Dechlorination of Pentachlorophenol by Zerovalent Iron in Presence of Carboxylic Acids

The dechlorination of pentachlorophenol (PCP) by zerovalent iron (Fe⁰) in presence of low molecular weight carboxylic acids was investigated. The experimental results showed that oxalic acid was advantaged among the selected acids for the dechlorination of PCP. The lower pH value and the higher dosage of Fe⁰ were favorable for the enhancement of dechlorination efficiency. With their strong complexing and pH buffering properties, carboxylic acids favored the fresh surface of iron, which benefits to the dechlorination of PCP by Fe⁰. Moreover, the oxalate-iron complexes have more reductive activities and then lead to the highest dechlorination efficiency of PCP by Fe⁰.