Abstract
This study introduced a new approach for simultaneously enhancing Cr(VI) removal performance and mitigating release of dissolved Fe during nanoscale zero-valent iron (nZVI)-mediated reactions. After entrapping nZVI-impregnated biochar (BC) in the matrix of calcium-alginate (CA) bead, the physicochemical characterization of nZVI/BC/CA composites revealed that nZVI/BC particles were embedded inside CA having a spherical shape and several cracks on its outer layer. The multi-functionality of nZVI/BC/CA composites consisting of reductant (nZVI), porous adsorbent (BC), and external screening layer (CA) enhanced the removal of Cr(VI) with the maximum adsorption capacity of 86.4 mg/g (based on the Langmuir isotherm) and little release of dissolved Fe. With the XPS analysis and fitting results of kinetics (pseudo second order) and isotherms (Redlich-Peterson model), plausible removal mechanisms of Cr(VI) were simultaneous adsorption and micro-electrolysis reactions by nZVI/BC/CA composites. The practical applicability of nZVI/BC/CA composites was further demonstrated through the fixed-bed column experiments. These results provide new insights into the design of high-performance engineered biochar for wastewater treatment.
Original language | English |
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Pages (from-to) | 410-420 |
Number of pages | 11 |
Journal | Environmental Pollution |
Volume | 247 |
DOIs | |
Publication status | Published - Apr 2019 |
Keywords
- Engineered biochar
- Green/sustainable remediation
- Hexavalent chromium
- Metal-biochar composite
- Solid-supported nZVI
ASJC Scopus subject areas
- Toxicology
- Pollution
- Health, Toxicology and Mutagenesis