鋁錳氧化物負(fù)載鋸末對砷、氟的吸附效能及機理
發(fā)布時間：2018-09-01 14:06
【摘要】：隨著人們對健康和公共衛(wèi)生的重視,飲用水中砷污染和氟超標(biāo)問題越來越受到人們的關(guān)注。本研究以鋸末為載體,通過負(fù)載鋁錳氧化物改性鋸末,制備改性鋸末顆粒吸附劑。采用鋸末作為吸附劑的載體,不僅能充分利用農(nóng)業(yè)廢棄物,也可以找到一個經(jīng)濟、環(huán)境友好的吸附材料。并對改性鋸末表面特性、吸附去除氟、砷的效率及吸附機理進行了探討。主要實驗結(jié)果如下:1.在SEM、FTIR、BET、XPS等分析基礎(chǔ)上,對改性鋸末進行了表面結(jié)構(gòu)研究。相比于原鋸末,改性鋸末在1055 cm-1處的(-OH)彎曲振動峰型更加凸顯;改性鋸末的表面有微粒聚集,比表面積從0.757 m2/g增加到34.04m2/g。經(jīng)測定改性鋸末含錳1.485mg/g,含鋁40.864mg/g。2.通過投加量、pH實驗可知,吸附劑的最佳投加量為1g/L;pH=3時吸附除F效果較差,這是因為pH=3時溶出大量的Al3+并與F-形成優(yōu)勢絡(luò)合物[AlF]2+、[Al F2]+、AlF3,而此時吸附劑表面帶正電荷(pHpzc=5.21);pH=3時吸附除As(III)、As(V)效果較好,改性鋸末對As(III)的吸附是先將As(III)氧化成As(V)再吸附,和As(III)的吸附過程不同,改性鋸末直接吸附As(V)。3.通過動力學(xué)實驗,Power模型擬合R2值較高,可以很好的解釋吸附F、As(III)、As(V)的動力學(xué)數(shù)據(jù),說明改性鋸末表面分布有不同吸附能的活性位點。吸附F、As(III)、As(V)的吸附速率受顆粒內(nèi)擴散影響,但不是唯一的控制因素。4.通過等溫實驗,Freundlich、Langmuir等溫線模型均能較好的描述改性鋸末對F和As(III)的吸附,最大吸附量qm分別達到了27.68mg/g和29.95mg/g;Freundlich等溫線模型可以很好的描述改性鋸末吸附As(V),相比于原鋸末,改性鋸末對As(V)的吸附容量顯著增大。5.共存陰離子實驗結(jié)果可以看出,陰離子存在對吸附F有較小的負(fù)面影響;陰離子對吸附As(III)、As(V)也有負(fù)面影響,其中PO43-影響最大,因為PO43-和As為同族元素。6.動態(tài)除F的實驗可以看出,穿透曲線受pH、填料層高度、進水流速及初始溶液濃度影響。從As(III)的穿透曲線可以看出,在初始濃度為100μg/L時,112h后達到了10μg/L;動態(tài)除As(V)的實驗可以看出,初始濃度為150μg/L時,348h后達到了10μg/L,吸附去除As(V)持續(xù)不超過10μg/L的時間比去除As(III)時間長。
[Abstract]:With the attention of people to health and public sanitation, people pay more and more attention to arsenic pollution and fluorine excess in drinking water. In this study, the modified sawdust particle adsorbent was prepared by loading aluminum-manganese oxide on the carrier of sawdust. Using sawdust as the carrier of adsorbent can not only make full use of agricultural waste, but also find an economical and environmentally friendly adsorption material. The surface characteristics of modified sawdust, the adsorption efficiency of fluoride and arsenic and the adsorption mechanism were also discussed. The main experimental results are as follows: 1. The surface structure of modified sawdust was studied on the basis of SEM,FTIR,BET,XPS analysis. Compared with the original sawdust, the (-OH) bending vibration peak at 1055 cm-1 is more prominent, and the surface area of the modified sawdust increases from 0.757 m2 / g to 34.04 m2 / g, and the surface area of the modified sawdust is increased from 0.757 m2 / g to 34.04 m2 / g. The modified sawdust contains manganese 1.485 mg / g and aluminum 40.864 mg / g 路2. The results of pH experiment show that the optimum dosage of adsorbent is 1 g / L (pH = 3) and the adsorption efficiency of F is poor. This is because pH= 3 dissolves a large amount of Al3 and forms a dominant complex [AlF] 2, [Al F2] AlF3 with F-, and at this time, the adsorbent adsorbs As (III) as (V) with a positive charge (pHpzc=5.21) at pH = 3. The modified sawdust adsorbs As (III) by oxidizing As (III) to As (V) and then adsorbing it. Different from the adsorption process of As (III), modified sawdust adsorbs As (V). 3 directly. The kinetic data of adsorption of FBA as (III) and as (V) can be well explained by fitting the R ~ 2 value of the modified sawdust model with higher R ~ 2 value, indicating that the surface distribution of modified sawdust has active sites with different adsorption energy. The adsorption rate of (III) as (V) is affected by particle diffusion, but it is not the only controlling factor. 4. Freundlichl Langmuir isotherm model can well describe the adsorption of F and As (III) by modified sawdust. The maximum adsorption capacity of qm is up to 27.68mg/g and 29.95 mg / g / g Freundlich isotherm model, which can describe the adsorption of As (V), by modified sawdust as compared with that of original sawdust. The adsorption capacity of modified sawdust on As (V) was significantly increased. The experimental results of co-existing anions show that the existence of anions has a small negative effect on the adsorption of F, and that anions have a negative effect on the adsorption of As (III) and as (V), especially PO43-, because PO43- and As are homologous elements. The experimental results of dynamic removal of F show that the penetration curve is affected by the height of the pH, packing layer, the influent velocity and the initial concentration of the solution. From the breakthrough curve of As (III), we can see that 10 渭 g / L is achieved after 112h at the initial concentration of 100 渭 g / L and 10 渭 g / L after 348h when the initial concentration is 150 渭 g / L, and the time of As (V) removal is longer than that of As (III) removal.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ424;X703
