1. Status Analysis of Printing and Dyeing Plants
The printing and dyeing industry is one of the four major pollution rectification industries in the country. In 2013, the COD of the printing and dyeing industry was less than 500 from the original. Increased the ppm to less than 200 ppm. For this reason, some small printing and dyeing plants could not withstand the pressure of sewage disposal and sewage treatment costs and closed down. Some printing and dyeing plants stopped business for rectification, spent large-cost sewage treatment engineering, and some added reverse osmosis membrane treatment. new technology in water reuse and employment process, from the original cost of sewage treatment l yuan / ton to 6 yuan / ton. Dyeing method to solve this problem is through improved equipment, through the transformation process technology, by dyeing wastewater reuse, reduce, or not to produce printing and dyeing wastewater to achieve zero emission is the ultimate goal of our printing plants. In this paper, the repeated dyeing of residual dyes with reactive dyestuffs can achieve the purpose of reducing the cost of sewage treatment and reducing the cost of additives and dyes without reconstructing the dyeing equipment. This will provide dye printing plants with the goal of reducing pollutant emissions and providing new emissions closer to zero emissions. Ideas.
2 Research and Analysis of Repeated Reuse of Reactive Dyeing Residual Solution
2.1 Reactive dyeing raffinate repeated reuse method
Method one: Make a auxiliary tank with the same capacity as the dyeing machine next to or above the gap dyeing machine, and connect it with the dyeing machine through the pump. After the dyeing of the reactive dyes is finished, pump the residual liquid to the auxiliary cylinder and the original dyeing liquid. Than, the amount of residual liquid will be about 10% less (the exact amount can be obtained by testing). When the lower cylinder is used for dyeing , add 10% water and the corresponding Yuanmingfen and soda ash in the auxiliary cylinder, put the residual liquid in the auxiliary cylinder back into the dyeing machine , and dye the second cylinder with the same dyeing process. Product, then repeat the above operation to use residual liquid to do the third, fourth, fifth ... N-cylinder product dyeing.
Method 2: (patent of invention: ZL201210142739.7): Without auxiliary cylinders, connect N dyeing machines of the same capacity through a pump and prepare the N-Cylinder to dye the same product with the same color. The liquid pump is pumped into the second dyeing tank, and 10% water and corresponding Yuan Mingfen and soda are added to start the dyeing of the second cylinder product. After the dyeing is finished, the residual liquid is pumped into the third dyeing tank, and 10 is added. % of water and corresponding Yuan Mingfen and soda ash , began to dye the third cylinder product, repeat the above operation to use the residual liquid to do the fourth and fifth. . . The dyeing of the Nth cylinder product.
2.2 Advantages of the Reuse Technology of Reactive Dyeing Residues
In theory, as long as the same product is dyed, reactive dyeing residue can be repeated reuse it, truly zero emissions residual staining solution, but in fact generally can repeat back 4-5 times. According to the use of 5 times to analyze the advantages of this residual solution recycling technology , reuse 5 times , that is, dyeing 6 cylinder products, dyeing l00 kg product with black as an example, dyeing formula : active black 6%, Yuanmingfen 60g/ L, soda 25 g/L, calculated as bath ratio of 1:10, see Table 1 for comparison.
Table 1 Comparison of process prescriptions
Process prescription
Yuan Mingfen/kg
Soda Ash/kg
Dye amount/g
Water consumption/T
Pollutant/T
Normal staining
60
25
6
l
0.9
First time reuse
6
2.5
5.7
0.1
0
Second time reuse
6
2.5
5.7
0.1
0
Third time reuse
6
2.5
5.7
0.1
0
Fourth time reuse
6
2.5
5.7
0.1
0
Fifth time reuse
6
2.5
5.7
0.1
0.9
Normally dyed 30 kilograms of dyes used 30 kilograms of dyes, 300 grams of Sangling powder, 125 kilograms of soda ash, 5 tons of dyeing water (excluding post-treatment water), 4.5 tons of sewage, and 28.5 kilograms of dyestuffs used for dyeing five-cylinder products. Yuanmingfen 30 kg, soda ash l2.5 kg, dyeing water (excluding post-treatment water) 0.5 tons, 0.9 tons of sewage. 5 times of dye saving can save dye 1.5 kg, Yuan Mingfen 270 Kilograms and 112.5 kg of soda ash can save 4.5 tons of dyeing water (excluding post-treatment water) and reduce 3.6 tons of sewage discharge. The amount of dye saved is relatively small, but it can save Yuanmingfen and soda ash, reduce water use, and reduce pollutant emissions. The reuse rate of Yuanmingfen and soda ash is 90%, the reuse rate of dyeing water is 90%, and the reuse rate of wastewater is 80%. . In the general wastewater treatment, the reuse rate of water is only 50%-60%, and the treatment cost is high, the treatment effect is sometimes not good , and the maintenance and replacement costs of the reverse osmosis membrane are also high , which is the advantage of repeated reuse of reactive dyeing residual liquid. Sex .
2.3 Repeated Reuse Test and Analysis of Reactive Dye Residue
2.3.1 Dyeing process
In order to ensure consistency between the five reused dyeing processes and the first dyeing process, the dyeing process of reactive dyes on cotton or regenerated cellulose fibers is performed using a constant temperature method.
Since the temperature after each residual solution recovery is in the range of 50-60°C, the temperature will be about 50°C after adding 10% of water and the corresponding Yuanmingfen and soda ash, and it can only be added at a constant temperature and alkali. The dyeing process can ensure the consistency of the process when the dye is reused. When the dyeing process is started , the residual solution heated by the pump is first heated to 60° C., and then dyed with reactive dyes for 20 minutes to start the dyeing process.
2.3.2 Monochrome black repeated reuse test
In order to verify the feasibility of recycling the raffinate staining, performed first by the temperature-monochrome black process following test method: Take good for bleaching cotton Christmas Crowns
Christmas Crowns,Christmas Pageant Crowns,Christmas Festival Pageant Crowns,Christmas Pageant Crown
YiWu Home Of Crowns Co.,Ltd , https://www.crystal-crowns.com