Abstract

Bentonite minerals of Rajmahal Hills and Hazaribagh district along with their derivatives have been used to remove hexavalent chromium and manganese from aqueous medium. Bentonites are smectite group of minerals having swelling power and cation exchange properties. Blue colour with benzidine solution indicates the presence of montmorillonite unit having SiO₂, Al₂O₃, K₂O, Fe₂O₃, FeO and traces of TiO₂ also. The adsorption isotherm and removal performance of hexavalent chromium and manganese have been examined by shaking 100 mL 2 ppm solution with 1 gram of bentonite and their derivatives up to different intervals of time and also with varying amount of bentonite up to fixed time intervals. The percentage removal of chromium (VI) ranges from 12% to 67.7% whereas percentage removal of manganese (VII) varies from 09% to 92.5%. Experimental data showed that the removal of Cr (VI) and Mn (VII) represented both Freundlich and Langmuir adsorption isotherms. Adsorption of Cr (VI) and Mn (VII) on to bentonites and their derivatives follow first-order kinetics. It is concluded that locally available bentonites may be exploited as a low-cost feasible adsorbent for removal of Cr (VI) and Mn (VII) in the laboratory as well as industrial level too.

Graphic abstract

Bentonite minerals of Rajmahal Hills and Hazaribagh district along with their derivatives have been used to remove hexavalent chromium and manganese from aqueous medium. The adsorption isotherm and removal performance of hexavalent chromium and manganese have been examined by shaking 100 mL 2 ppm solution with 1 gram of bentonite and their derivatives up to different intervals of time and also with varying amount of bentonite up to fixed time intervals. Percentage removal of chromium (VI) ranges from 12% to 67.7% whereas percentage removal of manganese (VII) varies from 09% to 92.5%. Experimental data showed that removal of Cr (VI) and Mn (VII) represented both Freundlich and Langmuir adsorption isotherms.

中文翻译：

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使用膨润土及其衍生物从水性介质中去除Cr和Mn

摘要

Rajmahal Hills和Hazaribagh区的膨润土矿物及其衍生物已用于去除水性介质中的六价铬和锰。膨润土是具有膨胀力和阳离子交换性质的绿土类矿物。带有联苯胺溶液的蓝色表示存在具有SiO ₂，Al ₂ O ₃，K ₂ O，Fe ₂ O ₃，FeO和痕量TiO ₂的蒙脱石单元也。通过将100 mL 2 ppm溶液与1克膨润土及其衍生物摇晃至不同的时间间隔，并以变化的数量的膨润土直至固定的时间间隔，对六价铬和锰的吸附等温线和去除性能进行了测试。铬（VI）的去除百分比范围为12％至67.7％，而锰（VII）的去除百分比范围为09％至92.5％。实验数据表明，Cr（VI）和Mn（VII）的去除代表了Freundlich和Langmuir吸附等温线。膨润土及其衍生物对Cr（VI）和Mn（VII）的吸附遵循一级动力学。结论是，本地可用的膨润土可作为一种低成本可行的吸附剂，在实验室以及工业水平上用于去除Cr（VI）和Mn（VII）。

图形摘要

Rajmahal Hills和Hazaribagh区的膨润土矿物及其衍生物已用于去除水性介质中的六价铬和锰。通过将100 mL 2 ppm溶液与1克膨润土及其衍生物摇晃至不同的时间间隔，并以不同数量的膨润土摇晃至固定的时间间隔，来检查六价铬和锰的吸附等温线和去除性能。铬（VI）的去除率范围为12％至67.7％，而锰（VII）的去除率范围为09％至92.5％。实验数据表明，去除Cr（VI）和Mn（VII）代表了Freundlich和Langmuir吸附等温线。