【摘要】：水熱條件下制備了純針鐵礦、赤鐵礦和不同比例的錳、鉻摻雜氧化鐵,采用現(xiàn)代測(cè)試技術(shù)分析了樣品的微觀結(jié)構(gòu)和表面性質(zhì),通過(guò)等溫吸附實(shí)驗(yàn)研究了樣品對(duì)不同價(jià)態(tài)硒的吸附特性,并探討了其吸附機(jī)制。取得的主要結(jié)果有:(1)在合成針鐵礦的體系中,低比例錳摻雜(R=0.1~0.2,R為摻雜金屬與鐵的摩爾比)促進(jìn)了針鐵礦的形成;隨著摻雜比例的升高,產(chǎn)物的形貌變得越細(xì)長(zhǎng)。錳摻雜比例較高時(shí)(R=0.3~0.5),隨著摻雜比例的升高,產(chǎn)物的結(jié)晶度不斷降低,顆粒尺寸逐漸變短;當(dāng)R=0.5時(shí),產(chǎn)物中出現(xiàn)了形貌不規(guī)則的摻錳磁鐵礦。在合成赤鐵礦的體系中,錳的摻雜比例R從0.1增加至0.5時(shí),產(chǎn)物中赤鐵礦的結(jié)晶度不斷減弱,顆粒尺寸也不斷變小;當(dāng)R=0.5時(shí),產(chǎn)物主要為摻錳磁鐵礦。鉻的摻雜比例R=0.1~0.5時(shí),針鐵礦和赤鐵礦的形成都受到了明顯的抑制作用,且產(chǎn)物中沒(méi)有形成其它結(jié)晶物質(zhì);隨著摻雜比例的升高,產(chǎn)物中針鐵礦和赤鐵礦的結(jié)晶度不斷減弱,其顆粒尺寸逐漸減小;當(dāng)摻雜比例R=0.5時(shí),產(chǎn)物中出現(xiàn)了大量非晶形顆粒物。(2)樣品的氮?dú)獾葴匚?脫附分析顯示,針鐵礦(Goe)和R=0.2時(shí)的錳、鉻摻雜產(chǎn)物(G-Mn0.2和G-Cr0.2)的比表面積分別為46.25、83.45和101.33 m2·g-1;3種樣品的平均孔徑分別為23.63、14.29和2.43 nm。赤鐵礦(Hem)和R=0.2時(shí)的錳、鉻摻雜產(chǎn)物(H-Mn0.2和H-Cr0.2)的比表面積分別為12.29、169.62和99.55 m2·g-1;它們的平均孔徑分別為6.75、0.75和0.97 nm。錳、鉻摻雜對(duì)針鐵礦和赤鐵礦的表面分形度(SFD)的影響較小,其中Goe及其摻雜產(chǎn)物的SFD在2.43~2.54間,Hem及其摻雜產(chǎn)物的SFD在2.56~2.73間。(3)Goe、G-Mn0.2和G-Cr0.2的Zeta電位零點(diǎn)分別為7.36、6.58和4.74,Hem、H-Mn0.2和H-Cr0.2的Zeta電位零點(diǎn)分別為6.41、5.42和5.71�？梢�(jiàn),錳、鉻摻雜都明顯降低了氧化鐵的表面電位零點(diǎn)。激光粒度分析顯示,Goe、G-Mn0.2和G-Cr0.2的顆粒平均粒度分別為630、915和765 nm,Hem、H-Mn0.2和H-Cr0.2的平均粒度分別為1025、534和523 nm�？梢�(jiàn),摻雜比例R=0.2時(shí),錳、鉻摻雜針鐵礦的顆粒粒度增加,而摻雜赤鐵礦的粒度卻明顯減小。(4)樣品對(duì)不同價(jià)態(tài)硒的等溫吸附實(shí)驗(yàn)表明,同種樣品對(duì)Se(Ⅳ)的吸附容量明顯高于對(duì)Se(Ⅵ)。錳、鉻摻雜升高了針鐵礦和赤鐵礦對(duì)Se(Ⅳ)和Se(Ⅵ)的吸附容量,其中對(duì)吸附Se(Ⅳ)的影響更明顯。當(dāng)Se(Ⅳ)的初始濃度為80 mg·g-1時(shí),Goe、G-Mn0.2和G-Cr0.2對(duì)Se(Ⅳ)的吸附容量分別約為10、16和25 mg·g-1;Hem、H-Mn0.2和H-Cr0.2對(duì)Se(Ⅳ)的吸附容量分別約為6、23和24 mg·g-1�？梢�(jiàn),摻雜比例R=0.2時(shí),鉻摻雜針鐵礦和赤鐵礦對(duì)Se(Ⅳ)的吸附容量都高于錳摻雜產(chǎn)物。(5)初始p H=4.0時(shí),Goe、G-Mn0.2和G-Cr0.2吸附Se(Ⅳ)以后體系的p H值分別升高至5.6、5.7和5.9,吸附Se(Ⅵ)以后的p H分別為4.3、4.9和5.2;Hem、H-Mn0.2和H-Cr0.2吸附Se(Ⅳ)以后的p H分別為4.3、5.4和5.3,吸附Se(Ⅵ)以后的p H分別為4.4、5.0和5.1。Zeta電位分析表明,各種樣品吸附Se(Ⅳ)和Se(Ⅵ)以后,樣品的Zeta電位零點(diǎn)都有所降低;Goe、Hem和鉻摻雜產(chǎn)物吸附Se(Ⅳ)以后的Zeta電位零點(diǎn)略低于吸附Se(Ⅵ)以后的值,錳摻雜產(chǎn)物吸附Se(Ⅳ)以后的Zeta電位零點(diǎn)反而高于吸附Se(Ⅵ)以后的值。這表明靜電引力、陰離子交換、表面配位等作用是樣品吸附Se(Ⅳ)和Se(Ⅵ)的重要機(jī)制,其中樣品對(duì)Se(Ⅳ)的配位吸附以雙齒配位作用為主,而對(duì)Se(Ⅵ)的配位吸附以單齒配位作用為主。
[Abstract]:Goethite, hematite and manganese and chromium-doped ferric oxide were prepared under hydrothermal conditions. The microstructure and surface properties of the samples were analyzed by modern testing techniques. The adsorption characteristics of different valence selenium on the samples were studied by isothermal adsorption experiments, and the adsorption mechanism was discussed. In iron ore system, low proportion of manganese doping (R = 0.1-0.2, R is the molar ratio of doped metal to iron) promotes the formation of goethite; with the increase of the doping ratio, the morphology of the product becomes more slender and longer. When the ratio of manganese doping is higher (R = 0.3-0.5), with the increase of the doping ratio, the crystallinity of the product decreases and the particle size gradually shortens; when R = 0.5 In the system of hematite synthesis, the crystallinity of hematite decreases from 0.1 to 0.5, and the size of hematite particles decreases continuously. When R = 0.5, the product is mainly manganese-doped magnetite. When the doping ratio of chromium is between 0.1 and 0.5, goethite and hematite are