磁分离——双泥龄脱氮工艺处理城市污水中试研究

Pilot Study on Magnetic Separation Combined with Dual Sludge Retention Time Nitrogen Removal Process for Municipal Wastewater Treatment

开发了超磁分离耦合双泥龄复合脱氮工艺,以超磁分离技术进行碳源分离和浓缩,采用双泥龄复合脱氮工艺对碳源分离后的出水进行脱氮,并在中试规模上开展研究。结果表明,经过长达750余天的连续运行,该超磁分离工艺在极短的HRT(约10 min)下可实现碳源截留率大于50%;双泥龄复合脱氮工艺出水总氮可稳定低于10 mg/L,满足北京市《城镇污水处理厂水污染物排放标准》(DB 11/890—2012)A级标准。缺氧池内生物膜厌氧氨氧化活性为45.75~71.03 mg/(L·d),向缺氧池投加亚硝态氮有利于恢复厌氧氨氧化活性,缺氧池采用间歇微曝气可提高短程硝化/厌氧氨氧化活性,促进自养脱氮,提高系统脱氮效率。这初步验证了超磁分离耦合双泥龄复合脱氮工艺的可行性,为该工艺的进一步研究奠定了基础。

This paper developed a pilot scale super-magnetic separation coupled with dual sludge retention time(SRT)nitrogen removal process,of which the super-magnetic separation technology was used to separate and concentrate carbon sources,and the dual SRT nitrogen removal process was employed to remove nitrogen from the effluent after carbon source separation.After more than 750 days of continuous operation,the super-magnetic separation process achieved a carbon source retention rate of more than 50%under a very short hydraulic retention time(HRT,approximately 10 min),and the total nitrogen in the effluent from the dual SRT combined nitrogen removal process remained below 10 mg/L,which met the level A limit specified in Discharge Standard of Water Pollutants for Municipal Wastewater Treatment Plants(DB 11/890-2012)of Beijing.The anammox activity of biofilm from the anoxic tank was 45.75-71.03 mg/(L·d).The addition of nitrite into the anoxic tank was conducive to recovering the anammox activity,and the intermittent micro-aeration in anoxic tank promoted the partial nitrification/anammox activity and autotrophic nitrogen removal,and improved the nitrogen removal efficiency of the system.This paper preliminarily verified the feasibility of the super-magnetic separation coupled with dual SRT combined nitrogen removal process,and laid a foundation for further study of the process.