太湖流域农村黑臭河流沉积物中磷形态的垂向分布特征

为揭示太湖地区农村黑臭河流表层沉积物中磷形态的分布特征及各形态磷之间的相关性,本文以宜兴市周铁镇掌下浜(北段)为例,沿河流从上游到下游河口共采集了13个表层沉积物样,应用SMT法(The Standards,Measurements and Testing Programme)对柱状沉积物中磷形态进行了分析,并对有机质与各磷形态及其之间进行相关性分析.结果表明:在垂向分布上,沉积物中各形态磷含量随深度加深总体均呈现下降趋势;总磷(Total Phosphorus,TP)的平均含量为659.33~4379.31 mg·kg-1,无机磷(Inorganic Phosphorus,IP)构成沉积物中磷的主要部分,占TP的66.59%~88.25%;盐酸提取态磷(Hydrochloric acid extractable phosphorus,Ca-P)占TP的44.17%~71.47%,占IP的62.17%~83.70%,是构成IP的主要部分.有机质含量与各形态磷之间皆表现出显著的正相关性,反映出垂向沉积剖面上有机质是磷形态含量的重要影响因素.IP、Ca-P、OP(Organic Phosphorus,有机磷)与TP均具有显著的相关关系,表明沉积物中TP含量的增加,主要来自Ca-P,其次是OP;沉积物中OP与Fe/Al-P(NaOH extractable phosphorus,铁铝磷)、Ca-P含量也具有显著的正相关关系,表明OP含量对Fe/Al-P、Ca-P的含量均有影响;Ca-P与Fe/Al-P含量之间存在显著的相关性,说明沉积物中Fe/Al-P的还原释放对Ca-P的形成具有一定的影响.

Vertical distribution characteristics of phosphorus fractions in the sediments of a rural malodorous black River in Taihu Lake Area

To reveal the vertical distribution characteristics and the correlation of various phosphorous fractions in the sediment of rural malodorous black river running to Lake Taihu, the north section of Zhangxia River of Zhoutie town, Yixing was taken as the research object. Thirteen sediment cores were collected from the upper reach till the lower reach along Zhangxia River. SMT method was applied to quantify various phosphorous fractions, and the correlations among fractions with organic matter were analyzed. The results show that,1in the vertical scale, total phosphorous (TP) concentration is declining downwards. The mean concentration of TP is between 659.33 mg·kg^-1 and 4379.31 mg·kg^-1. Inorganic phosphorus (IP), as the major phosphorous fraction in sediment, accounts for 66.59%~88.25% of TP. Ca-P is the major fraction of IP, accounting for between 62.17% and 83.70% of IP and 44.17%~71.47% of TP; 2The concentrations of organic matter and phosphorous are positively correlated, which indicates that organic matter is one of the most important factors that influence the vertical distribution of phosphorous fractions; 3IP,Ca-P and OP all have significantly positive correlations with TP, showing that the increase of TP concentration is mainly attributed to Ca-P, then OP. The positive correlations between OP and Fe/Al-P, and between OP and Ca-P show that the concentration of OP has impact on Fe/Al-P and Ca-P. In addition, the correlation between Ca-P and Fe/Al-P is more significant, which indicates that the reduction and release of Fe/Al-P has effects on the formation of Ca-P.