页岩-钢渣组合填料湿地强化脱氮除磷研究

以城市污水A/O工艺出水为处理对象,运用页岩和钢渣物化除磷、调控进水碳氮比和氮素氧化性等技术手段,在中试规模上研究了页岩和钢渣组合填料湿地的脱氮除磷效能及影响因素.结果表明,当COD面积负荷率、TN面积负荷率、TP面积负荷率、HRT(水力停留时间)分别为6.5～20.7 g·(m²·d)^-1、2.57～8.22 g·(m²·d)^-1、0.41～1.32 g·(m²·d)^-1、0.5～1.6d时,①氨氮、亚硝态氮和硝态氮的去除率分别为85.8%、56.3%和18.6%,TN去除率为58.0%,TN面积负荷去除率为3.58g·(m²·d)^-1,TN反应动力学常数为0.31 m·d^-1,TN面积负荷去除率随进水TN负荷的增加而线性增加.②TP去除率为90.4%,TP面积负荷去除率为0.89 g·(m²·d)^-1,TP反应动力学常数为0.86 m.d^-1,TP面积负荷去除率随进水TP负荷的增加而线性增加.③水温、HRT、氮素组分、C/N等因素对湿地系统的脱氮除磷效率有显著影响.TN面积负荷去除率随HRT、COD/TN值的增加而幂函数增加.TN面积负荷去除率随水温(、NO₂^--N+NO₃^--N)/TN值的增加而呈指数函数增加.

Studies on nitrogen and phosphorus enhancing removal in combined shale and steel slag subsurface constructed wetlands

Effluent of municipal wastewater treatment plant operated under A/O process was treated by constructed wetlands for reclamation and reuse. These methods, such as phosphorus removal by adsorption of shale and steel slag, regulating C/N ratio and nitrogen oxidability in influent of wetland, were employed to study efficiency and impact factors of nitrogen and phosphorus removal in pilot-scale in combined shale and steel slag subsurface constructed wetlands. Results indicate that, When COD area load rate, TN area load rate, TP area load rate and hydraulic retention time (HRT) is 6.5-20.7 g x (m2 x d)(-1), 2.57-8.22 g x (m2 x d)(-1), 0.41 -1.32 g x (m2 x d)(-1) and 0.5- 1.6d, respectively. Removal efficiency of ammonium nitrogen, nitrite nitrogen and nitrate nitrogen is 85.8%, 56.3% and 18.6%, respectively. Removal efficiency, area load removal rate and removal kinetic constant of total nitrogen are 58.0%, 3.58 g x (m2 x d)(-1) and 0.31m x d(-1), respectively. TN area load removal rate is linearly increased with the increase of total nitrogen area load rate. Removal efficiency, area load removal rate and removal kinetic constant of total phosphorus are 90.4%, 0.89 g x (m2 x d)(-1) and 0.86 m x d(-1), respectively. TP area load removal rate is linearly increased with the increase of total phosphorus area load rate. Water temperature, HRT, COD/TN ratio and (NO2(-) -N + NO3(-) -N) /TN ratio are primary factors impacting nitrogen and phosphorus area load removal rate. Along with HRT and COD/TN ratio increase, TN area load removal rate increases according to power function. Along with water temperature and (NO2(-) -N + NO3(-) -N)/TN ratio increase, TN area load removal rate increases according to exponential function.