Investigating the Effects of Different Levels of Ozonation on Physicochemical Parameters of Produced Wastewater of the Rainbow Trout Fish Culture

The role of ozone in water and wastewater treatment as an oxidant and as a disinfectant agent is very important. On the other hand, increasing the quality level required for wastewater, finding new types of microorganisms in the effluent and revealing more types of contaminating material in it has led designers to consider the process of extinction. The purpose of this study was to investigate the effect of various levels of ozonation of cold-water wastewater on pH and TDS, ORP, BOD, COD, phosphate, and MPN bacteria. To conduct this research, about 120 liters of untreated aquaculture wastewater treatment in cold storage in four treatments with 0 (without ozonation) levels as control treatment and 1, 3 and 5 mg/l ozone treatments as research treatments with triplicate were performed per treatment. Ozonation was carried out by an ozone generator with a yield of 5000 mg/l and for 48 hours and sampling was performed immediately at the end of the research period. Based on the results, with increasing ozone levels BOD, COD, TOC, TDS, EC, and MPN bacteria indices decreased significantly. However, in the case of ORP, with an increase in ozone level, the rate of this index also increased significantly. Also, the increase of ozonation level did not show a significant effect on phosphate index. In general, the results showed that with increasing ozone level, physicochemical indices of aquaculture wastewater improved and resulting before entering the water bodies. Therefore, it is recommended that at the discharge point of the rainbow trout culture centers ozonation by 5 mg / l improves the quality of produced wastewater.