Made available in DSpace on 2017-07-10T19:25:06Z (GMT). No. of bitstreams: 1 Cristiane Kreutz.pdf: 3880883 bytes, checksum: de8fc0d92d64fca6737540c7f40ce521 (MD5) Previous issue date: 2006-10-03 / O crescimento populacional e o consumo excessivo dos diversos segmentos da sociedade acarretam um incremento direto na demanda de água. A minimização e a conservação da água é hoje um importante fator para o desenvolvimento industrial, em decorrência da escassez do recurso. Neste trabalho, buscou-se identificar e avaliar a possibilidade de reúso da água de processo na COOPERATIVA AGROINDUSTRIAL LAR Unidade Industrial de Vegetais. Foram avaliadas as linhas de produção de milho enlatado e brócolis congelado. A etapa experimental consistiu em elaborar fluxogramas dos processos industriais envolvidos, identificar e estimar a demanda de água nos pontos de consumo, realizar balanço de massa dos produtos e insumos envolvidos e realizar coletas de amostras dos pontos com potencialidades de reúso. Os principais resultados indicaram, para o brócolis, um consumo de 33,11 kg de água / kg de matéria-prima e para o milho enlatado 4,35 kg de água / kg de matéria-prima e 3,03 kg de água / kg de matéria-prima, considerando o reúso já praticado. Foram identificadas três etapas que apresentam potencialidade de reúso de água, das quais duas apresentaram viabilidade técnica, estimando-se assim, uma redução no consumo de água limpa de até 76,7 % para a linha de milho enlatado.

Made available in DSpace on 2017-07-10T19:25:09Z (GMT). No. of bitstreams: 1 Nathalie.pdf: 1872403 bytes, checksum: 066688e7a8c000417cf984dd2ee4421c (MD5) Previous issue date: 2012-07-20 / This study aimed at evaluating the agronomic and environmental aspects as results from the continuing application of swine wastewater and mineral fertilizer in corn, black oats and soybeans. The experimental area has a history of swine wastewater application with trials that have been carried out since 2006, whose cycles under management are the seventh, eighth and ninth ones. Four doses of swine wastewater associated with the presence and absence of mineral fertilizer consisted on eight treatments applied to experimental plots. The agronomic and nutritional indices were determined in the three studied crops. The compounds of leachate collected at the beginning and end of each cycle were also recorded as well as soil characteristics at the beginning and end of each crop. The experimental design was in randomized blocks, under a 4x 2 factorial scheme with three replications. The results were submitted to ANOVA and means compared by Tukey test at 5% significance level. In maize crop, after a swine wastewater application, treated in digester, it could be observed that it could be partially used as an alternative fertilizer, since P and Mn+2 were supplemented with specific fertilization. A special management should be given to the accumulation of Fe+2, Cu+2 and Zn+2 in soil. Attention should be paid also to the levels of Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ and Zn+2 in leachate material. In black oats crop, after two applications of swine wastewater treated in digester, it was concluded that swine wastewater can be partially used as an alternative fertilizer, since N, P and S could be supplied. Some attention should be taken with Cu+2 and Zn+2 accumulation in soil and some special care should also be given to the leaching of Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ and Zn+2. In soybean crop, after three applications of wastewater treated in digester, the remaining wastewater could be partially used as an alternative fertilizer, since N, P, K+ and S were supplied by specific fertilization. There must have extra attention to the accumulation of Fe+2, Cu+2 and Zn+2 in soil as well as to percolation of Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ and Zn+2 According to leachate. / O presente trabalho teve como objetivo avaliar os aspectos ambientais e agronômicos decorrentes da aplicação continuada de água residuária da suinocultura e adubação mineral, nas culturas de milho, aveia e soja. A área experimental possui histórico de aplicação de água residuária da suinocultura, com experimentos conduzidos desde 2006, os quais são o sétimo, oitavo e nono ciclos conduzidos na área. Quatro doses de água residuária da suinocultura, associadas à ausência e presença de adubação mineral, consistiram em oito tratamentos aplicados às parcelas