为更好了解湿地沉积物磷循环过程,采用分级提取方法和31 P-NMR技术,开展黑土洼人工湿地沉积物中磷的种类组成和赋存形态研究。结果表明,沿湿地工艺流程,磷在湿地沉积物中存在一个逐渐累积的过程,沉积物中总磷、有机磷、无机磷及有机质含量均呈现上升趋势。沉积物中的磷主要以正磷酸盐、磷酸单酯、DNA、焦磷酸盐等四种形态存在,且以正磷酸盐与磷酸单酯占主导地位,但DNA-P和焦磷酸盐在湿地磷循环中的作用不容忽视,有机磷在湿地磷循环及沉积物磷"源-汇"转化中占有重要意义。相对而言,31PNMR技术具有样品前处理相对简单、组分分析完全等优点,该技术的推广应用,将有助于弥补以往湿地磷生物地球化学循环研究中知识缺位。
In order to better understand phosphorus (P) cycle in wetland ecosystem ,the characteristics of phosphorus fractions in sediments of Heituwa constructed wetland system were investigated using soil organic phosphorus (Po) fractionation scheme and 31 P-NMR technology .The concentrations of TP ,Pi ,Po and soil organic matter were all increased along the flow direction . Four kinds of P-compounds (orthophosphate ,orthophosphate monoesters ,orthophosphate diesters ,and pyrophosphate) were detected in the NMR spectrum .Orthophosphate and phosphate monoester accounted for the dominants position in sediment phosphorus .This study indicates that the Po in sediment plays an importance role in wetland ecosystem and suggested that more attention should be paid to Po ,especially to DNA-P and pyrophosphate in further research and management of constructed wet-lands .Compared with the traditional chemical analysis method ,31 P-NMR method has sample preparation relatively simple and is less destructive ,with components analyzed completely .Using 31 P-NMR technology ,the cognition of wetland phosphorus cycle , especially organophosphate ,will be expected to get new breakthrough .