Sequential treatment of young landfill leachate by aeration and UV/US/activated persulfate-hydrogen peroxide: performance, optimization and phytotoxicity evaluation.

A comprehensive treatment approach for young leachate landfill (YLL) from Fez City was investigated using an integral system involving aeration as a pretreatment before the binary oxidation process using hydrogen peroxide (HP)/persulfate (PS) as oxidants, in which UV-A irradiation and ultrasonic (US) are used as activators (HP-PS-US-UV-A). The initial treatment by aeration resulted in COD, color, and Abs removal efficiencies of 54%, 61%, and 55%, respectively. The efficiency of the AOP was statistically evaluated, and the optimal operating conditions were determined by Box-Behnken design (BBD) to investigate the effects of three operating variables (pH, [SO], and [HO]) on three target responses: COD, Abs, and color removal.