本文選題：小麥秸稈 + 吸附　； 參考：《濟南大學》2017年碩士論文

【摘要】：硝酸鹽大多數(shù)為離子型化合物,是無機污染物的一類,極易溶解在水體當中。硝酸鹽影響人體血液輸送氧的能力,嚴重危害人體健康。在眾多水處理工藝中,單一的水處理方法很難做到對硝酸鹽的徹底無害化處理。本研究利用吸附法高效吸附水源水中的硝酸鹽并結合微生物反硝化使硝酸鹽轉(zhuǎn)化為N2釋放從而實現(xiàn)無害化處理。選用農(nóng)作物小麥秸稈作為吸附劑原料,通過乙二胺交聯(lián)法和共沉淀法制備出磁改性小麥秸稈吸附劑,并對其進行物化表征來探究改性效果及吸附機制。通過靜態(tài)吸附和動態(tài)吸附試驗來探究不同吸附條件對吸附效果的影響并分析吸附機理。針對硝酸根的可生物還原特性,馴化培養(yǎng)反硝化菌對飽和吸附劑進行再生處理,探討吸附劑反硝化再生的可行性。主要結論如下:(1)以小麥秸稈為原料,利用乙二胺交聯(lián)法成功制造出改性小麥秸稈吸附劑,通過對不同實驗因素的分析,確定乙二胺改性小麥秸稈吸附劑最佳合成條件為:小麥秸稈投加量2g;乙二胺用量3mL;N,N-二甲基甲酰胺(DMF)用量10mL;三乙胺用量10mL;醚化過程時間60min,溫度90℃;催化過程時間60min,溫度90℃;接枝反應過程時間90min,溫度90℃。(2)對原小麥秸稈(WS)、附磁小麥秸稈(MWS)、乙二胺改性小麥秸稈(AWS)、磁改性小麥秸稈(M-AWS)四種秸稈吸附劑吸附效果進行對比,發(fā)現(xiàn)原小麥秸稈(WS)、附磁小麥秸稈(MWS)對硝酸根基本沒有吸附效果,而乙二胺改性小麥秸稈(AWS)、磁改性小麥秸稈(M-AWS)對硝酸根有很好的去除效率。本實驗最終確定選擇磁改性小麥秸稈作為吸附劑,吸附完成后可以在外加磁場作用下快速分離出來,在回收利用方面比單純乙二胺改性小麥秸稈有優(yōu)勢。(3)未處理的小麥秸稈等電點pHpzc為2.1,而通過乙二胺交聯(lián)法和共沉淀法制備的磁改性小麥秸稈吸附劑的等電點pHpzc為7.1;通過X-射線粉末衍射(XRD)和紅外光譜表征(FTIR)分析磁改性小麥秸稈吸附劑引入大量帶正電荷的季胺基官能基團,從而導致小麥秸稈的表面發(fā)生了非常明顯的電荷變化;改性后制備得到的磁改性小麥秸稈吸附劑表面負載了大量季胺基官能團和Fe3O4粒子,因此吸附劑表現(xiàn)出較高的正電荷性,有利于去除水溶液中的硝酸根。(4)磁改性小麥秸稈吸附硝酸根反應過程非�？�,一般在20min內(nèi)就能完成;反應過程受pH影響,pH在4-10范圍內(nèi),吸附劑對硝酸根有較高的去除率;受水環(huán)境溫度影響不大,溫度為20,30和40℃時,磁改性小麥秸稈對NO3-的吸附容量分別為54.5mg/g,51.7mg/g和49.8mg/g;該吸附劑吸附硝酸根的吸附等溫線符合Langmuir吸附等溫線模型;偽二級動力學模型能夠很好地描述磁改性小麥秸稈吸附劑對硝酸鹽的整個吸附過程,其擬合曲線基本不會與吸附數(shù)據(jù)發(fā)生偏移,相關系數(shù)(R2)較高,為0.998-0.999,說明吸附過程是化學吸附而且是一個限速吸附過程。(5)培養(yǎng)馴化反硝化菌5d以后,活性污泥基本上適應了本實驗的培養(yǎng)環(huán)境;15d-22d左右,活性污泥的生長速率明顯加快;22d-30d,活性污泥的生物量基本上達到穩(wěn)定狀態(tài)。經(jīng)過培養(yǎng)馴化,本實驗的活性污泥成功富集了一定數(shù)量的硝酸根還原菌,通過對菌群DNA的提取和菌群DGGE基因片段的分析可知反硝化菌成為優(yōu)勢菌群,微生物群落適用于硝酸根的還原。(6)磁改性小麥秸稈吸附劑對硝酸根吸附的動態(tài)實驗,填柱高度、過柱流速、初始硝酸根濃度、pH等因素對過柱實驗的影響較大。填柱高度大,能夠吸附更多的硝酸根,但是并沒有增加磁改性小麥秸稈吸附劑對硝酸根的吸附效率;進入吸附柱的硝酸根濃度高,則吸附柱內(nèi)的吸附劑很快被進水中硝酸根占據(jù),因此吸附柱在很短時間內(nèi)就達到飽和狀態(tài);控制過柱流速,延長接觸時間在一定情況下可以增加吸附效率,但時間過長也會影響實際工藝過程。因此,選擇恰當?shù)倪^柱條件可以有效提高過柱效率。(7)對硝酸根吸附飽和的磁改性小麥秸稈進行微生物反硝化再生,結果表明靜態(tài)吸附后,馴化后的厭氧型微生物對磁改性小麥秸稈吸附劑的一次還原效率約為93%,二次還原效率約為89%,第五次還原效率80%左右;動態(tài)吸附硝酸根后,通過一次和二次穿透點的不同,計算可知反硝化微生物對磁改性小麥秸稈吸附劑的一次還原效率約為89%,二次還原效率約為83%;吸附聯(lián)用微生物還原后可以達到硝酸根的徹底無害化處理。
[Abstract]:Most of the nitrate is ionic compound, which is a kind of inorganic pollutant. It is very easy to dissolve in water. Nitrate affects the ability of human blood to transport oxygen and seriously endangering human health. In many water treatment processes, a single water treatment method is difficult to do the thorough and harmless treatment of nitrate. This study uses adsorption method efficiently. The nitrate was adsorbed in water source water and combined with microbial denitrification to make nitrate conversion to N2 release to achieve the harmless treatment. The wheat straw was selected as the absorbent material, the magnetic modified wheat straw adsorbent was prepared by the ethylamine crosslinking method and the coprecipitation method, and its physicochemical characterization was carried out to explore the modified effect and adsorption. Mechanism. Through the static adsorption and dynamic adsorption