Treatment of Cadmium(I)-Rich Effluents (Kinetic Modelling and Mass Transfer)

Abstract
Removal of Cd(II) by sorption on China clay has been investigated. Removal increased from 41.0 to 80.3% by decreasing the cadmium concentration from 2.0 × 10−4 M to 0.5 × 10−4 M at pH = 6.5 and 30°C. Kinetic modelling of the process has been done using Lagergren's first-order rate equation. The rate of adsorption at pH = 6.5 and 30°C was found to be 5.0 × 10−2 min−1. The process of removal involves intraparticle diffusion. Mass transfer parameters have been calculated; the process is exothermic in nature. Studies with representative wastewater samples from plating units have also been undertaken.