硝化菌在不同载体中的富集效率研究

Enrichment Efficiency of Nitrifying Bacteria in Different Types of Carriers

利用MBBR型、纤维球、细菌球三种载体在污水厂生化池中进行硝化菌群的富集,通过测定反应活性速率及微生物多样性对载体富集硝化菌群进行研究。结果表明,三种载体均在富集30 d左右时效果最佳。此时,细菌球载体富集硝化菌群中氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)的反应比速率分别达到了2.72、1.68 mg/(gVSS·h),通常作为限制性因素的AOB比速率相较于活性污泥提高了42.41%;且载体中富集的AOB/NOB值最高可达2.10,相较于活性污泥(AOB/NOB值约为1),载体选择性富集了更多的AOB。因此,按50%的填充体积投加细菌球挂膜载体,其AOB和NOB的反应比速率可分别提高71.2%和44.7%。高通量测序结果表明,细菌球载体中硝化菌数量占比高达7.40%,为活性污泥中硝化菌含量的2.1倍。另外,菌群种属分析结果表明,载体生物膜中的菌群比活性污泥更加多样化,增加了系统的稳定性和抗冲击性。

Nitrifying bacteria were enriched in biochemical tanks of a wastewater treatment plant by using carriers of MBBR-type carrier,fiber ball and ceramic ball.The nitrifying bacterial community enriched on the carriers was analyzed by measuring the reaction rate and microbial diversity.The treatment performances of the three carriers were the best after 30 days of enrichment.At this time,the specific reaction rates of ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) enriched on ceramic ball reached 2.72 mg/(gVSS·h) and 1.68 mg/(gVSS·h),respectively,and the specific reaction rate of AOB,usually a limiting factor,was 42.41% higher than that of activated sludge.In addition,the ratio of AOB to NOB enriched on carriers was up to 2.10.Compared with that of activated sludge(about 1),the carrier selectively enriched more AOB.Therefore,specific reaction rates of AOB and NOB were increased by 71.2% and 44.7% respectively by adding 50% filling volume of ceramic ball carriers.High-throughput sequencing showed that the proportion of nitrifying bacteria in the ceramic ball was up to7.40%,which was 2.1 times of that in activated sludge.In addition,the bacterial genus composition showed that the bacterial community in biofilm on the carrier was more diverse than the activated sludge,thus increasing the stability and impact resistance of the system.