A New Development of Wastewater Treatment Unit for Paint Shop in Vehicle Industry

Abstract

In vehicle industry, the painting is applied using two types of paints to produce the final color required. The vehicle body is generally pressed and welded and transported to a pre-clean area. Here, high pressure water spray jets are directed at the body with the purpose of cleaning off dirt and debris from previous processes. This study covers the paint workshop inside the vehicle factory and its wastewater. ELPO process use water to ease its application, this waster is wasted containing Zinc (Zn) 2 ppm, Nickel (Ni) 1.5 ppm, copper (Cu) 1.5 ppm, cadmium0.3 ppm and less than 1000 mg/l TSS. This wastewater is mixed with other factory branches in the equalization tank, where, the various combinations of the waste create a unique treatment challenge. At the Equalization Tank the various wastewater streams are blended and homogenized into a predictable and consistent influent. The objective of this research is to submit treatment solution to the existing pollutants mentioned above occupying a small area and with minimum cost. This could be applied by raising the pH of the wastewater to the minimum solubility of the combined metals, Zn, Ni, P and then, adding coagulants and a flocculants to enhance settling of the resulted solids. The separation of the solids from the clean water is accomplished by use of a plate settler unit. Settled solids will be dewatered by filter press unit before its disposal to sanitary land fill. The effluent overflows to a multi-media filter for further polishing. PH is again adjusted to permitted discharge levels, usually less than 9, and the water is discharged to the city sewer.

The effluent wastewater showed high removal efficiency for all parameters in the full scale lab and after applying the system in the factory. The effluent was abiding all the environmental laws for applying to public sewers.