Experimental study on treatment of o-Aminobenzoic acid wastewater by microwave-assisted fenton oxidation process.

An experimental system of microwave-assisted Fenton oxidation was designed and tested.Using recalcitrant wastewater from o-Aminobenzoic production as the treatment object,the influence of initial pH,microwave radiation time,H_2O_2 mass concentration,Fe~(2+) mass concentration,catalyst dosage, and microwave power on degradation effect were investigated.The operating conditions of microwave-assisted Fenton oxidation were improved and optimized.Furthermore,mechanisms affecting factors in wastewater were analyzed,and the key and controlling steps of reactions were suggested.The optimal operating conditions tested were as following: pH=3,irradiation time=6 min,dosage of Fenton was H_2O_2=50(mg/L),(Fe~(2+)=)10(mg/L),dosage of catalyst=60(g/L),microwave power=850 W.Under these conditions,the removal rate reached 85% for COD_(Cr),85% for color and 90% for o-Aminbenzoic.The treatment operating cost was about 4.2 yuan per ton of wastewater.