A novel calcium-based magnetic biochar (Ca-MBC), made by pyrolyzing the mixture of rice straw, iron oxide (FeO) and calcium carbonate (CaCO), was developed in this study for remediation of co-pollution of arsenic and cadmium. Characteristics of the material showed that FeO and CaCO were adhered on the surface of biochar. The experiments on the effects of pH, adsorption kinetics and isotherm revealed that the Ca-MBC had a great ability to adsorb arsenic and cadmium within 0.5 h for cadmium and 12 h for arsenic with a maximum adsorption capacity of 6.34 and 10.07 mg g, respectively, and that the adsorption of both metals was pH-dependent from 2 to 12 with an optimal pH of pH 5. The mechanism of co-adsorption of Cd(II) and As(III) included both competitive and synergistic effects. The presence of As(III) enhanced Cd(II) adsorption by 3-16% while Cd(II) addition suppressed As(III) adsorption by 15-33%. The synergistic effects on As(III) and Cd(II) adsorption had resulted from the electrostatic interaction and the formation of type B ternary surface complexes. These new insights provide valuable information for the application of Ca-MBC as a potential adsorbent in treatment of water contaminated with As(III) and Cd(II).
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http://dx.doi.org/10.1016/j.jhazmat.2018.01.011 | 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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