库布齐沙漠颗粒物中磷的化学形态分析

Chemical Speciation of Phosphorus in Sand Particles from Kubuqi Desert

采用7步连续浸提法对库布齐沙漠响沙湾沙粒中磷的各种存在形态进行了分析测定，并对沙粒样进行了分级形态研究。结果表明：在库布齐沙漠响沙湾沙粒中总磷（TP）的含量为137．21～362．09μg／g，其主要成分为无机磷（IP），平均占TP的比例为94．60％；而有机磷（Or—P）的含量为7．88～19．12μg／g，平均占TP的5．40％。在所有不同粒度的沙样中，自生钙结合磷（Ca—P）含量最高，占TP的58．95％～80．05％，其次是原生碎屑磷（De—P）。占TP的8．13％～30．22％，二者占IP的绝大部分；其他各形态磷含量的高低顺序为：有机磷（Or—P）〉吸附态磷（Ads—P）〉铁结合态磷（Fe—P）〉闭蓄态磷（Obs—P）〉铝结合态磷（AI—P）。在所取沙漠颗粒物样中TP、Ca—P、De—P、Or—P、AI—P各自的含量都是随颗粒物粒度的减小而增大，而Ads—P含量则相反；Fe—P、Obs—P的含量受颗粒物粒度变化的影响不大。

Various phosphorus species in sand grains with different size from Kubuqi Desert are studied with sevenstep sequential extraction method. The results show that the concentration of total phosphorus （TP） in Xiangshawan sand of Kubuqi Desert ranges from 137. 21 μg/g to 362.09 μg/g, with main composition of inorganic phosphorus （ with average of 94.60% in TP）. The concentration of organic phosphorus ranges from 7.88 μg/g to 19.12 μg/g （with average of 5.40% in TP）. In the sand samples with different particle sizes, Ca-P is the most abundant species with 58.95% -80.05% in TP. De-P, the second abundant species, is 8.13% -30.22% in TP. The other species, in turn, are Or-P, Ads-P, Fe-P, Obs-P and AI-P. The contents of TP, Ca-P, De-P, Or-P and AI-P increase with decreasing in sand particle size, but Ads-P is contrary. And no remarkable dependency relationship between content and sand particle size for Fe-P and Obs-P species are found.