2011 Volume 52 Issue 2 Pages 224-228
The waste calcite, by-product of the carbonation reaction of flue gas desulfurization (FGD) gypsum, was evaluated as low-cost adsorbent for Cd(II) removal from wastewater. Batch experiments were performed in aqueous solution varying contact time, initial pH of Cd(II) solution, adsorbent dose, and Cd(II) concentration. The sorption rate of Cd(II) on the adsorbent was high during initial 1 h and decreased slowly reaching a plateau after about 12 h. The adsorption kinetics of Cd(II) could be best described by the pseudo-second order model while its isotherm was found to fit with the Langmuir model. The maximum adsorption capacity was 7.99 mg g−1. It is believed that waste calcite would be an addition to the list of low-cost adsorbents for Cd(II) removal in wastewater treatment.