本文關(guān)鍵詞：納米鐵銅去除地下水中硝酸鹽的實(shí)驗(yàn)研究　出處：《中國(guó)海洋大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

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【摘要】：隨著工業(yè)和農(nóng)業(yè)的迅速發(fā)展,近些年硝酸鹽已成為許多國(guó)家地下水中的常見(jiàn)污染物,并且污染日益嚴(yán)重。作為一種新的污染控制技術(shù),將納米零價(jià)鐵及其復(fù)合材料應(yīng)用于地下水硝酸鹽污染修復(fù),表現(xiàn)出了非常明顯的優(yōu)勢(shì),已成為環(huán)境研究熱點(diǎn)方向。地下水成分復(fù)雜,共存離子對(duì)納米鐵系材料去除硝酸鹽的影響目前沒(méi)有系統(tǒng)的研究,而且比較貼近于實(shí)際地下水環(huán)境的砂柱、砂槽實(shí)驗(yàn)還很少,納米顆粒在砂柱中的遷移沉積,以及對(duì)污染物的去除規(guī)律仍然不甚了解,因而非常有必要考慮地下水的實(shí)際水化學(xué)條件和水動(dòng)力條件,對(duì)納米鐵系材料去除硝酸鹽開(kāi)展系統(tǒng)的砂柱、砂槽實(shí)驗(yàn)研究�；谏鲜隹紤],本文采用液相還原法制備了納米級(jí)Fe/Cu金屬?gòu)?fù)合材料,采用TEM分析手段對(duì)納米材料的結(jié)構(gòu)進(jìn)行了表征,并且將其用于硝酸鹽污染物的去除。首先研究了初始硝酸鹽濃度對(duì)硝酸鹽去除的影響,確定了納米鐵銅的最佳投加量;在此基礎(chǔ)上,考察了Cl", SO42-,HCO3和PO43-四種無(wú)機(jī)陰離子在納米Fe/Cu顆粒投加不足和足量條件下對(duì)硝酸鹽的去除以及還原產(chǎn)物的影響。另外,研究了富里酸,溶解氧對(duì)納米Fe/Cu顆粒還原硝酸鹽過(guò)程的影響。開(kāi)展了納米Fe/Cu雙金屬的砂柱注入實(shí)驗(yàn)研究,分析了石英砂粒徑,納米顆粒濃度和納米顆粒體積對(duì)納米顆粒遷移影響,以及石英砂粒徑,納米顆粒濃度,納米顆粒體積和初始硝酸鹽濃度對(duì)硝酸鹽在砂柱中去除的影響。主要結(jié)論有以下幾點(diǎn)：(1)納米Fe/Cu足量時(shí),硝酸鹽被徹底還原,產(chǎn)物只有氨氮：納米Fe/Ca不足時(shí),硝酸鹽不能被全部還原,產(chǎn)物為氨氮和亞硝酸鹽。(2)當(dāng)納米顆粒的投加足量時(shí),Cl-, SO42-, HCO3和PO43-對(duì)硝酸鹽的去除均起到抑制作用,由大到小依次為：PO43SO42-HCO3-Cl-。其中P043-的作用幾乎不受P043-濃度的影響,而SO42-,HCO3和C1-三種離子濃度越大,抑制作用越強(qiáng)。另外,SO42-,HCO3-和C1-對(duì)氨氮的生成有促進(jìn)作用,由大到小依次為：SO42-HCO3-Cl-,且濃度越大,促進(jìn)作用越強(qiáng)。原因是,P043-通過(guò)吸附作用占據(jù)鐵表面的活性點(diǎn)位從而抑制硝酸鹽還原;Cl-, SO42-, HCO3-與Fe(Ⅱ), Fe(Ⅲ)和OH-形成綠銹,可以促進(jìn)硝酸鹽還原成氨氮,從而增大氨氮在產(chǎn)物中的比例,進(jìn)而降.低硝酸鹽的去除率。當(dāng)納米鐵銅投加足量時(shí),SO42和HCO3-抑制硝酸鹽和中間產(chǎn)物亞硝酸鹽的還原,其作用大小順序?yàn)椋篐CO3-SO42-,且濃度越大,作用越強(qiáng),原因是,Fe(Ⅱ), Fe(Ⅲ)和OH-在SO42-或HCO3-的參與下形成了綠銹,而Cl促進(jìn)了硝酸鹽的還原,可能是因?yàn)镃l-與Fe(Ⅱ)/Fe(Ⅲ)發(fā)生絡(luò)合作用,降低了鐵的氧化產(chǎn)物在納米顆粒上的沉積,從而提高了NO3-和NO2-與納米顆粒的接觸。(3)富里酸降低了納米鐵銅對(duì)硝酸鹽的還原速率,對(duì)其去除率沒(méi)有影響。而溶解氧降低了納米鐵銅對(duì)硝酸鹽的還原速率和去除率。(4)納米鐵銅雙金屬顆粒在砂柱中的截留分布情況隨介質(zhì)粒徑,顆粒濃度和顆粒體積的不同而不同,但均在砂柱的前半部分分布較多,離出口端愈近截留量愈小。納米鐵銅顆粒對(duì)硝酸鹽的還原過(guò)程中,隨著研究因素的不同,NO3--N,NH4+-N, NO2--N以及總氮的變化趨勢(shì)相同。取樣開(kāi)始,因?yàn)榧{米顆粒對(duì)硝酸鹽的吸附作用,使得NO3--N和總氮量為零,隨即被吸附的硝酸鹽開(kāi)始發(fā)生還原反應(yīng),因?yàn)榧{米顆粒足量,所以產(chǎn)物只有氨氮,隨著反應(yīng)進(jìn)行,納米顆粒活性降低,NO3--N和NO2--N出現(xiàn),同時(shí)氨氮量下降。NO3--N濃度隨時(shí)間不斷增大,NO2--N濃度先增大到最大濃度后下降,說(shuō)明納米顆粒已逐漸失去對(duì)硝酸鹽的還原能力。(5)砂柱中介質(zhì)粒徑影響納米鐵銅雙金屬顆粒的遷移,粒徑越大,越有利于納米顆粒的遷移,但是介質(zhì)粒徑對(duì)硝酸鹽的去除效果沒(méi)有影響。納米顆粒的注入體積對(duì)納米顆粒在砂柱中的分布規(guī)律沒(méi)有影響,但是注入體積越大,截留在砂柱中納米顆粒的量越多,所以越有利于硝酸鹽的還原。納米顆粒的注入濃度越大,越有利于納米顆粒的遷移,對(duì)硝酸鹽的去除效果越佳。初始硝酸鹽濃度越大,納米顆粒維持反應(yīng)活性的時(shí)間越短。