the main products. The crystallinity of goethite and hematite decreases gradually with the increase of doping ratio, and a large number of amorphous particles appear in the product when the doping ratio R=0.5. (2) Nitrogen isothermal adsorption/desorption of the sample. The results show that the specific surface areas of Mn and Cr-doped products (G-Mn 0.2 and G-Cr0.2) at Goethite (Goe) and R=0.2 are 46.25, 83.45 and 101.33 m2.g-1, respectively; the average pore sizes of the three samples are 23.63, 14.29 and 2.43 nm, respectively. Hematite (Hem) and Mn at R=0.2, and the specific surface areas of Cr-doped products (H-Mn 0.2 and H-Cr0.2) are 12.29, 169.62 and 99.55 m2, respectively. Their average pore diameters are 6.75, 0.75 and 0.97 nm, respectively. The influence of chromium doping on surface fractal degree (SFD) of goethite and hematite is small. Among them, the SFD of Goe and its doped products ranges from 2.43 to 2.54, the SFD of Hem and its doped products ranges from 2.56 to 2.73. (3) Zeta potential zeros of Goe, G-Mn0.2 and G-Cr0.2 are 7.36, 6.58 and 4.74, Hem, Hem, and their doped products are 7.56 to 2.73, respectively. Zeta potential zeros of H-Mn 0.2 and H-Cr0.2 are 6.41, 5.42 and 5.71, respectively. It can be seen that both Mn and Cr doping significantly reduce the surface potential zeros of ferric oxide. Laser particle size analysis shows that the average particle sizes of Goe, G-Mn 0.2 and G-Cr0.2 are 630, 915 and 765 nm, Hem, H-Mn 0.2 and H-Cr0.2 are 1025, 534 and 523 nm, respectively. (4) The adsorption capacity of the same sample for Se (IV) was significantly higher than that for Se (VI). Manganese and chromium doping increased the adsorption capacity of goethite and hematite for Se (IV) and Se (VI). The adsorption capacity of Goe, G-Mn0.2 and G-Cr0.2 for Se(IV) is about 10,16 and 25 mg (4) The adsorption capacity of the system was higher than that of the manganese-doped products. (5) When the initial P H=4.0, the P H values of the system after Goe, G-Mn0.2 and G-Cr0.2 adsorption of Se (IV) were increased to 5.6, 5.7 and 5.9, respectively, and the P H values after adsorption of Se (VI) were 4.3, 4.9 and 5.2, respectively; and the p H values after adsorption of Hem, H-Mn0.2 and H-Cr0.2 were 4.3, 5.4 and 5.3, respectively.3, and 5.3 after adsorption of Se (IV) respectively. Zeta potential analysis showed that Zeta potential zero point of all samples decreased after adsorption of Se (IV) and Se (VI); Zeta potential zero point of Goe, Hem and chromium doped products after adsorption of Se (IV) was slightly lower than that after adsorption of Se (VI); Zeta potential zero point of manganese doped products after adsorption of Se (IV) was higher than that of adsorption of Se (VI). These results indicate that electrostatic attraction, anion exchange and surface coordination are important mechanisms for the adsorption of Se (IV) and Se (VI). Bidentate complexation is dominant for the coordination adsorption of Se (IV) and monodentate complexation is dominant for the coordination adsorption of Se (VI).
【學(xué)位授予單位】：湖北民族學(xué)院
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O647.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王魯璐;李海英;王立賢;劉振義;;高比表面積羥基氧化鐵的制備及影響因素[J];現(xiàn)代化工;2016年08期

