Treatment of oil refinery wastewater using crude Coprinus cinereus peroxidase and hydrogen peroxide

Enzymatic treatment of a strong oil refinery wastewater was investigated using crude Coprinus cinereus peroxidase (CIP) from C cinereus UAMH 4103 and hydrogen peroxide. Phenolic compounds in the refinery wastewater were enzymatically converted to coloured polymeric products, which were subsequently removed by coagulation with alum. Unlike previously reported studies with synthetic phenolic wastewaters, neither the purity of enzyme nor the addition of poly(ethylene glycol) had an effect on the phenol transformation catalyzed by CIP. As a result of enzymatic treatment ([CIP](0) = 2 U mL(-1)) and alum coagulation of the wastewater containing 6.4 mM total phenol, the chemical oxygen demand and 5-d biochemical oxygen demand were reduced by 52% and 58%, respectively. Although these oxygen demands were reduced in the wastewater by the enzymatic treatment and subsequent coagulation, the dissolved organic materials in the crude CIP were apparently not affected by either process and tended to remain in the treated wastewater.