CN-122011803-A - Simple preparation and efficient recovery method based on polymethylene blue in composite printing and dyeing wastewater

CN122011803ACN 122011803 ACN122011803 ACN 122011803ACN-122011803-A

Abstract

The invention discloses a simple preparation and high-efficiency recovery method of polymethylene blue based on composite printing and dyeing wastewater, the method realizes the efficient recovery of the polymethylene blue in the composite printing and dyeing wastewater through a multistage grid-regulating tank-reaction tank-sedimentation tank-dehydration room. The composite printing and dyeing wastewater in the regulating tank is regulated to be acidic, then the composite printing and dyeing wastewater is reacted with peroxodisulfate in the reaction tank, after high-speed stirring, low-speed stirring, standing and separating, liquid-phase methylene blue is decolorized, solid-phase methylene blue is deposited, under the action of the sedimentation tank, the solid-phase methylene blue forms a filter cake, and the filter cake can be stored in a shade place for standby after vacuum drying. Compared with other dye recovery methods, the method has the advantages of simple operation, low cost, safety, high efficiency, no secondary pollution, wide applicable concentration range and the like, realizes the specific recovery of the polymethylene blue in the composite printing and dyeing wastewater, and has wide engineering application prospect.

Inventors

XU CHUNXIAO
FU YU
WANG LINGLI
WANG PU
HU XUEQI
Bai Shandi
HU PENGFENG
DAN PENGFEI

Assignees

华东师范大学

Dates

Publication Date: 20260512
Application Date: 20251010

Claims (6)

1. The efficient polymethylene blue recycling method based on the composite printing and dyeing wastewater is characterized by comprising the following specific steps of: Step 1, intercepting multi-size suspended particles by composite printing and dyeing wastewater through coarse and fine grids respectively, and entering an adjusting tank; step 2, regulating the pH value of the composite printing and dyeing wastewater entering the regulating tank to 3.0-5.0, and uniformly mixing; Step 3, adding peroxodisulfate into the acidic composite printing and dyeing wastewater with the pH value adjusted, so that the molar concentration ratio of the peroxodisulfate to methylene blue in the wastewater is (4-100): 1, stirring at a high speed by adopting a stirrer for 2-5 min, stirring at a low speed for 10min, and stopping stirring; Step 4, the reacted composite printing and dyeing wastewater enters a sedimentation tank to stand for 30-120 min so as to finish the decolorization of the liquid-phase methylene blue and the deposition of the solid-phase methylene blue; Step 5, the decolorized liquid phase enters a sewage and wastewater pipe network, and the solid phase enters a dehydration room for dehydration; step 6, obtaining a filter cake polymethylene blue after dehydration, wherein: the dye types in the composite printing and dyeing wastewater comprise but are not limited to methylene blue, phenol safranine, acid yellow 17 and rhodamine B, and a filter cake obtained after suction filtration is a polymer of peroxodisulfate and methylene blue, and shows the property of methylene blue under an ultraviolet spectrum.
2. The method of claim 1, wherein the pH adjusting agent comprises, but is not limited to, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and the like.
3. The method of claim 1, wherein the high speed stirring is selected from 600 r/min and the low speed stirring is selected from 100 r/min.
4. The method of claim 1, wherein the peroxydisulfate comprises potassium peroxydisulfate, sodium peroxydisulfate, and ammonium peroxydisulfate.
5. The method of claim 1, wherein the filter cake is dried in vacuum or dried and then stored in the shade for a long period of time or is dissolved for secondary use.
6. The method of claim 1, wherein the co-existing ions common in the composite printing wastewater have less interference on recovery efficiency, including but not limited to sodium, potassium, calcium, ammonium, nitrate, sulfate, carbonate, chloride, phosphate, etc.

Description

Simple preparation and efficient recovery method based on polymethylene blue in composite printing and dyeing wastewater Technical Field The invention relates to the field of printing and dyeing wastewater treatment, in particular to a high-efficiency recovery method based on polymethylene blue in composite printing and dyeing wastewater. Background The dye is one of the most critical pollutants produced in various industries such as textile, paper making, printing, food, rubber, plastics, cosmetics and the like, and the dye types used in various industrial processes are up to 10000 according to statistics, and the annual production of the dye is 10000-770000t at present, wherein the dye utilization amount of Asia accounts for more than 50% of the world, and the water pollution caused by the dye is also obvious. Taking the textile dyeing and finishing industry as an example, approximately 30t of water is required per ton of textile during dyeing, whereas 200t of water is required per ton of dye production, wherein approximately 10% of the industrial waste water is directly discharged. In recent years, the shortage of water resources has become a limiting factor for restricting the further development of industries such as textile, papermaking, printing and the like in China, and the development of related industrial wastewater treatment and recycling technologies is widely focused in order to realize the sustainable development of the industries and relieve the problem of the increasing shortage of healthy fresh water, wherein the degradation and recycling of dyes are one of the key technical challenges. Methylene blue (C 16H18N3 ClS) is a phenothiazine salt with a planar structure, has high stability in air, is alkaline in aqueous solution, has high biotoxicity and is difficult to degrade. As a typical water-soluble aromatic heterocyclic cationic dye, the dyeing technology of paper, wool, silk, cotton and other materials is well established. Meanwhile, methylene blue is also widely applied to the fields of medical treatment, aquaculture, analysis and identification and the like. However, environmental release of methylene blue can severely threaten ecosystem balance and lead to health risks. Therefore, the technology development significance of the efficient degradation and recovery process for methylene blue is remarkable. Currently, the treatment technology for methylene blue mainly comprises three types of physical, biological and chemical, the degradation effect on methylene blue is remarkable, and the related mechanism is deeply profiled. However, the development of processes such as methylene blue recycling is relatively deficient, wherein high power consumption steps such as blast aeration or distillation purification are mostly needed, the operation is complex, and the methylene blue in the composite dye system cannot be separately recovered. Therefore, the invention provides a simple, low-cost, green, low-energy-consumption and secondary-pollution-free efficient recovery method based on the polymethylene blue in the composite printing and dyeing wastewater. Disclosure of Invention The invention aims to provide a technical method for efficiently recycling polymethylene blue in a composite dye system by utilizing peroxodisulfate, aiming at the problems of difficult treatment of printing and dyeing wastewater, high cost and the like, the defects of immature dye recycling process, complex operation and the like, so as to realize resource recycling. The persulfate preparation technology used in the method is mature, the purchase channels are rich, no environmental risk exists in the use process, and the method has the advantages of safety, high efficiency, simplicity in operation, low cost, no secondary pollution and the like. In order to achieve the above purpose, the invention adopts the following technical scheme: A high-efficiency recovery method based on polymethylene blue in composite printing and dyeing wastewater comprises the following specific steps: Step 1, intercepting multi-size suspended particles by composite printing and dyeing wastewater through coarse and fine grids respectively, and entering an adjusting tank; Step 2, regulating the pH value of the composite printing and dyeing wastewater entering an regulating tank to 3.0-5.0, and uniformly mixing; step 3, adding peroxodisulfate into the acidic composite printing and dyeing wastewater with the pH value adjusted, so that the molar concentration ratio of the peroxodisulfate to methylene blue in the wastewater is (4-100): 1, and stopping stirring for 2-5 min at a high speed and then stirring for 10min at a low speed by adopting a stirrer; step 4, allowing the reacted composite printing and dyeing wastewater to enter a sedimentation tank and stand for 30-120 min to finish the decolorization of the liquid-phase methylene blue and the deposition of the solid-phase methylene blue; Step 5, the decolorized liquid phase enters a sewage and wa