人工回灌条件下地下环境要素对氯苯生物降解行为的影响研究

Effect of Underground Environment on the Biodegradation Behavior of Chlorobenzene During Artificial Recharge

为控制区域地面沉降,计划开展相应的地下水人工回灌,而在拟采用的回灌水源中监测到氯苯等有机组分,因而确定回灌过程中氯苯的环境行为是十分必要的。由于人工回灌过程会对地下环境产生扰动,所以不同回灌季节会导致地下环境温度以及溶解氧发生变化。基于此,开展了一系列的生物降解实验,研究不同地下环境要素下人工回灌过程中氯苯的生物降解作用。实验数据表明:一定浓度条件下氯苯的生物降解反应符合一级衰减动力学和Monod方程。由Monod方程得出:随着温度升高和溶解氧的增加,降解速率加快,降解效果更好。阿伦尼乌斯方程能够量化温度对生物降解速率的影响。不同浓度氯苯生物降解计算出最大的降解量为:在好氧与厌氧条件20,10,0℃下,分别为35,31,28μg/g和30,27,23μg/g。就温度和溶解氧对氯苯生物降解的影响来看,确定人工回灌最佳季节是夏季。

Organic components such as Chlorobenzene（CB） was detected in the water source for artificial recharge which was planned to control regional land subsidence.As artificial recharge will disturb the underground environment,recharge in different seasons will lead to variations of underground temperature and dissolved oxygen.In view of this,the authors mainly investigated the biodegradation of CB in different underground environments during artificial recharge.Data from pilot-scale biodegradation experiments in laboratory showed that the biodegradation of CB well fitted the first-order kinetics of decay and the Monod equations at certain concentration.It was obtained through Monod equation that when temperature and dissolved oxygen raised,the reaction rates of degradation accelerated,and thus the biodegradation effect was better.The Arrhenius equation could quantify the impact of temperature on the biodegradation rate.With different CB concentrations,the calculated maximum amount of biodegradation in aerobic and anaerobic conditions at 20℃,10℃,0℃ were 35,31,28 μg/g and 30,27,23 μg/g respectively.It’s concluded that the best season for artificial recharge is summer owing to the influence of temperatures and dissolved oxygen on CB biodegradation.