不同环境条件下生物炭对水中Cr(VI)离子的吸附与解吸

Sorption and desorption of Cr(VI) ions from water by biochars in different environmental conditions.

作者信息

Tytłak Aleksandra, Oleszczuk Patryk, Dobrowolski Ryszard

机构信息

Department of Environmental Chemistry, Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie-Skłodowska Square 3, 20-031, Lublin, Poland.

出版信息

Environ Sci Pollut Res Int. 2015 Apr;22(8):5985-94. doi: 10.1007/s11356-014-3752-4. Epub 2014 Nov 8.

DOI:10.1007/s11356-014-3752-4

PMID:25378029

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4381096/

Abstract

In the present research, the potential of two biochars produced by the thermal decomposition of wheat straw (BCS) and wicker (BCW) for Cr(VI) ions removing from wastewater was investigated. The pH and the presence of chlorides and nitrates were also investigated. The Freundlich and Langmuir models were applied for the characterization of adsorption isotherms. The Langmuir model has better fitting of adsorption isotherms than the Freundlich model. The sorption process can be described by the pseudo second-order equation. The optimal adsorption capacities were obtained at pH 2 and were 24.6 and 23.6 mg/g for BCS and BCW, respectively. X-ray photoelectron spectroscopy (XPS) studies confirmed that Cr(III) ions were the most abundant chromium species on the biochars' surface. The results indicated that the sorption mechanism of Cr(VI) on biochar involves anionic and cationic adsorption combined with Cr(VI) species reduction.

摘要

在本研究中，对通过小麦秸秆热解产生的两种生物炭（BCS）和柳条热解产生的生物炭（BCW）从废水中去除六价铬离子的潜力进行了研究。还研究了pH值以及氯化物和硝酸盐的存在情况。应用弗伦德利希模型和朗缪尔模型对吸附等温线进行表征。朗缪尔模型对吸附等温线的拟合比弗伦德利希模型更好。吸附过程可用伪二级方程描述。在pH为2时获得了最佳吸附容量，BCS和BCW的最佳吸附容量分别为24.6和23.6 mg/g。X射线光电子能谱（XPS）研究证实，三价铬离子是生物炭表面最丰富的铬物种。结果表明，六价铬在生物炭上的吸附机制涉及阴离子和阳离子吸附以及六价铬物种的还原。