粉煤灰预处理生物流化床技术处理有机废水的研究

通过大量试验和相关工程体会得出：有机废水在进入较低污泥浓度的生物流化床之前,通过粉煤灰的预处理,再配以高效射流曝气器,能有较好的处理效果。     

Replacement of a multiple hearth by a fluid bed incinerator the Greensboro case history

The incinerator at the T.Z. Osborne Plant in Greensboro, North Carolina burns sludge from its own waste water treatment plant and sludge pumped from the nearby North Buffalo plant. The two plants have a combined capacity of 36 million gallons per day of wastewater. Because of the age of and increasing high maintenance on the existing multiple hearth incinerator, and the need to increase treatment capacity, the Osborne plant concluded a study in 1992 evaluating its options for future municipal sewage sludge disposal. Options which were evaluated during the study included; (i) rehabilitation of the existing eight-year old multiple hearth unit; (ii) addition of a new multiple hearth; (iii) addition of a new fluid bed system; (iv) drying, composting, or land application. The chosen option, based on both economic and environmental considerations, was a new fluid bed system with a capacity of 2.55 tons per hour, approximately double that of the existing multiple hearth. Design of the new fluid bed system began in December 1994 and equipment delivery for the incineration system was begun in April 1995. Initial operation occurred in August 1996. Primary and secondary sludge, dewatered to 28% dry solids by centrifuge, is delivered by piston pumps to the twenty-foot freeboard ID incinerator. A shell and tube heat exchanger recuperates heat from the exhaust gas and preheats the combustion air to 1250°F, resulting in minimal auxiliary fuel use. The air pollution control device is a high-energy Tandem Nozzle® scrubber. Greensboro was the initial installation of this scrubber design on a fluid bed incinerator and its characteristics and performance are discussed. Ash is dewatered in an ash thickener/belt press system prior to disposal to landfill. The system includes a state of the art Programmable Logic Controller (PLC) system for computer control of the operation. The unit was commissioned in August 1996 and has been in continuous operation since that time except for a one week inspection and maintenance shutdown in February 1999. The plant operates 24 h/day, 7 days per week. The initial performance test showed the system to readily meet federal and state air emission standards. Particulate released was 0.002 grains per dry standard cubic foot, carbon monoxide was 22.5 parts per million volumetric (ppmv) and opacity was 0.4%. These results show a significant emission reduction with the fluid bed when compared to the multiple hearth. Annual tests conducted since then and continuous emission monitoring have shown the unit to be in consistent compliance. Since the fluid bed system became operational, the old multiple hearth system has been maintained on standby as a backup, but its use has not been required. Operational experience is discussed, the most interesting of which is the relatively trouble-free operation. The minor problems which occurred and their solutions are detailed. Also included is a comparison of operation and maintenance experience of the fluid bed and the multiple hearth. Current sludge disposal actual cost data are also provided including the average cost per ton of dry solids treated. The almost three years of operational experience to date has shown that the decision to install a new fluid bed system was the correct one on both an environmental and economic basis. It has provided benefits to all interested parties — the wastewater treatment plant, the regulators, the taxpayers, and the surrounding community.     

SBR生化法处理有机磷农药废水

采用ＳＢＲ生化法处理有机磷农药废水,生产规模试运行结果表明,ＳＢＲ生化法具有装置结构简单、运转录活、操作方便、ＣＯＤ和有机磷去除率高等特点。     

空难对湿地浮游植物的影响

浮游植物已经广泛应用于环境影响评价.包头"11·21"空难对南海子浮游植物的种类、种群结构、优势种(属)、细胞密度、种类数和细胞密度的空间分布产生了重要影响.调查表明:南海子浮游植物有5门27属,其中蓝藻门有5个属,隐藻门有2个属,硅藻门有5个属,裸藻门有2个属,绿藻门有13个属;蓝藻门和绿藻门为南海子的优势门类,其中微囊藻、平裂藻和栅藻为优势属;南海子浮游植物的Margelef种类丰度指数为0.9646,Shannon-Wiener多样性指数为0.7647,空难后南海子水体污染严重;浮游植物(特别是富营养化指示藻类)的种类数和细胞密度的高值区主要出现在污染水域.南海子水质的浮游植物生物学评价结果表明,空难事故后南海子水体已属于严重富营养化水平.      

供水系统水质生物稳定性与细菌生长相关分析

以上海市某水厂实际供水系统为研究对象,从水源、水厂净水工艺到输配水管网对城市供水水质生物稳定性与微生物生长相关性进行了系统分析.结果表明,由于水源污染和常规净水工艺局限性,水厂出水水质不能保障生物稳定性,在输配管网中,BDOC、浊度、余氯、异养菌数量存在明显的相关性.控制出厂水有机物含量,保持管网免受二次污染和强化消毒可有效减少管网中微生物繁殖生长.     

溶解氧对分段进水生物脱氮工艺的影响

采用分段进水生物脱氮工艺处理生活污水.设置0.9,0.6,0.4,0.3m³/h4组曝气量,相应的好氧区溶解氧(DO)浓度约为2.8,1.7,0.8,0.5mg/L左右.结果表明,在好氧区DO为0.5mg/L左右的低氧条件下,通过对系统进行适当的控制,可以取得较好的硝化效果,氨氮去除率可达98%以上.同时,由于低曝气量下混合液从好氧区到缺氧区携带的DO量减少,并且在好氧区发生了同步硝化反硝化作用,使得TN去除效果明显优于高曝气量的情况.另外,由于工艺结构的特点,分段进水生物脱氮系统可长期在低氧条件下运行,且污泥沉降性能良好.     

生物流化床反应器在处理含氯代芳香化合物废水中的应用

氯代芳香化合物是工业废水中重要污染物之一。本文介绍了氯代芳香化合物的降解机理、生物流化床的特点及其处理氯代芳香化合物的应用 ,为含氯代芳香化合物的废水处理提供参考     

复合生物反应器工艺对化纤废水的处理研究

在普通活性污泥系统的曝气池中投加一定量的填料构成复合生物反应器 ,可以增加曝气池中的生物体量至 6g/L左右 ,在HRT为 8h ,泥龄为 5d时 ,CODCr、氨氮的去除率分别提高了 2 0 %和9.6% ,容积负荷对复合生物反应器的脱氮能力影响较小。该工艺对污泥膨胀有较好的控制     

加压生物氧化法处理助剂厂废水的研究

用新研制开发的加压生物氧化设备对助剂厂可生化废水进行了处理试验,在曝气罐中废水压力为200kkPa、进水COD为2800-3000mg/L、曝气11-12h的条件下,处理后出水的COD≤200mg/L,达到行业排放标准。     

含Cr（Ⅵ）废水生物处理技术及其影响因素

本文综述了微生物还原处理含价铬的废水的研究进展。讨论了影响微生物还原Cr(Ⅵ）因素包括生物体密度、初始Cr（Ⅵ）的浓度、碳源、pH、温度、溶解氧、氧化还原电位、含氧阴离子和金属离子。微生物还原Cr（Ⅵ）技术作为一种富有创新的研究应用于Cr（Ⅵ）污染的环境恢复。