两种盐复合改性活性氧化铝除氟性能及再生研究
发布时间：2018-12-18 02:39
【摘要】：本文研究了一种简单有效的活性氧化铝复合改性方法。通过对比多种改性方法改性活性氧化铝后的除氟效果,筛选出一种最佳活性氧化铝改性方法为Fe2(SO4)3和A12(SO4)3两种盐改性法。首先通过静态吸附试验,研究了改性活性氧化铝对水中氟离子的吸附特性及影响因素,采用BET、SEM、XRD等分析方法对改性后的活性氧化铝的表面特性进行了表征。并研究了此改性活性氧化铝的再生方法。主要研究结果与结论如下：1.经过单因素实验和正交试验,确定Fe2(SO4)3-Al2(SO4)3复合改性为最佳改性方法。最佳改性条件为：Fe2(SO4)3浓度为0.2%,固液比1：5,改性时间1h；A12(SO4)3浓度为0.5%,固液比1：15,改性时间0.5h。2.通过静态吸附试验,研究了Fe2(SO4)3-Al2(SO4)3-MAA对水中氟离子的吸附特性：Fe2(SO4)3-Ah(SO4)3-MAA对水中氟的吸附动力学符合拟二级动力学模型。氟在Fe2(SO4)3-Al2(SO4)3-MAA上的吸附更符合Langmuir等温模型,25℃下Fe2(SO4)3-Al2(SO4)3-MAA的极限吸附量为6.25mg/g,吸附效果较理想。吸附过程△G00, △H00,AS00,说明Fe2(SO4)3-Al2(SO4)3-MAA对氟的吸附是自发的,是吸热、熵增加反应。3.研究了原水pH和共存阴离子对吸附效果的影响：Fe2(SO4)3-Al2(SO4)3-MAA除氟最佳pH范围为5-9,pH值为6.0左右时吸附效果最好。Fe2(SO4)3-Al2(SO4)3-MAA除氟过程中,共存P043-影响最大,HCO3-、CO32-次之,NO3-、Cl-SO42-对除氟效果基本无影响。4.对改性前后的活性氧化铝的表面性质进行了表征：通过BET和SEM分析结果看出,改性后的活性氧化铝比表面积增加,孔道增多,因而使得吸附量增加。经过氟吸附试验后的Fe2(SO4)3-Al2(SO4)3-MAA比表面积下降,吸附剂表面变得致密而光滑,氟吸附性能下降。根据XRD结果看出,活性氧化铝在经过Fe2(SO4)3-Al2(SO4)3复合改性后并没有改变其晶体结构。5.对经Fe2(SO4)3-Al2(SO4)3-MAA除氟实验后的溶液进行安全性评价：结果表明经过除氟实验后的溶液中Fe3+、Al3+的含量均低于国家饮用水标准,说明采用Fe2(SO4)3-A12(SO4)3-MAA进行饮用水除氟是安全的。6.对吸附饱和的Fe2(SO4)3-Al2(SO4)3-MAA进行再生研究：最佳再生条件是：先用05mol/L的NaOH解吸2h,再用Fe2(SO4)3-Al2(SO4)3进行活化。经5次吸附再生循环后,吸附容量为3.95mg/g,说明再生效果较好。
[Abstract]:In this paper, a simple and effective method for the modification of active alumina was studied. By comparing the defluorination effect of activated alumina modified by various modification methods, the optimum modification methods of active alumina were selected as Fe2 (SO4) 3 and A12 (SO4) 3 salt modification methods. Firstly, the adsorption characteristics and influencing factors of modified activated alumina to fluoride ion in water were studied by static adsorption test. The surface characteristics of modified activated alumina were characterized by BET,SEM,XRD and other analytical methods. The regeneration method of the modified active alumina was studied. The main results and conclusions are as follows: 1. Fe2 (SO4) 3-Al2 (SO4) 3 composite modification was determined as the best modification method by single factor experiment and orthogonal experiment. The optimum modification conditions are as follows: the concentration of Fe2 (SO4) 3 is 0.2, the ratio of solid to liquid is 1: 5, the time of modification is 1 h / 5, the concentration of SO4 3 is 0.5%, the ratio of solid to liquid is 1: 15, and the modification time is 0.5 h 路2. The adsorption characteristics of fluorine ions in water by Fe2 (SO4) 3-Al2 (SO4) 3-MAA were studied by static adsorption experiments. The adsorption kinetics of Fe2 (SO4) 3-Ah (SO4) 3-MAA for fluoride in water was in accordance with the pseudo-second-order kinetic model. The adsorption of fluorine on Fe2 (SO4) 3-Al2 (SO4) 3-MAA is more consistent with the Langmuir isothermal model. The limit adsorption capacity of Fe2 (SO4) 3-Al2 (SO4) 3-MAA is 6.25 mg / g at 25 鈩，
本文编号：2385183
[Abstract]:In this paper, a simple and effective method for the modification of active alumina was studied. By comparing the defluorination effect of activated alumina modified by various modification methods, the optimum modification methods of active alumina were selected as Fe2 (SO4) 3 and A12 (SO4) 3 salt modification methods. Firstly, the adsorption characteristics and influencing factors of modified activated alumina to fluoride ion in water were studied by static adsorption test. The surface characteristics of modified activated alumina were characterized by BET,SEM,XRD and other analytical methods. The regeneration method of the modified active alumina was studied. The main results and conclusions are as follows: 1. Fe2 (SO4) 3-Al2 (SO4) 3 composite modification was determined as the best modification method by single factor experiment and orthogonal experiment. The optimum modification conditions are as follows: the concentration of Fe2 (SO4) 3 is 0.2, the ratio of solid to liquid is 1: 5, the time of modification is 1 h / 5, the concentration of SO4 3 is 0.5%, the ratio of solid to liquid is 1: 15, and the modification time is 0.5 h 路2. The adsorption characteristics of fluorine ions in water by Fe2 (SO4) 3-Al2 (SO4) 3-MAA were studied by static adsorption experiments. The adsorption kinetics of Fe2 (SO4) 3-Ah (SO4) 3-MAA for fluoride in water was in accordance with the pseudo-second-order kinetic model. The adsorption of fluorine on Fe2 (SO4) 3-Al2 (SO4) 3-MAA is more consistent with the Langmuir isothermal model. The limit adsorption capacity of Fe2 (SO4) 3-Al2 (SO4) 3-MAA is 6.25 mg / g at 25 鈩，
本文编号：2385183
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