Li Juan, Zhang Linlin, Yu Shen, Hong Bing, Lin Ruihan, Li Qi, Jia Haifeng, Yang Dawen, Gu Chengwei, Jia Qimeng
Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
J Hazard Mater. 2024 Jun 5;471:134381. doi: 10.1016/j.jhazmat.2024.134381. Epub 2024 Apr 23.
Surface sediment in urban waterways originates from fine topsoil particles within catchments via surface erosion, often bonded with non-degradable metal(loid)s. This study posited that urban green infrastructures (UGIs) can influence anthropogenic metal(loid) transport from catchment topsoil to waterway sediment by retaining moveable particles. In multiply channeled downtown Suzhou, China, UGIs' spatial patterns were examined in relations to metal(loid)s source (catchment topsoil) - sink (waterway surface sediment) dynamics. Anthropogenic metal(loid)s - As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn - were spatially quantified in sediment at 144 waterway points and in topsoil at 154 UGIs' points across 7 subwatersheds. Integrated metal(loid) loads revealed significantly higher sediment loads (except for As) than topsoil, varying with element specificity and spatial unmatching across the subwatersheds. Loads of metal(loid)s in topsoil showed no significant differences among UGI types, but sediment loads of As, Cr, and Ni correlated positively with topsoil loads in roadside and public facility UGIs within 100 m- and 200 m-wide riparian buffer zones. However, waterfront UGIs negatively impacted on these correlations for Cr, Hg, and Ni loads within the riparian buffer zones. These findings highlight metal(loid) specificity and UGIs' spatial pattern effects on anthropogenic metal(loid) loads between catchment topsoil (source) and waterway surface sediment (sink), offering valuable guidelines for UGIs' design and implementation.
城市水道中的表层沉积物源自集水区内的细表土颗粒，通过表面侵蚀形成，通常与不可降解的金属（类金属）结合在一起。本研究假定，城市绿色基础设施（UGIs）可以通过截留可移动颗粒来影响人为金属（类金属）从集水区表土到水道沉积物的迁移。在中国苏州闹市区的多河道区域，研究了UGIs的空间格局与金属（类金属）源（集水区表土）-汇（水道表层沉积物）动态之间的关系。对7个次流域内144个水道点的沉积物和154个UGIs点的表土中的人为金属（类金属）——砷、镉、铬、铜、汞、镍、铅和锌进行了空间定量分析。综合金属（类金属）负荷显示，沉积物负荷（除砷外）显著高于表土，且随元素特异性和次流域间的空间不匹配而变化。表土中金属（类金属）的负荷在UGI类型之间没有显著差异，但在100米和200米宽的河岸缓冲区内，路边和公共设施UGIs中砷、铬和镍的沉积物负荷与表土负荷呈正相关。然而，滨水UGIs对河岸缓冲区内铬、汞和镍负荷的这些相关性产生了负面影响。这些发现突出了金属（类金属）的特异性以及UGIs的空间格局对集水区表土（源）和水道表层沉积物（汇）之间人为金属（类金属）负荷的影响，为UGIs的设计和实施提供了有价值的指导。
