【作者】 马明海；

【导师】 彭书传；

【作者基本信息】 合肥工业大学 ， 环境工程， 2007， 硕士

【摘要】 本文利用LDH独特的结构“记忆效应”，研究了LDO去除水中对硝基苯酚的效果及再生性能，同时考察了即时合成LDH处理对硝基苯酚的可行性，采用XRD、FT-IR、TEM等分析手段，并通过吸附热力学和动力学探讨了LDO吸附对硝基苯酚的机理，得出以下结论：(1)当Mg／Al=3∶1，pH=11，p=10mg／L，T=298K，t=2h，对硝基苯酚的去除率最高为33％。即时合成LDH去除对硝基苯酚是不可行的。(2)当pH=6，p=100mg／L，T=303K，LDO投加量为0.3g／100ml，150r／min时恒温振荡2h，对硝基苯酚的去除率高达82％。LDO对对硝基苯酚的最大吸附量为201.83mg／g，为理论阴离子交换容量的24.9％，大部分对硝基苯酚被吸附在LDO表面，进入LDH层间的对硝基苯酚离子呈单层倾斜27°排列。(3) LDO吸附对硝基苯酚是一个自发的、熵增的吸热过程，主要推动力是静电引力，吸附过程以颗粒内扩散为速率控制步骤。(4)通过高温焙烧法实现了吸附产物的再生。450℃焙烧2h的再生产物对500mg／L的对硝基苯酚的去除率高达89％。在前四次循环内再利用是可行的。再生产物中镁离子的流失是造成再利用效率下降的主要原因之一。更多还原

【Abstract】 The removal efficiency of p-nitrophenol （PNP） onto LDO and its regeneration were studied utilizing unique "memory effect" of LDH in this paper. The feasibility of treatment of PNP by synthesizing LDH in-situ was investigated simultaneously. The mechanism of PNP adsorption onto LDO was discussed by adsorption thermodynamics and kinetics. Such analysis instruments as XRD、FT-IR and TEM were adopted. Some main conclusions can be drawn as follows:（1） The removal efficiency of PNP achieved the peak -33% when Mg/Al = 3 : 1, pH=11, p=10mg/L, T = 298K, t=2 h. It showed that the treatment of PNP by synthesizing LDH in-situ was infeasible.（2） The removal efficiency of PNP arrived at 82% when pH = 6,ρ= 100mg/L, T = 303K, t = 2 h, r=150r/min, m/V=0.3g/100mL. The maximal adsorption capacity of PNP onto LDO was 201.83 mg/L, which only accounted for 24.9% of theoretical anion exchange capacity. Most of PNP were adsorpted on the surface of LDO; the arrangement mode of PNP in the interlayer of LDH was slantwise monolayer and the angle tilted was 27°.（3） The adsorption of PNP onto LDO was a spontaneous endothermic and an increasing entropy process. The adsorption occurred because of the static gravitation. Intraparticle diffusion being the rate-controlling step during the adsorption process.（4） The regeneration of the products was carried out by high temperature calcination. The removal efficiency of PNP reached to 89% by calcining 2 h under 450℃. The experiment indicated that regeneration of products was feasible within the four times recycle, and the decreasing of Mg²⁺ ion was one of the important factors resulting in the decline of re-adsorption efficiency.更多还原