Effective treatment of high-salinity landfill leachate using ultraviolet/ ultrasonication/ peroxymonosulfate system

Landfill leachate, as a complex medium with a high concentration of organic and mineral materials, is a serious problem for the environment. In the current study, the saline landfill leachate of Bushehr coastal city (Iran) was treated using ultraviolet/ultrasonic waves/peroxymonosulfate system. The initial TOC and TDS of the studied leachate was 915 mg/L and 7390 mg/L, respectively. The system had the maximum efficiency at conditions of pH 3, peroxymonosulfate (PMS) of 4 mM, and reaction time of 150 min. Based on the findings, the initial ratio of BOD5/COD (0.66) was reduced to 0.38 using the developed system. After treatment of the landfill leachate at the optimal condition, the values of COD, BOD5, and UV254 were reached to 983 mg/L, 348 mg/L, and 10.16 cm(-1), respectively. The concentration of all studied elements (except Pb, As, and Ca) increased after purification. According to the GC-mass spectrometry, the molecular weight and concentration of organic matter in raw leachate were higher than that of the treated one. The studied system had an energy consumption value of 86 kW.h/m(3) for the treatment of landfill leachate. The results confirm the effectiveness of the ultraviolet/ultrasonic waves/PMS system for the treatment of high saline landfill leachate. (C) 2020 Elsevier Ltd. All rights reserved.