巢湖地区不同风化程度岩石岩源磷赋存形态研究

Phosphorus forms of different weathering degree rocks in Chaohu Lake area

对巢湖地区6组不同风化程度的岩石进行磷素形态连续提取,这6组岩石包括殷坑组、龙潭组、灯影组青灰段、灯影组紫褐段、孤峰组及双山组的微风化、弱风化和强风化岩石,研究岩源磷磷素在风化作用下的转化规律.结果表明,随风化过程进行,6组岩石中总磷含量均降低,其中多数组别岩石中易溶性和弱吸附性磷(Ex-P)、铝结合磷(Al-P)、闭蓄态磷(De-P)、自生和生物磷灰石碳酸钙结合磷(Ca-P)和碎屑磷灰石及其他无机磷(Oc-P)呈下降趋势,而铁结合磷(Fe-P)及有机磷(Or-P)则呈上升趋势;大部分岩石磷素的主要赋存形态是碎屑磷灰石及其他无机磷;对比6组岩石磷素赋存形态分布、含量及相应的pH值可知,岩石的酸碱度对磷素的赋存形态影响较大.巢湖地区富磷岩层在风化过程中的磷素释放潜力大,因而岩石的风化作用是巢湖流域水体富营养化的重要因素之一.

Phosphorus forms of different weathering degree rocks of yinkeng,longtan,dengying,gufeng and shuangshan six group of Chaohu Lake basin were investigated by using the method of phosphorus sequential extraction.The total phosphorus was gradually reduced in the weathering process,Ex-P、Al-P、De-P、Ca-P and Oc-P were decreasing and Fe-P and Or-P were increasing in mostly groups and Oc-p was the main form in the most of the rock.The pH value was the most important influence factor of phosphorus forms compared with phosphorus forms distribution,content and the pH value in the six group samples.Weathering was one of the important factors of eutrophication of Chaohu Lake basin.