Study On Treatment Of DMF Containing Wastewater With Ion Exchange Resin

DMF is a fine organic solvent and an intermediate of fine chemical product which is widely used in industry. It is toxic and non-biodegradable. Pollution is becoming increasingly serious now, effectively and economically recovering DMF from wastewater has been a crucial research topic. The ion exchange resin was used to adsorb DMF from aqueous solution with the expectation of providing theoretical direction for further application.Comparing with001x7, D001,D113and D151resin,the ZGSPC106resin was selected as suitable adsorbent to treat simulated DMF wastewater of1000～3000mg/L based on the comparison of static adsorption capacity and adsorption. Then static and dynamic experiments were carried out to determine the optimum conditions for adsorption and regeneration such as pH, initial concentration, temperature, contact time, flow rate and so forth. The adsorption process was analyzed from the thermodynamic and kinetic aspects, furthermore, the adsorption mechanism was discussed by infrared spectroscopy analysis.Results of static experiments indicated that the ZGSPC106resin had high adsorption capacity with a maximal static saturated adsorption capacity of104.13mg/g (dry resin) at293K. The process was pH dependent and the optimum adsorption for DMF was found to occur at pH9.2of DMF solution. Moreover, the adsorption equilibrium could be attained within16min. Cations such as Na+, Ca2+, Mg2+and Fe3+could cause great interference owing to competitive adsorption.Dynamic experiments showed that the dynamic adsorption of DMF on rein was acceptable at flow rate5ml/min. With2mol/L hydrochloric as regenerant for saturated resin, the desorption efficiency reached as high as90%at10ml/min. Under selected conditions, the ZGSPC106resin had stable performance with regeneration rate close to95%and could be well reused due to its good stability.Thermodynamic calculations showed the feasibility, endothermic and spontaneous nature of the adsorption. The equilibrium data can be preferably modeled with the Langmuir isotherm, while kinetics data well followed the pseudo-second-order model and the adsorption rate was mainly controlled by the intraparticle diffusion.