本文選題：生物炭-鐵錳氧化物 + 砷　； 參考：《沈陽(yáng)農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：我國(guó)南方,尤其是湘江流域地區(qū),土壤砷污染問(wèn)題已經(jīng)越來(lái)越嚴(yán)重,治理農(nóng)田土壤砷污染、保障稻米質(zhì)量安全已成為近幾年研究熱點(diǎn)。本研究以生物炭(BC)為原料,通過(guò)浸漬法制備生物炭-鐵錳氧化物復(fù)合材料(FMBC),探討其對(duì)水環(huán)境中砷的吸附機(jī)制,在此基礎(chǔ)上,通過(guò)吸附試驗(yàn)和水稻盆栽試驗(yàn),研究了生物炭-鐵錳氧化物復(fù)合材料對(duì)砷有效性的影響,探究生物炭-鐵錳氧化物復(fù)合材料對(duì)稻田土壤調(diào)控的機(jī)制。主要研究成果如下:(1)篩選出吸附效果較好的生物炭-鐵錳氧化物復(fù)合材料,初步闡明其對(duì)砷的吸附機(jī)制生物炭-鐵錳氧化物復(fù)合材料具有非常大的比表面積,較大的pH和相對(duì)粗糙不規(guī)整的表面,其生物炭與鐵、錳氧化物復(fù)合材料質(zhì)量之比25:1:3,對(duì)砷的最大吸附量為6.25 mg ·g-1,是生物炭最大吸附量的2.2倍;其對(duì)砷的吸附機(jī)理是表面的官能團(tuán)(烷基、羰基、羥基和羧基等),通過(guò)表面的絡(luò)合以及離子之間的化學(xué)作用來(lái)吸附溶液中的砷;生物炭-鐵錳氧化物復(fù)合材料的表面鐵錳氧化物可以提供一個(gè)氧化還原體系,將砷(Ⅲ)氧化成砷(V)再進(jìn)一步吸附。(2)生物炭-鐵錳氧化物復(fù)合材料提高了紅壤對(duì)砷的吸附性添加生物炭-鐵錳氧化物復(fù)合材料,提高了紅壤對(duì)砷的吸附性能。添加生物炭-鐵錳氧化物的吸附效果好于生物炭,添加F1M3BC25的吸附量為0.687 g· kg-1,是添加BC最大吸附量(0.423 g · kg-1)的1.6倍。XPS結(jié)果表明,加入F1M3BC25后,土壤顆粒表面出現(xiàn)明顯的Fe2p3/2峰與Mn2p3/2峰,增強(qiáng)了砷(Ⅲ)氧化作用,使其轉(zhuǎn)化為更易被吸附的砷(V),進(jìn)而增大土壤對(duì)砷的吸附性能。(3)生物炭-鐵錳氧化物復(fù)合材料降低了砷對(duì)水稻毒害作用,并提高水稻產(chǎn)量與質(zhì)量添加生物炭-鐵錳氧化物復(fù)合材料(F1M3BC25)促進(jìn)了水稻的生長(zhǎng),降低了水稻各部分的砷的含量,提高了籽粒的產(chǎn)量,必需氨基酸比例有增加的趨勢(shì)。高、中和低三種污染水平土壤中,最佳的生物炭-鐵錳氧化物復(fù)合材料添加量為土壤質(zhì)量的2%,能最大程度的降低水稻各部分的砷含量。與空白對(duì)照相比,在高、中和低三種污染土壤中,2%F1MBC25使水稻籽粒的干物重分別增加了 60.3%、80.7%和46.0%,使籽粒中的砷含量分別降低了 54.7%、49.6%和34.4%,籽粒中必需氨基酸所占比例提高了 3.51%、2.54%和1.58%。F1M3BC25對(duì)高度污染的土壤砷的有效性產(chǎn)生的影響更大,生物炭-鐵錳氧化物復(fù)合材料能夠氧化土壤中的砷(Ⅲ),使砷的形態(tài)發(fā)生轉(zhuǎn)化,土壤溶液中主要存在形態(tài)是砷(Ⅴ),且與空白對(duì)照相比顯著降低,進(jìn)而增大土壤對(duì)砷的吸附能力。水稻根表鐵錳膜含量增加,減少根系對(duì)砷的吸收,降低了水稻地上部分砷的含量,對(duì)水稻籽粒吸收砷產(chǎn)生抑制作用。
[Abstract]:In southern China, especially in Xiangjiang River Basin, the problem of arsenic pollution in soil has become more and more serious. In recent years, it has become a hot research point to control arsenic pollution in farmland soil and ensure rice quality and safety. In this study, biological carbon and iron manganese oxide composites were prepared by impregnation method, and the adsorption mechanism of arsenic in water environment was discussed. On the basis of this, adsorption experiments and pot experiments of rice were carried out. The effect of biocarbonion-iron-manganese oxide composite on arsenic availability was studied, and the mechanism of biological carbon-iron manganese oxide composite on soil regulation in paddy field was investigated. The main research results are as follows: (1) A biological carbon-ferromanganese oxide composite with good adsorption effect was selected, and its adsorption mechanism for arsenic was preliminarily explained, the biological carbon-ferromanganese oxide composite has a very large specific surface area. The ratio of biochar to iron and manganese oxide composite material is 25: 1: 3, and the maximum adsorption amount of arsenic is 6.25 mg / g ~ (-1), 2.2 times as much as that of biochar. The adsorption mechanism of arsenic is that the functional groups (alkyl, carbonyl, hydroxyl and carboxyl) adsorb arsenic in the solution through the complexation of the surface and the chemical interaction between ions. The surface iron and manganese oxides of biocarbonion-ferromanganese oxide composites can provide a redox system. The further adsorption of arsenic (鈪，

本文編號(hào)：1828010