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

作　　者：向速林[1] 楚明航 刘丽贞[2] 朱林 吴永明[2] 梁培瑜 Xiang Sulin;Chu Minghang;Liu Lizhen;Zhu Lin;Wu Yongming;Liang Peiyu(School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,P.R.China;Institute of Microbiology,Jiangxi Academy of Sciences,Nanchang 330096,P.R.China)

机构地区：[1]华东交通大学土木建筑学院,南昌330013 [2]江西省科学院微生物研究所,南昌330096

出　　处：《湖泊科学》2024年第4期1121-1130,共10页Journal of Lake Sciences

基　　金：国家自然科学基金项目(42161022);江西省自然科学基金项目(20224BAB203042);江西省科技计划项目(20213AAG01012,20212BCJ23034,2023YRCS005,20212BBG71002,2021YSBG50004,2023YSBG10007)联合资助。

摘　　要：本研究采用化学连续提取法,分析赣江南昌段表层沉积物磷赋存形态特征及其生物有效性,并通过等温吸附实验探讨了沉积物磷释放风险。结果显示:赣江南昌段表层沉积物总磷(TP)含量范围为235.21~702.24 mg/kg,均值为522.93 mg/kg,具有较高的空间异质性。所有采样点位中无机磷(IP)均以闭蓄态磷(Oc-P)为主要赋存形态,各形态无机磷含量特征表现为:Oc-P>铁结合态磷(Fe-P)>碎屑钙磷(De-P)>自生钙磷(ACa-P)>可交换态磷(Ex-P)>铝结合态磷(Al-P);有机磷(OP)以残渣态有机磷(Res-P_(o))为主要赋存形态,按活性划分表现为:非活性有机磷(NOP)>中活性有机磷(MLOP)>活性有机磷(LOP)。生物有效磷(BAP)含量范围为61.59~218.27 mg/kg,占TP含量的比例为27.07%。BAP总量及占TP的比例均处于较低水平,沉积物内源磷释放风险较低。BAP中Fe-P平均占比为56.72%,表明沉积物磷潜在释放风险主要来源于Fe-P。TP、Fe-P和De-P之间均存在显著相关关系,表明外源输入可能是赣江沉积物磷的主要来源。采样期间赣江南昌段沉积物磷平衡浓度(EPC 0)高于上覆水溶解性活性磷(SRP)浓度,磷吸附饱和度(DPS)均低于沉积物磷大量流失的临界值25%,表明此阶段沉积物磷虽作为上覆水的“磷源”,但出现大量释磷的可能性不高。因此,沉积物内源磷释放引起赣江水体富营养化的风险不高,这意味着赣江水体应更多关注外源输入问题。本研究结果为赣江南昌段水环境的科学管理提供了数据支撑和科学依据。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 phosphorus content of each form was characterized as Oc-P>Iron-bound phosphorus(Fe-P)>detrital calcium phosphate(De-P)>authigenic 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-P_(o)).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,accounting 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 phosphorus 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(EPC 0)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

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 

分 类 号：X52[环境科学与工程—环境工程]