本文選題：鐵銅鑭復(fù)合氧化物 + 砷�。� 參考：《哈爾濱工業(yè)大學(xué)》2017年碩士論文

【摘要】：砷較大的毒性使得水源砷污染問(wèn)題受到了許多國(guó)家的關(guān)注。我國(guó)在2006年將飲用水砷濃度調(diào)整為10μg/L,更加嚴(yán)格的標(biāo)準(zhǔn)也進(jìn)一步促進(jìn)了除砷工藝研究的深入。在除砷技術(shù)中,吸附法由于經(jīng)濟(jì)有效的特點(diǎn)而受到大量研究,而吸附劑作為吸附法的核心,如何開(kāi)發(fā)一種能高效除砷的吸附劑是當(dāng)前的研究熱點(diǎn)。本研究旨在結(jié)合磁性鐵氧化物的磁分離性能、銅氧化物適用范圍大以及鑭氧化物對(duì)砷吸附能力強(qiáng)的優(yōu)點(diǎn),制備出能結(jié)合三者優(yōu)點(diǎn)的鐵銅鑭復(fù)合氧化物,并對(duì)其吸附砷的性能進(jìn)行研究考察。采用化學(xué)共沉淀法制備出一系列鐵銅鑭復(fù)合氧化物吸附劑,對(duì)比了各吸附劑對(duì)水中As(V)和As(III)的吸附效果,確定了鐵銅鑭比例為2:1:4,陳化溫度50℃,干燥溫度80℃為最佳制備條件。鐵銅鑭復(fù)合氧化物是由納米級(jí)的球狀、片狀及棒狀顆粒物團(tuán)聚而成,吸附劑表面不均勻,為多孔狀不規(guī)則結(jié)構(gòu),材料主體結(jié)構(gòu)可能為反立方尖晶石型,同時(shí)材料中可能含有Fe3O4、Fe Cu2O4、La(OH)3以及Cu O。該材料的BET表面積為27.89m2/g,平均孔徑為32.295 nm(4V/S)。材料的等電點(diǎn)為7.2,當(dāng)溶液p H7.2時(shí),材料表面顯正電性。通過(guò)磁滯回線確定了材料的矯頑力為50.109 emu/g,通過(guò)永磁體能將該材料從水中快速分離出來(lái)。Langmuir模型對(duì)As(V)和As(III)吸附過(guò)程的擬合效果最好,其相關(guān)系數(shù)R2均都達(dá)到了0.97以上,并且在這15、25、35℃溫度下對(duì)于As(V)的飽和吸附量分別達(dá)到了116.59、138.26、155.58 mg/g,對(duì)As(III)的飽和吸附量達(dá)到了88.35、93.18、103.83 mg/g;計(jì)算不同溫度下吸附反應(yīng)的熱力學(xué)參數(shù),能求得熱力學(xué)參數(shù)ΔG0、ΔH0、ΔS0,可見(jiàn)該材料吸附As(V)和As(III)為自發(fā)的吸熱過(guò)程。吸附實(shí)驗(yàn)在前480 min內(nèi)吸附速率較快,在720 min后趨于穩(wěn)定;As(V)和As(III)的吸附過(guò)程用準(zhǔn)一級(jí)動(dòng)力學(xué)方程和準(zhǔn)二級(jí)動(dòng)力學(xué)方程擬合,其相關(guān)系數(shù)R2均達(dá)到了0.98以上。改變p H和離子強(qiáng)度考察其對(duì)砷吸附的影響,結(jié)果顯示過(guò)酸或過(guò)堿都會(huì)影響到砷的吸附,p H 6~8時(shí)吸附量達(dá)到最大;離子強(qiáng)度的變化對(duì)As(V)、As(III)的吸附影響并不大,可能是因?yàn)锳s(V)、As(III)與材料形成了內(nèi)層絡(luò)合物。水中常見(jiàn)的離子中Ca2+、Mg2+對(duì)吸附幾乎沒(méi)影響,高濃度的HCO32-、F-、Si O32-、PO43-會(huì)對(duì)As(V)和As(III)造成較大的影響,且對(duì)As(III)的吸附性能影響大于As(V)。采用鐵銅鑭復(fù)合氧化物對(duì)吉林省某河流水體進(jìn)行吸附處理,確定材料對(duì)砷的吸附效果。若材料的投加量越大,水中剩余的砷含量則越低,當(dāng)材料投加量超過(guò)30 mg/L時(shí)吸附后即可滿足飲用水砷濃度標(biāo)準(zhǔn)。對(duì)實(shí)際水體進(jìn)行吸附動(dòng)力學(xué)實(shí)驗(yàn),發(fā)現(xiàn)鐵銅鑭復(fù)合氧化物對(duì)實(shí)際水體中砷的吸附符合準(zhǔn)二級(jí)動(dòng)力學(xué)模型,在前60 min內(nèi)吸附速率非�？�,吸附120 min后便使水體中砷含量低于10μg/L(國(guó)際飲用水標(biāo)準(zhǔn)砷含量上限)。處理一噸實(shí)際水體的成本為1.74元。
[Abstract]:The arsenical toxicity of arsenic has attracted the attention of many countries. In 2006, the concentration of arsenic in drinking water was adjusted to 10 mu g/L in China. The more strict standard also further promoted the research of arsenic removal technology. In the arsenic removal technology, the adsorption method has been extensively studied because of the economical and effective characteristics, and the adsorbent is used as absorption. At the core of the method, how to develop a highly efficient adsorbant for arsenic removal is the current research focus. This study aims to combine the magnetic separation properties of magnetic iron oxides, the large application range of copper oxide and the strong adsorption capacity of lanthanum oxide on arsenic, and to prepare the iron, copper and lanthanum compound oxide which can combine the three best points and adsorb arsenic on it. A series of iron copper and lanthanum oxide adsorbents were prepared by chemical coprecipitation method. The adsorption effects of