tests to explore the effects of different adsorption conditions on the adsorption effect and analyze the adsorption mechanism. In view of the bioreducibility of nitrate, the domesticated culture denitrifying bacteria regenerated the saturated adsorbent and discussed the feasibility of the denitrification regeneration of the adsorbent. The main conclusions are as follows: (1) wheat straw Straw was used as raw material to make the modified wheat straw adsorbent successfully. Through the analysis of different experimental factors, the optimum synthesis conditions of the modified wheat straw sorbents were: 2G of wheat straw, 3mL of ethylenediamine, N, N- two methyl formamide (DMF) dosage 10mL; three ethylamine dosage 10mL; etherification process. 60min, temperature 90 C; catalytic process time 60min, temperature 90 C; grafting reaction time 90min, temperature 90. (2) of wheat straw (WS), magnetic wheat straw (MWS), ethylenediamine modified wheat straw (AWS), magnetic modified wheat straw (M-AWS) four straw adsorbents adsorption effect was compared, found the original wheat straw (WS), magnetic wheat straw attached to the wheat straw. MWS has no adsorption effect on nitrate, while ethylene diamine modified wheat straw (AWS), magnetic modified wheat straw (M-AWS) has a good removal efficiency to nitrate root. Finally, the magnetic modified wheat straw was selected as an adsorbent. After the adsorption, it can be quickly separated under the effect of external magnetic field. The pure ethylenediamine modified wheat straw has advantages. (3) the pHpzc of the untreated wheat straw is 2.1, and the isoelectric point pHpzc of the magnetically modified wheat straw adsorbent prepared by the ethylenediamine crosslinking method and the coprecipitation method is 7.1; the magnetic modified wheat straw adsorbent is introduced by the X- ray powder diffraction (XRD) and the infrared spectrum characterization (FTIR). With the positive charge of Ji Anji functional group, the surface of wheat straw has a very obvious charge change, and the surface of the magnetic modified wheat straw adsorbent is loaded with a large number of Quaternary functional groups and Fe3O4 particles, so the adsorbent shows a higher positive charge and is beneficial to the removal of the nitrate in the aqueous solution. (4) (4) the reaction process of magnetic modified wheat straw adsorbed nitrate root is very fast and can be completed in 20min. The reaction process is affected by pH, and the adsorbent has a high removal rate of nitrate in the 4-10 range; the temperature is not affected by the temperature of water environment, the temperature is 20,30 and 40 C, the adsorption capacity of magnetic modified wheat straw to NO3- is 54.5mg, respectively. /g, 51.7mg/g and 49.8mg/g, the adsorption isotherm of adsorbent adsorbed nitrate conforms to the Langmuir adsorption isotherm model, and the pseudo two stage kinetic model can describe the whole adsorption process of the