CaC_(2)O_(4)-直接枣红B/壳聚糖复合材料的制备及对乙基紫的吸附性能

Preparation of CaC_(2)O_(4)-direct claret B/chitosan composite materials and adsorption properties for ethyl violet

以壳聚糖(CTS)和草酸钙-直接枣红B(CaC_(2)O_(4)-DB)杂化材料为原料,采用共混原位固载法制备草酸钙-直接枣红B/壳聚糖(CaC_(2)O_(4)-DB/CTS)复合材料。利用SEM、BET和FTIR对CTS和CaC_(2)O_(4)-DB/CTS的形貌及结构等进行表征分析,CaC_(2)O_(4)-DB的固载并未改变CTS的形貌结构,仅增加其比表面积和结合位点。详细考察了吸附时间、乙基紫(Ethyl violet,EV)初始浓度、溶液pH及温度等因素对CaC_(2)O_(4)-DB/CTS吸附EV的影响,初步探讨了CaC_(2)O_(4)-DB/CTS对EV的吸附动力学和吸附热力学行为。结果表明,CaC_(2)O_(4)-DB/CTS吸附EV在3 h内达到吸附平衡,且pH=8、投加量为6 g/L时,25℃的100 mg/L EV溶液(化学需氧量(COD)为187 mg/L)染料去除率高达95%,COD去除率达90%以上。该吸附过程是自发进行的,符合Langmuir等温线模型和准二级动力学模型,其吸附过程由颗粒内扩散和化学吸附共同控制。

A composite adsorbent of CaC_(2)O_(4)-DB/CTS was prepared using chitosan(CTS)and the hybrid materials of CaC_(2)O_(4) and direct claret B(CaC_(2)O_(4)-DB/CTS)by the method of blending in-situ immobilization.CTS and CaC_(2)O_(4)-DB/CTS were characterized by SEM,BET and FTIR.The immobilization of CaC_(2)O_(4)-DB only increases the specific surface area and binding sites without changing the morphology and structure of CTS.The effects of adsorption time,the initial concentration of ethyl violet(EV),pH and temperature of the solution on the adsorption properties of CaC_(2)O_(4)-DB/CTS composite material were investigated in detail,and the adsorption kinetics and thermodynamic behavior of EV on CaC_(2)O_(4)-DB/CTS were preliminarily discussed.The results show that the removal rate of dye and chemical oxygen demand(COD)reach 95%and 90%for 100 mg/L EV solution(COD is 187 mg/L),respectively,under conditions of room temperature,CaC_(2)O_(4)-DB/CTS dosage of 6 g/L,adsorption time of 3 h and pH=8.The adsorption behavior of EV by the adsorbent is spontaneous and in accordance with Langmuir model and the quasi-secondorder kinetic model.The adsorption process is controlled by intra-particle diffusion and the chemical adsorption.