SIMULTANEOUS BIOLOGICAL REDUCTIVE DECHLORINATION AND COPPER REMOVAL IN AN ELECTROCHEMICAL CELL

摘要

An electrochemical treatment method that stimulates microbial dechlorination activityrnand removes heavy metals from a wastewater was evaluated. Abiotic tests werernperformed using an electrochemical cell with and without the addition of copperrn(Cu~(2+)) to evaluate Cu~(2+) removal and the direct reduction of 2,6-dichlorophenol (2,6-rnDCP) on the cathode. Suspended growth tests were performed in an electrochemicalrncell with and without the addition of Cu~(2+) to evaluate Cu~(2+) removal and thernstimulation of the biological reduction of 2,6-DCP. Serum bottle batch tests were alsornperformed to evaluate the impact of Cu~(2+) on 2,6-DCP and 2-chlorophenol (2-CP)rndechlorination and to examine the removal of Cu~(2+) in the absence of an appliedrncurrent. Results of the serum bottle batch tests indicate that the rate of reduction ofrn2,6-DCP increased at higher levels of hydrogen addition and that Cu~(2+)inhibits thernreduction of 2,6-DCP at concentrations less than 0.2 mg/L. At Cu~(2+) concentrationsrnas low as 0.05 mg/L, no degradation of 2-CP occurred, indicating that Cu~(2+) greatlyrninhibits 2-CP degradation. Results from the suspended growth tests in anrnelectrochemical cell showed that when stimulated with a current, 2,6-DCP degradationrnrates increased with increasing current without the addition of Cu~(2+). 2,6-DCPrndegradation rates decreased at Cu~(2+) concentrations between 1.0 and 3.0 mg/L andrntotal inhibition was observed at a Cu~(2+) concentration of 5.0 mg/L. Control testsrnshowed that 2,6-DCP was not degraded abiotically and that Cu~(2+) was removed byrndeposition on the cathode.