[Distribution of phosphorus in surface sediments from the Yellow River estuary wetland]

Surface sediments were collected from Yellow River estuary wetland. The distribution of phosphorus in sediments was analyzed with modified SEDEX. The results indicated that the contents of TP in surface sediments varied from 12.12 micromol x g(-1) to 25.37 micromol x g(-1), and the mean value was 20.70 micromol x g(-1), in which the Detrital P and Authigenic P were the main forms. Median particle size was closely related with the distribution of phosphors, Exchangeable P, Authigenic P and Organic P mainly consisted of smaller sediment size, while Detrital P mainly consisted of larger sediment size. The distribution of P in sediment was affected by organic matter. Exchangeable P, organic P and refractory P increased with the increasing TOC. The bio-available phosphorus included exchangeable P, iron-bound P,organic P and ranged from 1.15-6.74 micromol x g(-1), with an average of 4.27 micromol x g(-1) for all sediment samples. The contribution of BAP to TP was 6.35% -30.4%.