以可生物降解固体为碳源的城市污水厂尾水反硝化脱氮研究

STUDY ON NITROGEN REMOVAL IN THE EFFLUENT FROM MUNICIPAL WASTEWATER TREATEMTN PLANT BY DENITRIFICATION USING BIODEGRADABLE POLYMERS AS CARBON SOURCES

针对城市污水厂尾水氮排放不达标的现象,提出以可生物降解聚合物作为固体碳源的反硝化生物滤池技术。研究结果表明,尾水中氮的去除率会随水力停留时间（HRT）的延长而增加,HRT≤8 h时,去除率增长速度较快;HRT〉8 h时,脱氮效率增长趋于平缓。选用聚羟基丁酸戊酸共聚酯（PHBV）为碳源,HRT为8 h时脱氮效果最佳,连续稳定运行30 d,出水硝态氮的去除率达96.1%~97.4%,出水中总氮浓度达GB 3838—2002《地表水环境质量标准》Ⅴ类水标准。

To avoid the occurrence of nitrogen emission substandard in the effluent from municipal wastewater treatment plant,the biodegradable polymers were studied as carbon sources fixed in the denitrification biofilter. The result showed that the hydraulic retention time（ HRT） was an important factor which influenced the removal efficiency. The removal rate of nitrogen increased with the extension of HRT. HRT was less than 8 h,the removal rate increased faster; while HRT was more than8 h,the growth of the denitrification efficiency tended to be stable. Under the condition of PHBV as carbon sources and HRT of 8h,nitrate nitrogen removal rate in effluent reached 96. 1% ~ 97. 4% after the system stable operating for 30 d,and the total nitrogen concentration met the V standard of GB 3838—2002 ＂Surface Water Environment Quality Standard＂.