Enhanced aqueous Cr(VI) removal using chitosan-modified magnetic biochars derived from bamboo residues
Enhanced aqueous Cr(VI) removal using chitosan-modified magnetic biochars derived from bamboo residues
复制标题
使用源自竹渣的壳聚糖改性磁性生物炭增强水相 Cr(VI) 去除率
DOI：
10.1016/j.chemosphere.2020.127694
复制
发表时间：
2020
期刊：
影响因子：
8.8
通讯作者：
Zhang Zengqiang
中科院分区：
文献类型：
--
作者：
Zhang Han;Xiao Ran;Li Ronghua;Ali Amjad;Chen Anle;Zhang Zengqiang
本研究的目的是制备壳聚糖修饰的磁性竹生物炭（CMBB），用于水溶液中Cr（VI）的脱毒。结果表明，壳聚糖改性在磁性竹生物炭（MBB）表面提供了更多的活性吸附位点，从而增强了对水溶液中Cr（VI）的去除。MBB和CMBB在25℃时对Cr（VI）的最大吸附量分别为75.8和127 mg g（-1）。增加溶液pH可抑制吸附剂对Cr（VI）的吸附。然而，CMBB在较宽的pH范围内（2-10）保持较高的Cr（VI）去除效率，即使在10.0的高pH下也能达到最大吸附量（40 mg g(-1)）的36%。温度升高对两种吸附剂对Cr（VI）的去除有促进作用。Na+、Ca2+、Fe3+、Cl-、SO42-、PO43-、腐植酸等离子强度升高和共存物质抑制了吸附剂对Cr（VI）的吸附效率。在第5次吸附-解吸循环后，CMBB和MBB对Cr（VI）的吸附效率分别保持在90%以上和50%以下。这些结果表明，CMBB可作为一种实用的吸附剂，用于废水中Cr（VI）离子的脱毒。(C) 2020 Elsevier Ltd.版权所有。
The purpose of this study was to fabricate a chitosan modified magnetic bamboo biochar (CMBB) for Cr(VI) detoxification from aqueous solution. Results showed that chitosan modification provided more active adsorption sites on the surface of magnetic bamboo biochar (MBB), and hence enhanced Cr(VI) removal from aqueous solution. The maximum adsorption capacities of MBB and CMBB for Cr(VI) at 25 degrees C were 75.8 and 127 mg g(-1), respectively. Increasing solution pH inbibited Cr(VI) adsorption by adsorbents. However, CMBB maintained a high Cr(VI) removal efficiencies over a broader pH range (2-10), and could attain 36% of the maximum adsorption (40 mg g(-1)) even at a high pH of 10.0. Rising temperature enhanced the Cr(VI) removal by two adsorbents. The escalating ionic strength and coexist substances, including Na+, Ca2+, Fe3+, Cl-, SO42-, PO43- and humate, inhibited the adsorption efficiency of Cr(VI) on adsorbents. After the fifth adsorption-desorption cycle, the adsorption efficiencies of CMBB and MBB for Cr(VI) remained above 90% and less than 50%, respectively. All these results indicated that CMBB could be a practical adsorbent that can be utilized for the detoxification of Cr(VI) ions from wastewater. (C) 2020 Elsevier Ltd. All rights reserved.