Method for treating COW-DM sewage with high chemical stability and biodegradation difficulty

Abstract

The invention provides a method for treating COW-DM sewage with high chemical stability and biodegradation difficulty. The method comprises the following steps in sequence: catalytic ozonation, A / O (anaerobic / oxic) tank biochemical reaction and sludge-water separation, and the emission standard is met finally, wherein 30-50 ppm of a solid catalyst is added in a catalytic ozonation reaction process, the height of the solid catalyst is 3-4 m, pH is 7-9, the temperature is 25-30 DEG C, the solid catalyst adopts metal or metal oxide supported on a carrier, the retention time for catalytic ozonation is 1-1.5 h, the ozone contact time is 20-30 min, the A / O tank biochemical reaction adopts an A tank and an O tank, the DO (dissolved oxygen) of the A tank is smaller than 0.5 mg / L, pH is 6.5-7.5, the DO of the O tank is 1.5-4.0 mg / L, pH is 7-8, MLSS (mixed liquor suspended solids) is controlled to be 3-6 g / L, the temperature is 20-35 DEG C, the retention time is 6-10 h, denitrification is performed in the A tank, and the required carbon source proportion BOD (biochemical oxygen demand) / TN (total nitrogen) is larger than 4.

Description

technical field [0001] The invention belongs to the field of environmental protection and relates to a sewage treatment process which is difficult to biodegrade. Background technique [0002] With the rapid development of my country's economy, high-concentration, highly toxic, and various types of sewage pose a threat to my country's precious water resources, and this highly chemically stable, refractory biodegradable sewage has large water volume, scattered drainage points, mineralization High concentration, complex composition, in addition to general organic matter, there are also pollutants such as grease, phenols, sulfides, halogen compounds, nitro compounds, dispersants or surfactants with bactericidal effect, poor biodegradability, difficult to handle, difficult to There are many degraded substances; while the existing traditional sewage treatment system has a relatively long process, mainly using oil separation, air flotation, biochemical treatment (activated sludge or ...

AI Technical Summary

Problems solved by technology

[0002] With the rapid development of my country's economy, high-concentration, highly toxic, and various types of sewage pose a threat to my country's precious water resources, and this highly chemically stable, refractory biodegradable sewage has large water volume, scattered drainage points, mineralization High concentration, complex composition, in addition to general organic matter, there are also pollutants such as grease, phenols, sulfides, halogen compounds, nitro compounds, dispersants or surfactants with bactericidal effect, poor biodegradability, difficult to handle, difficult to There are many degraded substances; while the existing traditional sewage treatment system has a relatively long process, mainly using oil separation, air flotation, biochemical treatment (activated sludge or contact oxidation), pure oxygen aeration, oxidation ditch, secondary Settling tank, BAF and other combinations, but with the improvement of sewage discharge standards, it is difficult for the effluent to meet the increasing water quality requirements

[0003] At the same time, with the improvement of environmental protection requirements, sewage reuse is also an inevitable requirement and direction of enterprise development, and the traditional sewage treatment system is also difficult to meet the treatment requirements of this highly chemically stable and refractory sewage.