AN ANAEROBIC FLUIDIZED BED BIOREACTOR SYSTEM FOR AN ADVANCED WASTEWATER TREATMENT

针对一种深度废水处理系统，开发了一种新的、简单的废水处理系统，该系统不需要传统的一级澄清池。它由厌氧颗粒床生物反应器(AFPB生物反应器)和好氧生物处理工艺组成。考察了悬浮物、有机物、磷和含氮化合物的同时去除。结果表明：(1)在AFPB生物反应器中，悬浮固体、胶体物质和磷被少量聚合的三氯化铝和弱阴离子聚合物凝聚，生成大尺寸的污泥颗粒，并迅速从系统中分离出来。(2)丝状细菌Beggiatoa sp.是形成高密度污泥颗粒的主要原因。(3)AFPB生物反应器不仅起到物理分离悬浮固体和磷化合物的作用，而且还起到生物去除有机物和含氮化合物的作用。通过将好氧生物处理过程中的澄清、硝化出水回用于厌氧生物反应器，可以有效地将进水中的悬浮有机物和可溶性有机物用于生物脱氮，实现稳定的脱氮。(4)本研究提出的工艺可以在较短的停留时间内同时去除多种污染物，如化学需氧量、悬浮固体和氮磷组分，即使在低至10ﾟC的水温下也能产生良好的出水水质。(5)厌氧生物反应器系统可用于污水污泥脱水出水等高浓度废水。

A new, simple wasterwater treatment system without the conventional primary clarifier was developed for an advanced waste water treatment system. It consisted of an anaerobic fluidized pellet bed bioreactor (AFPB bioreactor) followed by an aerobic biological treatment process. Simultaneous removal of suspended solids, organic matter, phosphorus and nitrogenous compounds was examined. The following results were obtained :(1) In the AFPB bioreactor, suspended solids, colloidal matter and phosphorus were coagulated using a small amount of polymerized aluminum chloride and weak anonic polymers to generate large sized sludge pellets which separated rapidly from the system.(2) A filamentous bacteria Beggiatoa sp.was greatly responsible for the formation of the sludge pellet with high density.(3) The AFPB bioreactor functioned not only physically to separate suspended solids and phosphorus compounds as agglomerates, but also biologically to remove organic substances as well as nitrogenous compounds. Suspended and soluble organic substances in the influent wastewater were effectively used for biological denitrification by recycling the clarified, nitrified effluent from the aerobic biological treatment process to the AFPB bioreactor, and a stable nitrogen removal could be accomplished.(4) The process proposed in this study could remove a variety of pollutants such as COD,suspended solids, nitrogen and phosphorus components simultaneously at the quite short retention time of 5h, producing good quality effluent even at water temperatures as low as 10ﾟC.(5) The AFPB bioreactor system could be applied to high strength of waste water such as filtrate from dehydration of sewage sludge.