Buyang Shijiao, Yi Qitao, Cui Hongbiao, Wan Keke, Zhang Siliang
School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China.
School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China; State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, 100038 Beijing, China.
Sci Total Environ. 2019 Jun 20;670:654-661. doi: 10.1016/j.scitotenv.2019.03.276. Epub 2019 Mar 19.
Sediment resuspension widely occurs in environments with hydrodynamic disturbances, where particles are sieved into different grain size groups. The particles of different grain size exhibit heterogeneity of their physical, chemical or biological features. This research addressed the association of metals on size fractional particles sieved by sediment resuspension in a canal of Taihu basin, a highly urbanized and human-impacted area. Surface sediment samples were collected from upstream to downstream sections of the canal to analyze the concentrations and fractionation of lead (Pb), zinc (Zn), and copper (Cu). One sediment sample was sieved into five different particle size groups (50-150 μm, 30-50 μm, 10-30 μm, 5-10 μm and <5 μm) through the wet sedimentation method. The strong adsorption ability of metals on fine particles is attributed to enrichment with organic matter and iron/aluminum (Fe/Al) oxides, with the increase in Pb, Zn, and Cu concentrations from 34.2 mg/kg, 263 mg/kg, and 32.5 mg/kg of 50-150 μm size group particles to 71.4 mg/kg, 698 mg/kg, and 137 mg/kg of <5 μm size group particles, respectively. The fine particles showed stronger sorption ability on Pb than Zn and Cu, with the Freundlich isotherm constant (K) values of the adsorption isotherms in the <10 μm size particle group ranging from 3.7 to 5.9 g/kg for Zn and Cu versus from 11 to 18 g/kg for Pb, probably causing difference on metals accumulation and releasing risk among metals in the downstream lakes with changeable environments.
沉积物再悬浮在存在水动力扰动的环境中广泛发生，在这种环境中颗粒被筛分成不同的粒径组。不同粒径的颗粒在物理、化学或生物学特征上表现出异质性。本研究探讨了在太湖流域一条高度城市化且受人类活动影响的运河中，通过沉积物再悬浮筛分的不同粒径颗粒上金属的关联情况。从运河的上游到下游段采集表层沉积物样本，以分析铅（Pb）、锌（Zn）和铜（Cu）的浓度及形态分布。通过湿沉降法将一个沉积物样本筛分成五个不同的粒径组（50 - 150μm、30 - 50μm、10 - 30μm、5 - 10μm和<5μm）。金属在细颗粒上的强吸附能力归因于其与有机质和铁/铝（Fe/Al）氧化物的富集，Pb、Zn和Cu的浓度分别从50 - 150μm粒径组颗粒的34.2mg/kg、263mg/kg和32.5mg/kg增加到<5μm粒径组颗粒的71.4mg/kg、698mg/kg和137mg/kg。细颗粒对Pb的吸附能力比对Zn和Cu更强，<10μm粒径颗粒组吸附等温线的弗伦德利希等温常数（K）值，Zn和Cu的范围为3.7至5.9g/kg，而Pb的范围为11至18g/kg，这可能导致在环境多变的下游湖泊中不同金属在积累和释放风险上存在差异。
