4种矿物质载体对硝化微生物富集培养的影响

Effects of Four Mineral Carriers on Enrichment Culture Process of Nitrifying Microorganisms

硝化微生物具有附着生长的特性,载体筛选是其高效富集培养的关键。该研究选取钠基膨润土、钙基膨润土、碳酸钙和硅藻土共4种矿物质作为载体进行硝化微生物富集培养,在其结构特征分析的基础上,研究不同矿物质对硝化微生物氨氧化速率和亚硝酸盐氧化速率的影响,筛选出最佳矿物质载体并进行不同投加比试验(空白、1%、2%、3%、4%),明确硝化微生物富集培养的最佳矿物质载体及投加比。结果表明,4种矿物质均显著提高氨氧化速率和亚硝酸盐氧化速率,较对照组分别增加81.9%~192.8%和93.2%~155.6%;其中,投加硅藻土后氨氧化速率和亚硝酸盐氧化速率均为最高,较对照组分别增加192.8%和155.6%;不同硅藻土投加比例均显著增加氨氧化速率和亚硝酸盐氧化速率,较对照组分别增加121.1%~262%和101.2%~216%;尽管比氨氧化速率和比亚硝酸盐氧化速率随着投加比的增加依次降低32%~59.1%和36.7%~60.8%,但4%投加比处理效果仍为最佳,富集培养过程中硝化微生物的增长符合逻辑斯蒂增长模型,其对载体的利用率随硅藻土投加比的增大而降低。

Nitrifying microorganisms,being essential in denitrification process of wastewater treatment,are characterized with attachment growth.For the purpose of boosting enrichment culture of nitrifying microorganisms,adequate carriers are used,onto which the microorganisms grow.This paper described the experiment for selecting desirable carrier,thus four kinds of minerals,i.e.sodium bentonite,calcium bentonite,calcium carbonate and diatomaceous earthwere,were undergone testing for the enrichment culture of nitrifying microorganisms.So the effects of different minerals on the oxidation rates of ammonia and nitrite of nitrifying microorganisms were investigated based on the probing into their structural characteristics.The experimental results showed that,compared with the control groups,after carriers were applied the ammonia oxidation rate increased by 81.9%to 192.8%while nitrite oxidation rate increased by 93.2%to 155.6%;and among others,the carrier of diatomaceous earth displayed the best performance,i.e.,ammonia oxidation rate and nitrite oxidation rate increased by 192.8%and 155.6%,respectively.Raising the proportion of diatomaceous earth dosed could increase the ammonia oxidation rate and nitrite oxidation rate of 121.1%to 262%and 101.2%to 216%,respectively,in spite of that the specific ammonia oxidation rate and specific nitrite oxidation rate decreased from 32%to 59.1%and from 36.7%to 60.8%,respectively;however,when proportion of diatomaceous earth dosed being equal to 4%,the best result was obtained.In addition,it proved that growth of nitrifying microorganisms in the enrichment culture process was consistent with the Logistic growth model,and as the diatomite dosing ratio was increased the carrier utilization ratio declined.