COD Removal in Refinery Wastewater through Adsorption on Activated Petroleum Coke

Chemical oxygen demand (COD) have been the crucially problematic parameters in refinery wastewater treatment. This study was conducted to investigate the COD removal effectiveness in refinery wastewater with the activated pretreatment petroleum coke (APPC) prepared by combination of chemical activation with KOH solution and physical activation with calcination at lower temperatures. Adsorption experiments were carried out to study the effects of APPC preparation conditions, such as the calcination temperature, calcination time, KOH concentration, and mass ratio of KOH solution and pretreated petroleum coke(PPC) as well as the mass ratio and mixing time of wastewater and APPC on COD removal. The results showed that with the increase of calcination temperature and calcination time, the removal of COD increased rapidly. The two factors were found to have the most significant effects on COD removal from refinery wastewater. KOH solution concentrations behaved a little effect on the COD removal. The increase of mixing time of KOH solution and PPC as well as adsorption time were beneficial to the COD removal. the adsorption equilibrium reached in 1h. The COD removal percent decreased with the increase of the mass ratio of wastewater and APPC.