Effect of the hydrodynamic cavitation for the treatment of industrial wastewater

In the present work, the degradation of tetramethyl ammonium hydroxide (TMAH) from synthetic liquid waste of electronic industry was investigated by using hydrodynamic cavitation process. The core of the experimenal apparatus was a Venturi tube having a diameter of 12 mm and a convergent of 2 mm. The experiments were performed using synthetic solutions with an initial TMAH concentration of 2 g/L. A factorial plant with 2 factors and 2 levels was planned to prove that the hydrodinamic cavitation was an effective methodf to degrade TMAH. The investigated factors were: solution pH (3 - 20) and time (5 -20 min). The experiments have been carried out at a fixed temperature of 20°C and a pressure of 4 bar. The inlet pressure of 4 bar was chosen as a result of preliminary experiments that showed as at this value the degradation yields were higher than those obtained at other pressure values. The experiments showed that pH solution was significant with a negative effect. The optimal performance (around 44%) of process for degradation of tetramethyl ammonium hydroxide was achieved at pH=3 after 20 minutes.