Reúso de águas residuárias tratadas: inovação tecnológica e aceitabilidade social

Abstract

Treated wastewater can be applied in many activities, however, depending on the required use, the quality level may not be achieved using conventional processes. This work analyzed the performance of the Water Phase Reform in the treatment of sanitary sewage, with and without the presence of emerging pollutants, aiming at the reuse of liquid effluents for potable and non- potable purposes, and evaluated the social acceptability regarding the practice of reuse. Experiments were carried out in batch reactors, using synthetic wastewater and Pt-based catalysts, supported on two types of carbon materials: KETJENBLACK (KJB) and ENSACO. The analysis of social acceptability to the reuse of treated wastewater had as main research instruments the questionnaire and semi-structured interviews, carried out with renowned experts in the sanitation sector. The average efficiency of the TOC removal process was 62.05% in tests with ENSACO carbon material and without the active metal, and 88.19% with KJB. For the COD parameter, the mean removal percentages were 57.57% and 63.48% in assays with ENSACO and KJB support, respectively. The process achieved an average efficiency in the reduction of total nitrogen of 34.63% in the analyzes with ENSACO carbon and 54.39% with KJB. In samples with emerging compounds, the Aqueous Phase Reform proved to be effective both in tests containing only the carbon material ESSACO and without platinum, and with Pt/ENSACO catalyst, with average removal percentages in the tests with ESSACO of 98.34% for caffeine, 99.55% for carbamazepine, 100% for diclofenac and 96.58% for ibuprofen. Gas production was higher in reactions with Pt/ENSACO catalyst, with average values of 19.20% for H2 and 11.70% for CH4. As for meeting the quality standards for reuse water, it was found that despite the vast majority of regulations and guidelines evaluated do not establish maximum values allowed for quality parameters, the Water Phase Reform is a promising technique for the treatment of sanitary sewage, with effective elimination of the emerging contaminants evaluated. As for the acceptability of the population to the practice of reuse, there was high public acceptance for applications with reduced human contact and low acceptability for uses involving direct consumption. However, even with all the cultural barriers, 84.6% of the participants were in favor of using reuse water from a new sewage treatment technique.