CN-118495754-B - Treatment method of fluorescent whitening agent wastewater

Abstract

The invention relates to the technical field of industrial wastewater treatment, and particularly discloses a method for treating fluorescent whitening agent wastewater. The invention firstly performs acid precipitation and impurity removal at specific pH and temperature, performs reverse osmosis concentration, and then performs secondary acid precipitation and impurity removal at specific pH and temperature, so that a large amount of organic matters in fluorescent brightening agent wastewater are removed in advance, the pressure of a micro-electrolysis process is reduced, the micro-electrolysis treatment efficiency is improved, and meanwhile, the micro-electrolysis coupling Fenton oxidation technology further improves the degradation degree of various organic matters in the wastewater, so that the treated wastewater can directly reach the emission standard. The invention has simple whole treatment process, safety and controllability, is suitable for the treatment of various fluorescent whitening agent wastewater, does not need biochemical treatment in the whole treatment process, effectively reduces the treatment cost of wastewater, simultaneously obtains byproduct salt with higher added value, realizes the comprehensive treatment and recycling of the fluorescent whitening agent production wastewater, and has higher practical value.

Inventors

• LIU XIAOMING
• LIU SHUOLEI
• LIANG YUNFEI
• LIANG BING

Assignees

• 河北深茂新材料科技有限公司

Dates

Publication Date

20260512

Application Date

20240620

Claims (9)

1. 1. A method for treating fluorescent whitening agent wastewater, wherein the fluorescent whitening agent wastewater refers to wastewater containing triazinylaminostilbene or modified fluorescent whitening agent thereof, and is characterized by comprising the following steps: step a, adjusting the pH of fluorescent whitening agent wastewater to be 1-4, adding activated carbon, heating to 60-85 ℃, preserving heat for 0.5-2 h, adding a filter aid, and filtering to obtain a first filtrate; Step b, regulating the pH value of the first filtrate to be neutral, and removing 70% -80% of water through reverse osmosis concentration to obtain concentrated wastewater; Step C, adjusting the pH of the concentrated wastewater to 3-4, adding activated carbon, heating to 60-85 ℃, preserving heat for 0.5-2 h, adding a filter aid, and filtering to obtain a second filtrate; d, adjusting the pH of the second filtrate to be 1-4, adding an iron-carbon filler, adding hydrogen peroxide into the system while performing aeration micro-electrolysis, adjusting the pH to be 6-9 after the micro-electrolysis is finished, adding activated carbon and a flocculating agent, and filtering to obtain a third filtrate; and e, concentrating the third filtrate to obtain byproduct salt.
2. 2. The method for treating wastewater with fluorescent whitening agent according to claim 1, wherein in the step a, the activated carbon is at least one of wood carbon, coal carbon and coconut shell carbon, and the addition amount of the activated carbon is 5-2% of the mass of the wastewater with fluorescent whitening agent, and/or In the step a, the filter aid is at least one of diatomite, perlite, cellulose, asbestos, graphite powder, sawdust or paper pulp, and the addition amount of the filter aid is 1-2 per mill of the mass of the fluorescent whitening agent wastewater.
3. 3. The method for treating wastewater containing fluorescent whitening agent according to claim 1, wherein in the step b, the neutral means a pH of 6 to 7.
4. 4. The method for treating wastewater with fluorescent whitening agent according to claim 1, wherein in the step c, the activated carbon is at least one of wood charcoal, coal charcoal or coconut shell charcoal, and the addition amount of the activated carbon is 5-2% of the mass of the concentrated wastewater, and/or In the step c, the filter aid is at least one of diatomite, perlite, cellulose, asbestos, graphite powder, sawdust or paper pulp, and the addition amount of the filter aid is 1-2 per mill of the mass of the concentrated wastewater.
5. 5. The method for treating fluorescent whitening agent wastewater according to claim 1, wherein in the step d, the addition amount of hydrogen peroxide is 0.2% -1% of the mass of the second filtrate.
6. 6. The method for treating fluorescent whitening agent wastewater according to claim 1, wherein in the step d, the iron-carbon filler is granular carbon and scrap iron in a mass ratio of 1-3:1, and the addition amount of the iron-carbon filler is 8% -12% of the mass of the second filtrate wastewater.
7. 7. The method for treating wastewater with fluorescent whitening agent according to claim 1, wherein in the step d, the time of the micro-electrolysis is 1-4 hours.
8. 8. The method for treating wastewater with fluorescent whitening agent according to claim 1, wherein in the step d, the flocculant is at least one of polyaluminum chloride, polyaluminum sulfate, polyaluminum ferric chloride and polyaluminum ferric sulfate, and the addition amount of the flocculant is 1-5% of the mass of the second filtrate.
9. 9. The method for treating wastewater with fluorescent whitening agent according to claim 1, wherein in the step d, the activated carbon is at least one of wood carbon, coal carbon or coconut shell carbon, and the addition amount of the activated carbon is 1% -3% of the mass of the second filtrate.