experimentais. Foram determinados índices agronômicos e nutricionais nas três culturas, avaliadas as composições dos lixiviados coletados no início e final de cada ciclo, bem como as características químicas do solo ao início e final de cada cultura. O delineamento experimental consistiu de blocos casualizados em esquema fatorial (4x2) com três repetições. Os resultados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de significância. Na cultura do milho, após uma aplicação de água residuária da suinocultura tratada em biodigestor, verifica-se que a água residuária da suinocultura pode ser parcialmente utilizada como fertilizante alternativo, desde que o P e Mn+2 sejam complementados com adubação específica. Cuidado especial deve ser dado ao acúmulo de Fe+2, Cu+2 e Zn+2 no solo. Devem-se atentar também para os níveis de Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ e Zn+2 no material percolado. Na cultura da aveia, após duas aplicações de água residuária de suinocultura tratada em biodigestor, conclui-se que essa pode ser parcialmente utilizada como fertilizante alternativo, desde que o N, P e S sejam complementados. Deve-se ter atenção com o acúmulo de Cu+2 e Zn+2 no solo, e com a lixiviação de Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ e Zn+2. Na cultura da soja, após três aplicações de água residuária de suinocultura tratada em biodigestor, constata-se que a mesma pode ser parcialmente utilizada como fertilizante alternativo, desde que o N, P, K+ e S sejam complementados com adubação específica. Deve-se ter atenção com o acúmulo de Fe+2, Cu+2 e Zn+2 no solo. Deve ser dada maior atenção à percolação de Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ e Zn+2 de acordo com o lixiviado

Made available in DSpace on 2017-05-12T14:48:19Z (GMT). No. of bitstreams: 1 Shaiane_completo.pdf: 1837663 bytes, checksum: d8cd160676d64177a4555a891f023aef (MD5) Previous issue date: 2011-02-11 / The swine wastewater (SWW) application in agriculture comes as an ancient, popular, and attractive alternative over disposing of it into waterbodies, since it has been an additional treatment for such waste. It also works as a source of water and nutrients to the soil-plant system. However, high concentrations of copper and zinc in these wastes have called some attention to environmental safety. In this context, this research aimed at evaluating the effects of a long-term SWW application on copper and zinc contents in soil-plant system in an area of annual crop. The research analyzed a database from six experiments which aimed at evaluating the effects of SWW applications associated with rates of chemical fertilizer (CF) on soil characteristics under corn, black oats, and soybeans croppings. The experiments were carried out from 2006 to 2009 at the Agricultural Engineering Experimental Area (NEEA), in Cascavel, PR, Brazil. Chemical characterization of soil, at 0.6 m layer, was done before carrying out the treatments and after managing each crop, totalizing six samples during the time of this research. The analyzed parameters were: pH, organic matter, cation exchange capacity, copper, and zinc rates. Analyses of leaves tissue for copper and zinc were determined on corn, black oats, and soybeans crops. The experimental design was in randomized blocks, in triple-factorial with four rates of SWW (0, 100, 200, and 300 m3 ha-1 during the period), two levels of chemical fertilization (with or without CF), and six time periods, with three replications. There was an increase in all parameters, especially an accumulation of copper and zinc on soil profile after successive SWW applications. Copper and zinc rates in the analyzed soil, according to agronomic recommendations, were high. However, they did not exceed the maximum level allowed by environmental regulations. The results of the analyses of the leaves tissue showed that the plants presented levels of copper and zinc within the range of agronomic recommendation. It can be concluded that, in a long term, SWW application favors the accumulation of heavy metals in soils and plants, which can enhance environmental impacts due to waterbodies contamination and their passing to the food chain. / A utilização de água residuária de suinocultura (ARS) em solos agricultáveis, ao invés de realizar a disposição deste resíduo nos corpos d água, tem sido uma alternativa antiga, popular e atrativa pelo fato de complementar o tratamento dos dejetos e servir de