Knöller Kay, Jeschke Christina, Simon André, Gast Martin, Hoth Nils
Department Catchment Hydrology, Helmholtz Centre for Environmental Research - UFZ, Halle/Saale, Germany.
Isotopes Environ Health Stud. 2012;48(1):76-88. doi: 10.1080/10256016.2011.622443. Epub 2011 Nov 17.
A mine dump aquifer in the Lusatian lignite mining district, Germany, is contaminated with acid mine drainage (AMD). The only natural process that can counteract the effects of the contamination is bacterial sulphate reduction. The technical measures chosen to handle the contamination include the injection of glycerol into the aquifer to supply electron donors and to accelerate the growth and activity of sulphate-reducing bacteria. An initial assessment of the hydrochemical conditions in the aquifer showed that sulphate concentrations are subject to alteration due to flow-related processes. Consequently, the decision whether sulphate reduction is occurring in the investigated aquifer section was based on the stable isotopic composition of dissolved sulphate and sulphide, which were used in combination with sulphate concentrations. The significant enrichment of both heavy sulphur and heavy oxygen in the remaining sulphate pool and a characteristic isotope fractionation pattern are a clear evidence for the activity of sulphate-reducing bacteria utilising the injected glycerol as an electron donor. This activity seemed to intensify over the observation period. The spatial distribution of sulphate reduction activity, however, appeared to be highly inhomogeneous. Rather than occurring ubiquitously, sulphate reduction activity seemed to concentrate in a defined reaction zone. Regardless of the inhomogeneous distribution, the overall turnover of sulphate during the period of investigation proves the applicability of this enhanced natural attenuation method to handle the restoration of aquifers contaminated with AMD.
德国卢萨蒂亚褐煤开采区的一个矿渣含水层受到酸性矿山排水（AMD）的污染。唯一能够抵消这种污染影响的自然过程是细菌硫酸盐还原作用。为处理这种污染而选择的技术措施包括向含水层注入甘油，以提供电子供体并加速硫酸盐还原菌的生长和活性。对含水层水化学条件的初步评估表明，硫酸盐浓度会因与水流相关的过程而发生变化。因此，关于在所研究的含水层区域是否发生硫酸盐还原作用的判定是基于溶解硫酸盐和硫化物的稳定同位素组成，并结合硫酸盐浓度来进行的。剩余硫酸盐池中重硫和重氧的显著富集以及一种特征性的同位素分馏模式，明确证明了利用注入的甘油作为电子供体的硫酸盐还原菌的活性。在观察期内，这种活性似乎有所增强。然而，硫酸盐还原活性的空间分布似乎极不均匀。硫酸盐还原活性并非普遍存在，而是似乎集中在一个特定的反应区内。尽管分布不均匀，但在调查期间硫酸盐的总体转化情况证明了这种强化自然衰减方法在处理受AMD污染含水层修复方面的适用性。
