活性污泥法对水溶性腐殖酸的去除效能与机制研究

采用人工配水的方式,研究了单级活性污泥法和两级活性污泥法对水溶性腐殖酸的去除效能,并通过测试污泥中腐殖酸的相对含量、污泥的元素组成、污泥的活性和进出水腐殖酸的分子量分布.对去除机制作了初步探讨.结果表明,在单级活性污泥处理系统中,不同浓度的腐殖酸均未对可生物降解有机物的去除构成影响,并且腐殖酸的去除率维持在67%-84%.随进水中腐殖酸浓度的增加去除率有所下降;通过两级活性污泥法试验.发现第l级活性污泥系统对腐殖酸的去除效果优于第2级.分别为71.3%和60.1%.且活性污泥系统对大分子量腐殖酸的去除效果优于小分子量腐殖酸.机制分析表明,腐殖酸难以作为微生物生长所需的碳源.主要依靠污泥吸附的方式,使水相中的腐殖酸进入泥相,再通过剩余污泥排放的方式去除.

Removal Efficiency and Mechanism of Aqueous Humic Acids by Activated Sludge Process

The removal efficiency of aqueous humic acids by a single-stage activated sludge process and a two-stage activated sludge process was studied using synthetic wastewater, and the removal mechanism was explored by testing the element composition of the sludge, relative content ofhumic acids in sludge, sludge activity and the molecular weight distribution of humic acids in influent and effluent. In the single-stage activated sludge process, the removal efficiency of aqueous humic acids was keeping between 67%-84%, decreasing with the enhancement of humic acids content in the influent, and the different content of humic acids in the influent would not affect the removal efficiency of biodegradable organic matter. In the two-stage activated sludge process, the removal efficiency of humic acids in the first stage was 71.3%, better than that (60.1%) in second stage, and the removal efficiency of larger molecular humic acids was better than the smaller. Mechanism study indicated that humic acids was very difficult to be used by microorganism as carbon source, and removed by excess sludge discharge through adsorbed by activated sludge.