硅藻土负载异养硝化-好氧反硝化菌的脱氮性能

将硅藻土经改性后作为异养硝化-好氧反硝化菌H1的载体,对负载条件以及固定化菌对环境的耐受性能进行了优化及研究.确定最佳吸附时间为24h,载体投加量为0.06g/mL(硅藻土/菌悬液).改性剂FeSO₄用量、pH值、温度不仅影响硅藻土载体吸附性,同时影响固定化H1活性.菌株经改性硅藻土负载后较游离菌对pH值及温度耐受性都有所增强,对溶解氧变化适应范围更广,当m(FeSO₄)/m(硅藻土)=3.5%、pH=7.5、温度为30℃、溶解氧为5.1mg/L左右时,固定化H1脱氮性能最佳.使用该固定化菌对生活污水进行连续式处理,8天后目标污染物的去除率趋于稳定,TN、NH₄⁺-N及COD去除率分别达到52.40%、55.64%与61.23%,表明改性硅藻土负载异养硝化-好氧反硝化菌在污水脱氮领域具有广阔的前景.

Study on the denitrification characteristics of heterotrophic nitrification-aerobic denitrifier loaded on diatomite

A heterotrophic nitrification-aerobic denitrifying bacterial strain H1 was loaded on modified diatomite used as the immobilized carrier. The immobilized conditions were optimized and the tolerance of immobilized bacterial stains for environment was studied. 24 hour of fixed time and 0.06g/mL(the weight of added diatomite to volume of bacterial suspension)were selected as the best immobilized conditions. The results showed that dosages of modifier FeSO₄,pH and temperature affected the adsorptive property of diatomite and the activity of immobilized cells. The bacterial strains loaded on diatomite exhibited more nitrate removal against changes in different pH and temperature compared to free cells and more adaptable at various dissolved oxygen conditions. The best results of denitrification using immobilized cells were achieved when the weight ratio of FeSO₄ to diatomite was 3.5%,pH was 7.5,temperature was 30℃,and dissolved oxygen level was 5.1mg/L. Finally,the disposal wastewater was treated with immobilized cells in the continuous bioreactor. After 8 days, the removal rate of TN,NH₄⁺-N and COD were 52.40%、55.64% and 61.23%,respectively,indicating that bacterial strain with heterotrophic nitrification-aerobic denitrification function loaded on modified diatomite in denitrification could have great prospect in further applications.