滇池是中国富营养化状态最为严重的湖泊，而入湖河流氮磷元素的输入是其主要原因。河流水质的低 C/N 特征是限制氮素去除的关键因素，采用固相反硝化技术能够为反硝化过程提供持续的碳源，因而能够强化受污染河流的脱氮效果。以滇池的重点控制入湖河流-新运粮河为研究对象，设计了微曝气生物滤池（Biological aerating filter，BAF）-固相碳源反硝化（Solid-phase denitrification，SPD）组合工艺，在河道旁路展开示范工程研究。组合工艺设计规模为800 m3·d-1，BAF（气水比为3∶1~5∶1）和SPD生物滤池的最大表面水力负荷分别为4.2和1.4 m3·m-2·h-1，其中SPD生物滤池采用新型固相碳源共混可生物降解聚合物与惰性载体共混作为生物膜载体。工艺研究结果表明，在BAF气水比为3∶1~5∶1、HRT为0.5~1 h和SPD滤池HRT为0.5~1 h的运行工况下，BAF对NH4+-N的平均硝化率达到了91.27%，SPD滤池的平均反硝化率93.60%，工艺出水NH4+-N、NO3--N和NO2--N平均浓度分别为0.68、0.70和0.02 mg·L-1。示范工程对各项污染物的去除效果良好，对TN、TP和CODCr的去除率分别达到84.93%、50.15%和31.39%；工艺出水TN、TP和CODCr平均浓度分别为1.75、0.20和22.96 mg·L-1，主要水质指标均达到了地表水V类水质标准。采用新型固相碳源填充的反硝化生物滤池强化了工艺针对低C/N水质特征污染水体的脱氮效果，组合工艺对滇池氮素输入控制具有重要的意义。%Over input of nitrogen and phosphorus contaminats is the major reason for the most serious eutrophication condition of Dianchi Lake in China. Low C/N restricts the removal efficiency of nitrogen compounds. Application of solid-phase technology could supply enough carbon source consistently for denitrification process, enhancing the removal performance of nitrogen. A biological aerated filter (BAF) combined with solid phase denitrification (SPD) biofilter was applied to water purification in the Xin Yunliang River bypass on a demonstration scale. Designed scale was 800 m3·d-1, with the maximum hydraulic loads of 4.2 and 1.4 m3·m-2·h-1 for BAF and SPD biofilter, respectively. Novel solid carbon source combined with inert carrier were applied in the SPD biofilter as biofilm carriers. Results indicated nitrification and denitrification were satisfactory at air/water ratio of 3∶1 to 5∶1 and HRT of 0.5 to 1.0 h for BAF and HRT of 0.5 to 1.0 h for SPD, with average nitrification and denitrification rates of 91.27% and 93.60% respectively. Effluent contents of NH4+-N, NO3--N and NO2--N were 0.68, 0.70 and 0.02 mg·L-1. Removals of TN, TP and CODCr were found to be 84.93%, 50.15% and 31.19%, respectively. Contents of TN, TP and CODCr in the effluent were 1.75 mg·L-1, 0.20 mg·L-1 and 22.96 mg·L-1 respectively, meeting the Class V limits of Environmental Quality Standards for Surface Water. Further analysis pointed out that such a process combination was effective for purifying low C/N ratio water and thus controlling nitrogen input into Dianchi Lake.
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