山东省南四湖底泥中磷的形态分布特征

利用分级提取法分析了山东省南四湖下级湖区及其主要入湖河流底泥中磷的化学形态,并研究了磷在表层沉积物与沉积柱芯中的形态分布规律.结果表明,表层沉积物中各形态磷的空间分布规律不明显,且含量存在较大的差异.表层沉积物中活性磷(可交换态磷、铝结合态磷、铁结合态磷三者之和)的含量占总提取磷的 41%~65%,提示沉积物中磷的生物可利用性较高.沉积物柱芯中活性磷含量较大,以交换态磷和铁结合态磷为主,铝结合态磷含量较少;闭蓄态磷、自生磷、碎屑磷和有机磷在垂向上的含量分布较为稳定,有机磷含量最低.在表层沉积物和沉积柱芯中无机磷占绝对优势,表明南四湖底泥主要为无机相沉积.

Phosphorus species and distribution characteristics in sediment of Nansi Lake

By the method of sequential extraction, various species of phosphorus were extracted and determined on each sediment samples in the downstream Nansi Lake and its inflows. Distribution characteristics of phosphorus species in surface sediments and sediment cores were analysed. There was no significant regularity in the horizontal distribution of phosphorus species, but there existed obvious variances in contents. Bio-available phosphorus (BA-P), sum of exchangeable phosphorus (Ex-P), Al bound phosphorus (Al-P) and iron bound phosphorus (Fe-P), accounted for 41%~65% of the total extracted phosphorus in the sediments, suggesting a high bio-availability in the surface sedimentary phosphorus. There was large content of bio-available phosphorus in sediment cores, which was mainly consisted of Ex-P and Fe-P but less Al-P. The contents of occlude phosphorus (Oc-P), auto-calcium-bound phosphorus (Aca-P), debris phosphorus (De-P) and organic phosphorus (Or-P) were quite stable in sediment cores comparatively. Inorganic phosphorus was the overwhelmingly dominant species in both surface sediments and sediment cores, indicated that sediments in Nansi Lake was mainly deposited by inorganic phase.