title: Adsorption removal of thiocyanate from aqueous solution by calcined hydrotalcite.
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 degrees 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 of thiocyanate 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.
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan 250100, China. yujiang@sdu.edu.cn
authors.forename: Yu-Jiang
authors.initials: YJ
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Xiao-Jin
authors.initials: XJ
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.forename: Nan
authors.initials: N
authors.lastname: Cao
authors.forename: Na
authors.initials: N
authors.lastname: Wei
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Bi
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D007700:Kinetics; D008276:Magnesium Hydroxide / Q000737:chemistry*; D013861:Thiocyanates / Q000302:isolation & purification*; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D013861:Thiocyanates; D014867:Water; C010467:hydrotalcite; D000536:Aluminum Hydroxide; D008276:Magnesium Hydroxide