生物活性滤池饮用水除氨氮的影响因素

Factors influencing ammonia removal of biological activated filter in drinking water treatment

以实际沉淀池出水进行配水,通过模型实验,探讨了生物活性滤池(BAF)除氨氮的影响因素及作用机理。结果表明,滤前水中有机物含量和滤料粒径对BAF除氨氮能力影响较大。当采用沉淀池出水中自身携带的有机物时,BAF-1除氨氮效率为97%;当沉淀池出水中另配入2mg·L-1牛肉膏+2mg·L-1蛋白胨+2mg·L-1葡萄糖时,由于受到异养菌对溶解氧和生存空间竞争的限制,其除氨氮效率下降至51.0%。活性炭粒径采用0.8～1.2mm的BAF-1氨氮去除率比采用1.0～2.0mm的BAF-2高1.5%～16.7%。当滤前水氨氮浓度低于1.60mg·L-1时,BAF-1的氨氮去除率接近100%;当氨氮浓度逐渐升高时,由于受到溶解氧的限制,去除率逐渐下降。对滤前水进行预曝气充氧,能提高BAF-1的除氨氮效率。滤速对BAF-1除氨氮影响不显著。反冲洗可适当提高BAF-1的除氨氮效率。

The factors influencing ammonia removal of biological activated filter （BAF） and the mechanisms were discussed on pilot-scale basis by using modified settling tank effluent. The results showed that the organic content of influent and filter media size influenced ammonia removal of BAF significantly. When using the effluent of settling tank as the influent of BAF, the ammonia removal percentage of BAF-1 （filter media size range of carbon 0.8-1.2 mm） reached 97%; as 2 mg·L^-1 of peptone, 2 mg·L^-1 of beef extract and 2 mg·L^-1 of glucose were added to the influent, only 51.0% of influent ammonia was removed due to the competition of heterotrophic bacteria for oxygen and space. On the other hand, the ammonia removal efficiency of BAF-1 was 1.5%-16.7% higher than that of BAF-2 （filter media size range of carbon 1.0-2.0 mm）. Almost complete ammonia removal was achieved by BAF-1 when influent ammonia concentration was less than 1.60 mg·L^-1. As influent ammonia concentration increased gradually, the ammonia removal performance decreased because of the lack of dissolved oxygen. The ammonia removal of BAF-1 was enhanced as pre-aeration for the influent was performed. The influence of filter flow rate for ammonia removal was negligible. Backwashing was beneficial to ammonia removal of BAF-1 in this study.