Method for treating salt-containing sewage

Abstract

The invention relates to a method for treating salt-containing sewage. The pH value of the salt-containing sewage is adjusted to between 8 and 12, the salt-containing sewage is biochemically treated by an activated sludge process, the effluent after the activated sludge process treatment is treated by an ozone-catalytic oxidation process adopting a solid catalyst, and the effluent after the ozone-catalytic oxidation process treatment is discharged through a biofilter; and in the ozone-catalytic oxidation process adopting the solid catalyst, the solid catalyst is granular activated carbon loaded with an active component which is one or more of tin, copper, manganese, titanium, cobalt, vanadium and nickel. The method can effectively purify the sewage which has high salt content and is refractory to biodegrade, and the effluent after treatment has the COD of less than or equal to 50 mg / L and the NH3-N of less than or equal to 8 mg / L, so that the strict sewage discharge standard of developed regions is met. The method has the advantages of simple treatment process, no need of sewage dilution, clean and clear effluent after treatment and realization of direct standard discharge.

Description

technical field [0001] The invention relates to a treatment method for oil refinery sewage, which is particularly suitable for the standard-reaching discharge treatment method of high-concentration saline sewage in oil refineries. Background technique [0002] At present, oil refinery sewage generally adopts a centralized mixed treatment method, that is, the oily sewage, salty sewage, acid water stripping purified water and domestic sewage discharged from various production units are mixed and then treated through the oil separation-flotation-biochemical combination process and then discharged. Can still meet COD≤100mg / L, NH 3 - National emission standard of N≤15mg / L. However, with the deteriorating quality of crude oil processed by refining and chemical enterprises and the increasingly stringent requirements for wastewater reuse due to water shortages, this method and process of centralized and mixed wastewater treatment has increasingly exposed larger problems. First of ...

AI Technical Summary

Problems solved by technology

Experiments have shown that high-concentration saline wastewater from oil refineries contains about 8% to 20% of non-biodegradable substances, and ordinary biochemical treatment or combined biochemical treatment is difficult to meet strict discharge standards (such as COD≤60mg / L or COD≤50mg / L)