强化启动对内循环生物流化床硝化效果的影响

通过改变内循环生物流化床的启动水质,提高N/C组成以强化流化床后期的硝化作用.结果表明,高N/C和低进水COD强化启动后处理生活污水,在HRT为2h时,可以同时高效去除COD和氨氮,氨氮的平均去除率为74%.耗氧速率试验表明,强化启动后,流化床中生物膜的异养菌活性大幅度降低,氨氧化细菌活性明显提高,硝化细菌活性变化不大.对反应系统微生物醌进行的跟踪分析表明,强化启动后,生物膜中的硝化细菌数量明显增加,微生物种群的分布均匀性变化较小,以革兰氏阴性菌为主.扫描电镜观察显示,低N/C启动条件下,生物膜厚且致密,异养菌所占比例高;高N/C启动条件有利于硝化细菌的生长,生物膜相对稀薄.

The effect of strengthening start-up on nitrifying performance of biofilm in internal-circulation bio-fluidised bed

Through changing the start-up water quality of internal-circulation bio-fluidized bed, the N/C composition was enhance to strengthen the nitrifying action of fluidized bed of late period. After the strengthening start-up (high N/C and low COD) treating living waste water with the HRT 2h, a high simultaneous removal efficiency of COD and ammonia nitrogen could be realized; the average ammonia nitrogen removal rate was 74%. The test of oxygen consumption rate showed that after the strengthening start-up, the activity of hetertrophic bacteria in the biofim of fluidized bed decreased greatly, the activity of ammonia oxidize bacteria enhanced obviously, the activity of nitrifying bacteria changed not great. The track analysis results of bacterial quinone of the system showed that after the strengthening start-up of ammonia removal, the number of nitrifying bacteria in the biofilm increased obviously; the distribution even change of the microbial community was small with the gram-negative bacteria being the dominant. The observation of scanning electric microscope showed that the biofilm under low N/C start-up condition was thick and dense, the heterotrophic bacteria had high proportion; high N/C start-up condition was favorable to the growth of nitrifying bacteria, the biofilm was thin relatively.