1 Oily wastewater treatment in oil fields
At present, membrane separation technologies for oily wastewater treatment in oil fields mainly include microfiltration and ultrafiltration. Their role is mainly to retain micron-sized suspended solids, emulsified oil and dissolved oil in sewage. In simple cases, the emulsified oil is blocked by the membrane based on the size of the oil droplets, and the dissolution of the dissolved oil is based on the intermolecular interaction of the membrane and the solute. The stronger the hydrophilicity of the membrane, the stronger the ability to block the passage of free oil and the higher the water flux.
2 Oily wastewater treatment in the machining industry
Wastewater from the machining industry is mainly produced in the workpiece cleaning process. The content of emulsified oil is high and it is difficult to remove. Therefore, the ceramic membrane was used for processing, and the research proved that the effect was good, and the appropriate process parameters were obtained.
3 Oily wastewater treatment in cold-rolled steel emulsion
Cold-rolled emulsion wastewater is a kind of oily wastewater. Its composition is complex, mainly composed of mineral oil or vegetable oil, emulsifier and water. The oil content is relatively high, generally about 2% to 10%, and the emulsification of this part of the oil is high. It is difficult to meet the national wastewater discharge standards by conventional oily wastewater treatment methods. Cold rolling emulsion treatment is a major technical problem that plagues China's steel rolling industry. The zirconia microfiltration membrane is used to treat the cold-rolled emulsion wastewater, and the mass transfer and high-frequency recoil are used to pollute the retardation membrane and reduce the impact of operating energy consumption. The cleaning effect of various cleaning agents is compared to determine the effective and stable cleaning method, which lays a foundation for further application of industrialization.
4 Oily wastewater treatment in the catering industry
For the catering industry, the oily sewage has a high oil content, which contains both emulsified oil and dissolved oil, which is difficult to handle. The ceramic membrane is used to treat oily sewage in the catering industry. Combining the effects of a single cleaning agent and comprehensive cleaning, cleaning time, and cleaning agent concentration on the cleaning effect, it is an effective cleaning method.