A kind of iron and steel industry nitrogen-containing wastewater treatment method

Abstract

The invention discloses a method for treating nitrogen-containing wastewater in the iron and steel industry, including CMBR technology. The specific steps are as follows: (1) introduce nitrogen-containing wastewater into the CMBR reaction tank through a regulating tank, add carbon source and potassium dihydrogen phosphate, and maintain dissolved oxygen 0.2-0.5mg / L; (2) Introduce the mixed solution after 16 hours of reaction in step 1 into the activated sludge separator, and discharge the separated sludge into the sludge storage tank, or introduce it into the CMBR reaction tank to continue the reaction, The clear liquid is discharged to the clear water tank for storage, and the reuse amount and discharge amount are determined according to the actual situation; the invention integrates anoxic, aerobic, sedimentation, concentration, and separation, which greatly reduces the occupied area and shortens the process flow, and the membrane permeability The water quality of the passing liquid is stable and meets the first-level requirements of the "Water Pollution Discharge Standard for the Iron and Steel Industry".

Description

Technical field [0001] The invention relates to the field of industrial sewage treatment, in particular to a method for treating nitrogen-containing wastewater in the iron and steel industry. Background technique [0002] In the iron and steel industry, a large amount of nitric acid is used during production. Most of these nitric acid will be converted into nitrate and then discharged into the wastewater treatment system, resulting in excessive total nitrogen in wastewater. [0003] The existing method for treating this type of wastewater adopts the "anoxia + aerobic + precipitation" method, specifically under anoxic conditions, adding carbon sources and phosphate salts as nutrients, using the biodegradation of denitrifying bacteria to remove wastewater The nitrate nitrogen in the anoxic tank enters the aerobic tank, the residual carbon source is removed by aerobic microorganisms, and then the aerobic effluent enters the sedimentation tank for mud-water separation, the supernatant ...

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Problems solved by technology

[0002] In the production of the steel industry, a large amount of nitric acid will be used, most of which will be converted into nitrate, and then discharged into the wastewater treatment system, resulting in excessive total nitrogen in wastewater

[0003] The existing method of treating this type of wastewater adopts the "anoxic + aerobic + precipitation" method. Specifically, under anoxic conditions, carbon sources and phosphorus salts are added as nutrients, and the biodegradation of denitrifying bacteria is used to remove wastewater. The nitrate nitrogen in the anoxic tank enters the aerobic tank, the remaining carbon source is removed by aerobic microorganisms, and then the aerobic effluent enters the sedimentation tank for mud-water separation, the supernatant is discharged up to the standard, and the bottom sludge enters the thickening tank to increase the solid content rate, and then carry out mechanical dehydration, and transport the mud cake for disposal; practice has proved that this method has the following disadvantages: (1) The sludge load is low and the floor area is large, and multiple sets of anoxic pools, aerobic pools, and sedimentation pools need to be built , Concentration tank; (2) Microorganisms are easy to lose with the effluent, and the treatment effect is unstable

When the wastewater flows in different tanks, the effluent will entrain a large number of microorganisms, and the microbial biomass of a single tank will decrease, thus affecting the removal of pollutants in the wastewater; (3) The mud-water separation effect of the sedimentation tank is poor

The concentration of activated sludge is very close to that of water, and the method of gravity sedimentation is conducive to the separation of activated sludge and water, thus affecting the quality of effluent water; (3) The utilization rate of carbon sources is not high

The traditional process is prone to overdosing when adding carbon sources, and an aerobic process must be used to ensure the stable COD of the effluent; (4) The treatment process is complicated, the degree of automation is low, and the operation and maintenance are difficult

[0004] Self-cleaning Concentrated Membrane Bioreaction Technology (CMBR) is a high-efficiency sewage treatment technology that uses membrane separation technology and circulating carrier biofilm method (biochemical technology) to combine ultra-frequency vibration on-line cleaning and high-frequency shear biodegradation technology, which can be widely used It is applied to the treatment of domestic and industrial wastewater, and its application to the denitrification treatment of nitrate in the wastewater of the iron and steel industry has not been reported yet.

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