【摘要】 用717阴离子交换树脂自二元水溶液中选择吸附分离水杨酸和苯酚。采用静态及动态法研究了二元水溶液中树脂对每种吸附质的吸附行为,考察了pH、浓度、时间等对吸附的影响,探讨了等温吸附和吸附动力学特性。结果表明,pH是影响选择吸附分离的主要因素,pH=4.5时,苯酚的存在几乎不影响水杨酸的吸附;pH=11时,苯酚能替换树脂上已吸附的水杨酸而导致水杨酸的吸附量大为降低;pH为4～8时,树脂对水杨酸的吸附能力远比苯酚好,有很高的吸附选择性,利于水杨酸与苯酚的选择吸附分离。静态吸附表明,树脂对水杨酸和苯酚的吸附均符合Freundlich等温吸附方程,为优惠吸附;吸附动力学符合Lagergren准一级速率方程。动态吸附表明,用1.5 g树脂装柱,吸附出水在475 mL内几乎只含苯酚,水杨酸被吸附于树脂上,用5%NaCl+2%NaOH溶液可将树脂上吸附的水杨酸完全洗脱,有效实现了水杨酸和苯酚的选择性吸附分离。更多还原

【Abstract】 The anion exchange resin 717 was used to selectively adsorb and separate the salicylic acid and phenol from their binary aqueous solution.The adsorption behavior of 717 resin for each adsorbate was studied via both dynamic and static methods.The effects of pH value,adsorbate concentration and adsorption time on the adsorption process were investigated,and the isotherm adsorption and adsorption kinetics were also studied.The experimental results show that the pH value of the solution plays the most important role in the adsorption and separation process.At pH of 4.5,the existence of phenol in the solution essentially does not affect the salicylic acid adsorption of the 717 resin,while when the pH is 11,the phenol can be adsorbed by 717 resin to substitute the adsorbed salicylic acid on it,which substantially decreases the salicylic acid adsorption capacity of the resin.In the pH range of 4 ~8,the 717 resin has very high selective adsorption ability and adsorption capacity for the salicylic acid,and its adsorption capacity for salicylic acid is more than an order of magnitude larger than that for the phenol.With such high adsorption selectivity,the 717 resin is favorable to be used for the separation salicylic acid from the binary aqueous solution of salicylic acid and phenol.The static adsorptions show that the adsorptions of salicylic acid and phenol by 717 resin are in accordance with Freundlich isotherm model,and the adsorption kinetics data fit well with the Lagergren pseudo-first order rate equation.Dynamic adsorption of the mixed binary aqueous solution of salicylic acid and phenol by 717 resin shows that,in a column with resin of 1.5 g,the first 475 mL of the exit water after adsorption contains essentially only the phenol because almost all the salicylic acid are adsorbed by the resin.It was found that the salicylic acid adsorbed on the resin can be easily eluted by the 5%NaCl+2%NaOH solution at room temperature.更多还原