Dechlorination of pentachlorophenol by zero-valent zinc affected by dissolved oxygen and reduced sulfur

摘要

The aim of this study is to find the affection of the dissolved oxygen (DO) and reduced sulfur (RS) on the effectiveness, intermediates, reaction pathways and kinetics of pentachlorophenol (PCP) dechlorination by using commercial microscale zero-valent zinc during batch tests. The dechlorination of chlorophenols using Zn~0 showed more significant under the lower DO condition (0.06mg/L) than the higher DO (7.50mg/L). The pseudo-first-order rate constant of PCP dechlorinated by Zn~0 under the lower DO condition (1.88 ×10~(-2) h~(-1)) was 84.3 higher than that under the higher DO condition (1.02 ×10~(-2) h~(-1)). The dechlorination of chlorophenols using Zn~0 showed more significant without RS dosing than with RS dosing. The pseudo-first-order rate constant of PCP dechlorinated by Zn~0 with RS dosing (0.8 × 10~(-2) h~(-1)) was 2.35 folds smaller than that without RS dosing. Results reveals that both dissolved oxygen and reduced sulfur could retard the dechlorination of PCP by Zn~0.