Classical Fenton and Sequencing Batch Reactor Treatment of Pesticide Wastewater

Abstract

This chapter examined Fenton and sequencing batch reactor (SBR) treatment of pesticide industrial wastewater. The optimum operating conditions for Fenton pretreatment of the pesticide wastewater were H2O2/COD molar ratio 3.0, H2O2/Fe2+ molar ratio 10, pH 3 and reaction time 60 min. The COD and TOC removal were 58.51 and 39.76%, respectively and biodegradability (BOD5/COD ratio) increased from 0.02 to ~ 0.30 after 60 min reaction time. The reaction followed pseudo-first order kinetics with a rate constant (k) of 0.0083 min−1. In the post-treatment by aerobic SBR, five different Fenton operating conditions were investigated and H2O2/COD molar ratio 3.0, H2O2/Fe2+ molar ratio 25, pH 3 and reaction time 60 min appeared to be the most significant (p < 0.05) operating conditions. The Fenton–SBR treatment at 12 hr HRT achieved COD, TOC and BOD5 removal efficiency of 96.7, 97.7 and 93.3%, respectively. The Fenton-SBR process was effective for the treatment of pesticide wastewater.