摘要：

针对垃圾发电厂UASB-AOAO-MBR工艺处理高浓度钙离子渗滤液时运行不稳定的问题，研究含2 000~8 000 mg/L钙离子渗滤液对UASB、AOAO单元处理效果的影响，并分析了钙离子冲击下UASB、AOAO单元内细菌群落结构的变化情况。结果表明：调节池、UASB均能去除渗滤液中的部分钙离子，当渗滤液中钙离子质量浓度为2 000~8 000 mg/L时，调节池、UASB分别去除400~1 820、1 620~3 300 mg/L钙离子，有效降低钙离子对AOAO池及膜处理单元的冲击；当渗滤液钙离子质量浓度超过6 000 mg/L时，极易引起UASB中水质酸化，同时AOAO氨氧化功能减弱，导致脱氮系统崩溃。钙离子冲击造成UASB单元内Methanosaeta丰度从9.21%降至2.01%，抑制了废水中乙酸向甲烷的转化，引发反应器内pH降低；钙离子冲击使AOAO池Nitrospira丰度从7.57%减少至1.21%，导致氨氧化活性降低；钙离子冲击还造成AOAO池Thauera丰度从4.44%上升至16.85%，强化了对COD的去除，但对反硝化作用贡献极少。钙离子冲击抑制了UASB单元、AOAO单元对渗滤液的处理效果，建议在UASB前加装除硬设施，确保UASB进水钙离子质量浓度小于3 800 mg/L，减少对渗滤液生化系统的冲击。研究为UASB-AOAO-MBR垃圾渗滤液处理系统的稳定运行提供借鉴。

关键词: 钙离子冲击, 发电厂垃圾渗滤液, 硝化作用, 反硝化作用

Abstract:

To address the operational instability of the UASB-AOAO-MBR process of landfill power plant when treating leachate with high calcium ion concentrations, this study investigated the impact of leachate containing 2 000-8 000 mg/L Ca²⁺ on the performance of the UASB and AOAO units, and the response relationship between calcium shock and the changes of bacterial community structure in UASB and AOAO tanks. The results showed that both the regulating tank and the UASB could partially remove Ca²⁺ from the leachate. When the influent Ca²⁺ concentration was 2 000 to 8 000 mg/L, the regulating tank and UASB removed 400-1 820 mg/L and 1 620-3 300 mg/L of Ca²⁺, respectively, effectively mitigating the impact on the AOAO and membrane units. However, when Ca²⁺ concentration exceeded 6 000 mg/L, acidification readily occurred in the UASB with weakened ammonia oxidation in the AOAO, leading to the collapse of the nitrogen removal system. Calcium shock reduced the abundance of Methanosaeta in the UASB from 9.21% to 2.01%, inhibiting acetic acid conversion to methane and causing pH drop. In the AOAO unit, the abundance of Nitrospira decreased from 7.57% to 1.21%, resulting in lower ammonia oxidation activity. Meanwhile, the abundance of Thauera increased from 4.44% to 16.85%, primarily contributing to COD removal with minimal enhancement of denitrification. The findings indicated that calcium shock inhibited the performance of both UASB and AOAO units. It was recommended to install a hardness-removal facility prior to the UASB to maintain influent Ca²⁺ below 3 800 mg/L, thereby reducing the shock to the biochemical system and supporting the stable operation of the UASB-AOAO-MBR process for landfill leachate treatment.

Key words: calcium ion shock, power plant landfill leachate, nitrification, denitrification

中图分类号: 

• X703