| Dimethyl formamide(DMF)is a kind of important organic solvent,which is widely used in synthesis of polyacrylonitrile,polyamide,and so on.DMF is stability,poor biodegradability,and damage to skin,respiratory organs and eyes.The national maximum allowable concentration of DMF in ground water is 25 mg L-1.The main method for treating low concentration DMF wastewater is by degradation,but it can not reach the target and the cost is high.The direct discharge of DMF wastewatershows not only loss of DMF,known as a waste of resources,but also environmental issues.To improve energy saving and lower consumption,the multi-effect distillation was used to remove the light component in DMF wastewater.Then chromatography was used to analysis the concentration of DMF and heavy component.And the experimental results showed that at appropriate operating conditions,the recovery rate of DMF was greater than 95%,and the purity of DMF product was more than 99.5%by multi-effect distillation.For the low concentration DMF wastewater,which was lack of recycling value,was treated by using Fenton reagent.The effects of initial concentration,H2O2 and Fe2+ on the degradation rate and economic evaluation were discussed.Then the chemical method(alkalize method)in DMF wastewater treatment was investigated.The effects of temperature and reaction time on the degradation rate of DMF and the recycling of dimethylamine were studied.Based on the Radfrac strict algorithm model in Aspen software,the influence of process design parameters on the water content of the DMF product in the kettle was studied,such as the theoretical plate number,the feed position,the reflux ratio and the output quantity of top tower.Combined with the industrial data,referring to the simulation data,the new structured packing,efficient groove-tray distributor and new float valve trays were proposed.The best production parameters were obtained,and qualified DMF products were successful recoveried to create economic value for enterprises. |
PDF Full Text Request