Electrocoagulation using commercial grade aluminium electrode for the removal of crystal violet from aqueous solution.

The current research work studies the removal of crystal violet (also known as gentian violet), a kind of dye, from simulated wastewater by electrocoagulation using scrap aluminium roofing sheet as electrode in a batch electrochemical cell. Optimization of different operational parameters - pH, current density, time, initial concentration - was carried out experimentally. The equilibrium was attained at 1 hour and at pH 11. After suitable optimization, a removal of above 90% was achieved at an optimum current density of 20 mA/m2. Also, the adsorption behaviour of crystal violet in electrocoagulation was also studied and the isothermal and kinetic models were proposed to be the Dubinin-Radushkevich model and pseudo-first order model. The mechanism involved during the process was suggested as chemisorption. The adsorption thermodynamic studies were a clear indication that the process is spontaneous and endothermic as well as thermodynamically favourable too. Both chemical and physical characterization of the flocs generated during the electrolysis was explained by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) respectively.