硫铁耦合系统深度脱氮除磷中试研究

Advanced Removal of Nitrogen and Phosphorus in Combined Pilot System of Sulfur and Iron

利用硫铁耦合填充床反应器对污水厂二级出水进行深度脱氮除磷,并优化运行参数,分析微生物种群。结果表明,硫铁耦合填充床反应器能够有效去除二级出水中的NO_3^--N,当HRT>0.29 h时,对硝酸盐氮的去除率达到85%以上;当HRT=0.29 h、进水硝酸盐氮浓度为16.5mg/L时,反应器的最大脱氮负荷为1 023 mg/(L·d);出水磷酸盐浓度<0.5 mg/L;通过反冲洗可将沉积的磷酸铁等沉淀排出,实现稳定运行,且反冲洗后0.5 h即可恢复正常水平;种群分析得出Thiobacillus在填料层上、中层的相对丰度较高,分别为14%和17%,下层中Sulfurimonas的相对丰度较高,为13%。

Advanced removal of nitrogen and phosphorus was achieved in the combined pilot system of sulfur and iron. Based on the building of the pilot sulfur and iron packed-bed, operating parame- ters of the system were optimized sulfur and iron coupled packed-bed and the microbial community was analyzed. The results showed the reactor could effectively remove NO3^--N from the secondary effluent. 85% of NO3^- - N was removed when the HRT was longer than 0.29 h. The maximum nitrogen load was 1 023 mg/（L·d）, when HRT was 0.29 h and the influent NO3^- -N was 16.5 mg/L. The effluent phosphate concentration was lower than 0.5 mg/L. After the backwash, FePO4 precipitate was discharged, and the system reached a stable status. The pilot system resumed to normal performance within 0.5 h after the backwash. Microbial community analysis showed that the relative abundance of Thiobacillus in the top and middle layers of filler was higher, which was 14% and 17%, respectively, and the relative abundance of Sulfurimonas （ 13% ） in bottom layers was higher than others.