Application of membrane separation technology in the treatment of emulsified oil wastewater

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In many processes in industries such as steel, smelting, and machining (cold rolling. Metal processing, acid leaching, polishing, etc.) all generate large amounts of oily wastewater. Traditional treatment methods (chemical demulsification, air flotation, and various gravity separation techniques) not only fail to remove oil effectively but also generate large amounts of difficult-to-treat oily sludge, failing to meet wastewater discharge standards. It also has disadvantages such as lengthy processing procedures, high processing costs, and large space requirements. 　　Application of membrane separation technology in the treatment of emulsified oil wastewater The composition of emulsified oil wastewater is very complex, mainly containing mineral oil. Emulsifiers, surfactants, etc., especially the content of oils and fats is very high. Not only do these oily substances exist in the form of particles measuring microns and sub-micron sizes, making them highly stable, but they also have a high COD value; their direct discharge would cause severe environmental pollution. Due to the coagulation resistance of oily wastewater, traditional chemical methods are often ineffective in achieving oil-water separation. Furthermore, traditional media filters (sand filtration, anthracite) also struggle to remove fine oil droplets smaller than 20μm. 　　Systems for designing and constructing inorganic membrane products (ceramic hollow fiber membranes and stainless steel tubular membranes). It effectively solves the challenges associated with the separation of emulsified oil wastewater and other highly viscous, high-solid-content industrial fluids. Compared to other inorganic membrane separation systems, it addresses the issues present in those systems, such as complex sealing requirements, leakage problems, low production safety, inadequate cleaning, short membrane lifespan, and high operating costs. 　　Thanks to its stable performance and unique design, inorganic membrane separation systems have been successfully applied to the industrial treatment of emulsified oil wastewater. Application results show that the effluent quality is excellent and stable, membrane cleaning and regeneration are easy, production safety is high, and operating costs are low. Inorganic membrane separation systems provide the most economical and effective solution for the treatment of emulsified oil wastewater. 　　System and technical advantages 　　Compared with traditional processes, the quality of the effluent is not affected by fluctuations in the quality of the influent ； No large amounts of chemicals are required; oil recovery is easy to implement and has a wide range of applications. It can handle rinsing liquids and degreasing solutions with an oil content of 0.5–1.0%, as well as cutting fluids with an oil content of 2–10% ； The oil concentration can be concentrated to 40-70%. 　　Compared to organic membranes, it offers higher filtration precision, resistance to high temperatures and contamination, ease of cleaning, low tendency to scale, a longer service life, simple operation and maintenance, a straightforward system design, and a small footprint. Its treatment cost is less than half that of traditional processes; it represents a typical model of clean production, enabling the maximum degree of waste resource utilization and water recovery. 　　Steel, smelting, and machining – recycled process water