It is a process to remove the oil in the oily sewage to make the water quality meet the discharge standard. The oily sewage in the power plant is mainly the drainage of the oil storage tank group, the drainage of the oil tanker, the flushing water of the oil unloading platform, the drainage of the oil pump room, the drainage of the oil pipeline, the drainage of the steam turbine and the bearing oil system of the rotating machinery in the main workshop, and the drainage of the oil tank area. Rainfall drainage and ground flushing water, etc. The oil content is about 600-10000mg/L. Discharge of oily sewage into rivers, lakes or bays will pollute water bodies and affect the survival of aquatic organisms; when used for agricultural irrigation, it will block soil pores and hinder the growth of crops. Therefore, the oily sewage must be treated before it can be discharged.
Oily sewage treatment process
Sources of oily sewage include petroleum, chemical and other industrial sectors. Flocculation, flotation, filtration and other methods are often used. According to the water quality characteristics of the produced oily sewage and the requirements of the effluent water quality, the sewage treatment process should adopt biological treatment to achieve the expected purpose. The optional treatment processes are: 1 Oily sewage treatment Salting out method The basic principle of oily sewage treatment Salting out method is to compress oil The thickness of the electric double layer at the interface between the particle and the water surface destabilizes the oil particle. The simple salting-out method has a large amount of dosage (1%~5%), the speed of aggregation is slow, the sedimentation and separation generally takes more than 24 hours, the equipment occupies a large area, and the treatment effect on the oily emulsion stabilized by surfactant is not good. . However, due to the simple operation and low cost of this method, it is widely used, and it is more widely used as primary treatment. 2 Inorganic flocculants commonly used in the flocculation method of oily sewage treatment are aluminum salts and iron salts, especially the inorganic polymer coagulants that have appeared in recent years, such as polyferric sulfate and polyaluminum chloride, because of their small dosage, high efficiency, and optimal The wide range of pH value and other advantages have attracted people’s attention day by day. Although the processing speed of the inorganic flocculant is fast and the device is smaller than that of the salting-out method, the agent is more expensive and the amount of sludge generated is large. At present, organic polymer flocculants can also be used as auxiliary agents for other methods in the treatment of oily sewage. 3 Oily sewage treatment Electrocoagulation degreasing method The method of electrolytic treatment of oily sewage with metal aluminum or iron as anode is mainly suitable for the secondary treatment of cooling lubricating fluid after chemical flocculation in the mechanical processing industry. Electrocoagulation has the advantages of good treatment effect, small footprint, simple operation, and relatively less scum, but it has a large consumption of anode metal, requires a large amount of salts as auxiliary agents, high power consumption, and high operating costs. shortcoming. 4 Coarse granulation method for oily sewage treatment The effect of coarse granulation method on oil removal is related to the existence and amount of surfactant. The existence of a small amount of surfactant can inhibit the effect of the coarse-grained bed, so this method will fail to remove oil from the emulsified oily sewage containing surfactant. The coarse granulation method does not require additional chemicals, no secondary pollution, small equipment footprint, low infrastructure costs, and good prospects, but the effluent content is high, so further treatment is often required.
Oil sewage treatment system
According to the oil content in the wastewater and the requirements of its treatment depth, different oily wastewater treatment systems can be used. The systems commonly used in the treatment of oily sewage in power plants are: ① oil separation-floating-discharge into urban sewage pipes; ②oil separation-floating-biological-chemical discharge into water bodies; The oil—coarsely grained—discharges into water bodies. The dirty oil separated from the grease trap and floating pool can be collected into the dirty oil pool and used as boiler fuel after being dehydrated. Treated wastewater can also be used as water for ash handling systems.

Huatai environmental engineering company supply different kinds of sewage treatment, any need please email to info01@cnoilmachine.com