长江输送颗粒态磷的生物可利用性及其环境地球化学意义

模拟不同采样时间长江输送悬浮态颗粒物实验,通过测定藻类增长潜力来讨论颗粒态磷的生物可利用性.结果表明,悬浮物中生物可利用磷(SSBAP)含量在不同采样时间(2001年2月、5月、12月和2002年8月)的平均值分别为(288 3±49 4),(228 2±38 2),(251 6±32 9)和(182 0±8 1)mg·kg-1.不同藻种的SSBAP BAP平均值为:铜绿微囊藻(Microcystisaerugilnosa)54 2%,斜生栅藻(Scendesmusobliquus)60 3%.在4次采样中,通过大通站的BAP浓度均大于水体富营养化的限制值(0 02mg·L-1),说明SSBAP对长江流域、河口及近海区营养盐的贡献是不容忽视的,颗粒态磷是长江河口及近海区富营养化的潜在污染源,它对河口及近海的生态环境造成很大影响.

Bioavailability of phosphorus in the Changjiang River suspended sediment and it's environmental geochemistry significance

Bioavailable phosphorus in the suspended sediment (SSBAP) was studied by simulating transportation of suspended sediment(SS)in the Changjiang River in different sampling dates (2001-02-14,2001-05-23, 2001-12-15,2002-08-10). The amount of SSBAP was estimated by algal growth potential. The results showed that SSBAP contents were about (288.3±49.4), (228.2±38.2), (251.6±32.9), (182.0±8.1)mg·kg^-1 in different sampling dates. SSBAP/BAP were 54.2% by Microcystis aerugilnosa and 60.3% by Scendesmus obliquus, respectively. Concentrations of BAP from 4 samplings at Datong Station were higher than the thresholds for eutrophication (0.02 mg·L^-1), indicating the importance of SSBAP flux to phosphorus levels in Changjiang River, the estuary and the coastal area. Phosphorus bound to particulates should be a potential source regarding to the algal bloom in Changjiang River estuary and the coastal area, which affects the ecosystem of the areas.