adsorbents on As (V) and As (III) in water were compared. The ratio of iron, copper and lanthanum was determined to be 2:1:4, the aging temperature was 50, and the drying temperature was 80. Fe3O4, Fe Cu2O4, La (OH) 3 and Cu O. have a BET surface area of 27.89m2 /g, and the average pore size is 32.295 nm (4V/S). The isoelectric point of the material is 7.2, when the material may contain the anti cubic spinel type, and the material may contain the BET surface area of the material with 27.89m2 /g. The surface of the material is positive on the surface of P H7.2. The coercive force of the material is determined to be 50.109 emu/g by the hysteresis loop. The best fitting effect of the.Langmuir model to the adsorption process of As (V) and As (III) through the permanent magnet can be quickly separated through the permanent magnet, and the correlation coefficient R2 is above 0.97, and the temperature of the 15,25,35 is at the 15,25,35 temperature. The saturated adsorption capacity of As (V) reached 116.59138.26155.58 mg/g, respectively, and the saturated adsorption capacity of As (III) reached 88.35,93.18103.83 mg/g. The thermodynamic parameters of the adsorption reaction at different temperatures could be calculated. The thermodynamic parameters, Delta G0, Delta H0, and delta S0, can be obtained. The adsorption rate was faster in the first 480 min and stable after 720 min; the adsorption process of As (V) and As (III) was fitted with quasi first order kinetic equation and quasi two order kinetic equation, and the correlation coefficient R2 reached over 0.98. The effect of P H and ionic strength on arsenic adsorption was changed, and the results showed that both excess acid or excess alkali would affect the absorption of arsenic. The adsorption capacity of P H 6~8 reaches the maximum, and the changes in ionic strength have little influence on the adsorption of As (V) and As (III). It is probably because As (V), As (III) forms an inner complex with the material. The adsorption of As (III) is greater than that of As (V). The adsorption effect of iron copper and lanthanum compound oxide on the water of a river in Jilin province is used to determine the adsorption effect of the material on arsenic. If the amount of material is increased, the residual arsenic content in water is lower, and the adsorption of arsenic in drinking water can be satisfied when the amount of material is more than 30 mg/L. The adsorption kinetics experiment was carried out in the actual water body. It was found that the adsorption of arsenic in the actual water body was in accordance with the quasi two order kinetic model. The adsorption rate was very fast in the first 60 min. After the adsorption 120 min, the arsenic content in the water body was less than 10 mu g/L (the limit of arsenic content in the international drinking water standard). The cost of treating a ton of actual water body was 1.7. 4 yuan.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TU991.2;O647.3
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本文編號(hào)：2090583