重庆典型区域雨水管道沉积物中氮磷污染特征分析

为了解重庆市旧城区雨水管道沉积物中氮磷的污染特性,采集了生活区、交通干道、文教区、商业区等典型区域的雨水管道沉积物,利用化学提取法分析沉积物中氮磷的含量分布及赋存形态.结果表明:不同区域雨水管道沉积物中氮含量的空间差异性显著,含量大小都表现为文教区商业区居住区交通干道,其中,总氮(TN)含量为(3.05±2.23)mg·g-1,有机氮(ON)含量为(2.77±1.98)mg·g-1,硝酸盐氮(NO-3-N)含量为(0.029±0.024)mg·g-1,氨氮(NH3-N)含量为(0.254±0.220)mg·g-1;而磷与氮不同,空间差异性不明显,总磷(TP)含量表现为商业区交通干道居住区文教区,其中,TP含量为(1.89±0.22)mg·g-1,磷酸盐(PO-3-P)含量为(0.155±0.022)mg·g-1;不同区域雨水管道沉积物中氮磷的赋存结构并无较大差异,表现为TN中ON占主导(92.45%),无机氮(IN)中NH3-N占主导(88.87%),而磷主要以颗粒态(PP)为主;氮形态与pH呈负相关,与有机碳(OC)呈正相关,而磷与pH、OC相关性不显著;TP呈现出显著富集的特性.

Analysis on characteristics of nitrogen and phosphorus in storm sewer sediments in Chongqing City

In order to characterize nitrogen and phosphorus in storm sewer sediments in Chongqing,sewer sediments from different urban areas were collected and the contents and compositions of nitrogen and phosphorus were analyzed. The results showed that the content of TN was (3.05±2.23) mg·g^-1, ON was (2.77±1.98) mg·g^-1, NO₃^--N was (0.029±0.024) mg·g^-1, NH₃-N was (0.254±0.220) mg·g^-1, and the size of nitrogen in storm sewer sediments was residential area >cultural district >business forum >traffic road. Phosphorus showed different characteristics. The content of TP was (1.89±0.22) mg·g^-1, PO₃^--P was (0.155±0.022) mg·g^-1, and the size of TP was business forum >traffic road >residential area>cultural district. Compositions of nitrogen and phosphorus were similar. Nitrogen in storm sewer sediments was predominantly organic(92.45% of TN), while NH₃-N was the main forms of IN (88.87% of IN). In comparison, PP was the main form of phosphorus.The content and composition of nitrogen was positively correlated with organic carbon (OC) and negatively with pH. In comparison, the correlations between phosphorus and pH and OC were not significant, and TP showed significantly enriched features.