Treatment of truck wash water using electrocoagulation

摘要

The scarcity of fresh water resources and the need for additional water supplies are critical in many regions of the world. Treatment of wastewater and its reuse can partially resolve this issue. Due to the increase in use and number of heavy duty vehicles for transportation purpose the wastewater generated from truck wash has been escalated during last several decades. Our results show that electrocoagulation (EC) can be an effective technique to treat truck wash water (TWW), and this treated TWW is reusable. Effects of different combination of electrodes, such as Fe-Fe, Al-Fe, and Al-Al, operating time, current density (CD), and pH inside the EC reactor were studied to optimize treatment conditions for lowering chemical oxygen demand (COD), and concentrations of some selected toxic metal ions in TWW. The best removal efficiency of 79% for COD was obtained by Fe-Fe combination after 8min of operating time and at 2mA/cm(2) of CD. Iron, zinc, and lead concentrations were reduced below EPA maximum contaminant levels for all three types of electrode combinations. The EC-floc was characterized using X-ray diffraction, scanning electron microscope/energy dispersive X-ray spectroscopy, and Fourier transform-infrared spectrometer. The ionic substitution of iron by aluminum was confirmed in the isomorphs subsisted in the floc.