Guan Xiao-Hong, Chen Guang-Hao, Shang Chii
Department of Civil Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, PR China.
Water Res. 2005 Sep;39(15):3433-40. doi: 10.1016/j.watres.2004.07.033.
This paper attempted to study the feasibility of reusing water treatment works sludge ("alum sludge") to improve particulate pollutant removal from sewage. The main issues focused upon were: (1) the appropriate dosage of the alum sludge, (2) the appropriate operating conditions, and (3) the possible mechanisms for enhancement by adding alum sludge. Actual alum sludge and sewage were applied to a series of jar tests conducted under various conditions. It has been found that both the SS and COD removal efficiencies could be improved by the addition of the alum sludge, which was mainly attributed to the removal of relatively fine particles with a size of 48-200 microm. The appropriate dosage of the alum sludge was determined to be 18-20 mg of Al/L. Increasing the mixing speed or reducing the floc size of the alum sludge enhanced the SS and COD removal and the dispersed alum sludge could remove particulate contaminants with smaller size than the raw sewage. ToF-SIMS evidence revealed that the aluminum species at the surface of the alum sludge were effectively utilized for improving the SS and COD removal. It was postulated that the sweep flocculation and/or the physical adsorption might play key roles in the enhancement of particulate pollutant removal from sewage.
本文试图研究再利用水处理厂污泥（“明矾污泥”）提高污水中颗粒污染物去除率的可行性。主要关注的问题有：（1）明矾污泥的合适投加量；（2）合适的运行条件；（3）添加明矾污泥实现强化效果的可能机制。将实际的明矾污泥和污水应用于一系列在不同条件下进行的烧杯试验。结果发现，添加明矾污泥可提高悬浮物（SS）和化学需氧量（COD）的去除效率，这主要归因于去除了粒径为48 - 200微米的相对细小颗粒。确定明矾污泥的合适投加量为18 - 20毫克铝/升。提高混合速度或减小明矾污泥的絮体尺寸可提高SS和COD的去除率，且分散的明矾污泥能够去除比原污水中粒径更小的颗粒污染物。飞行时间二次离子质谱（ToF - SIMS）证据表明，明矾污泥表面的铝物种被有效用于提高SS和COD的去除率。据推测，扫掠絮凝和/或物理吸附可能在提高污水中颗粒污染物去除率方面起关键作用。
