(215k) Removing Microorganisms From Wastewater in a Painting Industry By Advanced Oxidation Processes

Advanced Oxidation Processes (AOP) are defined as those which involve the generation of hydroxyl radicals in sufficient quantity to affect water purification. Ozonation, in particular, is a well known technique to remove several pollutants from water and an alternative to bleach for general disinfection processes; in addition, ozonation combined with hydrogen peroxide treatment has been widely studied as a most efficient alternative, decreasing reaction time and increasing pollutant removal efficiency.

The goal of this work was test the efficiency of AOP to remove microorganisms found in wastewater effluent from a painting industry. The treated water can then be reused in the paint production process. The presentation will summarize the main results obtained in the assays carried out in a 2L capacity Halia® AOP bench test reactor with the aim of eliminating those microorganisms as a tertiary treatment. Two treatments were tested: ozonation and ozonation with the addition of hydrogen peroxide (O₃, O₃+H₂O₂). For the ozonation treatment a concentration of 2 ppm of ozone was applied and water sample was circulating through the reactor by 30 minutes in order to warranty complete reaction. In the other treatment a 2 ppm of O₃ and a 1 ppm of H₂O₂were combined and the reaction time, in this test, was 15 minutes. The characterization of water samples was done before and after the treatments, analyzing: DQO, turbidity, colour and microbiological counts.

For both treatments, the results showed that the microorganisms were completely removed, DQO values decreased up to around 50%, as well as turbidity and colour, validating the use of this technology for this application.