Tratamento do efluente de uma fábrica de tinta de tatuagem usando cavitação hidrodinâmica associada à ozônio e peróxido de hidrogênio

Abstract

The expansion of tattoo ink factories has attracted the interest of environmentalists due to the high polluting potential of the wastewater produced in these industries. Conventional effluent treatment processes cannot fully degrade all substances generated in the paint manufacturing, introducing recalcitrant pollutants into the environment, such as surfactants, which are resistant to biological degradation. Due to this resistance, the need for more advanced methods to treat these pollutants has arisen. The aim of this study was to use hydrodynamic cavitation associated with the addition of high oxidation potential substances, to degrade an effluent sample generated in a tattoo paint factory. Experimentally, the sample was subjected to the hydrodynamic cavitation process using an orifice plate as a cavitation generator. The optimization of the hydrodynamic cavitation apparatus was based on surfactants removal at differents pHs and inlet pressure into the cavitation chamber, carried out in triplicate. After this step, different ozone charges and hydrogen peroxide volumes were used to investigate the synergy between hydrodynamic cavitation and oxidants in the removal of surfactants and in the reduction of total organic carbon (TOC). The best experimental conditions obtained in the tests were conducted at a pH of 2.5, a pressure of 4.5 bar and an ozone charge of 3.1 g/h, with a removal efficiency of 88% for surfactants and 34% for the removal of TOC. The addition of hydrogen peroxide did not improve the removal efficiency of the compounds. The use of hydrodynamic cavitation to treat the effluent sample proved to be a good option to assist in the treatment of wastewater containing surfactants and high concentrations of organic matter.