Chloroacetaldehyde removal by zero valent iron enhanced hydrolytic acidification pretreatment

Abstract

Chloroacetaldehyde is a typical refractory toxic petrochemical wastewater to environment, whereas conventional treatment strategies in the wastewater treatment plants are inapplicable to transforming it into nontoxic forms. Therefore, we explored zero valent iron enhanced hydrolytic acidification solution to tackle this problem. Experimental results indicated that zero valent iron enhanced hydrolytic acidification technology possessed the capability to chloroacetaldehyde detoxication, 20.23% and 19.32% increasing dechlorination ratio achieved at initial CAE concentration of 50 and 100 mg/L with 5 g/L ZVI at 48 h. Moreover, ZVI reduced cell death resulted from 0.31, to 1.59 DNA/g VSS reduced at aforementioned parameters. Also, ZVI did not significantly affect predominant butyric acid-type fermentation, but it facilitated the total volatile fatty acids more 43.10, 26.06 and 25.39 mg COD/g VSS produced at 50 and 100 mg/L with at 48 h, particularly, it enhanced the yields of short-chain fatty acid Ac which can be directly used by microbes.