Effects of electrokinetic treatment of a heavy metal contaminated soil on soil enzyme activities
Effects of electrokinetic treatment of a heavy metal contaminated soil on soil enzyme activities
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动电处理重金属污染土壤对土壤酶活性的影响
DOI：
10.1016/j.jhazmat.2009.08.033
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发表时间：
2009-12-30
影响因子：
13.6
通讯作者：
Wu, Dan-Ya
中科院分区：
文献类型：
--
作者：
Cang, Long;Zhou, Dong-Mei;Wu, Dan-Ya
直流电场对土壤中污染物的去除越来越受到人们的关注，但其对土壤酶活性的影响却知之甚少。在实验室条件下研究了电动力学（EK）处理对重金属污染土壤酶活性的影响，并探讨了EK处理对土壤酶活性影响的机理。1-3 V cm（-1）电压梯度处理420 h后，土壤pH、电导率（EC）、土壤有机碳、溶解性有机碳（DOC）均显著高于对照。分析了土壤重金属含量和酶活性。结果表明，在不控制阴极液pH和控制阴极液pH的条件下，土壤铜的平均去除率分别为65%和83%，镉的平均去除率均在90%以上。土壤蔗糖酶和过氧化氢酶活性均有所提高，最高酶活性是初始酶活性的170倍。土壤脲酶和酸性磷酸酶活性均低于初始值。相关分析表明，土壤转化酶和酸性磷酸酶活性与土壤pH、EC和DOC均呈显著正相关（P < 0.05），而土壤脲酶活性与土壤理化性质无相关性。直流电对溶液转化酶和过氧化氢酶蛋白活性的影响表明，直流电对溶液转化酶活性影响不大，对过氧化氢酶活性有负影响。从土壤和溶液中转化酶和过氧化氢酶活性的变化可以看出，EK处理的主要效应机制是改变了土壤性质。(C)2009爱思唯尔有限公司版权所有。
There is a growing concern on the potential application of a direct current (DC) electric field to soil for removing contaminants, but little is known about its impact on soil enzyme activities. This study investigated the change of enzyme activities of a heavy metal contaminated soil before and after electrokinetic (EK) treatments at lab-scale and the mechanisms of EK treatment to affect soil enzyme activities were explored. After treatments with 1-3 V cm(-1) of voltage gradient for 420 h, soil pH, electrical conductivity (EC), soil organic carbon, dissolved organic carbon (DOC). soil heavy metal concentration and enzyme activities were analyzed. The results showed that the average removal efficiencies of soil copper were about 65% and 83% without and with pH control of catholyte, respectively, and all the removal efficiencies of cadmium were above 90%. The soil invertase and catalase activities increased and the highest invertase activity was as 170 times as the initial one. The activities of soil urease and acidic phosphatase were lower than the initial ones. Bivariate correlation analyses indicated that the soil invertase and acidic phosphatase activities were significantly correlated with soil pH, EC, and DOC at P < 0.05, but the soil urease activities had no correlation with the soil properties. On the other hand, the effects of DC electric current on solution invertase and catalase enzyme protein activities indicated that it had negative effect on solution catalase activity and little effect on solution invertase activity. From the change of invertase and catalase activities in soil and solution, the conclusion can be drawn that the dominant effect mechanism is the change of soil properties by EK treatments. (C) 2009 Elsevier B.V. All rights reserved.