生物移动床应用于污水深度处理的微生物机理及工艺优化策略研究

With the features of both activated sludge and fixed biofilm process, MBBR (Moving Bed Biofilm Reactor) has outstanding merits in wastewater treatment process. Preliminary experiments showed the effluent could meet the requirements of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant class I B after the formation of biofilm when MBBR filler was added into the aeration tank of CASS (Cyclic Activated Sludge System) process. This result demonstrates MBBR is able to be applied predominantly in activated sludge process and its related variants to accomplish advanced treatment, which can noticeably lower the expenses for reconstruction. However, the microbial mechanism of the integration of MBBR and activated sludge process is still not thoroughly clarified, which results in relatively aimless control and instable operation of MBBR process. In this project, the microbiological mechanism will be investigated for MBBR’s use in advanced treatment of municipal sewage. Based on microbiological experimental results, it is expected to guide the process, and further provide microbiological theoretical guidance in the upgrade and retrofit of old WWTP and the development of new MBBR-based WWTP. This research is of vital significance for the popularization and application of MBBR in advanced treatment of municipal sewage, which may have foreseeable broad application prospects and great economic and environmental benefits.

MBBR工艺（Moving Bed Biofilm Reactor）兼具活性污泥和固定式生物膜的特点，在污水处理方面具有独特的优势。前期试验表明，将MBBR填料投入到CASS工艺曝气池中，挂膜成功后出水水质由二级标准提升至稳定的一级B标准，证明MBBR工艺有望应用于活性污泥及其变种工艺的升级改造，不仅能够有效实现污水的深度处理，也能够大大降低水厂改造的成本。然而，由于目前对MBBR与活性污泥共池工艺所涉及的微生物机理尚不明确，造成工艺调整相对盲目，运行不稳定等，从而阻碍了该工艺的推广应用。在本项目研究中，拟从微观生物学角度探索MBBR在污水深度处理过程中的微生物机理，并基于微生物试验结果优化工艺运行策略，从而为MBBR应用于老旧污水厂升级改造和MBBR型污水厂的建造提供微生物理论指导。本研究有利于MBBR工艺在市政污水深度处理中的推广应用，具有广阔的应用前景和较大的经济效益和环保效益。

基于悬浮填料的污水处理工艺兼具活性污泥和固定式生物膜的特点，在污水处理领域具有独特的优势。然而，由于该工艺所使用的填料存在固有弊端，且涉及的微生物机理尚不明确，从而阻碍了该工艺的推广应用。本项目通过改进填料配方，制备出密度更接近于水，并具有生物亲和性能的新型悬浮生物填料。新型填料的挂膜速度显著提高，生物量提高20%-60%，在不同的污水处理工艺中均显示出良好的污染物去除性能。微生物学研究表明：生物亲和性填料有利于功能微生物的富集，为不同生境的微生物提供了良好的代谢场所。此外，固定相与悬浮相中的微生物群落结构及种属特性差异显著。基于微生物试验结果，优化了基于悬浮填料的污水处理工艺运行策略，并在此基础上，对两座污水处理厂的提标改造工况进行分析，并优化工艺运行参数，改造后的出水达到“城镇污水处理厂污染物排放标准（GB 18918-2002）”的一级A标准。本项目有利于基于悬浮填料的污水处理工艺的推广应用，具有广阔的应用前景和较大的经济效益和环保效益。