摘要
还原性无机硫(RIS)包括硫酸盐还原产物和活性铁(FeHR)形成的酸可挥发性硫(AVS)、硫的中间产物元素硫(S0)及沉积物中硫铁元素的最终积累物质黄铁矿硫(Spy),RIS不仅可以影响沉积物重金属的生物有效性,还控制铁还原及内源磷的释放等生源要素的地球化学行为。为了研究三峡库区沉积物中RIS分布特征及其环境意义,于2017年7—8月和12月采集三峡库区云阳至秭归段17个点的表层沉积物样品并测定其RIS含量。结果表明:与其他湖泊、河流相比,三峡库区表层沉积物RIS含量较低,其中,AVS的含量为0.06~0.65μmol/g,S0为0.50~1.66μmol/g,Spy为0.96~17.54μmol/g.AVS和S0含量夏季高于冬季,云阳至秭归段RIS变化趋势大致为先降低后增加再降低,有较明显的季节和地域差异。相关性分析、主成分分析和聚类分析表明,研究区沉积物生物可利用磷(BAP)、FeHR及上覆水体SO42-含量为沉积物RIS的主要限制因子。库区冬季RIS与有机磷(Org-P)和可交换态磷(Ex-P)呈显著相关性,当硫化物含量增加时,会促进Org-P的矿化分解和Ex-P向上覆水体迁移,增加释磷风险。同时,本研究从硫驱动富营养化的角度评估了三峡库区存在污染风险的水域。除库区内已发生过典型水华的重点支流外,长滩河和九畹溪也存在富营养化问题。
Reduced inorganic sulfur(RIS) includes acid volatile sulfur(AVS) formed from sulfate reduction products and reactive iron(FeHR),elemental sulfur(S~0),an intermediate product of sulfur,and pyrite sulfur(Spy),the ultimate accumulation material of elemental sulfur and iron in sediments.RIS can affect not only the biological effectiveness of sediment heavy metals,but also control the geochemistry of biogenic elements such as iron reduction and release of endogenous phosphorus behavior.In order to study the distribution characteristics of RIS in the sediments of the Three Gorges Reservoir area and its environmental significance,surface sediment samples were collected from 17 points in the section from Yunyang to Zigui in the Three Gorges Reservoir area in July-August and December 2017,and the RIS content was measured.The results showed that,compared with other lakes and rivers,the RIS content of surface sediments in the Three Gorges Reservoir area was lower,with AVS content ranging from 0.06 to 0.65 μmol/g,S~0 from0.50 to 1.66 μmol/g,and Spyfrom 0.96 to 17.54 μmol/g.The AVS and S~0 contents are higher in summer than in winter,and the trend of RIS in the section from Yunyang to Zigui is roughly decreasing,then increasing and then decreasing,with obvious seasonal and regional difference.Correlation analysis,principal component analysis and cluster analysis showed that bioavailable phosphorus(BAP),FeHRand SO42-content in the overlying water were the main limiting factors of sediment RIS in the study area.The winter RIS in the reservoir area was significantly correlated with organic phosphorus(Org-P) and exchangeable phosphorus(Ex-P),and when the sulfide content increased,it promoted the mineralized decomposition of Org-P and the migration of Ex-P to the overlying water column,increasing the risk of phosphorus release.Meanwhile,this study assessed the waters at risk of pollution in the Three Gorges Reservoir area from the perspective of sulfur-driven eutrophication.In addition to the key tributaries in the reservoir area where typical water blooms have occurred,the Changtan River and Jiuwan River also have eutrophication problems.
作者
王耀
茅昌平
贾志敏
王帅
饶文波
Wang Yao;Mao Changping;Jia Zhimin;Wang Shuai;Rao Wenbo(College of Earth Sciences and Engineering,Hohai University,Nanjing 211100,P.R.China;Yellow River Institute of Eco-Environmental Research,Zhengzhou 450003,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2023年第2期460-472,I0004,共14页
Journal of Lake Sciences
基金
江苏省自然科学基金项目(BK20191304)资助。
关键词
三峡库区
表层沉积物
还原性无机硫形态
影响因素
硫铁磷耦合关系
Three Gorges Reservoir
surface sediment
reduced inorganic sulfur form
influence factors
sulfur-iron-phosphorus coupling relationship
