Solar wastewater treatment plant for aqueous solution of pesticide

A pesticide (Vydine) considered priority substances by the Jordanian environment ministry and dissolved in water at 25 mg L⁻¹ (or at maximum water solubility) has been degraded at solar pilot plant scale using direct solar UV-light, solar UV combined with H₂O₂ or Fe(II) and solar photo-Fenton. Two different solar irradiation conditions (med day irradiation under clear sky and late hour irradiation under clear sky) have been tested and discussed, using mainly pesticide concentration, TOC mineralization, COD removal and BOD for comparison of treatment effectiveness. A cute toxicity assays were also employed for evaluating the photocatalytic treatments, and comparison between these results. Direct solar UV photolysis is less efficient in term of pesticide degradation than other AOP’s. In contrast, solar photo-Fenton reaction produced higher pesticide degradation in a shorter time (40 min was sufficient for 88% pesticide removal with 20 mg L⁻¹ H₂O₂ and 20 mg L⁻¹ Fe (II)). In these conditions, the BOD₅ was increased from zero for pure pesticide solution to 54 mg O₂/L and acute toxicity was decreased from 19 to 6 toxicity unit.