Details

Autor(en) / Beteiligte

• Liu, Chen
• Zhang, He-Xin

Titel

Modified-biochar adsorbents (MBAs) for heavy-metal ions adsorption: A critical review

Ist Teil von

• Journal of environmental chemical engineering, 2022-04, Vol.10 (2), p.107393, Article 107393

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• With the rapid growth of new-energy batteries and metallurgical industry, water pollution caused by toxic heavy-metals from these sectors has increased to a new level, which is seriously threating the eco-system and human health. Thus, the effective disposal of metal-bearing water has become a vital requirement. To resolve such a problem, developing eco-friendly biochar-based adsorbents has become urgent. As an eco-friendly material, biochar has attracted increasingly attention due to its low-cost, high surface area and abundant functional groups. However, pristine biochar also shows low adsorption efficiency for heavy-metals. Consequently, improving its adsorption efficiency via modification is considered as one of most effective techniques. In the last 15 years, various methods were proposed to modify biochar. However, review articles on the usage of modified-biochars for heavy-metals adsorption are unavailable. To summarize these newly-developed modification methods including organic-modified, nonmetal-modified, metal-modified, metal/organic-modified, and metal/mineral-modified, this review will focus on the preparation, characterizations and applications of modified-biochar adsorbents (MBAs) for heavy-metals. More emphasis will be on the adsorption of MBAs for heavy-metals in a single-metal, mixed multi-metal, and mixed metal/organic matter solution systems. Meanwhile, the adsorption mechanism of MBAs for Cr(VI), Cd (II), Pb(II) and Cu(II) will be highlighted. It is found that the adsorption mechanism of MBAs in different mixed multi-metal solution systems is complicated and competitive adsorption is inevitable. Typically, the effect of functional groups from MBAs on heavy-metals adsorption is diverse, more studies are required in the future. Finally, the present state and future perspective will be discussed. [Display omitted] •Modified-biochar for heavy-metals adsorption in various systems was reviewed.•Competition among heavy-metals in mixed multi-metal system is a key process.•Functional groups on MBAs surface play a key role in heavy-metals adsorption.•Biochar modification is a vital way to rise its sorption ability for heavy-metals.•Adsorption mechanism of MBAs for heavy-metals in mixed solution system is diverse.