添加碳源对潜流+表面流组合湿地脱氮除磷的影响

采用向ANOXIC-OXIC（A/O）工艺出水中添加城市污水的方法,在中试规模上研究了外加碳源对潜流+表面流组合湿地脱氮除磷的影响.结果表明,直接处理A/O工艺出水时（工况Ⅰ）,湿地进水COD/TN仅为1.00,(NO^-₂+NO^-₃)/TN为0.48,COD、TN和TP的面积负荷去除率分别为1.82、1.59、0.14 g·(m²·d)^-1.A/O工艺出水中添加少量城市污水后（工况Ⅱ）,湿地进水COD/TN为3.55,(NO^-₂+NO^-₃)/TN为0.44,COD、TN和TP的面积负荷去除率分别为19.03、5.42、0.29 g·(m²·d)^-1.工况Ⅱ的TN和TP面积负荷去除率分别比工况Ⅰ提高了3.4倍和2.1倍.HRT、水温、(NO^-₂+NO^-₃)/TN和COD/TN对湿地脱氮除磷效能有显著影响,在HRT为0.5～1.0d, COD、TN和TP的面积负荷率分别为3.8～38.7、5.07～13.08、0.57～1.92 g·(m²·d)^-1时, TN面积负荷去除率随HRT增加而指数下降,随水温和(NO^-₂+NO^-₃)/TN的升高而线性增加,随COD/TN的增加呈幂函数增加.TP面积负荷去除率随COD/TN的增加呈幂函数增加.

Effects of External Carbon Source on Nitrogen and Phosphorus Removal in Subsurface Flow and Free Water Surface Integrated Constructed Wetland

By adding municipal wastewater in effluent of ANOXIC-OXIC (A/O) reactor as external carbon source, effects of external carbon source on nitrogen and phosphorus removal in subsurface flow and free water surface integrated constructed wetland were studied in pilot-scale. Results indicate that, COD/TN and (NO2(-) + NO3(-))/TN in influent of wetland are 1.00 and 0.48, respectively, and load removal rates of COD, TN and TP are 1.82, 1.59 and 0.14 g (m2 x d)(-1), respectively, as directly treating effluent of A/O reactor in wetland (working condition I). COD/TN and (NO2(-) + NO3(-))/TN in influent of wetland are 3.55 and 0.44, respectively, and load removal rates of COD, TN and TP are 19.03, 5.42 and 0.29 g (m2 x d)(-1), respectively, as adding municipal wastewater in effluent of A/O reactor as external carbon source in wetland (working condition II). Compared with working condition I, load removal rates of TN and TP for working condition II increase 3.4 times and 2.1 times, respectively. Impact factors of load removal rate of TN and TP are water temperature, HRT, COD/TN and (NO2(-) + NO3(-))/TN, respectively, when ranges of influent load rates are 3.8 - 38.7 g x (m2 x d)(-1) for COD, 5.07 - 13.08 g x (m2 x d)(-1) for TN and 0.57 - 1.92 g x (m2 x d)(-1) for TP, respectively, and range of HRT is 0.5 - 1.0 d. TN load removal rate decreases by exponent function along with increase of HRT, linearly increases along with increase of water temperature and (NO2(-) + NO3(-))/TN, and increases by power function along with increase of COD/TN. TP load removal rate also increases by power function along with increase of COD/TN.