Treatment of highly polluted grey waters using Fenton, UV/H2O2 and UV/TiO2 processes

Household or office wastewater consists of two parts of faecal and non-faecal wastewater. Non-faecal section, which accounts for more than 60% of household wastewater, is known as grey water. Treating this part of sewage and using it in various areas can greatly reduce the consumption of potable water. In this research, three methods of advanced oxidation processes including Fenton, UV/H2O2, and UV/TiO2 were investigated for treatment of two grey water sourced from Shif Island and Persian Gulf University restaurant in Bushehr province of Iran. These grey waters were highly polluted with COD content of 600 mg/L and 1400 mg/L, respectively. The efficiency of each process was determined by measuring the COD removal rate. Results showed that at optimum reaction conditions, the COD removal efficiency of the UV/H2O2 process was the best, compared to the other two processes. The COD removal efficiency of UV/H2O2 process at pH = 3 and H2O2 = 1500 and 750 mg/L for grey water of the Shif Island and Persian Gulf University restaurant were 88% and 90%, respectively. Therefore, the treated gray waters can be reused economically.