Zhiyong Dong, Zhen Zhang
Thursday 2 july 2015
8:30 - 8:45h at Asia (level 0)
Themes: (T) Hydro-environment, (ST) Impacts of pollutants on the water environment
Parallel session: 10G. Environment - Impact
Hydrodynamic cavitation is a novel technique that has been found to be substantially application in wastewater treatment, especially in degradation of refractory pollutants. Cavitation means phenomena of formation, growth and collapse of cavitatin bubbles. Microjets and shock waves due to collapse of cavitation bubbles can release high intensity energy, which generate strong oxidation conditions of chemical process such as hydroxyl radical (OH*) and hydrogen peroxide (H2O2). This paper experimentally studied effects of the hydrodynamic cavitation due to triangular multi-orifice plates with Venturi tube on degradation of hydrophilic and hydrophobic mixing pollutants. The different combinations of triangular multi-orifice plates with Venturi tube to generate hydrodynamic cavitation were carried out. A mixture of p-nitrophenol and nitrobenzene was prepared for hydrophilic and hydrophobic mixing wastewater in the hydrodynamic cavitation reactor, and the degradation rates due to the hydrodynamic cavitation were analyzed by an ultraviolet spectrophotometer. Effects of different flow velocities, cavitation numbers, orifice numbers, orifice sizes, initial wastewater concentrations and wastewater circulation cycles through the cavitation reactor on degradation of the hydrophilic and hydrophobic mixture were experimentally investigated. The experiment also studied free hydroxyl radical production due to the hydrodynamic cavitation at the different combinations of multi-orifice plates with Venturi tube.