Abstract: The recycle of wastewater is an effective way to reduce fresh water consumption and wastewater discharge. According to the characteristics of wastewater and working conditions of circulating water systems in ethylene plant, a wastewater pretreatment and water quality stabilizing technology for recycling pretreated wastewater to circulating water systems was developed and applied in the ethylene plant of SINOPEC Maoming Company successfully. The application results show that the quality of treated wastewater can meet the make-up water standard for industrial circulating water system by using the pretreatment procedure composed of BAF, oxidation and filtration. The water quality stabilizing technology well keeps the circulating water system contained recycle wastewater for a long-term and stable running. This combined technology possesses the advantages of short processing scheme, less investment, reliable and low operation cost, thus providing good economic effect.

Key words: ethylene plant, recycle of wastewater, treatment, water quality stabilization