Efluentes de banheiros químicos: como é feito o seu manejo e quais são os efeitos do seu descarte em estações de tratamento de esgotos?

Abstract

Chemical toilets are a worldwide ubiquitous temporary sanitation solution on different occasions such as festivals and mobile work sites. Deodorizing substances are commonly used in chemical toilets in order to inhibit microbiological activity and therefore inhibit the formation of odors, making the environment within chemical toilets more amenable for use. Commonly used deodorizers are composed of one or more surfactants, aromatic essences, dyes, and active ingredients of high toxicity, such as formaldehyde, a known carcinogenic compound. The present study evaluated compliance with applicable Brazilian and state regulations in Minas Gerais regarding the use of deodorizers, handling, transportation and final disposal of chemical bath effluents through a qualitative-quantitative approach. It was observed that despite the prohibition of the compound formaldehyde in the formulation of sanitizing products, established by ANVISA in Brazil, the Aqua Kem product, appointed as sales leader in the state, has such a compound in high concentrations in its formulation. It was also observed the lack of legislation and regulations on the management of chemical toilet effluent toilets in Minas Gerais, as well as the lack of compliance and inspection of existing regulations. This study also evaluated whether the Chemical Safety Data Sheets (MSDSs) of chemicals marketed in Minas Gerais have sufficient information on the risks to human health and the environment, based on information obtained from the agency database Regulatory bodies and research entities of international renown. Additionally, it was verified if such documents were available for public consultation and it was observed that two eight products diagnosed as marketed in the state, only four had a datasheet made available by the manufacturer. At the end of the analysis of the FISPQs, it was concluded that only the Porta Pak product of the American manufacturer Walex had satisfactory information in its MSDS. Finally, this study evaluated the biodegradability of chemical bath deodorizers under anaerobic conditions. For this, tests of anaerobic biodegradability were developed in the laboratory by means of the test of Specific Methanogenic Activity - AME, with the aid of AMPTS II - Automatic Methane Potential Test System II. The objective of the tests was to evaluate the effects of the addition of different concentrations and types of chemical bath deodorizers (Aqua Kem and Aqua Kem Green) on the biodegradability of sewage under anaerobic conditions using anaerobic sludge from reactor UASB - Upflow Anaerobic Sludge Blanket. From the data obtained in the laboratory it was observed that as long as basic care is taken to receive chemical toilet effluents from sewage treatment plants that have anaerobic treatment systems, such as dumping the material after 32 hours of the addition of deodorizers products. In addition to performing it in a gradual way, as a launch in the system in a period of one hour for a 10 m³ truck that was the scenario proposed by this work, would not cause operational problems to the treatment plant.