engleski

Adsorption of arsenic on MgAl layered double hydroxide

Groundwater in the Eastern Croatia, as well in the South-eastern Hungary, contains relatively high concentrations of arsenic that can cause chronic As toxicity to humans. Therefore, the aim to engineer an effective composite sorbent that can be applied for arsenic water remediation by installing it in the groundwater is very important. The presented results are obtained in the frame of the NATO collaborative linkage grant Advanced Techniques for Arsenic Removal from Water related to the abovementioned problem. As sorbing system, layered double hydroxide (LDH) was used. MgAl LDH samples with a Mg:Al molar ratio of 2:1 were synthesized in nitrate form at pH values of 9.1, 9.6, 11.2 and 13.1. As a consequence of synthesis in air, at increasing pH values increasingly higher amounts of carbonate anions are incorporated into the interlamellar space. Adsorption of arsenic from groundwater samples from Slavonia region, as well as adsorption of commercially obtained arsenic samples, on MgAl layered double hydroxide was investigated. Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for determination of arsenic concentration after adsorption. It was shown that in both cases the adsorption process could be interpreted in terms of Kroeker adsorption isotherm regardless to the presence of other ions in the groundwater. Additionally, the influence of phosphate concentration on adsorption of commercially obtained arsenic samples was examined and it was shown that (at least in examined range of arsenic and phosphate concentration) there is no significant influence of phosphate on arsenic adsorption.

Adsorption ; arsenic ; MgAl layered double hydroxides

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