Removal of malachite green from aqueous solutions by electrocoagulation/peanut shell adsorption coupling in a batch system.

A electrocoagulation (EC)/peanut shell (PS) adsorption coupling technique was studied for the removal of malachite green (MG) in our present work. The addition of an appropriate PS dosage (5 g/L) resulted in remarkable increase in the removal efficiency of MG at lower current density and shorter operating time compared with the conventional EC process. The effect of current density, pH of MG solution, dosage of PS and initial concentration of MG were also investigated. The maximum removal efficiency of MG was 98% under optimum conditions in 5 min. And it was 23% higher than that in EC process. Furthermore, the unit energy demand (UED) and the unit electrode material demand (UEMD) were calculated and discussed. The results demonstrated that the EC/PS adsorption coupling method achieved a reduction of 94% UED and UEMD compared with EC process.