摘要
本研究分析了广西典型海湾表层沉积物8种重金属(As、Cd、Cr、Cu、Hg、Ni、Pb和Zn)的赋存形态,采用改进的三级连续提取法对不同形态的重金属进行提取,并探究沉积物重金属形态与理化性质之间的相关性,基于可利用形态重金属含量计算次生相与原生相比值(ratio of secondary phase to primary phase,RSP)和风险评估编码(risk assessment code,RAC),进而对表层沉积物进行潜在生态风险评估。结果表明,广西近岸海湾表层沉积物中弱酸可提取态Cd最高(62.37%),其次是可还原态Pb(46.04%)和可氧化态Hg(49.79%),而As(88.90%)、Cr(63.82%)、Cu(52.05%)、Ni(52.90%)和Zn(43.65%)以残渣态为主,稳定性较好;弱酸可提取态Cu、Ni、Pb和Zn易于在富含氮、磷和总有机碳的环境下释放,生物可利用态Cu、Ni和Pb易于结合黏土质沉积物,而pH对各重金属赋存形态释放的影响较低;Zn和Ni的RAC值分别为17.16%和12.11%,处于低风险,Cd的RSP值和RAC值分别为8.24和62.37%,处于重度污染水平和高风险,应优先防控。
In order to investigate the geochemical patterns of heavy metals(HMs)and their potential ecological risks in the coastal area of Guangxi,this study examined the patterns of eight HMs(As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn)in the surface sediments of typical bays of this region.The modified three-step sequential extraction method was used to extract the fractions of HMs,and the relationships between HM fractions and physicochemical properties were analyzed.The ratio of secondary phase to primary phase(RSP)method and risk assessment code(RAC)method were calculated based on the available forms of HM content,and then the potential ecological risk of surface sediments was assessed.The results showed that weak acid extractable fractions of Cd(62.37%)was the most abundant in surface sediments from the near-shore bays in Guangxi,followed by reducible fractions of Pb(46.04%)and oxidizable fractions of Hg(49.79%).Conversely,As(88.90%),Cr(63.82%),Cu(52.05%),Ni(52.90%),and Zn(43.65%)were mainly in a stable residual state,with good stability.Weak acid extractable fractions of Cu,Ni,Pb,and Zn are easily released in an environment rich in nitrogen,phosphorus,and total organic carbon.Bioavailable Cu,Ni,and Pb are readily combined with clay sediments,while the pH value has little effect on the release of each HM fraction.The RAC values of Zn and Ni were 17.16%and 12.11%,respectively,indicating low risk.The RSP value and RAC value of Cd were 8.24 and 62.37%,respectively,indicating severe pollution and high risk.Accordingly,prioritized preventive and control measures are warranted to mitigate the serious threat.
作者
赵淑雯
苏琼源
黄亮亮
温彩霞
朱祖浩
郑晶贝
卢佳妮
李楠
ZHAO Shuwen;SU Qiongyuan;HUANG Liangliang;WEN Caixia;ZHU Zuhao;ZHENG Jingbei;LU Jiani;LI Nan(College of Environmental Science and Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology,Guilin 541004,China;Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas,Guilin 541004,China;Scientific Research Academy of Guangxi Environmental Protection,Nanning 530022,China;Guangxi Key Laboratory of Beibu Gulf Marine Resources,Environment and Sustainable Development,Fourth Institute of Oceanography,MNR,Beihai 536000,China;Laboratory for Coastal Ocean Variation and Disaster Prediction,College of Ocean and Meteorology Guangdong Ocean University,Zhanjiang 524088,China)
出处
《海洋环境科学》
北大核心
2025年第1期35-46,共12页
Marine Environmental Science
基金
国家自然科学基金资助项目(U20A2087)
广西重点研发计划项目(桂科AB22035050)
广西研究生教育创新计划项目(YCSW2024316)。
关键词
重金属
赋存形态
生态风险
广西海湾
heavy metals
geochemical fraction
ecological risks
bays in Guangxi
