Fading Research And Its Application Of Formamidine Sulfinic Acid On Water-soluble Yellow Dyes

The emergence of synthetic dyes has made the textile dyeing and finishing industry develop rapidly.However,it is accompanied by increasingly serious environmental pollution problems.Therefore,the environmental impact of dye wastewater produced in the production process of relevant enterprises has attracted more and more attention.Due to high chroma and complex composition,it is difficult to treat dye wastewater.Therefore,it is of great practical significance to study the degradation and fading of dyes for solving the environmental pollution caused by dye wastewater.50 kinds of common yellow dyes on the market were selected in this study.The Fade treatment of formamidine sulfite(FAS)was was studied to lay a foundation for further study on the feasibility of FAS treatment of dye wastewater.The results show that:(1)For high chroma yellow dyes(e.g.sunset yellow,egg yolk,lemon yellow)solutions,the fading effect is mainly affected by FAS concentration and hydroxyl radical concentration,and temperature has little effect on fading.Twenty-two dyes which can be completely fade by FAS solution were screened out.They are sunset yellow,egg yolk,lemon yellow,golden yellow,yellow 3RS,frozen yellow,golden yellow,Telon Yellow RLN micro,Telon Yellow A2 R,Telon Yellow M-5GL,Nylosan Yellow E2 RL,Option Golden Yellow MF-RL,Dorolan Yellow E-2R,Nylanthrene Yellow B-4NGL,Erionyl Yellow A-R,Argacid Yellow E-HF,Isolan orang NHF-S,Telon Flavine M-7G,Argacid Yellow N-7G,Eriofast Yellow R,Eriofast Orange 4R,Active Yellow R.At the same time,it was found that FAS solution had bleaching effect on paper dyed with 17 yellow dyes,such as sunset yellow,egg yolk,lemon yellow,golden yellow,yellow 3RS,bright yellow,Telon Yellow RLN micro,Telon Yellow M-5GL,Isolan Yellow NHF-S,Nylosan Brilliant Flavine E-8GZ,Nylosan Yellow E2 RL,Telon Orange M-GSN,Argacid Yellow E-HF,Isolan orang NHF-S,Telon Flavine M-7G,Eriofast Orange 4R,Active Yellow R.(2)The fading mechanism of acid yellow 17,brilliant yellow,reactive yellow 3 and alkaline yellow 1 dyes was further studied.The results showed that FAS could fade acid yellow 17,brilliant yellow and reactive yellow 3.the fading mechanism might be through destroying the structure of-N=N-and FAS could not fade alkaline yellow 1.The fade of acid yellow 17,bright yellow and reactive yellow 3 dyes is mainly related to FAS concentration,hydroxide concentration and reaction temperature.The fade of FAS on these dyes began to fade in 30 minutes after the addition of FAS.Under suitable FAS solution concentration,the fading rate of FAS to dyes is above 90%.(3)Through the study of egg yolk,sunset yellow,yellow 3RS and frozen yellow with better fading effect,it was found that FAS solution completely exposed to air could fade these four dyes within 6 days,but the fading ability of FAS solution gradually declined from the 7th day.Adding stabilizers consisting of phenolphthalein,EDTA and sodium bicarbonate can obviously prolong the service life of FAS solution,and the fading effect of FAS solution with stabilizer is better than that of FAS solution without stabilizer at the 8th day.Three FAS solutions were used to bleach egg yolk dyed paper.It was found that the bleaching effect of FAS solution with stabilizer was better than that of FAS solution without stabilizer from the 7th day.In conclusion,FAS can completely fade 22 kinds of yellow dyes,and the fading effect is mainly affected by FAS and hydroxide concentration.FAS has bleaching effect on 17 kinds of yellow dyes on paper.FAS can fade acid yellow 17,bright yellow and reactive yellow 3,the fading mechanism may be through the destruction of-N=N-structure.The fading effect is related to FAS concentration,hydroxide concentration and reaction temperature.The stabilizer composed of EDTA and sodium bicarbonate can obviously prolong the service life of FAS solution.The above research lays a foundation for further research on the fading of dye wastewater in the future.