在可控氧化还原电位（Eh）和pH环境下，五氯苯酚在氧化锰悬浮液中的氧化作用。

Oxidation of pentachlorophenol in manganese oxide suspensions under controlled Eh and pH environments.

作者信息

Petrie Robert A, Grossl Paul R, Sims Ronald C

机构信息

Department of Civil and Environmental Engineering, Utah State University, Logan 84322, USA.

出版信息

Environ Sci Technol. 2002 Sep 1;36(17):3744-8. doi: 10.1021/es0109491.

DOI:10.1021/es0109491

PMID:12322746

Abstract

Abiotic oxidation of pentachlorophenol (PCP) by manganese(IV) oxide (MnO2) was examined in orderto understand the physiochemical environment(s) where PCP oxidation occurs. An Eh-pH potentiostat was used to simulate natural groundwater environments where MnO2 (0.025 g L(-1)) and PCP (0.020 g L(-1)) suspensions were incubated from Eh -300 to 300 mV and pH 4.5 to 7.0. The pH-Eh region where maximum PCP sorption occurred corresponded to the same region where the greatest concentrations of soluble Mn(II) where measured (Eh > -100 mV and pH <5.0). Reduced Mn species [Mn(II,III)] released by reductive dissolution were readsorbed and restricted further abiotic oxidation of PCP by the MnO2 surface. A greater transformation of PCP to primarily tetrachloro-1,4-benzoquinone (p-chloranil) and smaller amounts of lesser chlorinated phenols occurred under increasing pH and Eh conditions.

摘要

为了了解五氯苯酚（PCP）发生氧化反应的物理化学环境，对二氧化锰（MnO₂）非生物氧化五氯苯酚的过程进行了研究。使用电位滴定仪模拟天然地下水环境，将MnO₂（0.025 g L⁻¹）和PCP（0.020 g L⁻¹）悬浮液在-300至300 mV的氧化还原电位（Eh）和4.5至7.0的pH值条件下进行孵育。PCP吸附量最大时的pH-Eh区域与可溶性锰（II）浓度最高的区域相对应（Eh > -100 mV且pH < 5.0）。还原溶解释放出的低价锰物种[Mn(II,III)]被重新吸附，从而限制了MnO₂表面对PCP的进一步非生物氧化。在pH值和Eh值升高的条件下，PCP更多地转化为主要产物四氯-1,4-苯醌（对苯二酚），同时生成少量低氯代酚。