Garbou Amel M, Clausen Christian A, Yestrebsky Cherie L
Environmental Chemistry Laboratory, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816, United States.
Environmental Chemistry Laboratory, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816, United States.
Chemosphere. 2017 Jan;166:267-274. doi: 10.1016/j.chemosphere.2016.09.139. Epub 2016 Oct 1.
Chlorophenols are highly toxic, environmentally-persistent compounds which have been classified as probable human carcinogens by the United States Environmental Protection Agency. Due to the high toxicity of these compounds, it is necessary to treat water and soils with concentrations of chlorophenols above the detection limit set by regulatory agencies. The aim of this work is to demonstrate the capabilities of using ball-milled magnesium for the dechlorination of PCP. Comparison of dechlorination processes were performed in an attempt to determine the most effective system for degradation of PCP to phenol. Three systems with powerful capabilities of treatment were studied: ball-milled zero-valent magnesium (ZVMg), ball-milled zero-valent magnesium carbon (ZVMg/C), and ball-milled zero-valent magnesium with palladium (ZVMg/Pd). In addition to measuring PCP disappearance, all byproducts were identified and quantified for each degradation system. The results of these studies indicate that all three of the systems degrade PCP within 30 min. The most rapid and complete PCP dechlorination is achieved using ball-milled Mg/Pd and a matrix consisting of at least 0.02 g Mg0/mL ethanol, and 10 μL acetic acid/mL ethanol, in which case 20 ng/μL of PCP was dechlorinated to chlorophenols in approximately 15 min with complete dechlorination achieved in six days. Carbon mass balances of 90.16% for Mg, 94.76% (Mg/C) and 97.05% (Mg/Pd) verify dechlorination was responsible for declining concentrations of PCP. The reactions of PCP degradation and phenol formation were found to follow pseudo-first order kinetics for all systems. Further work will consist of optimization and development of field-scale applications.
氯酚是剧毒且具有环境持久性的化合物，美国环境保护局已将其列为可能的人类致癌物。由于这些化合物毒性高，有必要对氯酚浓度高于监管机构设定检测限的水和土壤进行处理。这项工作的目的是证明使用球磨镁对五氯苯酚进行脱氯的能力。对脱氯过程进行了比较，以确定将五氯苯酚降解为苯酚的最有效系统。研究了三种具有强大处理能力的系统：球磨零价镁（ZVMg）、球磨零价镁碳（ZVMg/C）和球磨零价镁钯（ZVMg/Pd）。除了测量五氯苯酚的消失情况外，还对每个降解系统的所有副产物进行了鉴定和定量。这些研究结果表明，所有这三种系统都能在30分钟内降解五氯苯酚。使用球磨的Mg/Pd以及由至少0.02 g Mg0/mL乙醇和10 μL乙酸/mL乙醇组成的基质可实现最快且最完全的五氯苯酚脱氯，在这种情况下，20 ng/μL的五氯苯酚在约15分钟内脱氯为氯酚，并在六天内实现完全脱氯。Mg的碳质量平衡为90.16%，Mg/C为94.76%，Mg/Pd为97.05%，这证实了脱氯是五氯苯酚浓度下降的原因。发现所有系统中五氯苯酚降解和苯酚形成的反应均遵循准一级动力学。进一步的工作将包括现场规模应用的优化和开发。
