Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Inorganically modified clay minerals
T2 - Preparation, characterization, and arsenic adsorption in contaminated water and soil
AU - Mukhopadhyay, Raj
AU - Manjaiah, K.M.
AU - Datta, S.C.
AU - Yadav, R.K.
AU - Sarkar, Binoy
PY - 2017/10/1
Y1 - 2017/10/1
N2 - The use of modified clay minerals for adsorbing arsenic (As) in contaminated soils is an underexplored area of research. The adsorption behavior of As onto inorganically modified smectite and kaolinite both in aqueous and soil media was studied. X-ray diffraction, infra-red spectroscopy, scanning and transmission electron microscopy studies confirmed successful modification of smectite through Fe-exchange and Ti-pillaring, and kaolinite through phosphate binding. The modified smectites were more efficient than phosphate-bound kaolinite in adsorbing As both in water and soil systems. Kinetic study revealed that the clay products reached adsorption equilibrium within 3 h, and the data well fitted to the power function and simple Elovich equation (R2 > 0.90). The Freundlich isotherm model best described the As adsorption data (R2 > 0.86) of the modified clay products in both the systems. The Ti-pillared smectite exhibited the highest As adsorption capacity (156.54 μg g− 1) in the aqueous medium, while the Fe-exchanged smectite was the best material in the soil system (115.63 μg g− 1). The partition coefficient (Kd) and adsorption efficiency (%) data also maintained the similar trend. Precipitation of As and binuclear complex formation also took place in the soil system which made the metalloid non-labile as the time passed. The inorganically modified clay products reported here hold a great potential to adsorb As in contaminated groundwater, drinking water as well as soil.
AB - The use of modified clay minerals for adsorbing arsenic (As) in contaminated soils is an underexplored area of research. The adsorption behavior of As onto inorganically modified smectite and kaolinite both in aqueous and soil media was studied. X-ray diffraction, infra-red spectroscopy, scanning and transmission electron microscopy studies confirmed successful modification of smectite through Fe-exchange and Ti-pillaring, and kaolinite through phosphate binding. The modified smectites were more efficient than phosphate-bound kaolinite in adsorbing As both in water and soil systems. Kinetic study revealed that the clay products reached adsorption equilibrium within 3 h, and the data well fitted to the power function and simple Elovich equation (R2 > 0.90). The Freundlich isotherm model best described the As adsorption data (R2 > 0.86) of the modified clay products in both the systems. The Ti-pillared smectite exhibited the highest As adsorption capacity (156.54 μg g− 1) in the aqueous medium, while the Fe-exchanged smectite was the best material in the soil system (115.63 μg g− 1). The partition coefficient (Kd) and adsorption efficiency (%) data also maintained the similar trend. Precipitation of As and binuclear complex formation also took place in the soil system which made the metalloid non-labile as the time passed. The inorganically modified clay products reported here hold a great potential to adsorb As in contaminated groundwater, drinking water as well as soil.
U2 - 10.1016/j.clay.2017.07.017
DO - 10.1016/j.clay.2017.07.017
M3 - Journal article
VL - 147
SP - 1
EP - 10
JO - Applied Clay Science
JF - Applied Clay Science
SN - 0169-1317
ER -