[Abstract]:With the rapid development of industry and agriculture in recent years, nitrate has become common in many countries of pollutants in groundwater, and pollution is becoming increasingly serious. As a new pollution control technology, nano zero valent iron and composite materials used in groundwater nitrate pollution remediation, showed very obvious advantages, has become a hot research environment the direction of groundwater. Complex components and coexisting ions on the effect of nano ferric nitrate removal material there is no system, and relatively close to the actual sand column groundwater environment, sand tank experiment is less, migration and deposition of nanoparticles in the sand column, and the pollutant removal law is still not fully understood, so it is necessary to consider the actual Groundwater Hydrochemical conditions and hydrodynamic conditions, the nanometer iron material on nitrate removal in sand column system, sand tank experiments. Based on the research The above considerations, this paper adopts liquid Fe/Cu nano metal composite material was prepared by reduction, by means of TEM analysis of nano materials were characterized, and used for the removal of nitrate pollutants. Firstly, the initial nitrate concentration on the nitrate removal effect, determine the best dosage of nano iron and copper add amount; on this basis, the effects of Cl, SO42-, and the effect on removal of nitrate reduction products of HCO3 and PO43- four kinds of inorganic anions and lack sufficient conditions in adding nano Fe/Cu particles. In addition, the study of fulvic acid, dissolved oxygen reduction effect of nitrate on the process of nano Fe/Cu particles. The sand column nano Fe/Cu double metal injection experiment, quartz sand particle size analysis, effects of the concentration of the nano particles and nano particle volume on migration of nanoparticles, and quartz sand particle size, particle concentration, particle Effect of volume and initial nitrate concentration on the removal of nitrate in the sand column. The main conclusions are as follows: (1) a sufficient amount of nano Fe/Cu, nitrate was completely restored, the only product of ammonia: nano Fe/Ca is insufficient, the nitrate can not be reduced completely, is the product of ammonia and nitrite (2.) when the nano particles added enough, Cl-, SO42-, HCO3 and PO43- on the removal of nitrate have played an inhibitory effect, from large to small is as follows: PO43SO42-HCO3-Cl-. the effect of P043- was not affected by the concentration of P043- and SO42-, HCO3 and C1- three kinds of ion concentration, inhibition stronger. In addition, SO42-, HCO3- and C1- to promote the production of ammonia, from large to small is as follows: SO42-HCO3-Cl-, and the higher the concentration, the stronger the effect of promoting. The reason is that the adsorption of P043- by occupying the active iron surface to point inhibition of nitrate reduction; Cl-, SO42-, HCO3-涓嶧e(鈪，

本文編號(hào)：1389801