Concurrent adsorption and reduction of chromium(VI) to chromium(III) using nitrogen-doped porous carbon adsorbent derived from loofah sponge

被引：0

作者：

Chen Feng ^{[1
]}

Guo Shihao ^{[1
]}

Wang Yihao ^{[1
]}

Ma Lulu ^{[1
]}

Li Bing ^{[1
]}

Song Zhimin ^{[1
]}

Huang Lei ^{[2
,3
]}

Zhang Wen ^{[4
]}

机构：

[1] School of Environmental and Biological Engineering, Henan University of Engineering, Zhengzhou , China

[2] School of Environmental Science and Engineering, Guangzhou University, Guangzhou , China

[3] Guangzhou University-Link?ping University Research Center on Urban Sustainable Development, Guangzhou University, Guangzhou , China

[4] John A Reif, Jr Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ , USA

来源：

Frontiers of Environmental Science & Engineering | 2022年 / 16卷 / 05期

关键词：

Chromium(VI); Nitrogen-doped porous carbon; Adsorption; Reduction; Loofah sponge;

D O I：

暂无

中图分类号：

TQ424 [吸附剂]; X505 [环境污染防治方法与设备];

学科分类号：

0817 ; 071012 ; 0713 ; 083002 ;

摘要：

· A high-efficiency N-doped porous carbon adsorbent for Cr(VI) was synthesized.· The maximum adsorption capacity of Cr(VI) reached up to 285.71 mg/g at 318K.· The potential mechanism for Cr(VI) adsorption by NHPC was put forward.· DFT analyzed the adsorption energy and interaction between NHPC and Cr(VI).To develop highly effective adsorbents for chromium removal, a nitrogen-doped biomass-derived carbon (NHPC) was synthesized via direct carbonation of loofah sponge followed by alkali activation and doping modification. NHPC possessed a hierarchical micro-/mesoporous lamellar structure with nitrogen-containing functional groups (1.33 at%), specific surface area (1792.47 m2/g), and pore volume (1.18 cm3/g). NHPC exhibited a higher Cr(VI) adsorption affinity than the HPC (without nitrogen doping) or the pristine loofah sponge carbon (LSC) did. The influence of process parameters, including pH, dosage, time, temperature, and Cr(VI) concentration, on Cr(VI) adsorption by NHPC were evaluated. The Cr(VI) adsorption kinetics matched with the pseudo-second-order model (R2≥0.9983). The Cr(VI) adsorption isotherm was fitted with the Langmuir isotherm model, which indicated the maximum Cr(VI) adsorption capacities: 227.27, 238.10, and 285.71 mg/g at 298K, 308K, and 318K, respectively. The model analysis also indicated that adsorption of Cr(VI) on NHPC was a spontaneous, endothermal, and entropy-increasing process. The Cr(VI) adsorption process potentially involved mixed reductive and adsorbed mechanism. Furthermore, computational chemistry calculations revealed that the adsorption energy between NHPC and Cr(VI) (?0.84 eV) was lower than that of HPC (?0.51 eV), suggesting that nitrogen doping could greatly enhance the interaction between NHPC and Cr(VI).

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