Description

Treatment method of fluorescent whitening agent wastewater Technical Field The invention relates to the technical field of industrial wastewater treatment, in particular to a method for treating fluorescent whitening agent wastewater. Background The optical brightening agent is a fluorescent dye and is widely applied to industries such as textile, detergent, papermaking, printing, leather, plastics, synthetic fiber, paint, printing ink and the like. A large amount of high-concentration and difficult-to-treat organic wastewater can be discharged in the production process of the fluorescent whitening agent, and the existence and development of enterprises are restricted while the water body environment is seriously polluted. The fluorescent whitening agent is mainly characterized in that (1) the waste water has complex components, organic pollutants mainly comprise benzene containing amino groups, nitro groups, sulfonic groups and other groups and derivatives thereof, the organic pollutants inhibit the activity of microorganisms, so that the biodegradability of the waste water is extremely poor, (2) the salt content in the waste water is higher, the osmotic pressure balance of biological cells can be greatly influenced in a biochemical reaction unit, so that the microorganisms die, in addition, the existence of certain inorganic salts can also serve as biological inhibitors to inhibit the action of biological enzymes, so that the growth of the microorganisms is inhibited, and (3) the fluorescent whitening agent is mainly artificially synthesized macromolecular organic matters, the relative molecular mass of which varies from hundreds to thousands, and most of the fluorescent whitening agents cannot be degraded by the microorganisms, and the degradation effect is mainly from the adsorption effect of activated sludge. Therefore, due to the characteristics of complex and variable water quality components, high toxicity, poor biodegradability and the like of the fluorescent whitening agent production wastewater, the wastewater discharge requirement cannot be met by adopting a biochemical treatment unit. At present, the fluorescent whitening agent wastewater is treated by a biochemical method after being subjected to advanced oxidation such as physical, chemical and the like, so that the treatment flow is long and the process is complex. The prior art discloses a method for treating fluorescent whitening agent wastewater by adopting electrocatalytic oxidation, micro-electrolysis and biochemistry, wherein the wastewater treated by the method is single, chlorine and the like can be generated in the electrocatalytic oxidation process, and the problems of safety and secondary pollution exist. Therefore, there is an urgent need for a method for treating wastewater of a whitening agent that is economical and efficient and does not cause secondary pollution. Disclosure of Invention Aiming at the problems that the existing fluorescent whitening agent wastewater contains more organic matters, the treatment difficulty is high, the treated wastewater is single, secondary pollution can be caused to the environment and the like, the invention provides a method for treating the fluorescent whitening agent wastewater. The method mainly realizes the deep degradation of various refractory organic matters in fluorescent whitening agent wastewater by acid precipitation and impurity removal, reverse osmosis concentration, secondary acid precipitation and impurity removal and iron-carbon micro-electrolysis coupling Fenton oxidation technology, and simultaneously obtains high-quality byproduct salt, realizes the recycling of production wastewater, has no secondary pollution problem, and has higher economic benefit and environmental benefit. In order to solve the technical problems, the technical scheme provided by the invention is as follows: A method for treating fluorescent whitening agent wastewater comprises the following steps: step a, adjusting the pH of fluorescent whitening agent wastewater to be 1-4, adding activated carbon, heating to 60-85 ℃, preserving heat for 0.5-2 h, adding a filter aid, and filtering to obtain a first filtrate; Step b, regulating the pH value of the first filtrate to be neutral, and concentrating by reverse osmosis to obtain concentrated wastewater; Step C, adjusting the pH of the concentrated wastewater to 3-4, adding activated carbon, heating to 60-85 ℃, preserving heat for 0.5-2 h, adding a filter aid, and filtering to obtain a second filtrate; d, adjusting the pH of the second filtrate to be 1-4, adding an iron-carbon filler, adding hydrogen peroxide into the system while performing aeration micro-electrolysis, adjusting the pH to be 6-9 after the micro-electrolysis is finished, adding activated carbon and a flocculating agent, and filtering to obtain a third filtrate; and e, concentrating the third filtrate to obtain byproduct salt. Compared with the prior art, the method for treating the fluoresce