School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China; Anhui Engineering Research Center of Industrial Wastewater Treatment and Resource Recovery, Hefei University of Technology, Hefei, Anhui 230009, China; Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, Anhui 230009, China.
School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China; Anhui Engineering Research Center of Industrial Wastewater Treatment and Resource Recovery, Hefei University of Technology, Hefei, Anhui 230009, China; Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, Anhui 230009, China.
Water Res. 2023 Sep 1;243:120415. doi: 10.1016/j.watres.2023.120415. Epub 2023 Jul 26.
Acidic pit lakes represent hydrological features resulting from the accumulation of acid mine drainage in mining operations. Long-term monitoring is essential for these extreme and contaminated environments, yet tracking investigations integrating microbial geochemical dynamics in acidic pit lakes have been lacking thus far. This study integrated historical data with field sampling to track decadal biogeochemical changes in an acidic pit lake. With limited artificial disturbance, significant and sustained biogeochemical changes were observed over the past decade. Surface water pH slowly increased from 2.8 to a maximum of 3.6, with a corresponding increase in bottom water pH to around 3.9, despite the accumulation of externally imported sulfate and metals. Elevated nutrient levels stimulated the macroscopic growth of Chlorophyta, resulting in a shift from reddish-brown to green water with floating algal bodies. Furthermore, microalgae-fixed organic carbon promoted the transition from the initial chemolithotrophy-based population dominated by Acidiphilium and Ferrovum to a heterotrophic community. The increase in heterotrophic iron- and sulfate-reducers may cause an elevation in ferrous levels and a decline in copper concentrations. However, most metals were not removed from the water column, potentially due to insufficient biosulfidogenesis or sulfide reoxidation. These findings offer novel insights into microbial succession in extreme ecosystem evolution and contribute to the management and remediation of acidic pit lakes.
酸性矿坑湖是采矿作业中酸性矿山排水积聚形成的水文特征。长期监测对于这些极端和污染环境至关重要，但迄今为止，还缺乏对酸性矿坑湖中微生物地球化学动态进行综合跟踪调查的研究。本研究通过整合历史数据和野外采样，对一个酸性矿坑湖进行了长达十年的生物地球化学变化跟踪。在过去的十年中，尽管有外部输入的硫酸盐和金属，在有限的人为干扰下，仍观察到显著且持续的生物地球化学变化。地表水 pH 值从 2.8 缓慢增加到最大值 3.6，相应的底层水 pH 值增加到 3.9 左右，尽管有外部输入的硫酸盐和金属。营养物质水平的升高刺激了绿藻的宏观生长，导致水体从红棕色变为绿色，漂浮着藻类生物。此外，微藻固定的有机碳促进了从最初以化能自养菌（如 Acidiphilium 和 Ferrovum）为主的种群向异养群落的转变。异养铁还原菌和硫酸盐还原菌的增加可能导致亚铁水平升高和铜浓度下降。然而，大多数金属并未从水柱中去除，这可能是由于生物硫化作用不足或硫化物再氧化。这些发现为极端生态系统演化中的微生物演替提供了新的见解，并有助于酸性矿坑湖的管理和修复。
