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

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

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.

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.