包埋固定化微生物的硫自养反硝化实验研究

Study on Sulfur-Based Autotrophic Denitrification by Immobilized Pellets

采用升流式颗粒污泥床,外加Na2S2O3作为电子供体,在室温下连续运行220 d,结合硫自养反硝化与固定化包埋技术进行脱氮实验,考察包埋颗粒的驯化条件、影响因素和最佳运行条件.进水负荷(以N计)维持0.22 kg/(m3.d),包埋颗粒经23 d驯化成功,NO3--N(100 mg/L)几乎完全去除.连续实验结果表明,脱氮效果受温度、进水NO 3-浓度和HRT因素影响,受温度制约最大,春秋季室温下进水负荷可达0.96 kg/(m3.d),最低水力停留时间(HRT)达到1 h,NO3--N和TN的去除率均达到90%～100%,最高去除速率均达到39.8 mg/(L.h),冬季最低HRT达2 h.系统出水无NO2--N和S2-累积.分子生物学实验显示包埋颗粒经驯化得到反硝化功能菌并逐渐增殖.

Autotrophic denitrification by immobilized microorganisms was investigated in this study.Using thiosulfate as the electron donor,the lab scale up-flow sludge blanket reactor ran continuously for 220 days under the room temperature to investigate the effects of cultivate conditions,influence factors and optimal operating parameters.It took 23 days to finish the initial domestication stage.A nearly complete removal of nitrate（100 mg/L） was attained at nitrate loading rates（NLR） of 0.22 kg/（m3·d）.The results revealed that the denitrification efficiency was dependent on temperature,influent nitrate concentration and hydraulic retention time（HRT）,and temperature was the most important factor.In spring and autumn,nitrate and total nitrogen removal efficiency remained 90%-100% at the NLR of 0.96 kg/（m3·d）.The shortest HRT and the highest denitrification rate could achieved 1h and 39.8 mg/（L·h） separately.While in winter the shortest HRT was 2 h and no nitrite or sulfide accumulation was detected.Molecular biological analysis indicated that denitrifying bacteria were re-enriched successfully in the immobilized pellets.