改性填料在城市污水处理厂提标改造中的应用

Application of Modificationg Filler in A Enovation Program for A City Sewage Treatment Plant

介绍了采用改性填料的MBBR工艺在山西省长治市污水处理厂提标改造工程中的应用。该升级改造工程规模为10万m^(3)/d,采用Bardenpho+MBBR工艺对原Bardenpho工艺进行了升级改造,在没有扩建池容的基础上,通过增加填料膜面积及相关设备,出水污染物中的COD、氨氮、总磷达到《地面水环境质量标准》(GB3838-2002)中的Ⅴ类标准。实际运行显示,采用改性填料的MBBR工艺处理效果较好,出水水质稳定。

Aim at controlling nitrogen in stormwater runoff by traditional bioretention systems,a saturated zone is usually set up at the bottom of the system to strengthen the removal of nitrogen,but there are still a variety of influencing factors that may lead to nitrogen leakage after setting up the saturated zone.The length of the antecedent dry period is related to the existence of the saturation zone within the system,which directly affects the nitrogen concentration in the initial effluent of the system during the next rainfall,so it is necessary to examine in depth the influence of the antecedent dry period on nitrogen removal in the system.A bioretention system with a 40 cm saturated zone was set up to compare the pollutant removal of the system and analyze the mechanism of nitrogen removal at different antecedent dry period conditions.The results showed the nitrogen removal of the system was high due to low initial outflow nitrate level at continuous influent and short antecedent dry periods.Nitrate and total nitrogen concentrations were higher in the initial outflow from the system at long antecedent dry periods,and nitrogen removal was at a low level despite low ammonia concentration.The main reason for the differences in pollutant removal at different antecedent dry periods was that the length of the drought period affects the processes and degrees of nitrogen transformation in the media and saturated zone,which in turn affects nitrogen's removal.The predominance of dissimilatory nitrate reduction to ammonium in the media at alternate wet and dry conditions in bioretention systems differs significantly from the traditional belief that nitrate undergoes predominantly denitrification in the system.