Novel hybrid system based on hydrodynamic cavitation for treatment of dye waste water: A first report on bench scale study

In this article, a first report on novel hybrid technique (hydrodynamic cavitation + hydro gels packed bed adsorption) has been reported for dye degradation and subsequent adsorption of dye molecules. Initially, hydrodynamic cavitation (HC) was employed for the degradation of crystal violet dye molecules and subsequent adsorption of dye molecules have been carried out by adopting synthesized polymer hydro gels. Poly-acrylic acid (PAA)/nano composite hydro gels have been synthesized via ultrasound assisted emulsion polymerization technique. Modified bentonite clay was used as a cross-linker during the synthesis of PAA in the presence of ultrasound for the uniform dispersion of bentonite clay in the hydro gel matrix and to improve the adsorption capacity of the hydro gels. The morphology of synthesized hydro gels has been studied by XRD and TEM analysis. Operational parameters such as effect of inlet pressure on CV dye removal, effect of bentonite clay content in PAA hydro gel, effect of quantity of hydro gel loading in packed bed, effect of pH, and effect of inlet flow rate to the packed bed on integral removal of crystal violet dye in the hybrid system have been investigated. The combined process of hydrodynamic cavitation and packed bed hydro gel demonstrated the higher percentage removal of the crystal violet dye as compared to packed bed hydro gel alone. Synergistic effect of combined technique was evaluated based on the total organic carbon removal from the dye solution. (C) 2017 Elsevier Ltd. All rights reserved.