A high removal rate (>99.7%) of combined arsenite (As(III)) and Cd (Cd(II)) in low concentration (1000 μg/L) from contaminated water was achieved by a calcined MgZnFe-CO layered double hydroxide (CMZF) adsorbent. Batch control studies and a series of spectroscopy detection technologies were employed to investigate the removal mechanism and interactions between As(III) and Cd(II) on the interface of water/CMZF. Synergistic adsorption and photooxidation occurred based on the systematical kinetic and isotherm studies. The enhanced removal of As(III) was achieved by the photooxidation, formation of ternary As(III)Cd(II) surface complexes and enhanced hydrogen bond. Meanwhile, oxidative formed negative charged As(V) could reduce the electrostatic repulsion force between Cd(II) cations and play a role as anion bridging, consequently resulted in a stronger attraction between CMZF and Cd(II). Combined with the verdicts of relevant characterizations such as XRD, XPS and EPR, it was assumed that the deep co-removal mechanism could be attributed to the coupling of various processes including intercalation, complexation, photooxidation of As(III) and precipitation of CdCO. Moreover, the successful removal of As(III) and Cd(II) from real water matrix qualified the CMZF a potentially attractive adsorbent for both As(III) and Cd(II) deep treatment in practical engineering.
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http://dx.doi.org/10.1016/j.chemosphere.2019.03.009 | DOI Listing |
Talanta
January 2025
Residues and Resource Reclamation Centre (R3C), Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore. Electronic address:
Heavy metals and metalloids are the most common environmental pollutants. Toxicity characteristic leaching procedure (TCLP) is a standard operating procedure that is used to assess heavy metal and metalloid compositions, and evaluate the hazardous nature of waste and waste-derived materials for reuse or disposal, such as determining landfill suitability. However, TCLP and the following detections are time-consuming and require bulky laboratory-based instruments and trained personnel.
View Article and Find Full Text PDFHuan Jing Ke Xue
January 2025
College of Environmental and Resource Sciences, Zhejiang A&F University, Lin'an 311300, China.
Cadmium (Cd) and arsenic (As) often coexist in water and agricultural soils around mining areas, and it is difficult to remove them at the same time due to their opposite chemical behaviors. Therefore, this study employed a co-precipitation-pyrolysis method to synthesize silica-based magnetic biochar (SMB) materials for the remediation of water contaminated with both Cd and As. The optimization of preparation conditions involved introducing three different types of silicates (NaSiO, CaSiO,and SiO) into the biomass-magnetite mixture, followed by pyrolysis at various temperatures (300℃, 500℃, and 700℃), and the optimal preparation conditions were determined based on the composite batch experiments.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Korea Biochar Research Center, Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Korea.
Pristine or modified nanoscale zero-valent iron (nZVI) synthesized though conventional chemical reduction have been widely recommended for remediating metal(loid)-contaminated water. However, their eco-friendliness is often challenged with the concomitant bio-toxicity and secondary environmental risks. Alternatively, this study utilized waste tea leaves extract and remaining residue as the reducing agent and pyrolytic matrix to innovatively fabricate a green synthesized nZVI impregnated tea residue biochar (G-nZVI/TB).
View Article and Find Full Text PDFEnviron Sci Process Impacts
December 2024
School of Chemistry and Chemical Engineering, University of Surrey, Guildford, Surrey GU2 7XH, UK.
J Environ Manage
November 2024
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
An iron-manganese sludge-derived amendment was proposed to remediate arsenic (As) and cadmium (Cd) co-contaminated soil, with a strong adsorptive capacity across pH 4 to 10. The Langmuir model defined maximum adsorption at 78.17 mg/g for As(III), 110.
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