fonte de água e nutrientes para o sistema solo-planta. Entretanto, a constatação de altas concentrações de cobre e zinco nestes resíduos vem causando preocupação com relação à segurança ambiental. Nesse contexto, este trabalho visa avaliar os efeitos do uso prolongado de ARS sobre os teores de cobre e zinco, no sistema solo-planta, em área de cultivo anual. O trabalho consiste na análise de um banco de dados oriundo de seis experimentos que visavam analisar o efeito da aplicação de ARS associada a taxas de adubação química (AD) nas características do solo, sob cultivo de milho, aveia e soja. Os experimentos foram realizados entre os anos de 2006 e 2009, no Núcleo Experimental de Engenharia Agrícola (NEEA), em Cascavel, PR. A caracterização química do solo, na camada de 0,0-0,6 m de profundidade, foi realizada antes da aplicação dos tratamentos e após o manejo de cada cultura, totalizando seis amostragens no tempo. Foram avaliados os parâmetros de pH, matéria orgânica, capacidade de troca catiônica, e teores de cobre e zinco. Análises de tecido foliar para os elementos cobre e zinco foram determinadas nas culturas do milho, aveia e soja. O delineamento experimental foi em blocos casualizados em esquema fatorial triplo com quatro taxas de ARS (0, 100, 200 e 300 m3 ha-1 no ciclo), dois níveis de adubação química (com ou sem AD) e seis períodos de tempo, com três repetições. Observou-se aumento em todos os parâmetros avaliados, destacando-se acúmulo de cobre e zinco no perfil do solo após sucessivas aplicações de ARS. Os teores de cobre e zinco no solo, frente às recomendações agronômicas, encontraram-se altos, todavia, não foram superiores aos limites máximos permitidos pela legislação ambiental vigente. Os resultados da análise de tecido foliar mostraram que as plantas apresentaram teores de cobre e zinco dentro dos limites de recomendação agronômica. Conclui-se que aplicações de ARS a longo prazo favorecem o acúmulo de metais pesados no solo e nas plantas, o que pode potencializar impactos ambientais pela contaminação dos corpos hídricos e a transferência destes na cadeia alimentar.

Made available in DSpace on 2017-05-12T14:48:28Z (GMT). No. of bitstreams: 1 Cristiane Kreutz.pdf: 3880883 bytes, checksum: de8fc0d92d64fca6737540c7f40ce521 (MD5) Previous issue date: 2006-10-03 / O crescimento populacional e o consumo excessivo dos diversos segmentos da sociedade acarretam um incremento direto na demanda de água. A minimização e a conservação da água é hoje um importante fator para o desenvolvimento industrial, em decorrência da escassez do recurso. Neste trabalho, buscou-se identificar e avaliar a possibilidade de reúso da água de processo na COOPERATIVA AGROINDUSTRIAL LAR Unidade Industrial de Vegetais. Foram avaliadas as linhas de produção de milho enlatado e brócolis congelado. A etapa experimental consistiu em elaborar fluxogramas dos processos industriais envolvidos, identificar e estimar a demanda de água nos pontos de consumo, realizar balanço de massa dos produtos e insumos envolvidos e realizar coletas de amostras dos pontos com potencialidades de reúso. Os principais resultados indicaram, para o brócolis, um consumo de 33,11 kg de água / kg de matéria-prima e para o milho enlatado 4,35 kg de água / kg de matéria-prima e 3,03 kg de água / kg de matéria-prima, considerando o reúso já praticado. Foram identificadas três etapas que apresentam potencialidade de reúso de água, das quais duas apresentaram viabilidade técnica, estimando-se assim, uma redução no consumo de água limpa de até 76,7 % para a linha de milho enlatado.

Made available in DSpace on 2017-05-12T14:48:33Z (GMT). No. of bitstreams: 1 Nathalie.pdf: 1872403 bytes, checksum: 066688e7a8c000417cf984dd2ee4421c (MD5) Previous issue date: 2012-07-20 / This study aimed at evaluating the agronomic and environmental aspects as results from the continuing application of swine wastewater and mineral fertilizer in corn, black oats and soybeans. The experimental area has a history of swine wastewater application with trials that have been carried out since 2006, whose cycles under management are the seventh, eighth and ninth ones. Four doses of swine wastewater associated with the presence and absence of mineral fertilizer consisted on eight treatments applied to experimental plots. The agronomic and nutritional indices were determined in the three studied crops. The compounds of leachate collected at the beginning and end of each cycle