【摘要】 人工湿地运行的长效性值得关注,以山东省武河人工湿地为例,2017年10月选取10个和4个代表性采样点分别采集原位水样和柱状沉积物样,对该湿地正常运行10年后,其对水体磷的净化效果和沉积物磷的分布特征及其内源释放风险进行了研究。结果表明:武河人工湿地运行10年后,对水体磷仍具有较好的净化效果,净化效率在50%左右,出水口总磷(TP)浓度为0.29 mg L-1,符合地表水Ⅳ类水质标准。4个沉积物柱样均显示,沉积物各磷形态含量大小顺序为:无机磷(IP)>钙磷(Ca-P)>铁铝结合态磷(Fe/(Al-P)>不稳定态磷(LP)>有机磷(OP),IP含量最高,约占总磷的69%～95%,OP含量极低,与湿地来水息息相关;在IP中,沉积物Ca-P含量最高,表现为较为稳定的特性;空间分布上,不同点位各磷形态含量差异显著,进水口较近区域含量较高,垂向上,除Ca-P外,其他磷形态含量总体呈现随深度增加而减少的趋势,湿地来水影响明显。静态释放实验表明,湿地不同点位沉积物磷的内源释放速率差异明显,4个点位总磷的沉积物-水界面释放速率分别为-1.98、-9.32、-11.99和-8.65 mg m-2d-1,均以吸附为主,距离进水口较近区域,沉积物对磷的吸附能力有所降低,这对人工湿地的长期运行具有指导意义。相关性分析表明,除Ca-P外,沉积物其他磷形态同有机质(LOI)表现出较好相关性,沉积物磷形态和LOI来源相对一致,主要为临沂城区工业废水和生活污水的尾水,受农业面源污染的影响较小。更多还原

【Abstract】 Long-term r unning effectiveness of the con structed wetlands is worthy of attention. Taking the Wuhe constructed wetland of Shandong Province as an example, ten in-situ water samples and four intack columnar sediment samples were collected in October, 2017. The removal effect of phosphorus(P) in the water body, and its distribution and endogenous release risk in the sediment were studied in the Wuhe constructed wetland for 10 years. The purification effect of P in the water body was better, with a removal rate of about 50%, and the concentration of total P(TP) in the outlet water was 0.29 mg L-1, which achieved the design goal of the Ⅳ standard of surface water quality.The content of P forms in the sediment decreased in the order of inorganic P(IP) > Ca-P > Fe/(Al-P) > labile P(LP)> organic P(OP), and the IP content accounted for about 69% to 95% of TP. The OP content was extremely low,which was closely linked with the inflow water of wetland. The content of Ca-P in the sediment was the highest and remained relatively stable. The significant difference was found in the P content among different points, and the P content was higher near the inlet area. The contents of P forms(except Ca-P) in the sediment decreased with the depths and were influenced obviously by the P content of the inflow water. Static release experiments showed that the P endogenous release rates in the sediment were significantly different among different points. The TP release rates were-1.98,-9.32,-11.99 and-8.65 mg m-2 d-1 in the four points, respectively, and it mainly was adsorbed. The P adsorption capacity in the sediment was reduced near the inlet area, which would show the guiding significance for long-term operation of constructed wetlands. The sediment P forms(except Ca-P) had significant correlations with organic matter(OM), which reflected that they had the similarly source mainly from the tail water of industrial wastewater and domestic sewage of Linyi, and less affected by agricultural non-point source pollution.更多还原