adsorption behavior of cu(ii) in aqueous solutions by sqd-85 resin

the adsorption and desorption properties of sqd-85 resin for cu(ii) had been investigated. a series of experiments were conducted in a batch system to assess the effect of the system variables, i.e. initial ph, contact time and temperature. the results show that the optimal ph for the adsorption was 5.99 in the hac-naac system, and the maximum adsorption capacity was estimated to 324 mg/g at 298 k. the apparent activation energy ea and adsorption rate constant k298k values were 6.19 kj/mol and 9.73×10−5 s−1 , respectively. the isotherms of adsorption data fitted well to langmuir model. thermodynamic parameters (δg, δs, δh) suggested that cu(ii) adsorption by sqd-85 resin was endothermic and spontaneous in nature. thomas model was applied to determine the characteristic parameters of column useful for process design. desorption studies revealed that cu(ii) ion could be eluted with 1.0 mol/l hcl solution., which indicated that cu(ii) in aqueous solution could be removed and recovered by sqd-85 resin efficiently. adsorption mechanism was also proposed for the adsorption of cu(ii) onto sqd-85 resin using ft-ir spectrometry technique.