were also recorded as well as soil characteristics at the beginning and end of each crop. The experimental design was in randomized blocks, under a 4x 2 factorial scheme with three replications. The results were submitted to ANOVA and means compared by Tukey test at 5% significance level. In maize crop, after a swine wastewater application, treated in digester, it could be observed that it could be partially used as an alternative fertilizer, since P and Mn+2 were supplemented with specific fertilization. A special management should be given to the accumulation of Fe+2, Cu+2 and Zn+2 in soil. Attention should be paid also to the levels of Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ and Zn+2 in leachate material. In black oats crop, after two applications of swine wastewater treated in digester, it was concluded that swine wastewater can be partially used as an alternative fertilizer, since N, P and S could be supplied. Some attention should be taken with Cu+2 and Zn+2 accumulation in soil and some special care should also be given to the leaching of Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ and Zn+2. In soybean crop, after three applications of wastewater treated in digester, the remaining wastewater could be partially used as an alternative fertilizer, since N, P, K+ and S were supplied by specific fertilization. There must have extra attention to the accumulation of Fe+2, Cu+2 and Zn+2 in soil as well as to percolation of Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ and Zn+2 According to leachate. / O presente trabalho teve como objetivo avaliar os aspectos ambientais e agronômicos decorrentes da aplicação continuada de água residuária da suinocultura e adubação mineral, nas culturas de milho, aveia e soja. A área experimental possui histórico de aplicação de água residuária da suinocultura, com experimentos conduzidos desde 2006, os quais são o sétimo, oitavo e nono ciclos conduzidos na área. Quatro doses de água residuária da suinocultura, associadas à ausência e presença de adubação mineral, consistiram em oito tratamentos aplicados às parcelas experimentais. Foram determinados índices agronômicos e nutricionais nas três culturas, avaliadas as composições dos lixiviados coletados no início e final de cada ciclo, bem como as características químicas do solo ao início e final de cada cultura. O delineamento experimental consistiu de blocos casualizados em esquema fatorial (4x2) com três repetições. Os resultados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de significância. Na cultura do milho, após uma aplicação de água residuária da suinocultura tratada em biodigestor, verifica-se que a água residuária da suinocultura pode ser parcialmente utilizada como fertilizante alternativo, desde que o P e Mn+2 sejam complementados com adubação específica. Cuidado especial deve ser dado ao acúmulo de Fe+2, Cu+2 e Zn+2 no solo. Devem-se atentar também para os níveis de Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ e Zn+2 no material percolado. Na cultura da aveia, após duas aplicações de água residuária de suinocultura tratada em biodigestor, conclui-se que essa pode ser parcialmente utilizada como fertilizante alternativo, desde que o N, P e S sejam complementados. Deve-se ter atenção com o acúmulo de Cu+2 e Zn+2 no solo, e com a lixiviação de Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ e Zn+2. Na cultura da soja, após três aplicações de água residuária de suinocultura tratada em biodigestor, constata-se que a mesma pode ser parcialmente utilizada como fertilizante alternativo, desde que o N, P, K+ e S sejam complementados com adubação específica. Deve-se ter atenção com o acúmulo de Fe+2, Cu+2 e Zn+2 no solo. Deve ser dada maior atenção à percolação de Cu+2, Fe+2, Mn+2, NO3-+NO2-, Na+ e Zn+2 de acordo com o lixiviado

