Avaliação dos parâmetros oxigênio dissolvido e Ph em esgotos domésticos tratados provenientes de lagoas de estabilização

Abstract

Any activity involving the use of water in industries as in household consumption generates effluents, released into water bodies. When released untreated, they can cause serious damage to the environment, causing a major impact on aquatic ecosystems. One example are the effluents from wastewater, heavily contributing to the pollution of existing water springs, consuming oxygen in the process of decomposition, causing damage to the aquatic ecosystem. Depending on the concentration of some parameters indicating the pollution level of water bodies, an assessment of the water quality for human consumption and other uses can be performed. Among these parameters, the dissolved oxygen (DO) and potential of hydrogen (pH) were adopted as they are important standards to verify the extension of impacts of the receiving bodies of water, as well as how improper they are for multiple uses. In the state of Ceara, the State Superintendent of Environment (SEMACE) is the supervisory institution and the effluents generated by industries and household consumption must be within the standards established by Ordinance no. 154 of July 22, 2002. In this study, the DO concentration (mgO2L-1) and the pH level were assessed within treated wastewater samples, from stabilization ponds in cities at the state of Ceara. According to the obtained results, it was found that, regarding the DO concentration, the samples of all cities met the established value by the Ordinance previously mentioned, while only in one city the pH level was within the established range by the same Ordinance. The procedures for analysis of the parameters mentioned above were the described ones in the Standard Methods for the Examination Water and Wastewater (APHA, 2012) and executed in the environmental chemistry laboratory of the Industrial Technology Center (NUTEC), a Foundation in Ceara.