溪沙蚕对污水厂生物滤池运行的影响及防治措施

在厦门市污水处理二厂的好氧生物滤池（CN池）中发现了溪沙蚕，其对滤池的主要影响是易造成滤头堵塞。对溪沙蚕的防治措施有：①防止海水进入污水管道；②保证生物滤池的正常过滤和反冲洗；③在溪沙蚕繁殖期到来之前，清除CN池底部的沉泥；④在溪沙蚕繁殖季节，对CN池进行强力反冲洗，并适当增加反冲洗次数，以加速溪沙蚕受精卵排出生物滤池。     

不同中水回用模式的技术经济分析

根据国内外中水回用的工程实践，总结了目前城市中水回用的典型处理工艺、回用途径，提出了城市中水回用的7种模式，从技术经济角度分别对这几种模式进行了分析，提出了适合我国国情的城市中水回用模式，展望了我国中水回用的发展趋势。     

新型双污泥脱氮除磷工艺处理生活污水

将活性污泥法与生物膜法相结合，开发出一种新型脱氮除磷处理工艺，成功地解决了传统工艺中硝化细菌与除磷菌之间的泥龄矛盾问题。试验结果表明，该工艺对COD、NH3-N、TP的去除率分别高达85％、95％、90％，同时处理效果稳定，对水质的适应能力也较强。     

贝壳填料曝气生物滤池的硝化特性研究

贝壳粗糙的表面及其合有的大量碳酸钙，可作为生物膜的载体及硝化反应的碱度来源。以海产弃物贝壳为生物膜载体，通过改变进水氨氮浓度及pH值，考察了贝壳填料曝气生物滤池的硝化脱氮规律。结果表明：对于氨氮〈120mg／L的原水，贝壳溶解提供的碱度能够满足硝化反应的需要，因此硝化反应进行得比较完全，对氨氮的去除率不受进水氨氮浓度的影响，可达90％以上；而当进水氨氮浓度达240mg／L时，因贝壳溶解提供的碱度不能完全满足硝化反应之所需，硝化反应将停滞，但对氨氮的去除率仍可达65％左右。此外，进水pH值对贝壳填料曝气生物滤池去除氨氮的效果及出水pH值基本没有影响。     

未来科技城再生水厂一期工程工艺设计方案

该文介绍了未来科技城再生水厂一期工程的工艺流程和设计情况。根据水厂进出水水质特征,生物处理工艺采用A/A/O底曝氧化沟,深度处理工艺采用生物滤池+滤布滤池+超滤膜,出水经二氧化氯消毒后供再生水管网。对各处理构筑物的选择和设计参数的选用进行了重点说明,以期为同类水厂的设计提供经验借鉴。     

Influence of filter media depth and vegetation on Faecal Coliform removal by stormwater biofilters

Biofilters are promising technologies that widely applied in the treatment of urban stormwater. However, the microbial removal capacity performance depends greatly on the design of biofilters. Hence, this laboratory study attempts to investigate the influence of filter media depths (i.e. 150, 250, 350 and 450 mm) and the variation of native plants, that is, Cow Grass (Axonopus compressus) and Pearl Grass (Axonopus compressus, dwarf) in removing stormwater microorganism particularly Faecal Coliform (FC). Findings showed that a minimum media depth of 300 mm was required to achieve >1 log FC removal. The mean removal of FC at 450 mm depth filter exceeded 2 log for both Cow and Pearl grass biofilter columns. Results showed that there was no statistically significant difference in vegetation type on the performance of FC removal, however, Cow grass biofilter column revealed higher FC mean log removal compared to Pearl grass biofilter column.     

Comparison of biological reactors (biofilter,biotrickling filter and modified RBC) for treating dichloromethane vapors

BACKGROUND: Bioreactors used for waste gas and odor treatment have gained acceptance in recent years to treat volatile organic compounds (VOCs). Different types of bioreactors (biofilter, biotrickling filter and rotating biological reactor) have been used for waste gas treatment. Most studies reported in the literature have used one of these systems to treat several types of inorganic and organic gases either individually or in mixtures. Each of these reactors has some advantages and some limitations. Though biodegradation is the main process for the removal of pollutants, the mechanisms of removal and the microbial communities may differ among these bioreactors. Consequently their performance or removal efficiency may also be different. RESULTS: At low loading rate (<35 g m^?3 h^?1), all three bioreactors showed comparable removal efficiencies and elimination capacity, but at higher loading rates, rotating biological contactors (RBC) showed a better performance with higher removal efficiency (40–50%) than both the biofilter and biotrickling filter (20–40%). The biofilter showed a sharp drop in removal efficiency and elimination capacity at high loading rates. CONCLUSIONS: The modified RBC had no clogging problems and no increase in pressure drop when compared with the other bioreactors. It can thus handle pollutant load for a longer period of time. This is the first study attempting to compare the performance of three different bioreactors for removal of the same VOC under different conditions. Copyright © 2010 Society of Chemical Industry     

Effect of packed structure on flow behaviour in a trickle bed biofilter

The effects of operation conditions on the flow behaviour in gas–liquid countercurrent trickle bed biofilter were experimentally examined. In order to prevent gas channelling in the biofilter, packings with a relatively large void fraction, which have a role to maintain a high void fraction in the bed, were added. The gas and liquid velocities of the packed structure and the packings were changed, and the residence time distributions (RTDs) of the gas and liquid were measured. It was found that the addition of void supporters was very effective in the suppression of gas channelling.     

Performance of Granular Activated Carbon (GAC) Adsorption and Biofiltration in the Treatment of Biologically Treated Sewage Effluent

Abstract

In this study, the performance of GAC adsorption and biofiltration systems in treating biological treated sewage effluent (BTSE) was evaluated in terms of organic removal efficiency, organic fractions, and molecular weight distribution (MW) of organic matter (OM) removed. The GAC biofilter removed 23.5% and 61% of the hydrophobic fractions and hydrophilic fractions of OM in the BTSE respectively. MW distribution studies of GAC filter and GAC adsorption revealed the following: Hydrophobic fraction of the effluent showed a peak at 345 dalton after GAC biofiltration and 256 dalton after GAC adsorption, whereas, with hydrophilic fractions, peaks at 46,178 and 345 daltons were observed after GAC biofiltration and peaks at 46,178 and 256 daltons after GAC adsorption. Transphilic fraction showed the peaks at 12,783 dalton with GAC biofiltration, and 1,463 dalton with GAC adsorption. The performance of the GAC biofilter was successfully mathematically modelled.