3，5-二硝基苯甲酸氧化纤维素酯的吸附性能研究

he adsorption property of dialdehyde cellulose 3, 5-dinitrobenzoate (DCNB) for creatinine and urea was studied under simulated biological conditions. The influences of adsorption time, the initial concentration, the dose of adsorbent and pH value on the adsorption of DCNB were investigated. The results showed that when the adsorption temperature was 37 ℃, the adsorption equilibrium of creatinine onto DCNB (DS=0.93) was reached after 6 hours, with a saturated adsorption capacity (AC) of 2.974 mg/g in100 mg/L creatinine dialysate. The equilibrium time of adsorption for urea was 5 hours and the saturated AC of urea was 14.75 mg/g in 3 g/L urea dialysate. Equilibrium data of creatinine and urea both fit well with Freundich equation. The Freundich index (1/n) was less than 1, which implied that the adsorption was preferential process. The dose of adsorbent had a great influence on the adsorption property of DCNB. The adsorption quality (AQ) of creatinine and urea increased and the AC decreased with the increase of the dose of adsorbent. The AC of creatinine first decreased and then increased, while the AC of urea first increased and then decreased as the pH value increased from 5 to 11.