ABSTRACT
In this study, the efficiency of contaminant removal from a compact wastewater treatment plant (CWTP) in a university campus under different rain conditions was evaluated. Wastewater samples were collected weekly for 1 year and the physicochemical parameters were monitored. Removal efficiency higher than 77%, reaching values above 95% for samples with lower wastewater flow rates, was found for biological oxygen demand (BOD) and total and fecal coliforms. The pH values remained in the range of 6.0-8.0. However, pH values below 6.8 impaired the nitrification rate and, therefore, the removal of total Kjeldahl nitrogen (TKN) and ammonia was lower than the expected, with concentration values above those set by the Brazilian regulation for wastewater discharge. The results show that the flow rate of wastewater at the entrance of the CWTP is directly related to the rain events, thus affecting its efficiency, mainly in the removal of total solids, turbidity, and organic matter. The assessment of the treated wastewater reuse on site for agricultural purposes showed to be a prominent and more sustainable alternative regarding the discharge of wastewater into water bodies.
Subject(s)
Wastewater , Water Purification , Agriculture , Brazil , Nitrogen/analysis , Rain , Universities , Waste Disposal, Fluid , Wastewater/analysis , WaterABSTRACT
RESUMO Estações Compactas de Tratamento de Efluentes (ECTEs) são uma ótima alternativa para a implantação de sistemas descentralizados de esgoto doméstico que possam atender pequenas comunidades. No entanto, tais sistemas ainda são pouco utilizados e há pouca experiência em relação à sua operação. Diante de tal demanda, esta pesquisa visou avaliar a eficiência e realizar o acompanhamento operacional de uma ECTE composta por reator Upflow Anaerobic Sludge Blanket (UASB), seguido de filtro aerado submerso (FAS), que está localizada no município de Uru, em São Paulo, Brasil. Durante a pesquisa, o sistema mostrou-se uma alternativa viável de tratamento para pequenas comunidades, pois apresentou boa eficiência, com valores médios de remoção de demanda bioquímica de oxigênio (DBO5) e demanda química de oxigênio (DQO) de 91 e 85%, respectivamente. O monitoramento realizado durante a pesquisa também contribuiu para melhorias gerais no sistema.
ABSTRACT Compact Wastewater Treatment Plants (CWTPs) are a great alternative to implementing decentralized sewage systems that can serve small communities. However, such systems are still poorly used and there is little experience regarding their operation. Based on such demand, this research aimed to evaluate the efficiency and to conduct an operational monitoring of a CWTP composed by an Upflow Anaerobic Sludge Blanket (UASB) reactor, followed by Submerged Aerated Filter (SAF), in the city of Uru, São Paulo, Brazil. During the research, the system proved to be a viable alternative for small communities, because it showed good efficiency, with average removal values of biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) of 91 and 85%, respectively. The monitoring carried out during the research also contributed to general improvements in the system.