本文編號：2217433
[Abstract]:With the attention of people to health and public sanitation, people pay more and more attention to arsenic pollution and fluorine excess in drinking water. In this study, the modified sawdust particle adsorbent was prepared by loading aluminum-manganese oxide on the carrier of sawdust. Using sawdust as the carrier of adsorbent can not only make full use of agricultural waste, but also find an economical and environmentally friendly adsorption material. The surface characteristics of modified sawdust, the adsorption efficiency of fluoride and arsenic and the adsorption mechanism were also discussed. The main experimental results are as follows: 1. The surface structure of modified sawdust was studied on the basis of SEM,FTIR,BET,XPS analysis. Compared with the original sawdust, the (-OH) bending vibration peak at 1055 cm-1 is more prominent, and the surface area of the modified sawdust increases from 0.757 m2 / g to 34.04 m2 / g, and the surface area of the modified sawdust is increased from 0.757 m2 / g to 34.04 m2 / g. The modified sawdust contains manganese 1.485 mg / g and aluminum 40.864 mg / g 路2. The results of pH experiment show that the optimum dosage of adsorbent is 1 g / L (pH = 3) and the adsorption efficiency of F is poor. This is because pH= 3 dissolves a large amount of Al3 and forms a dominant complex [AlF] 2, [Al F2] AlF3 with F-, and at this time, the adsorbent adsorbs As (III) as (V) with a positive charge (pHpzc=5.21) at pH = 3. The modified sawdust adsorbs As (III) by oxidizing As (III) to As (V) and then adsorbing it. Different from the adsorption process of As (III), modified sawdust adsorbs As (V). 3 directly. The kinetic data of adsorption of FBA as (III) and as (V) can be well explained by fitting the R ~ 2 value of the modified sawdust model with higher R ~ 2 value, indicating that the surface distribution of modified sawdust has active sites with different adsorption energy. The adsorption rate of (III) as (V) is affected by particle diffusion, but it is not the only controlling factor. 4. Freundlichl Langmuir isotherm model can well describe the adsorption of F and As (III) by modified sawdust. The maximum adsorption capacity of qm is up to 27.68mg/g and 29.95 mg / g / g Freundlich isotherm model, which can describe the adsorption of As (V), by modified sawdust as compared with that of original sawdust. The adsorption capacity of modified sawdust on As (V) was significantly increased. The experimental results of co-existing anions show that the existence of anions has a small negative effect on the adsorption of F, and that anions have a negative effect on the adsorption of As (III) and as (V), especially PO43-, because PO43- and As are homologous elements. The experimental results of dynamic removal of F show that the penetration curve is affected by the height of the pH, packing layer, the influent velocity and the initial concentration of the solution. From the breakthrough curve of As (III), we can see that 10 渭 g / L is achieved after 112h at the initial concentration of 100 渭 g / L and 10 渭 g / L after 348h when the initial concentration is 150 渭 g / L, and the time of As (V) removal is longer than that of As (III) removal.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ424;X703
【共引文獻】
相關(guān)期刊論文 前1條
1 萬祥云;朱泮民;;顆粒狀污泥活性炭流化床吸附處理含銅礦山廢水[J];化工環(huán)保;2013年04期
，本文編號：2217433
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