Biochemical pretreatment process of oily wastewater

Abstract

The invention discloses a biochemical pretreatment process of oily wastewater, and the pretreatment process comprises: firstly oily wastewater is introduced into a grill well for mainly removing floating debris and large particles of suspended solids; the effluent of the grill well automatically flows into a laminar-flow oil separation tank and an inclined-plate oil separation tank for mainly removing floating oil, dispersed oil and suspended oil; the effluent of the inclined-plate oil separation tank automatically flows into a water collecting tank, then the wastewater is elevated and introduced into an adjusting tank through a lifting pump, and after a period of residence, the purpose of regulating water quality and quantity is achieved; the wastewater in the water collecting tank can also be introduced into an accident tank through the lifting pump; the effluent of the adjusting tank automatically flows into first-stage and second-stage flotation devices for mainly removing suspended solids, emulsified oil and colloidal substances in the wastewater; and the effluent of the second-stage floatation device automatically flows into a biochemical treatment unit. Through the process provided by the invention, on one hand, the wastewater entering the accident tank hardly contains floating oil and suspended oil, and on the other hand, when the wastewater is introduced into the accident tank, the normal operation of the subsequent processes is hardly influenced within a short time.

Description

technical field [0001] The invention relates to a biochemical pretreatment process for oily sewage in petrochemical sewage treatment plants, which is mainly adapted to the biochemical pretreatment process for oily sewage, and belongs to the field of sewage treatment process design for oily sewage treatment plants in petrochemical industries. Background technique [0002] The biochemical pretreatment process of oily sewage is mainly to remove pollutants such as suspended solids, slick oil, dispersed oil, suspended oil, sludge (slag), emulsified oil and colloid. A grid well is generally installed at the entrance of the sewage treatment plant, and a grid machine is installed in the grid well to mainly remove the floating matter and large particle suspended matter in the oily sewage. The outlet water of the grid well is pumped or flowed into the advection type grease trap or oil collection / adjustment tank to mainly remove floating oil, dispersed oil and suspended oil, and the pa...

AI Technical Summary

Problems solved by technology

[0010] The main problems in the biochemical pretreatment process of oily sewage mentioned above are: ① During the oil recovery operation, the thickness of the oil layer in the adjustment tank cannot be seen. If the oil recovery is not timely, the effective volume of the adjustment tank will be affected to a certain extent; if the oil recovery exceeds the actual The amount of oil stored, the water content in the oil collection will be very high; ② Only by relying on the oil collection / adjustment tank first-level oil separation, the control ability of the oil content in the water outlet of the adjustment tank is poor; ③Once there is a problem with the floating oil receiver, it cannot be effectively collected Oil

④ The process location of the accident pool is unreasonable. If the accident pool is set before the oil separation system, the sewage entering the accident pool will contain slick oil and suspended oil, which will make the operation and management of the accident pool difficult; if the accident pool is set behind the regulating tank, when the incoming water When the accident pool is improved, all follow-up processes will stop running

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