文章基本信息

标题：Waste shrimp shell-derived hydrochar as an emergent material for methyl orange removal in aqueous solutions
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作者：Chao He ; Hengliang Lin ; Leilei Dai 等
期刊名称：Environment International
印刷版ISSN：0160-4120
电子版ISSN：1873-6750
出版年度：2020
卷号：134
页码：1-9
DOI：10.1016/j.envint.2019.105340
出版社：Pergamon
摘要：Shrimp processing and consumption generate large amounts of waste shrimp shell (WSS) rich in chitin and protein. Herein, we successfully synthesized WSS-based hydrochar (WSH) adsorbent through deproteinization and deacetylation followed by hydrothermal carbonization (HTC) and acid washing. For comparison, another hydrochar (CCH) adsorbent was synthesized from HTC of commercial chitosan under identical conditions. Specifically, WSH contained rich nitrogen-containing functional groups with a long aliphatic chains structure. Acid etching of calcium carbonate in WSS led to a higher specific surface area of WSH (12.65 m2/g) which was nearly 6 times higher than that of CCH (2.13 m2/g). The lower deacetylation degree of WSH was responsible for higher amide I and amino groups retained therein. Under an optimal initial solution pH of 4.0, WSH could rapidly achieve a superb adsorption capacity of 755.08 mg/g for methyl orange molecule. Moreover, the adsorption process followed a pseudo-second-order kinetics model and was well described by a monolayer adsorption pattern based on the Langmuir isotherm model with correlation coefficients higher than 0.9989. Prominent adsorption performance of WSH for methyl orange was mainly attributed to electrostatic interactions, while steric hindrance effect had a detrimental impact on the adsorption capacity of CCH. Superb adsorption capacity and excellent regeneration performance suggest WSH could be a promising and affordable adsorbent candidate for anionic dye removal.
关键词：N-containing functional groups ; Biochar ; Chitosan ; Adsorption isotherm ; Electrostatic interaction ; Steric hindrance