Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Modified and pristine biochars for remediation of chromium contamination in soil and aquatic systems
AU - El-Naggar, Ali
AU - Mosa, Ahmed
AU - Ahmed, Naveed
AU - Niazi, Nabeel Khan
AU - Yousaf, Balal
AU - Sarkar, Binoy
AU - Rinklebe, Jörg
AU - Cai, Yanjiang
AU - Chang, Scott X
PY - 2022/9/1
Y1 - 2022/9/1
N2 - Chromium (Cr) contamination in soil and water poses high toxicity risks to organisms and threatens food and water security worldwide. Biochar has emerged as a promising material for cleaning up Cr contamination owing to biochar's strong capacity to immobilize Cr. This paper synthesizes information on biochar modification for the efficient remediation of Cr contamination in soil and water, and critically reviews mechanisms of Cr adsorption on pristine and modified biochars. Biochar modification methods include physical activation via ball milling or ultraviolet irradiation, chemical activation via magnetization, alkali/acid treatment, nano-fabrication or loading of reductive agents, and biological activation via integrating biochars with microorganisms and their metabolites. Modified biochars often have multi-fold enhancement in Cr adsorption/reduction capacity than pristine biochars. Iron (Fe)-supported magnetic biochars have the most promising Cr removal abilities with high reusability of the biochars. Pre-pyrolysis modification with Fe could load Fe 3O 4 micro-/nanoparticles on biochars, and increase the surface area and electrostatic attraction between chromate anions and biochar surfaces, and reduce Cr(VI) to Cr(III). Post-pyrolysis modification could enrich oxygen-containing functional groups such as CO and -OH on biochar surfaces and promote Cr reduction and adsorption. Future research directions for Cr mitigation using advanced biochar products are discussed in this review.
AB - Chromium (Cr) contamination in soil and water poses high toxicity risks to organisms and threatens food and water security worldwide. Biochar has emerged as a promising material for cleaning up Cr contamination owing to biochar's strong capacity to immobilize Cr. This paper synthesizes information on biochar modification for the efficient remediation of Cr contamination in soil and water, and critically reviews mechanisms of Cr adsorption on pristine and modified biochars. Biochar modification methods include physical activation via ball milling or ultraviolet irradiation, chemical activation via magnetization, alkali/acid treatment, nano-fabrication or loading of reductive agents, and biological activation via integrating biochars with microorganisms and their metabolites. Modified biochars often have multi-fold enhancement in Cr adsorption/reduction capacity than pristine biochars. Iron (Fe)-supported magnetic biochars have the most promising Cr removal abilities with high reusability of the biochars. Pre-pyrolysis modification with Fe could load Fe 3O 4 micro-/nanoparticles on biochars, and increase the surface area and electrostatic attraction between chromate anions and biochar surfaces, and reduce Cr(VI) to Cr(III). Post-pyrolysis modification could enrich oxygen-containing functional groups such as CO and -OH on biochar surfaces and promote Cr reduction and adsorption. Future research directions for Cr mitigation using advanced biochar products are discussed in this review.
KW - Charcoal
KW - Biochar modification
KW - Immobilization
KW - Toxic trace elements
KW - Hexavalent chromium
KW - Sorption
U2 - 10.1016/j.chemosphere.2022.134942
DO - 10.1016/j.chemosphere.2022.134942
M3 - Journal article
C2 - 35577128
VL - 303
SP - 134942
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
IS - Pt 1
M1 - 134942
ER -