硫磺和黄铁矿为填料的生物滤池自养反硝化强化处理二沉尾水

Enhanced Treatment of Secondary Effluent via Autotrophic Denitrification Biofilter Process Using Sulfur and Pyrite as Fillings

采用硫自养反硝化工艺处理模拟污水厂二沉尾水,分别以硫磺/白云石、黄铁矿/白云石为填料,考察不同填料下生物滤池的脱氮除磷效果.结果表明,在HRT(水力停留时间)为1 h的条件下,硫磺/白云石反应器在10 d内能迅速启动,出水ρ(NO_3^--N)小于1.00 mg/L,去除率高达99%,反应器的最佳实际HRT为45 min.进水中的DO对硫磺/白云石反应器反硝化效果没有明显影响,但会对黄铁矿/白云石反应器的反硝化效果产生影响.去除进水中的DO后,在HRT为4 d下,黄铁矿/白云石反应器出水NO3--N和TP的质量浓度分别为10.31和0.10 mg/L,其去除率分别为67.2%和90.7%.采用高速水流反冲洗后,两个反应器的脱氮效果均能在2 d内迅速恢复.在12℃的低温条件下,硫磺/白云石和黄铁矿/白云石反应器的处理效果均变化不大.去除一定量的NO_3^--N时,硫磺/白云石反应器的SO_4^(2-)生成量与理论值相符合,黄铁矿/白云石反应器的略高于理论值.研究显示,硫磺/白云石体系可有效去除二沉尾水中的NO_3^--N,而黄铁矿/白云石体系具有同时脱氮除磷的功能.

A sulfur-based autotrophic denitrification process was applied to treat the synthetic secondary effluent of a wastewater treatment plant. Sulfur/dolomite and pyrite/dolomitewere respectively usedas fillings to investigate the nutrientsremoval performance. Under the hydraulic retention time（ HRT） of 1 h,the sulfur/dolomite reactor started up quickly within ten days,which resulted in the effluent concentrations of NO3--N being less than 1. 00 mg/L,representing above 99% nitrate removal. Meanwhile,the optimal HRT of the sulfur/dolomite system was 45 min. The dissolved oxygen（ DO） in the influent could not affect the denitrification performance of the sulfur/dolomite reactor,but it could affect the performance of the pyrite/dolomite reactor. After removing the DO in the influent,the NO3--N and TP effluent concentrations in the pyrite/dolomite reactor were 10. 31 and 0. 10 mg/L under the HRT of 4 d,with the corresponding removal rates of 67. 2% and 90. 7%,respectively. Using high speed water flow backwashing,nitrogen removal efficiency in the two reactors could be restored quickly in two days. At the low temperature of 12 ℃,the removal performances of the two reactionsystems were not sensitive to temperature. The production of sulfate in the sulfur/dolomite reactor wasin accordance with the theoretical value,but it was slightly higher than the theoretical value in the pyrite/dolomite reactor. The results showed that the sulfur/dolomite system could effectively remove nitrate in the secondary effluent, and the pyrite/dolomite system could simultaneously remove nitrate and phosphorus.