【作者】 韩攀；

【导师】 韩润平；

【作者基本信息】 郑州大学 ， 环境科学， 2010， 硕士

【摘要】 沸石比表面积大,离子交换性强,再生容易,广泛应用于水处理中,但对阴离子染料的吸附性能较差；壳聚糖资源丰富、生物相容性好、具有优良的吸附性能且可以降解,广泛应用于环境工程、生命科学等领域,但由于价格昂贵应用受到一定限制。为改善沸石吸附性能,提高壳聚糖的利用率,本文将壳聚糖负载于天然沸石表面,制备了壳聚糖改性沸石吸附剂(CCZ),并研究了其对刚果红、亮绿和酸性铬蓝K的静态吸附行为,以及刚果红和亮绿混合体系中两者的竞争吸附行为。静态吸附试验研究了吸附时间、吸附剂用量、溶液pH值、盐浓度、染料浓度、溶液温度等条件对CCZ吸附水溶液中阴离子染料(刚果红、亮绿、酸性铬蓝K)的影响。研究结果表明：当pH值为4时,CCZ对三者的吸附量最佳；其中,对刚果红的吸附在pH为4-10范围内变化不大。溶液初始浓度和温度对吸附速率均有不同程度的影响,平衡吸附量都随溶液初始浓度的增加而增大,平衡吸附行为可以用Langmuir方程来描述,室温下CCZ对刚果红、亮绿和酸性铬蓝K的饱和吸附量qm分别为10.0、40.7、29.8 mg·g-1。与沸石相比,CCZ对三种染料的最大吸附量均有所提高。CCZ对三种染料的吸附过程可分为快速和慢速两个阶段；其中,刚果红和酸性铬蓝K的吸附动力学过程用Elovich动力学方程描述较好,亮绿的吸附则用准二级动力学方程描述较好。CCZ对三种染料的吸附包含多种机理,但主要靠静电引力进行。CCZ对刚果红、亮绿和酸性铬蓝K的表观吸附活化能分别为：66.0、37.3和57.4kJ·mol-1,ΔG均为负值,表明吸附过程是自发的。CCZ对刚果红和亮绿的双组份吸附实验表明,在混合体系中存在着竞争吸附,且两者是同时被吸附的。此外,CCZ吸附刚果红和酸性铬蓝K后,可采用0.01 mol·L-1的NaOH溶液处理的方法再生,一次再生率分别为98.7%和40.9%；CCZ吸附亮绿后可用微波在320 W下辐照10 min的方法再生,一次再生率可达98.7%。更多还原

【Abstract】 Zeolite has a relatively large surface area, and good adsorption properties, which has been widely used in water treatment, but it has a low capacity on the adsorption of anionic dyes. Chitosan is a renewable and abundant natural macromolecule compound, which is nontoxic, biocompatible and biodegradarable, and it has been widely used in environmental engineering, life sciences and other fields, but it is expensive. To improve the adsorption properties of zeolite and the utilization of chitosan, the research designed an adsorbent, chitosan coated zeolite (CCZ), which was prepared by coating chitosan onto the surface of zeolite, for removal of congo red (CR), light green (LG) and acid chrome blue K (AK) from synthetic solutions.In the batch adsorption, the effect of various experimental conditions, such as contact time, adsorbents dose, pH values, coexisting ions, initial concentration of the adsorbate and temperature were carried out. The experimental results showed that the appropriate initial pH for the three dyes adsorption on CCZ was 4. During the pH value 4～10, the adsorption quantity of CCZ binding CR was approximately constant. Adsorbate concentration and temperature had varying degrees on the adsorption rates. The adsorption quantities of dyes increased with the increase of the adsorbate concentration, and all the isothermal data followed the Langmuir model. The maximum adsorption capacity (qm) of CR, LG and AK from Langmuir model was 10.0,40.7 and 29.8 mg·g-1, respectively. Compared with zeolite, adsorption quantities of CCZ for three dyes were all improved. The kinetics process of adsorption consisted of two phases:an initial rapid phase and a slower second phase. The Elocich model showed good correlation for the adsorption of CR and AK on CCZ, while for LG adsorption, it was the pseudo-second-order model fitted best. Electrostatic attraction may be the main mechanism of the three dyes adsorption. The activation energy (Ea) of CCZ binding CR, LG and AK was determined as 66.0, 37.3 and 57.4 kJ·mol-1, respectively. The negative values of AG indicated that the adsorption processes were spontaneous. In the binary system, CR and LG were simultaneously adsorbed, and there was competitive adsorption between them. In addition, the used CCZ, which was used to remove CR and AK, could be regenerated by NaOH solution (0.01 mol·L-1) and the regeneration rate could reach 98.7% and 40.9%, respectively. But the LG-loaded CCZ was regenerated by microwave irradiation with 320 W for 10 min, and the regeneration rate was 98.7%.更多还原