Development of a Reactor in a Continuous System Using Advanced Oxidation Processes to Reduce Chemical Oxygen Demand in Industrial Effluent

Industrial effluent is the liquid discharged by industrial production. This effluent must be treated and comply with the current environmental legislation before being released in a receiving body. However, in order to remove some specific contaminants or complement the conventional effluent treatment system, advanced oxidation processes (AOPs) are used. Among AOPs, there is the treatment with ultraviolet lamp (UV) and hydrogen peroxide (H2O2). Thus, this study develops a continuous reactor in laboratory-scale using UV light and H2O2 as treatment to reduce the chemical oxygen demand (COD) of a synthetic dairy effluent. For this purpose, a reactor was built using polyvinyl chloride ducts, a peristaltic pump, and three 54-W UV lamps. Effluent flow rate of 40 L/h, total volume of 10 L, and H2O2 concentration of 10 ppm were used. The synthetic effluent was prepared in order to simulate an effluent of the dairy industry. The COD of the effluent was monitored over three hours. It was observed that it is possible to fit the COD parameter to legislation requirements after one hour of treatment. In addition, 67.27% and 72.73% of COD were reduced after two and three hours of treatment, respectively. It is concluded that the reactor elaborated assists in the final polishing of an effluent of the dairy industry, considerably reducing COD.