Research And Application Of New Dyeing Technology Of Cotton Fiber By Reactive Dyes For Deep Water-saving And Pollution-reduction

This topic has studied a new type of deep water-saving and pollution-reducing technology,namely in-situ mineralization dyeing technology of cotton fiber.This technology is mainly aimed at the problems of low dye utilization,complicated post-treatment process,large water consumption,large amount of waste discharge,and high energy consumption of thermal energy in the dyeing of cotton fiber reactive dyes,and this technology ensures the physical and chemical properties of dyed products,reduces the number of cleansing after dyeing,and reduces the amount of pollutants discharged,thereby achieving the purpose of deep water saving,pollution reduction,and energy-saving green clean production.The key parts of in-situ mineralization dyeing technology can be divided into dyeing stage and mineralization stage.Because the mineralization reaction needs to be carried out under acidic conditions,when using soda ash fixation,the mineralization process consumes a large amount of acid and produce bubbles easily,which is not conducive to the progress of the mineralization reaction.Therefore,in the dyeing stage,the self-made XGA is used instead of soda ash as a fixing alkali agent,fixing effect similar to soda ash.After the fixation is completed,no dyeing raffinate is discharged,and in-situ mineralization series auxiliaries are directly added,so that the waste dyes are mineralized and decomposed in the original place where they are generated.After the end of mineralization,1-2 washings are performed to reduce the concentration of electrolytes and to remove a little floating color remaining due to the shielding effect of the electrolytes.By optimizing the XGA dosage,fixing time and the coupling agent XKH,XBC,XYS dosage,mineralization time and other parameters of the dyeing stage,the optimal in-situ mineralization dyeing process was obtained.When the dye amount was 7.0%(owf),the fixing alkali agent XGA amount was 2.0%(owf)and the fixing time was 80 minutes;the coupling agent XKH amount was 2.0%(owf),and the coupling agent XBC amount was 1.0%(owf).The amount of the coupling agent XYS was 5.0%(owf)and the mineralization time was 30 min.Through the study of dyeing characteristics,dynamics and thermodynamic properties,the effects of fixing alkali agent XGA and soda ash on the reactive dyeing mechanism of cotton products were discussed.The results showed that the adsorption process of the different alkali agents accorded with the pseudo-second-order kinetic model,and the adsorption isotherm types all met the Freundlich model.The XGA solid color exhaustion rate and fixation rate are similar to those of conventional soda ash.Therefore,it can be shown that the alkali agent XGA can replace the soda ash as the fixing alkali agent.In the company's production trials using in-situ mineralization technology,the color,color fastness,and production weaving of cotton yarns are basically the same as those of traditional processes.Compared with the traditional process,the use of in-situ mineralization dyeing technology reduces water consumption by 41.07%,steam savings by 29.54%,electricity savings by 10.77%,and the total CODCr of total pollutants decreases by 69.24%,the total biological oxygen demand(BODs)decreased by 78.12%,total nitrogen decreased by 48.04%,total phosphorus decreased by 36.39%,and the color value of wastewater decreased by 49.57%.This technology achieves the effect of deep water saving,environmental protection and energy saving,and meets the actual production requirements of the company.