Fast and efficient hydrodehalogenation of chlorinated benzenes in real wastewaters using Raney alloy

Abstract This work focuses on an efficient reductive pathway of chlorinated benzenes removal from real wastewater. Raney alloy (50:50 wt% Al/Ni) was utilized as a reducing agent in a basic environment of sodium hydroxide. Laboratory tests were performed on real wastewater containing excessive levels of chlorinated benzenes. These were previously used as solvents and degreasing agents and now represent acute harm to the aquatic environment. The experimental conditions – alloy dosage, reaction time, and hydroxide concentration were optimized during this stage. The laboratory stage was followed by an on-site application on a 100 L scale using fully automatized technology. Both the results of laboratory and pilot tests point to possible future large-scale implementation of the proposed technology. There are several factors that support this statement; the technology is robust, easy to implement, economical, and reliably removes up to 99 % of selected contaminants from water; thus improving its overall quality. Moreover, the proposed technology represents no danger to the environment by means of used reagents as reported herein.