Em dois agroecossistemas distintos (Piracicaba, SP, Brasil e Okeechobee, FL, EUA) cultivados com citros objetivou-se avaliar: i) a concentração de nutrientes, metais pesados no efluente de esgoto tratado (EET) e sua qualidade para o uso agrícola, e; ii) os efeitos da irrigação com EET na fertilidade do solo e nutrição das plantas. Em Piracicaba, SP, foi conduzido um experimento com três blocos casualizados e cinco tratamentos. Quatro lâminas de irrigação distintas com EET foram aplicadas durante 21 meses em laranjeiras [Citrus sinensis (L.) Osb.] sobre Citrus paradisi Macfad. x Poncirus trifoliata Raf] com base na evapotranspiração da cultura (ETc) sendo: 100%, 125%, 150% e 200% da ETc, além do tratamento sem irrigação (0%). Em Okeechobee, FL, foi realizado um estudo de caso em um pomar comercial cultivado com pomeleiros [(Citrus paradise Macf.) sobre (Citrus aurantium L.)]. Neste local comparou-se dois talhões; um irrigado com EET (durante 11 anos) e outro irrigado com água. Os EETs utilizados nos dois estudos apresentaram qualidade satisfatória para o uso agrícola (FAO, 1992). No primeiro agroecossistema houve correlação negativa entre as lâminas de irrigação com EET e a acidez ativa, acidez potencial, saturação por alumínio e os teores de K trocável e Pb disponível. Por outro lado, correlações positivas foram encontradas entre S, B, Cu e Na no solo e as lâminas de irrigação. Comparando-se a lâmina de irrigação 100% da ETc e o controle (0%), houve um aumento na abundância natural de 15N e nas concentrações de S, B e Na, e um decréscimo de P, K, Mn, Al e Cr nas folhas. As menores concentrações destes elementos foram associadas às lâminas excessivas (> 100% da ETc). A influência máxima das lâminas de irrigação com EET na altura das plantas foi obtida entre as lâminas 93 e 107% da ETc. Quanto ao segundo agroecossistema, houve um aumento na concentração de NH4 +, NO3 -, Mg, S, B, Cl, Co, Cu, Fe, Mn, Mo, Ni e Zn disponíveis no solo após 11 anos de irrigação com EET. Já no tecido foliar houve um acréscimo de Ca, Mg, B, Fe, Cu, Mn, Ni, e Zn. As concentrações de Cd, Co, Mo e Pb foram encontradas abaixo do limite de detecção no tecido foliar. O efeito do EET é pronunciado no longo prazo, e pode suprir parcialmente alguns nutrientes do programa de adubação. Mesmo após longo período de irrigação com EET, o risco de salinização do solo e acúmulo de metais pesados parecem mínimos. Com base nestes resultados fica evidente que além de ser uma fonte alternativa de água, o EET influencia positivamente na fertilidade do solo e nutrição dos citros. / Considering two different agroecosystems (Piracicaba, SP, Brazil and Okeechobee, FL, USA) cultivated with citrus, the objectives of the study were to evaluate: i) the concentration of nutrients, heavy metals in reclaimed wastewater (RWW) and its quality for the agricultural use; and ii) the effects of RWW irrigation on soil fertility and plant nutrition. At Piracicaba, SP, an experiment were carried out with three randomized blocks and five treatments. Four different RWW irrigation rates were applied over 21 months, in orange trees [Citrus sinensis (L.) Osb] on Citrus paradisi Macfad. x Poncirus trifoliata Raf], based on crop evapotranspiration (ETc): 100%, 125%, 150% and 200% of ETc as well as a treatment without irrigation (0%). At Okeechobee, FL, a survey study was carried out in a commercial citrus grove cultivated with grapefruit [(Citrus paradise Macf.) on (Citrus aurantium L.)]. At this site two citrus blocks were compared; one irrigated with RWW (11 years) and the other with well water. The RWW used in both studies displayed satisfactory quality for the agricultural use (FAO, 1992). The first agroecosystem had negative correlation between RWW irrigation rates and active acidity, potential acidity, aluminum saturation, exchangeable K and available Pb. Whereas positive correlations were found for S, B, Cu and Na in soil with RWW rates. Comparing the irrigation rate of 100% of ETc with the control plot (0%), increasing contents of N, 15N, S, B, and decreasing contents of P, K, Mn, Al and Cr were observed in the leaf tissue. Lower concentrations of these elements were associated with the over irrigation rates (> 100% of ETc). The greatest effect of the irrigation rates on plants height was found between 93 and 107% of ETc. At the second agroecosystem, increasing concentration of NH4 +, NO3 -, Mg, S, B, Cl, Co, Cu, Fe, Mn, Mo, Ni and Zn in soil were found after 11 years of RWW irrigation. In leaf tissue also increasing concentrations of Ca, Mg, B, Fe, Cu, Mn, Ni and Zn were determined. Concentration of Cd, Co, Mo and Pb were below the detection limit of detection in the leaf tissue. The effects of the RWW irrigation are pronounced after long term application, and can partially supply some nutrients from the fertilization program. Even after long term RWW irrigation, the risks of soil salinization and heavy metals accumulation can be considered as low. The results highlight that besides an alternative waster source, RWW can provide benefits on soil fertility and citrus nutrition.

