Affiliations: School of Environmental Science and Engineering,
Shandong University, Jinan 250100, China | State Key Laboratory of Environmental Aquatic
Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of
Sciences, Beijing 100085, China | Key Laboratory of Colloid and Interface Science of
Education Ministry, Shandong University, Jinan 250100, China
Abstract: A hydrotalcite with Mg/Al molar ratio 2 was prepared by
co-precipitation method and was characterized by XRD, TG/DTA, Zeta potential
and BET surface area. The hydrotalcite was calcined at 500°C, with the
dehydration from interlayer, the dehydroxilation from the brucite-like layer
and the decomposition of carbonate successively, transformed into the mixed
oxide type. The removal of thiocyanate from aqueous solution by using the
original hydrotalcite and calcined hydrotalcite (HTC-500) was investigated. The
results showed that the thiocyanate adsorption capacity of calcined
hydrotalcite was much higher than that of the original form. Calcined
hydrotalcite was particularly effective at removing thiocyanate, and that the
effective range of pH for the thiocyanate removal are between 5.5–10.0.
The experimental data of thiocyanate removal fit nicely with Langmuir isotherm,
and the saturated adsorption uptake was 96.2 mg SCN^-/g
HTC-500. The adsorption ofthiocyanate by calcined hydrotalcite follows
first-order kinetics. And the intercalation to the structure recovery for
calcined hydrotalcite. But the presence of additional anions could affect the
adsorption behavior of thiocyanate.
