Babak Tavakoli - Department of Chemistry and Chemical Engineering, Rasht Branch, Islamic Azad University, Rasht, Iran
Omid Alizadeh - Department of Chemistry and Chemical Engineering, Rasht Branch, Islamic Azad University, Rasht, Iran
Fatereh Dorosti - Department of Chemistry and Chemical Engineering, Rasht Branch, Islamic Azad University, Rasht, Iran

Guilan Province compost leachate was treated utilizing a hybrid process including chemical treatment followed by electro-proxone and ultra filtration (UF). The effects of different parameters including ratio of natural / chemical coagulant (۱:۵, ۱:۱۵, ۱:۲۵), pH (۵-۸), time (۱۰-۹۰ min), ozone dose (۱۰-۹۰ mg L-۱), current intensity (۵۰-۵۰۰ mA), TMP (۰.۵-۳.۵ bar) and temperature (۲۰-۵۰ °C) on COD and turbidity removal were investigated. At optimum conditions of the coagulation process (Salvia hispanica mucilage/FeCl۳ = ۱:۱۵ and pH = ۶.۵), ۳۶.۱۹ % and ۵۶.۹ % removal efficiencies were obtained for COD and turbidity, respectively. Effluent from the chemical treatment went through. Results from the electro-proxone process showed that by increasing the current intensity from ۵۰ to ۳۵۰ mA, COD removal efficiency reaches form ۱۴ % to  ۷۹ %. By changing O۳ concentration from ۱۰ mg L-۱ to ۹۰ mg L-۱, COD reduction increased and reached from ۲۹ % to ۸۴ %. UF reactor was used for final polishment of the treated wastewater at the optimum TMP of about ۱.۵ bar and pH = ۷.۵. By increasing the temperature from ۲۰ °C to ۴۰ °C, permeation flux increased from ۷۶.۷ Lm-۲ h-۱ to ۱۰۴.۱ Lm-۲ h-۱. However, following the increase of the permeation flux, the removal efficiency of COD and turbidity decreased slightly to ۵۴ % and ۹۰ %, respectively. This study showed that the employed hybrid method is capable of treating the hardly biodegradable compost leachate and obtaining the environmental standards.

Compost leachate, E- proxone, Salvia hispanica mucilage, Wastewater treatment