Cadmium (Cd) and arsenic (As) are commonly co-adsorbed onto iron oxides in the soil environment, especially in south China. This study aimed to elucidate the regulatory mechanisms in determining the As(Ⅴ)-Cd(Ⅱ) interactions on a goethite interface after excluding pH interference. At pH 6.0, the results obtained illustrated that As(Ⅴ) and Cd(Ⅱ) adsorbed onto goethite obeyed the pseudo-second-order kinetic model, and the adsorption processes were mainly chemical adsorption. Furthermore, As(Ⅴ) adsorbed onto goethite were mainly inner ring adsorption and monolayer adsorption both in the single adsorption process and in co-adsorption processes with Cd(Ⅱ). For comparison, Cd(Ⅱ) adsorbed onto goethite also demonstrated inner ring adsorption and monolayer adsorption during single adsorption, and As(Ⅴ)-Cd(Ⅱ) co-adsorption were transformed to outer ring adsorption and multilayer adsorption processes. Through analysis by Zeta potential, X-ray diffraction, and X-ray photoelectron spectroscopy, electrostatic adsorption and formation of ternary complexes (Fe-As-Cd) were proven to be the critical mechanisms in determining the interactions between As(Ⅴ) and Cd(Ⅱ) during their co-adsorption processes. The results obtained in this study should help us to further understand the micro-chemical interaction processes of heavy metals on the soil environment.
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http://dx.doi.org/10.13227/j.hjkx.202207194 | DOI Listing |
Ecotoxicol Environ Saf
January 2025
Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China. Electronic address:
Microorganisms that utilize organic matter to reduce Fe oxides/hydroxides constitute the primary geochemical processes controlling the formation of high-arsenic (As) groundwater. Biogenic secondary iron minerals play a significant role in As migration. However, the influence of quinone electron shuttles and competitive anionic phosphate on this process has not been thoroughly studied.
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January 2025
School of Environment and Energy, South China University of Technology, Guangzhou 510006, People's Republic of China.
The anionic species of antimony(V) and phosphate(V) are commonly found in the contaminated soil of mining areas, exerting a significant influence on the sorption of heavy metals and thus affecting their migration. This study quantitatively discussed the sorption mechanism of Sb and P in promoting the sorption of Cd or Cu on goethite through a series of extraction methods. In the single sorption system, the majority of Cu (87-98%) is adsorbed on goethite in the form of EDTA-extractable Cu (EF Cu, possibly inner-sphere complexes) under pH conditions of 3.
View Article and Find Full Text PDFJ Colloid Interface Sci
April 2025
MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China. Electronic address:
The natural minerals with semiconducting properties possess photochemical activity through generating reactive oxygen species (ROSs) and affect the fate of adsorbed organic pollutants. Iron oxyhydroxides occur in different polymorphic structures under various geological and climatic conditions in natural environment. However, the difference in their photoactivity has not been well understood.
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December 2024
Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States.
J Hazard Mater
January 2025
Department of Environmental Geochemistry, IRNASA (CSIC), C/ Cordel de Merinas 40-52, Salamanca 37008, Spain. Electronic address:
This study explored the feasibility of depositing protective coatings with an Sb scavenger function on mine waste rocks derived from the exploitation of stibnite deposits. Encapsulation treatments were performed using ferrous sulfate as the coating precursor. Different Fe/Sb molar ratios (0.
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