BACF处理高氨氮进水的硝化与反硝化作用

采用生物活性炭滤池(BACF)深度处理高NH₄⁺-N微污染水源水.结果表明,BACF对NH₄⁺-N的去除率与进水NH₄⁺-N浓度有关,当进水NH₄⁺-N<1.0mg/L时,去除率达95%以上;当进水NH₄⁺-N较高(1.5～4.9mg/L范围)、进水DO≤10mg/L时,去除率随进水浓度的增加而下降,最低降到30%左右.限制生物活性炭滤池硝化作用的主要因素是进水的DO,由于硝化菌与异养菌的共同竞争,在滤床0.4m深度内DO被消耗殆尽,出水DO基本为0(小于0.2mg/L),滤床被自然分成好氧区与缺氧区,在好氧区发生硝化与有机物的降解反应,在缺氧区则发生反硝化反应,由于碳源受限,反硝化反应进行得不彻底,造成滤池出水NO₂^--N升高.在缺氧区内除存在反硝化菌外,还存在好氧的硝化菌与异养菌.

Nitrification and Denitrification in BACF for Treating High Ammonia Source Water

A high ammonia micropolluted source water advanced treatment for ammonia removal by biological activated carbon filter was tested. The removal rate of ammonia was high than 95 % when influent concentration was under 1.0mg/L. The removal rate decreased with the influent concentration increased when the ammonia concentration was in range of 1.5 - 4.9mg/L and the influent DO was under 10mg/L, and the minimum removal rate was about 30%. The key factor of restrict nitrification in BACF was the influent DO. When the influent ammonia concentration was high, the DO in water was depleted quickly by nitrify and hetetrophic bacteria in 0.4m deep of filter and the filter layer was divided to aerobic zone and anoxic zone. The denitrlfication was occurred in the anoxie zone, and because of very low concentration of electron donor led to accumulation of the denitrifieation intermediates such as NO2^-. Aerobic bacteria was existed in the anoxic zone.