2 魏世勇;劉茜;劉凡;馮雄漢;譚文峰;;Fe(Ⅱ)存在條件下氧化鐵-高嶺石復(fù)合物的形成與轉(zhuǎn)化[J];土壤學(xué)報(bào);2010年06期

3 曾丁才;吳宏海;林怡英;杜娟;;針鐵礦/水界面反應(yīng)性的實(shí)驗(yàn)研究[J];巖石礦物學(xué)雜志;2009年04期

4 朱建明;秦海波;李璐;馮志剛;蘇宏?duì)N;;湖北恩施漁塘壩高硒土壤中硒的結(jié)合態(tài)[J];環(huán)境科學(xué)學(xué)報(bào);2008年04期

5 鄭雅杰;劉昭成;;氧化鐵的制備方法及其應(yīng)用[J];粉末冶金材料科學(xué)與工程;2007年04期

6 鈄啟升;張輝;鄔劍波;楊德仁;;氧化鐵和羥基氧化鐵納米結(jié)構(gòu)的水熱法制備及其表征[J];無(wú)機(jī)材料學(xué)報(bào);2007年02期

7 牟素華;胡啟托;顏玲;;湖北恩施地區(qū)地方性硒中毒研究進(jìn)展[J];中國(guó)公共衛(wèi)生;2007年01期

8 梁美娜;劉海玲;朱義年;王丹;;復(fù)合鐵鋁氫氧化物的制備及其對(duì)水中砷(V)的去除[J];環(huán)境科學(xué)學(xué)報(bào);2006年03期

9 韋薇;管春平;牛存龍;;微量元素硒與地方性疾病研究綜述[J];楚雄師范學(xué)院學(xué)報(bào);2006年03期

10 汪福順;劉叢強(qiáng);梁小兵;魏中青;李軍;徐海;;湖泊沉積物中微量金屬二次遷移過(guò)程中微生物作用的實(shí)驗(yàn)研究[J];湖泊科學(xué);2006年01期

相關(guān)博士學(xué)位論文 前3條

1 劉海波;熱處理鋁代針鐵礦的結(jié)構(gòu)演化及其表面反應(yīng)性[D];合肥工業(yè)大學(xué);2013年

2 胡子文;摻雜焦碳及納米氧化鐵吸附生態(tài)環(huán)境水體中重金屬試驗(yàn)研究[D];成都理工大學(xué);2013年

3 魏世勇;氧化鐵—層狀硅酸鹽礦物二元體的形成、微觀結(jié)構(gòu)和表面性質(zhì)[D];華中農(nóng)業(yè)大學(xué);2010年

相關(guān)碩士學(xué)位論文 前5條

1 張佩;鋁同晶替代對(duì)針鐵礦吸附Pb(Ⅱ)的影響及其CD-MUSIC模擬[D];華中農(nóng)業(yè)大學(xué);2015年

2 喻大松;陜西紫陽(yáng)和青海平安富硒環(huán)境中硒分布特征及其對(duì)人體健康的影響[D];西北農(nóng)林科技大學(xué);2015年

3 王琦;土壤腐殖酸對(duì)氧化鐵形成轉(zhuǎn)化的影響[D];華中農(nóng)業(yè)大學(xué);2012年

4 蘇敏;摻雜納米α-FeOOH的制備及應(yīng)用研究[D];北京交通大學(xué);2010年

5 李艷玲;納米氧化鐵的制備及其性能表征[D];中國(guó)海洋大學(xué);2004年

，

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