Managed aquifer recharge (MAR) is a low-energy subsurface water treatment system with the potential of being an important component of sustainable water reuse schemes. Alongside common wastewater contaminants, MAR systems have been shown to attenuate a range of trace organic chemicals (TOrCs). Despite several factors being possibly important for TOrC attenuation, many have not been investigated in depth. This research effort investigated three factors affecting attenuation of the moderately degradable TOrCs: primary substrate, adaptation of the microbial community to presence of TOrCs, and groundwater temperature. The overall goal was to optimize TOrC attenuation using different MAR configurations considering how these factors affect TOrC attenuation. The primary substrate composition and concentration significantly impacted attenuation of the moderately degradable TOrCs. Lower primary substrate concentrations and more refractory carbon generally resulted in better TOrC transformation, a more diverse microbial community in the infiltration zone and more diverse capabilities for TOrC degradation. The enzyme group cytochrome P450 may be important for TOrC transformation since its genes were more abundant under carbon-starving primary substrate conditions. Adaptation of the microbial community by pre-exposure to TOrCs was not required in order to degrade them. However, adaptation to the primary substrate was necessary for TOrC biotransformation due to its effect on the microbial community. Attenuation of most TOrCs was unaffected by changes in temperature. Some moderately degradable TOrCs, however, were better attenuated at higher temperatures likely due to increased microbial activity. Others were better degraded at lower temperatures likely due to favorable sorption conditions. In the context of applying MAR systems to potential water reuse schemes within Saudi Arabia, a reconnaissance study of TOrC occurrence in treated wastewater effluents was undertaken. Most of the TOrCs targeted were detected at similar concentrations to US effluents at comparable plants. One of the plants studied, however, displayed a significantly different TOrC footprint from the other treatment plants due to the large number of international visitors in its sewershed. Findings from this occurrence study as well from other tasks provided inputs to a risk assessment framework to compare the effectiveness of MAR systems as part of a multiple-barrier water reuse scheme.

A report produced through an agreement between the City of Coolidge and the University of Arizona.

Prepared by Richard A. Herbert with contributions from Coolidge Regional Park Interdisciplinary Team.

Scarcity of water for irrigation is a serious hindrance for small-scale farmers in sub-Saharan Africa. The use of good quality water for irrigation has resulted in increasing pressure on such water which has prompted sourcing of wastewater as an alternative. One possibility, being investigated by eThekwini Water and Sanitation (Durban, South Africa), is to install anaerobic baffled reactors within local communities to treat wastewater to allow its use for agriculture. The success of wastewater irrigation depends on the ability of the soil to assimilate the water, nutrients and any other contaminants that are applied to it. The aim of this project was to investigate the potential of an anaerobic baffled reactor (ABR) effluent as both an irrigation and nutrient source for use in peri-urban agriculture. The effluent was slightly alkaline (pH 7.40–7.60) and in class C2S1 (medium-salinity/low sodicity water) according to the United States Soil Salinity Laboratory classification for irrigation waters. It was very low in heavy metals, values being below permissible levels according to the Food and Agricultural Organisation (FAO) of the United Nations and the South African Department of Water Affairs and Forestry (DWAF) guidelines for water use in agriculture. The total solids were low thus particulate matter was minimal with a greater concentration of the major elements found in solution. An investigation was carried out to ascertain the behaviour of the effluent when applied to soil and how the soil was able to adsorb plant nutrients from it. A soil column study was undertaken in the laboratory with three contrasting soil types namely a sandy soil (Longlands, E horizon), an organic soil (Inanda, A horizon) and a clayey soil (Sepane, A horizon). The effluent was leached through the soil while distilled water was concurrently used as a control. Results indicated that after application of 16 pore volumes, leachates from the columns contained concentrations of Na, equal to that in the incoming effluent for all soils. The concentrations of Ca and Mg were lower in the leachates than in the original effluent indicating adsorption in the soils. Phosphorus was the element that was most strongly adsorbed in all soils. While its adsorption in the Ia could be attributed to organic matter and the presence of iron oxides and oxyhydroxides, the clay type and amount in the Sepane was likely to have been responsible for P adsorption. The NO₃-N, which was initially low in the effluent, increased as leaching progressed, while the NH₄-N decreased. In the water-leached columns, elements were leached out of soil because none were added with the water. At the end of leaching, columns were allowed to drain and then sectioned into 2 cm segments. The 0-2 cm, 8-10 cm and 14-16 cm segments representing the top, middle and bottom parts of the column were analysed