Mn@海藻酸微球吸附去除盐酸四环素及其类Fenton再生

以海藻酸钠为基体,制备出了Mn@海藻酸复合吸附剂.采用FE-SEM、EDS和FT-IR对产品的结构进行了表征,研究了Mn@海藻酸复合吸附剂吸附去除盐酸四环素水溶液的过程,主要考察了溶液初始浓度、p H和吸附时间对盐酸四环素吸附过程的影响,同时进行了动力学、等温模型和热力学分析,并对吸附剂的再生进行了评价.结果表明,盐酸四环素溶液初始浓度越大,平衡吸附量越大;强酸不利于Mn@海藻酸微球吸附反应的进行;随着时间的延长,吸附量呈逐渐增加的趋势.动力学模拟结果表明,吸附过程符合准二级动力学模型,等温吸附曲线符合Langmuir等温模型;热力学参数ΔG0,ΔH0,ΔS0,表明该吸附过程为自发吸热过程.通过构造Fenton-like反应体系,表面富集有盐酸四环素的Mn@海藻酸微球吸附剂可有效实现原位再生,重复使用.研究结果对含盐酸四环素废水的处理提供重要的理论依据.

Adsorption of tetracycline hydrochloride by Mn@alginate microspheres and their Fenton-like regeneration

Mn@alginate composite microspheres were successfully prepared by using sodium alginate as raw materials. The as-obtained Mn@alginate products were characterized by using FE-SEM, EDS and FT-IR. Whereafter, the Mn@alginate were used for the adsorption of tetracycline hydrochloride from aqueous solutions. Various factors affecting the adsorption process, such as initial concentration of tetracycline hydrochloride, pH and contacting time were discussed, respectively. Moreover, adsorption kinetics, isotherm models and adsorption thermodynamics were analyzed. The regeneration of Mn@alginate was also evaluated. The results show that higher initial concentration of tetracycline hydrochloride has lead to greater equilibrium adsorption capacity. The adsorption amounts were further increased with the time prolonged. Strong acidity was not good for the adsorption of tetracycline hydrochloride onto Mn@alginate composite adsorbents. The adsorption of tetracycline hydrochloride by Mn@alginate was found in good correlation with the pseudo-second-order kinetic equation and Langmuir isothermal model. Absorption of the tetracycline hydrochloride from aqueous solutions is spontaneous and endothermic, and they were dominated by chemical adsorption and physical adsorption simultaneously. The adsorptive enrichment of tetracycline hydrochloride onto the surface of Mn@alginate adsorbent could be effectively regenerated and recycled through Fenton-like reaction.