Abstract: Recycling the blowdown from circulating cooling water can not only save the fresh water resource, but also reduce the wastewater discharge. Combined with the engineering example of the recycling of blowdown from circulating water in a petrochemical enterprise, this paper introduces the combined process of pretreatment, ultrafiltration and reverse osmosis for the recycling of blowdown from circulating water, discusses the selection of major processing equipment and the operating parameters, gives the operating cost and benefit evaluation of the recycling project, and analyzes the main factors influencing the water treatment effect, providing reference for the engineering design of similar wastewater recycling projects

Key words: Petrochemical enterprise, Blowdown from circulating water, Ultrafiltration/UF, Reverse osmosis/RO