管式生物过滤器内生物膜蓄积的生物控制方法及控制机制

A severely problem in gas biofiltration has widely concerned researchers that excessive biomass accumulated in the filter media of biofilters over long-term operational periods. The control of biomass accumulation in biofilters is being a research hot point. Due to its cost-effectiveness and environmental-friendliness, biological method is a promising approach for controlling biomass accumulation in gas biofiltration. However, the biological control method is still at its preliminary stage as some puzzles such as unconspicuous control approaches and little knowledge about the control mechanism. In our previous studies on tubular biofiltration, a small inset which called Blattaria survived for some months, and some Moth (Diptera) flies infested in the chamber of the tubular biofilter (TBF) at a middle envirmental temperature. Both of them can graze the biomass accumulated in the filter media of the TBF. In this project, the characteristics of and the effect of key factors on biomass accumulation in the filter media of the TBF are analysed, some species of protozoa, metazoan and small insects including Blattaria and Moth (Diptera) flies which can prey on the biomass accumulated in the filter media are screened and identified, and the quantitative relationship between target microzoon and the biomass accumulation is also explored. Then a biological control method and its mechanisms for biomass accumulation, and the method and its mechanisms for controlling the target macrozoon in the TBF could be established through this study. This research would be helpful for solving the problem of excessive biomass accumulation in gas biofilters.

气相生物过滤器长期运行后填料内生物膜过度蓄积的难题已经引起了普遍重视，其控制方法研究已成为当前热点。控制生物膜蓄积的生物方法具有经济有效、环境友好的优点，但是仍然处于研究起步阶段，存在控制途径不明晰和过程机制不明确等问题。申请者近期在对管式生物过滤的前期研究中发现了长期存活的蜚蠊目昆虫和中温条件大量繁殖的双翅目蛾蚋科昆虫，它们均可直接吞食反应器内蓄积生物膜。本项目研究管式生物过滤器填料内生物膜的蓄积特征和重要因子对生物膜蓄积的影响规律，筛选和控制具有捕食蓄积生物膜作用的原生动物、后生动物和昆虫纲蜚蠊目及蛾蚋科昆虫，明确目标动物与生物膜蓄积之间的数量关系，构建一种控制生物膜蓄积量的生物方法，揭示生物控制方法的作用机制，进而探究控制捕食动物的方法及控制原理，为解决气相生物过滤器内生物膜过度蓄积问题提供方法与理论依据。

气相生物过滤器长期运行后会出现填料内生物量过度蓄积的问题。利用生物捕食作用控制生物量蓄积的生物方法具有经济有效、环境友好的优点和广阔的应用前景。本项目以预制管状构型的聚氨酯海绵填料为核心单元，构建了管式生物过滤器（TBF）实验系统。以活性污泥接种并成功启动反应器，通过控制高负荷条件长期运行TBF系统，在其长期运行后出现了填料内生物量的过度蓄积现象。分别使用蜚蠊目Blatta orientalis和蛾蚋科Psocodinae昆虫等微小动物作为研究对象，考察目标动物对TBF反应器性能及其填料内生物量蓄积的影响。研究结果表明，TBF对甲苯废气的长期处理性能在高负荷条件下（5.6 kg COD m-3 d-1）可达74%以上，但是长期运行会出现反应器性能降低和填料内生物膜发生过度蓄积。此时通过人工投放蜚蠊目Blatta orientalis昆虫，TBF反应器填料内生物量蓄积得到了有效控制，甲苯去除性能出现先继续下降后逐渐上升的现象。而通过人工投放蛾蚋科Psocodinae昆虫，短时间里TBF反应器内会大量出现Psocodinae幼虫和羽化后成虫，其幼虫可以穿透聚氨酯填料，羽化后的成虫可以附在填料表面，填料内的生物膜容易会被过度吞噬，从而导致反应器性能的急剧降低。因此，蜚蠊目Blatta orientalis和Psocodinae昆虫对TBF反应器填料内生物量蓄积控制分别主导积极和消极的影响。项目实施后，研发获得了一种控制气相生物过滤器中生物膜过度蓄积的方法、一种调控气相生物过滤器内生物量的方法、一种处理恶臭和有机废气的生态棚、一种蜂箱式生物过滤反应器等研究成果。此外，还在磁性碳纳米管处理染料废水、烟气脱硫废水处理工艺改造、高浓度果胶废水处理、改性磁性纳米颗粒固定内生菌Bacillus nealsonii处理重金属废水、水质净化多功能帷幕和直立浸没式水质原位净化帷屏技术研究方面取得一定进展。以上研究为生物方法控制气相生物过滤器内生物量过度蓄积的问题以及水质安全保障问题提供了技术选择及相关理论依据。