High-alkalinity high-concentration printing and dyeing wastewater anaerobic pretreatment system and process

Abstract

The invention relates to the technical field of sewage treatment, and discloses a high-alkalinity high-concentration printing and dyeing wastewater anaerobic pretreatment system and process. The system comprises a high-concentration wastewater regulating tank, a high-pressure microbubble CO2 absorption tower and an anaerobic reactor which are connected in sequence; the high-pressure microbubble CO2 absorption tower is connected with a CO2 storage system; the CO2 storage system comprises a liquid CO2 storage tank, a CO2 vaporizer and a gas pressure regulating device which are connected in sequence; a first water diversion tank and a first lift pump which are respectively connected with the high-concentration wastewater regulating tank and the high-pressure microbubble CO2 absorption tower are arranged between the high-concentration wastewater regulating tank and the high-pressure microbubble CO2 absorption tower, and a second water diversion tank and a second lift pump which are respectively connected with the high-pressure microbubble CO2 absorption tower and the anaerobic reactor are arranged between the high-pressure microbubble CO2 absorption tower and the anaerobic reactor. According to the method, CO2 is adopted to adjust the pH value of sewage, so that corrosion of the reactor is avoided, mass propagation of sulfate reducing bacteria is avoided, the COD removal effect isnot influenced, the alkalinity of the wastewater is not reduced, and alkali callback cost is avoided.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to an anaerobic pretreatment system and process for printing and dyeing wastewater with high alkalinity and high concentration. Background technique [0002] Printing and dyeing wastewater is the main source of pollution in the textile industry. The discharged sewage mainly includes the following types: Dyeing water: low-concentration wastewater with moderate chroma and low COD (500-1000 mg / L). It is the main sewage discharged by printing and dyeing factories, generally accounting for 50-60% of its discharge; printing water: low-concentration wastewater, high chroma, moderate COD (1500-2500mg / L), high ammonia nitrogen and total nitrogen, and is the main sewage discharged by printing and dyeing factories, generally accounting for 20% of its discharge. ~30%; desizing wastewater: high-concentration wastewater, extremely high COD (8000-18000mg / L), high alkalinity, is the sewage...

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Problems solved by technology

[0007] The present invention is to overcome in the prior art, when processing desizing wastewater and alkali weight reduction wastewater in printing and dyeing wastewater, when adding acid to adjust the pH, it is easy to cause corrosion of reactors and pipelines, reducing the life of treatment equipment; using sulfuric acid will lead to sulfuric acid Salt-reducing bacteria proliferate in large numbers, unable to produce biogas or biogas contains a large amount of impurity hydrogen sulfide, and the anaerobic removal effect of organic matter cannot meet the treatment requirements; and adding acid will reduce the alkalinity of wastewater, and water purification agents need to be added again to generate alkali Call back costs, increase the problem of treatment costs, provide a high-alkalinity and high-concentration printing and dyeing wastewater anaerobic pretreatment system and process, in the anaerobic pretreatment using CO 2 Adjusting the pH of the sewage will neither cause corrosion of the reactor nor cause a large number of sulfate-reducing bacteria to multiply, and the biological activity of anaerobic microorganisms will not be inhibited, and the COD concentration of the effluent will be low; at the same time, it will not reduce the alkalinity of the wastewater and avoid the generation of alkali callback fee

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