Análise do potencial de reúso de água para fins não potáveis a partir do efluente tratado de estações de tratamento de esgotos na região metropolitana do Rio de Janeiro

Abstract

The use of water is a major factor in the process of forming cities, as well as in the socioeconomic development of the population in general. As urban centers grow, water demand increases. The pollution of the main sources of water and the recurrent condition of water scarcity aggravated by the effects of climate change, such as that which occurred in 2014 in the Metropolitan Region of Rio de Janeiro (MRRJ), considerably affected water availability, which facilitates the search for alternative sources for meeting less noble demands. This work aims to analyze the supply and demand potential of reused water for non-potable purposes from the treated effluent from Wastewater Treatment Plants (WWTP) at MRRJ. The methodology consists in the identification of WWTPs whose characteristics such as location, installed treatment capacity favor the definition of reuse water generators and the survey of the location, industrial typology and demand for water from potential consumers in the study area, with emphasis on the water treatment industries. responsible for the country's third largest consumptive use, behind agriculture and urban supply. This study pioneers a georeferenced inventory of potential generators and consumers at MRRJ, which proves to be a promising tool in the identification of business regions / clusters, especially around the WWTPs. It was possible to verify the existence of a great potential for the generation of reused water in view of the installed capacity of secondary effluent flow. Based on the statistical treatment of the data provided for treated effluent from the Alegria, Penha, Pavuna and Sarapuí WWTPs and the reuse water from the Alegria and Penha WWTPs, a comparison of the average values obtained from the parameters with the legislation of the State of São Paulo (2020) and the USEPA legislation that establish quality standards for water reuse for urban purposes. For industrial purposes, the treated effluent and reused water met NBR 15900 - water for concrete kneading, as well as the recommended standards for tumbling processes (stage of the bearing manufacturing chain). In addition, they presented satisfactory results when analyzed in compliance with the recommended specification for the use of reused water in cooling towers whose consumption can reach 95% of the total water demanded in the transformation industry. The reuse of water shows potential and presents itself as a strategic alternative source for non-potable purposes in the Metropolitan Region of Rio de Janeiro.