A novel lignin-based hierarchical porous carbon for efficient and selective removal of Cr(VI) from wastewater

• Published in: International journal of biological macromolecules 2022-04, Vol.204, p.310-320
• Main Authors: Liang, Hongxu, Ding, Wei, Zhang, Hongwei, Peng, Pai, Peng, Feng, Geng, Zengchao, She, Diao, Li, Yan
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon; Chromium - chemistry; Cr(VI); Hydrogen-Ion Concentration; Kinetics; Lignin; Lignin-based; Porosity; Waste Water - chemistry; Water Pollutants, Chemical - chemistry; Water Purification
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2022.02.014

A novel lignin-based hierarchical porous carbon (L-HPC) was prepared to remove Cr(VI) from water by using industrial alkali lignin through simple hydrothermal-induced assembly and alkali activation strategy. The adsorbent were characterized by SEM-EDS mapping, TEM, BET, XPS, FTIR, Raman spectroscopy and zeta potential. The characterization results indicated that L-HPC contained three-dimensional connected channels and many adsorbing N, O and other adsorption groups, which is very beneficial for Cr(VI) adsorption. The kinetics showed that the L-HPC adsorption of Cr(VI) was chemical adsorption and mainly controlled by intraparticle diffusion. The isotherm and thermodynamics indicated that L-HPC adsorption of Cr(VI) conforms to the Freundlich model, L-HPC is a kind of multimolecular layer adsorbent, and the adsorption capacity of Cr(VI) by L-HPC was 887.8 mg/g, which was significantly higher than values for other adsorbents. Ion competition simulation and actual water body tests showed that L-HPC exhibits high selectivity for Cr(VI) adsorption, adsorption cycle experiments show that L-HPC maintains over 83% performance after 12 cycles. Cost analysis shows that L-HPC is suitable for mass production. Therefore, L-HPC is a Cr(VI) adsorbent with high efficiency, high selectivity, and high reusability, which is broadly applicable and shows favorable prospects. •A novel lignin-based hierarchical porous carbon were prepared.•The maximum adsorption capacity of L-HPC for Cr(VI) was 887.8 mg/g.•The adsorption mechanism of Cr(VI) by L-HPC was investigated.•L-HPC has high selective adsorption ability for Cr(VI).•L-HPC maintains 83.78% adsorption capacity after 12 regeneration cycles.