【作者】 张长；

【导师】 曾光明； 余健；

【作者基本信息】 湖南大学 ， 环境工程， 2004， 硕士

【摘要】 近10年来，湘江中、下游普遍受到各种有机物、氨氮、铁、锰和重金属的污染，一些河段水质指标经常达不到现行《地面水环境质量标准》中Ⅲ类水源水质标准要求。以湘江为水源的大部分水厂，由于受常规处理工艺的局限，出厂水中常含有较多的污染物质，水质常达不到生物稳定。本研究通过试验探讨了生物过滤对湘江微污染源水的处理特性，结果表明，生物过滤可有效去除微污染源水中的有机物、NH₄⁺-N、Fe和Mn，提高饮用水生物稳定性，生物过滤对TOC去除率为25～32％，对BDOC的去除率为41.3～65％，对AOC的去除率为59.2～84.2％，对COD_Mn的去除率为40.2～49.4％，对UV₂₅₄的去除率为60.6～66.5％，对NH₄⁺-N的去除率达67～90％，对铁的去除率可达88～95％，对锰的去除率为36～87％。溶解性有机物的去除效果与有机物分子量的分布密切相关，GAC-石英砂生物过滤对于分子量小于1000和分子量在3000～6000之间的有机物有较好的去除特性，去除率分别可达54.46％和54.57％，这些有机物可能主要由苯酸脂类、酮类、酚类等合成有机物和腐殖酸类物质组成。生物过滤具有良好的去浊特性，当进水浊度小于5NTU时，生物过滤能在较长时间内保持出水浊度低于0.1 NTU，浊度的去除是传统吸附截留和生物吸附共同作用的结果；在生物滤柱内，生物膜量的分布都是随水流方向自上而下逐渐降低的；生物膜在滤料表面以菌胶团形式存在，而且并未完全覆盖滤料表面。假单胞菌和芽孢杆菌分别为生物滤柱内的优势菌属和亚优势菌属，生物膜的组成除了细菌，还包括放线菌、霉菌、藻类、单体钟虫和一些线虫等后生动物，这些微生物通过复杂的食物链共同组成了一个稳定的微生物生态系统。空床接触时间和水温的增加可以改善生物过滤的处理性能；用未加氯水反冲洗对生物膜量影响较小；滤池关闭对生物过滤影响较小，重新启动后能在较短时间内恢复。更多还原

【Abstract】 In recent ten years,the middle and lower reaches of Xiangjiang River has been polluted by various organic matter, NH4+-N, Fe and Mn.The water quality of these reaches usually couldn’t be up to the standard of the third grade of source water quality standard which the current surface water environmental quality standards had prescribed.A majority of water plant which use the Xiangjing River water as the water source are disable to remove the most pollutant because of using the conventional filtration,thus the effluent water of these plants couldn’t attain the biological stability. This research examined the results of the treatment of micro-polluted Xiangjiang River source water by biofiltration.The results show that the removal rate of TOC can be reached 25~32% , the removal rate of BDOC can be reached 41.3~65% , and the removal rate of AOC can be reached 59.2-84.2% respectively.The removal rate of CODMn can be reached 40.4-49.4%, the removal rate of UV254 can be reached 60.6-66.5%,the removal rate of NH4+-N can be reached 67~90%,the removal rate of Fe can be reached 88~95%, and the removal rate of Mn can be reached 36~87% respectively.For the efficient removal of organic matter, NH4 + -N, Fe and Mn,the biofilter has the ability to enhance the biological stability of drinking water.The removal of dissolved organic matters is strongly related to the molecular weight of the organic matters.The GAC-sand biofilter is capable of removing the organic matters with small molecular weight (<1000) and with molecular weight of 3000~6000.The removal rate of organic matter with small molecular weight (<1000) and with molecular weight of 3000~6000 is 54.46% and 54.57% respectively, and these organic matter mainly consist of synthetical compound(keto compound, hydroxybenzene and phenyl acid ester)and humic acid. The biofiltration has superior characteristic of turbidity removal,when the influent turbidity is bellow 5 NTU,the effluent turbiduty of the biofilters can maintain less than 0.1NTU for acceptable long time.The mechanism of turbidity removal is mainly attribute to the combined action of traditional adsorption and biosorption. The biomass in the biofilters decrease gradually from the top layer to the bottom layer along the water flow.The biofilm on the media surface mainly presented in zoogloea form.The dominant bacterial genusand sub-dominant bacterial genus were Pseudomonas and Bacillus respectively.We found that the species that made up the biofilm were comparatively complete by means of the microscope. It included bacteria, filamentous fungus,mold, vorticella and metazoan etc., which formed a stable microbial ecosystem jointly. The increase of EBCT and water temperature can improve the effect of biofiltration.Backwash with nonchlorinated water has less impact on bifiltration.Shutdown of the biofilters has minor impact on biofiltration performance,the biofilters can return to normal operation quickly after restart.更多还原