for inorganic-N, phosphorus and potassium. The elemental content of the 0-2 cm segment was significantly higher (p<0.05) than the lower segments in all columns for soluble P in all soils. This reflects the immobile nature of P in soils and confirmed the high amounts of P retained by the soils. There were significant differences between the effluent and the water-leached soils in terms of P retention. The amount of inorganic-N and K in the top layer was not significantly different from the other layers. In the Ia 0–2 cm segment, a pH increase of about 1.3 pH units was recorded in the effluent-leached columns when compared to the equivalent segment in the water-leached columns. A glasshouse study was undertaken to assess the availability to maize of nutrients from the effluent. Maize was grown for 6 weeks in pots filled with the same soil types used in the columns study except that a similar sandy soil, Cartref (Cf, E horizon), replaced the Lo due to inadequate availability of the latter. Fertilizer (N, P and K) was applied at the full recommended rate, half the recommended rate and zero fertilizer for each of the three soils used. This corresponded to 0, 100, 200 kg N ha⁻¹ for all soils; 0, 40, 80 kg P ha⁻¹ and 0, 50, 100 kg K ha⁻¹ for the Cf; 0, 10, 20 kg P ha⁻¹ and 0, 102.5, 205 kg K ha⁻¹ for Ia; and 0, 30, 60 kg P ha⁻¹ and 0, 5, 10 kg K ha⁻¹ for Se. Lime was applied to the Ia soil at the rate of 10 t ha⁻¹. Plants were watered with either effluent or tap water. Dry matter yield and nutrient concentrations for effluent-irrigated maize were significantly higher (p<0.05) than for all equivalent fertilizer applications in the water-irrigated plants. The unfertilized effluent-irrigated plants were not significantly different from the fertilized water-irrigated plants, but performed as well as the water-irrigated plants at half fertilization irrespective of soil type. Phosphorus deficiency was observed in the Ia and Se soils but not in the Cf soil, irrespective of fertilizer treatment. Plants grown on the Cf soil irrigated with effluent and fully fertilized had the highest above-ground dry matter yield (4.9 g pot⁻¹) and accumulated the most nutrients namely N, P, K, Ca and Mg than all other treatments. After harvest the most marked changes had occurred in the Cf soil for P as the effluent-irrigated soils were significantly higher (p<0.05) than the water-irrigated soils reflecting the P input from the effluent. The effect of effluent on soil and plants was further investigated by planting maize on the Ia soil without lime application. Plants that received effluent irrigation and no lime had significantly higher (p<0.05) dry matter yields and accumulated more N, P and K than the water-irrigated with no lime as well as the equivalent limed treatments. This suggests an interaction effect between the lime and the effluent with its effects obvious on above-ground dry matter yield and plant N, P and Mg. A soil column experiment using the Cf, Ia and Se soils and planted with maize was conducted to assess the ability of plants to take up nutrients with concurrent leaching. Plants from the Cf soil recorded the lowest above-ground dry matter yield which was observed from the less vigorous growth as compared to plants in the Ia and Se soils. This growth pattern could also be explained by the low N accumulation in the plants from the Cf soil. Unlike N, P in plants grown on the Cf soil was significantly higher (p<0.05) than in the plants on the Ia and Se soils, despite having the least P gain from the effluent. The readily available P triggered both more uptake and also greater losses through leaching. The rate at which P was being supplied from the effluent was greater than its uptake by the plants and with limited capacity to hold onto P in this sandy soil there was inevitably loss though leaching. A pot experiment was conducted to investigate the interaction effects between lime and effluent. Lime type (calcium hydroxide or dolomite) was applied to two acidic top soils namely Inanda and Avalon at 0%, 25%, 50%, 75% and 100% of the recommended rates for these soils. Maize was planted and after 6 weeks it was harvested and evaluated for above-ground dry matter yields and plant nutrient concentrations. Non-significant effects were recorded for above-ground dry matter, N, P and K as a result of altering the liming rate and type within each soil. The effects of lime application were apparent in the soils after harvest as increasing the lime rate caused an increase in pH and an inverse relationship with the exchangeable acidity and acid saturation in soils, as expected. Although the unlimed treatments did not impact on the acidity as much as the limed treatments, effluent irrigation was shown to reduce soil acidity after harvest when compared to the soils at the beginning of the experiment. Phosphorus accumulation in plants was also unaffected by either lime rate or type which showed that effluent irrigation could influence P availability and further liming would not accrue benefits to the soil so as to influence plant P uptake. Based on these data, ABR effluent could be perceived as a resource rather than a waste product. It could conveniently be used for irrigation provided there is soil and plant monitoring to assess build-up of elements especially in the long term. Further investigations have to be carried out on other crop types both in the field and glasshouse to ascertain nutrient uptake and effect on different soil types. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.