Details

Autor(en) / Beteiligte

• Wu, Zhengde
• Zhao, Chen
• Zeng, Wengen
• Wang, Ximo
• Liu, Chuanfu
• Yu, Zhongye
• Zhang, Jian
• Qiu, Zumin

Titel

Ultra-high selective removal of CR and Cr(VI) from aqueous solutions using polyethyleneimine functionalized magnetic hydrochar: Application strategy and mechanisms insight

Ist Teil von

• Chemical engineering journal (Lausanne, Switzerland : 1996), 2022-11, Vol.448, p.137464, Article 137464

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •PEI functionalized magnetic hydrochar (MHTCP-5) with easy recovery was fabricated via an easy and effective approach.•The ultra-high selectivity of PEI for both CR and Cr(VI) ions was first proposed in this study.•MHTCP-5 can dramatically shorten the time required for Cr(VI) removal (<5 min).•MHTCP-5 can effectively reduce the concentration of Cr(VI) below WHO standard for drinking water (0.05 mg/L).•The adsorption-reduction mechanisms of CR and Cr(VI) on MHTCP-5 were systematically investigated. Herein, a novel polyethyleneimine (PEI) functionalized magnetic hydrochar (MHTCP-5) adsorbent with low cost and easy recovery is unveiled, which exhibits excellent adsorption capacity for CR and Cr(VI) from aqueous solution. And the maximum adsorption capacities are respectively 1019.2 and 287.7 mg/g, exceeding those of most previously reported biochar-based adsorbents. Surprisingly, MHTCP-5 possesses ultra-high selectivity for both CR and Cr(VI) from mixed solutions, which was the first time proposed in this study. In addition, a series of adsorption experiments are conducted under different conditions to investigate the adsorption behavior of MHTCP-5. The results suggest that the adsorption of CR and Cr(VI) onto MHTCP-5 followed Elovich and Freundlich models, and the surfactants have a significant influence on the adsorption capacity due to electrostatic interactions. Moreover, MHTCP-5 exhibits extremely fast adsorption rate for Cr(VI) ions, which can reduce the Cr(VI) concentration below WHO allowable value (0.05 mg/L) for drinking water within only 5 min, and the cycle experiments manifest that MHTCP-5 still exhibits excellent Cr(VI) adsorption capacity after 17 cycles. The adsorption-reduction mechanisms of CR and Cr(VI) onto MHTCP-5 are systematically investigated based on FT-IR and XPS. Additionally, the outstanding removal efficiency of CR and Cr(VI) in simulated wastewater as well as the superior reusability and fixed-bed column adsorption capacity of MHTCP-5 adsorbent indicate that the adsorbent has great potential in the treatment of actual wastewater containing CR and Cr(VI).