Applications of Hydrodynamic Cavitation for Industrial Wastewater Treatment

Abstract

Hydrodynamic cavitation is emerging technology for wastewater treatment, where research is still limited in its applications for different types of wastewater. Organic solvents are inextricable part of many processes from chemical industries. Due to the toxicity of some of these and higher oxygen demand effluent treatment for removal of solvents becomes imperative for sustainability of industry and environment. Hydrodynamic cavitation for the degradation of organic solvent wastewater containing Acetone, Methyl ethyl ketone (MEK) and Toluene was investigated using vortex diode as a cavitating device. The effect of different operating conditions and physico-chemical parameters such as inlet pressure, initial solvent concentration and nature of solvent on degradation rate of solvent from wastewater was studied. The results with novel cavitation reactor in the form of vortex diode compared with orifice plate as conventional cavitation reactor. Experiments have been conducted in pilot scale cavitation reactor at initial concentration of solvent ranging from 100 ppm to 500 ppm. The degradation of solvents was analyzed on the basis of COD removal. The results reveal that efficiency of COD removal varies substantially with change in physical operating conditions and the nature of solvent. Furthermore, it was investigated to nd mechanism for degradation and to verify its dependence on nature of solvent. It has been shown that vortex diode offers superior performance over conventional cavitaing device, thus it can be considered as alternative for conventional cavitating devices. The studies presented allow one to select and optimise the specific process, depending on the nature of industrial organic solvent wastewater.