湖泊科学2024，Vol.36Issue(4)：1121-1130,10.DOI:10.18307/2024.0425
鄱阳湖流域赣江(南昌段)沉积物磷赋存形态特征及释放风险分析
Characteristics and release risk of phosphorus fractions in sediments of Nanchang section of Ganjiang River,Lake Poyang Basin
摘要
Abstract
In this study,the characteristics and bioavailability of phosphorus fractions in surface sediments of Ganjiang River were analyzed by chemical sequential extraction method.The risk of sediment phosphorus release was explored by isothermal adsorption experiments.The results showed that total phosphorus(TP)content in the surface sediments of Nanchang section of Ganjiang River had a range from 235.21 to 702.24 mg/kg,with an average of 522.93 mg/kg,implying a high degree of spatial heterogeneity.In all sampling sites,the occluded phosphorus(Oc-P)was the principal storage form of inorganic phosphorus(IP).The inorganic phos-phorus content of each form was characterized as Oc-P＞Iron-bound phosphorus(Fe-P)＞detrital calcium phosphate(De-P)≥authi-genic calcium phosphate(ACa-P)＞exchangeable phosphorus(Ex-P)＞aluminum-bound phosphorus(Al-P).Organic phosphorus(OP)was mainly stored in the form of residual organic phosphorus(Res-Po).According to the division of activity,it was ordered as follows:inactive organic phosphorus(NOP)＞medium-active organic phosphorus(MLOP)＞active organic phosphorus(LOP).The content of bioactive phosphorus(BAP)had a range from 61.59 to 218.27 mg/kg,with an average of 145.54 mg/kg,account-ing for 27.07％of TP content.The total amount of BAP and its proportion to TP were relatively low,indicating a low risk of internal phosphorus release from the sediments.The content of Fe-P in BAP accounted for 56.72％,showing that the potential risk of phos-phorus release from sediments mainly came from Fe-P.There were significant correlations between TP,Fe-P,and De-P,indicating that external inputs may be the primary source of phosphorus in the sediments of Ganjiang River.During the sampling period,the equilibrium phosphorus concentration(EPC0)of the sediments was higher than that of the overlying water's dissolved reactive phosphorus(SRP).The values of the degree of phosphorus saturation(DPS)were lower than the critical value of 25％for the large amount of phosphorus loss from the sediments,indicating that although the sediments acted as"phosphorus source"for the o-verlying water at this stage,the possibility of large amounts of phosphorus release was not high.Therefore,the risk of eutrophication of Ganjiang River caused by sediment phosphorus release is low,implying that more attention should be paid to external inputs to Ganjiang River water body.This study can potentially provide data support and theoretical basis for the water management of Gan-jiang River.关键词
鄱阳湖流域/赣江/沉积物/磷形态/生物有效磷/释放风险Key words
Lake Poyang Basin/Ganjiang River/sediment/phosphorus fractions/bioavailable phosphorus/release risk引用本文复制引用
向速林,楚明航,刘丽贞,朱林,吴永明,梁培瑜..鄱阳湖流域赣江(南昌段)沉积物磷赋存形态特征及释放风险分析[J].湖泊科学,2024,36(4):1121-1130,10.基金项目
国家自然科学基金项目(42161022)、江西省自然科学基金项目(20224BAB203042)和江西省科技计划项目(20213AAG01012,20212BCJ23034,2023YRCS005,20212BBG71002,2021YSBG50004,2023YSBG10007)联合资助. （42161022）
