应用质量通量评估地下水中BTEX和乙醇的自然衰减

近年来，应用于修复石油烃污染地下水的监测自然衰减技术得到了广泛深入研究，同时质量通量方法已逐渐成为评 估地下水燃油污染场地自然衰减监测修复效能的重要手段。通过在室内砂槽中添加乙醇汽油组分，监测其自然衰减，利用 质量通量方法，得出了BTEX和乙醇的质量减少率、自然衰减速率常数K；结合非反应示踪剂溴离子，评价了BTEX和乙醇 自然衰减因素中吸附和微生物的联合降解效应。结果表明，自然衰减是地下水中燃油组分修复的重要机制，质量通量方法 是评估自然衰减的有效方法之一。BTEX和乙醇在自然衰减过程中被去除的比例分别为78.88%和98.71%，其中约98%的 BTEX 因吸附和生物降解联合作用被去除，接近100%的乙醇因内在生物降解作用被去除；BTEX 的自然衰减速率为 0.077d-1~0.167d-1，乙醇为0.353d-1，自然条件下乙醇比BTEX更容易衰减。
In recent years, application of the Monitoring Natural Attenuation (MNA) method in petroleum hydrocarbon removal from groundwater was widely studied. Alternatively, mass flux calculation becomes an important way to evaluate the remediation effect of MNA on removing gasoline pollutants in groundwater. In this study, ethanol and BTEX from gasoline, associated with bromide as a non-active tracer, were injected into a sand tank and their degradation was monitored. Based on mass flux method, mass reduction rates and first-order natural attenuation rate constants of BTEX and ethanol were obtained. The results showed that the mechanism of nature attenuation is important for removing fuel components in groundwater, and mass flux is an effective method to evaluate the nature attenuation, with the removal rates of BTEX and ethanol in natural attenuation to be 78.88% and 98.71%, respectively. About 98% of BTEX was removed by adsorption and intrinsic biodegradation as well as approximate 100% ethanol removed by intrinsic biodegradation. The first-order natural attenuation rates of BTEX ranged from 0.077 d-1 to 0.167 d-1. Compared with BTEX, ethanol had a larger rate (0.353 d-1), indicating that ethanol was more rapidly to be attenuated than BTEX under natural condition.