【摘要】：本文研究了一種簡單有效的活性氧化鋁復(fù)合改性方法。通過對比多種改性方法改性活性氧化鋁后的除氟效果,篩選出一種最佳活性氧化鋁改性方法為Fe2(SO4)3和A12(SO4)3兩種鹽改性法。首先通過靜態(tài)吸附試驗(yàn),研究了改性活性氧化鋁對水中氟離子的吸附特性及影響因素,采用BET、SEM、XRD等分析方法對改性后的活性氧化鋁的表面特性進(jìn)行了表征。并研究了此改性活性氧化鋁的再生方法。主要研究結(jié)果與結(jié)論如下：1.經(jīng)過單因素實(shí)驗(yàn)和正交試驗(yàn),確定Fe2(SO4)3-Al2(SO4)3復(fù)合改性為最佳改性方法。最佳改性條件為：Fe2(SO4)3濃度為0.2%,固液比1：5,改性時間1h；A12(SO4)3濃度為0.5%,固液比1：15,改性時間0.5h。2.通過靜態(tài)吸附試驗(yàn),研究了Fe2(SO4)3-Al2(SO4)3-MAA對水中氟離子的吸附特性：Fe2(SO4)3-Ah(SO4)3-MAA對水中氟的吸附動力學(xué)符合擬二級動力學(xué)模型。氟在Fe2(SO4)3-Al2(SO4)3-MAA上的吸附更符合Langmuir等溫模型,25℃下Fe2(SO4)3-Al2(SO4)3-MAA的極限吸附量為6.25mg/g,吸附效果較理想。吸附過程△G00, △H00,AS00,說明Fe2(SO4)3-Al2(SO4)3-MAA對氟的吸附是自發(fā)的,是吸熱、熵增加反應(yīng)。3.研究了原水pH和共存陰離子對吸附效果的影響：Fe2(SO4)3-Al2(SO4)3-MAA除氟最佳pH范圍為5-9,pH值為6.0左右時吸附效果最好。Fe2(SO4)3-Al2(SO4)3-MAA除氟過程中,共存P043-影響最大,HCO3-、CO32-次之,NO3-、Cl-SO42-對除氟效果基本無影響。4.對改性前后的活性氧化鋁的表面性質(zhì)進(jìn)行了表征：通過BET和SEM分析結(jié)果看出,改性后的活性氧化鋁比表面積增加,孔道增多,因而使得吸附量增加。經(jīng)過氟吸附試驗(yàn)后的Fe2(SO4)3-Al2(SO4)3-MAA比表面積下降,吸附劑表面變得致密而光滑,氟吸附性能下降。根據(jù)XRD結(jié)果看出,活性氧化鋁在經(jīng)過Fe2(SO4)3-Al2(SO4)3復(fù)合改性后并沒有改變其晶體結(jié)構(gòu)。5.對經(jīng)Fe2(SO4)3-Al2(SO4)3-MAA除氟實(shí)驗(yàn)后的溶液進(jìn)行安全性評價：結(jié)果表明經(jīng)過除氟實(shí)驗(yàn)后的溶液中Fe3+、Al3+的含量均低于國家飲用水標(biāo)準(zhǔn),說明采用Fe2(SO4)3-A12(SO4)3-MAA進(jìn)行飲用水除氟是安全的。6.對吸附飽和的Fe2(SO4)3-Al2(SO4)3-MAA進(jìn)行再生研究：最佳再生條件是：先用05mol/L的NaOH解吸2h,再用Fe2(SO4)3-Al2(SO4)3進(jìn)行活化。經(jīng)5次吸附再生循環(huán)后,吸附容量為3.95mg/g,說明再生效果較好。
[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，

本文編號：2385183