好氧-厌氧联合生物反应器对矿山酸性废水的净化效能与机理

It is of great significance to reduce the heavy metal pollution of acid mine drainage (AMD). The application of microbial remediation is limited for some reason, such as the high COD value of the effluent due to the low rate of carbon source utilization, and toxicity of low pH and high metal ion concentration to aSRB, which affect the processing efficiency. Our previous study showed that the pretreatment of aerobic neutralization can precipitate Fe2+ at lower pH, recovering of heavy metals step by step and reducing the toxicity to aSRB as well. However, the key factors affecting its treatment efficiency need to be further explored and the microbial mechanism of purifying efficacy is unclear. In this study, a continuous "aerobic contact oxidation-neutralization-anaerobic EGSB" joint reactor was established. Based on the screening of aSRB with high activity and by using the agricultural waste as carbon source for the treatment of AMD, the performance of the BCOR-EGSB system will be evaluated and optimized by the examination of purifying efficiency when the continuous system is stable. The microbial community structure and function of the microbial in the reactor will be analyzed by high-throughput sequencing technology and the microbial mechanism of the microbial community will be proposed. The mechanism of immobilization of heavy metal ions by synergistic effect between agro-waste aSRB will be elucidated by SEM and XRD mineralogical characterization of precipitates. The project is expected to provide the theoretical basis and practical guidance for the industrial application of AMD Purification, which is of great significance to the protection and repair of the whole ecological environment

降低酸性矿山废水（AMD）的重金属污染具有重要研究意义。微生物修复法存在营养源不能充分利用导致出水COD高和AMD中低pH、高浓度金属离子毒性而影响处理效果等问题。前期研究表明，利用好氧中和预处理可以将铁离子在较低pH下沉淀，实现重金属分步回收和降低对aSRB的毒性，但影响其处理效率的关键因子有待进一步探讨，调控其效能的微生物机理也尚不明了。本研究拟建立连续型“好氧接触氧化-中和-厌氧EGSB”联合反应器，在筛选驯化高活性aSRB 的基础上，利用农业废弃物为碳源处理AMD，通过连续系统稳定运行时对AMD处理效果的考查，研究提高各反应器单元以及联合工艺处理AMD效能的关键影响因子；同时，通过高通量测序技术对反应器中微生物群落结构和功能的分析，揭示其微生物机理；结合沉淀物的SEM、XRD分析，阐明农业废弃物协同aSRB固定重金属离子的机制。项目有望为AMD处理的工业应用提供理论依据和实际指导。

降低酸性矿山废水（AMD）的重金属污染具有重要研究意义。微生物修复法存在营养源不能充分利用导致出水COD高和AMD中低pH、高浓度金属离子毒性而影响处理效果等问题。前期研究表明，利用好氧中和预处理可以将铁离子在较低pH下沉淀，实现重金属分步回收和降低对aSRB的毒性，但影响其处理效率的关键因子有待进一步探讨，调控其效能的微生物机理也尚不明了。本项目首先从典型矿区 AMD 废水和底泥分别中富集了铁氧化菌和 aSRB，通过耐性实验分别筛选得到了耐高重金属离子和 SO42- 浓度的高活性菌株组成铁氧化菌菌群和耐酸 aSRB 菌群；通过静态培养筛选得到了 aSRB 最优的固体缓释碳源为木薯渣，通过分子生物学法分析最优固体碳源条件下微生物群落结构和功能基因响应，结合 SEM 和 XRD揭示了其协同固定重金属的机理，主要是吸附和生成不溶的金属硫化物。其次，设计制作了 “好氧接触氧化-中和-厌氧 EGSB” 连续生物反应器，处理 AMD 并分步回收重金属，研究了影响 AMD处理效果及金属回收效率相关的关键工艺参数，结果表明其关键因子是铁离子浓度，温度，载体形式，以及主要作用微生物类群的丰度。最后，通过对联合生物反应器中沉淀物的矿物学分析和各反应器微生物群落结构、功能基因动态变化的分子生物学分析，研究了“工艺条件-微生物功能-去除效率”的关联，揭示了“好氧接触氧化-中和-EGSB”工艺中微生物净化 AMD 的 机理，为 AMD 微生物修复的工艺设计、过程监控及功能微生物的定向筛选了提供新的理论依据。