O crescente aumento da demanda por água na produção de alimentos aponta as necessidades de se buscar fontes alternativas de abastecimento. O esgoto doméstico tratado é uma maneira de mitigar este problema, entretanto, para que possa ser utilizado na agricultura, é necessário adequá-lo às exigências legislativas. O uso do ozônio na desinfecção de efluentes domésticos vem sendo utilizado devido ao seu caráter fortemente oxidante, permitindo o ajuste de seus parâmetros ao reúso agrícola. Desta forma, o objetivo deste trabalho foi avaliar a viabilidade sanitária e agrícola do efluente doméstico tratado com ozônio. O experimento foi realizado em bancadas de laboratório no qual foram aplicadas as dosagens: 0; 8; 15; 30; 45; e 60 mg L-1 de ozônio. O tempo de aplicação, para cada dosagem foi, respectivamente, em segundos: 0; 14; 27; 54; 81; e 108. Foram avaliados parâmetros microbiológicos, físicos e químicos: coliformes totais, Escherichia coli, pH, turbidez, oxigênio dissolvido, condutividade elétrica, carbono orgânico total, nitrogênio total, fósforo total, potássio, magnésio, cálcio e sódio. A ozonização não alterou significativamente as propriedades físicas e a composição química da água residuária, indicando importante vantagem em termos de potencial reúso agrícola. Entretanto, a contagem de E. coli não foi reduzida suficientemente para que o efluente possa ser utilizado na agricultura. Os resultados indicam a importância da investigação dos efeitos do ozônio na eficiência do tratamento de esgoto, buscando o entendimento das interações com o intuito de identificar dosagens e tempo de exposição ideais para tornar as águas residuárias seguras ao reúso agrícola.
Palavras-chave: agricultura; efluente tratado; ozonização
The increasing demand for water in food production highlights the need to seek alternative sources of supply. Treated domestic sewage is a way to mitigate this problem, but it must comply with legislation to be used safely in agriculture. Ozone has been used for disinfection of domestic effluents due to its strong oxidizing character, allowing the adjustment of its parameters for agricultural reuse. This study therefore aimed to evaluate the sanitary and agricultural viability of domestic effluent treated with ozone. The experiment was carried out on laboratory benchtops and doses of 0, 8, 15, 30, 45, and 60 mg L−1 of ozone were applied. The application time for each dose was 0, 14, 27, 54, 81, and 108 seconds, respectively. Microbiological, physical, and chemical parameters were evaluated: total coliforms, Escherichia coli, pH, turbidity, dissolved oxygen, electrical conductivity, total organic carbon, total nitrogen, total phosphorus, potassium, magnesium, calcium, and sodium. Ozonation did not significantly alter the physical and chemical composition of wastewater, indicating an important advantage in terms of potential agricultural reuse. However, the pathogenic load of E. coli was not reduced enough for the effluent to be used in agriculture. The results suggest an investigation of the effects of ozone on the efficiency of sewage treatment, seeking to understand these interactions to identify ideal doses and exposure time, making wastewater safe for agricultural reuse.
Keywords: agriculture; ozonation; treated effluent
The increasing demand for water in food production highlights the need to seek alternative sources of supply. Treated domestic sewage is a way to mitigate this problem, but it must comply with legislation to be used safely in agriculture. Ozone has been used for disinfection of domestic effluents due to its strong oxidizing character, allowing the adjustment of its parameters for agricultural reuse. This study therefore aimed to evaluate the sanitary and agricultural viability of domestic effluent treated with ozone. The experiment was carried out on laboratory benchtops and doses of 0, 8, 15, 30, 45, and 60 mg L−1 of ozone were applied. The application time for each dose was 0, 14, 27, 54, 81, and 108 seconds, respectively. Microbiological, physical, and chemical parameters were evaluated: total coliforms, Escherichia coli, pH, turbidity, dissolved oxygen, electrical conductivity, total organic carbon, total nitrogen, total phosphorus, potassium, magnesium, calcium, and sodium. Ozonation did not significantly alter the physical and chemical composition of wastewater, indicating an important advantage in terms of potential agricultural reuse. However, the pathogenic load of E. coli was not reduced enough for the effluent to be used in agriculture. The results suggest an investigation of the effects of ozone on the efficiency of sewage treatment, seeking to understand these interactions to identify ideal doses and exposure time, making wastewater safe for agricultural reuse.
Keywords: agriculture; ozonation; treated effluent
