To describe the risks related to GW reuses, the scientific approach performed in this study was to characterize domestic GW in order to select an appropriate treatment. The biological process chosen is an aerobic fluidized bed reactor. As this process has never been developed for GW, an optimization step based on the study of its hydrodynamic behavior and the kinetics of biodegradation of GW was performed. The treatment performances were then determined. The treated GW produced in this study reached the threshold values expected by the French regulation for irrigation of green spaces with treated wastewater. Indeed, the COD and the TSS obtained in treated GW were respectively 26 mg O2.L-1 and 5.6 mg.L-1. The fluidized bed reactor has been used to treat 144 L.d-1 of GW for 16 months. Three lawn plots were irrigated respectively with raw GW, treated GW and tap water asa reference. Contrary to the lawn plot irrigated with raw GW, the risk analysis performed in this study has shown no significant difference between the law plot irrigated with treated GW and the one irrigated with tap water. This study shows that treated GW produced from the fluidized bed reactor developed in this experiment can be used for irrigation of green spaces.