Chemical Speciation of Phosphorus in Sand Particles from Kubuqi Desert

Various phosphorus species in sand grains with different size from Kubuqi Desert are studied with seven step 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 g/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. DeP, the second abundant species, is 8.13%~30.22% in TP. The other species, in turn, are OrP, AdsP, FeP, bsP and AlP. The contents of TP, CaP, DeP, OrP and AlP increase with decreasing in sand particle size, but AdsP is contrary. And no remarkable dependency relationship between content and sand particle size for FeP and ObsP species are found