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Adsorption-desorption behavior of heavy metals in aquatic environments: Influence of sediment, water and metal ionic properties
- Source :
- Journal of hazardous materials. 421
- Publication Year :
- 2021
-
Abstract
- Limited knowledge of the combined effects of water and sediment properties and metal ionic characteristics on the solid-liquid partitioning of heavy metals constrains the effective management of urban waterways. This study investigated the synergistic influence of key water, sediment and ionic properties on the adsorption-desorption behavior of weakly-bound heavy metals. Field study results indicated that clay minerals are unlikely to adsorb heavy metals in the weakly-bound fraction of sediments (e.g., r = −0.37, kaolinite vs. Cd), whilst dissociation of metal-phosphates can increase metal solubility (e.g., r = 0.61, dissolved phosphorus vs. Zn). High salinity favors solubility of weakly-bound metals due to cation exchange (e.g., r = 0.60, conductivity vs. Cr). Dissolved organic matter does not favor metal solubility (e.g., r = −0.002, DOC vs. Pb) due to salt-induced flocculation. Laboratory study revealed that water pH and salinity dictate metal partitioning due to ionic properties of Ca2+ and H+. Selectivity for particulate phase increased in the order Cu>Pb>Ni>Zn, generally following the softness (2.89, 3.58, 2.82, 2.34, respectively) of the metal ions. Desorption followed the order Ni>Zn>Pb>Cu, which was attributed to decreased hydrolysis constant (pK1 = 9.4, 9.6, 7.8, 7.5, respectively). The study outcomes provide fundamental knowledge for understanding the mobility and potential ecotoxicological impacts of heavy metals in aquatic ecosystems.
- Subjects :
- China
Geologic Sediments
Environmental Engineering
Chemistry
Health, Toxicology and Mutagenesis
Metal ions in aqueous solution
Ionic bonding
Water
Pollution
Metal
Adsorption
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Environmental chemistry
Desorption
Metals, Heavy
Dissolved organic carbon
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Environmental Chemistry
Solubility
Clay minerals
Waste Management and Disposal
Ecosystem
Water Pollutants, Chemical
Environmental Monitoring
Subjects
Details
- ISSN :
- 18733336
- Volume :
- 421
- Database :
- OpenAIRE
- Journal :
- Journal of hazardous materials
- Accession number :
- edsair.doi.dedup.....64e445ae947ceac8ef7867c7caa25475