THE EFFECT OF DEMULSIFIER AND DEWATERING AGENT ON SEPARATION OF PHASES FROM OILY WATER

Environmental pollution with crude oil and its derivates has become a growing problem due to their toxic and carcinogenic effects on live organisms. Proper collection and treatment of oily wastewaters is very important for prevention and disabling of harmful effects on the environment. The most important step in the oily wastewater treatment process is separation of oil and aqueous phase. Consequently, it is important to examine the conditions which enable the maximum separation effect and provide satisfactory quality of the aqueous phase before discharge into natural recipients. This paper examines the effects of temperature and addition of demulsifier and dewatering agent on phase separation in oily wastewaters. The best separation rate and the highest quantity of the aqueous phase are achieved with the addition of demulsifier in concentration of 500 mg/l and the dewatering agent in concentration of 500 mg/l at 60 °C. The quality of the aqueous phase after separation shows low values of mineral oils and high COD (Chemical Oxygen Demand) values due to the remaining demulsifier and dewatering agent in aqueous phase. For that reason it is necessary to use additional treatments, such as adsorption on active carbon or biological treatment before discharge into natural waters