magnetic modified wheat straw adsorbent for nitrate, and the fitting curve will not offset the adsorption data, and the correlation coefficient (R2) is higher, which is 0.998. -0.999 shows that the adsorption process is chemical adsorption and a speed limiting adsorption process. (5) after the cultivation of the acclimated denitrifying bacteria 5D, the activated sludge basically adapts to the culture environment of this experiment. The growth rate of activated sludge is obviously accelerated at about 15d-22d, and the biomass of activated sludge is basically stable. After cultivation and domestication, A certain number of nitrate reducing bacteria were enriched in the activated sludge in this experiment. By the extraction of DNA and the analysis of the DGGE gene fragment of the bacteria group, the denitrifying bacteria became the dominant bacteria group, and the microbial community was suitable for the reduction of nitrate. (6) the dynamic experiment of the adsorption of nitrate on the magnetic modified wheat straw adsorbent, the height of the column and the height of the column. The column flow rate, the initial nitrate concentration, pH and other factors have great influence on the column experiment. The height of the column is large and it can absorb more nitrate, but it does not increase the adsorption efficiency of the magnetic modified wheat straw adsorbent to the nitrate root; the adsorbent in the adsorption column is quickly occupied by the nitrate root in the suction column. Therefore, the adsorption column is saturated in a very short time; controlling the flow velocity of the column and prolonging the contact time can increase the adsorption efficiency in a certain condition, but the time is too long will also affect the actual process. Therefore, the selection of proper column conditions can effectively improve the efficiency of the column. (7) the magnetic modified wheat straw saturated with nitrate is adsorbed. Microbial denitrification was carried out. The results showed that after the static adsorption, the first reduction efficiency of the anaerobic microorganism was about 93%, the two reduction efficiency was about 89%, and the fifth reduction efficiency was about 80%. After the dynamic adsorption of nitrate, the denitrification was calculated by the difference of the first and two penetration points. The one time reduction efficiency of microorganism to magnetic modified wheat straw adsorbent is about 89%, and the two reduction efficiency is about 83%, and the adsorption combined with microorganism can achieve the thorough innocuous treatment of nitrate.

【學位授予單位】：濟南大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU991.2;X712

【參考文獻】

相關期刊論文 前4條

1 譚優(yōu);劉云國;徐沛斌;王欣;文清波;;水稻秸稈陰離子吸附劑的制備及其性能的研究[J];中國環(huán)境科學;2012年08期

2 王穎;辛杰;李雪;阮愛東;;化學催化還原地下水中硝酸鹽的研究進展[J];水處理技術;2010年07期

3 陳繼富,張超美,劉金香;高蛋白整秸稈氨化飼料研究及其應用前景[J];作物雜志;2005年02期

4 韓魯佳,閆巧娟,劉向陽,胡金有;中國農(nóng)作物秸稈資源及其利用現(xiàn)狀[J];農(nóng)業(yè)工程學報;2002年03期

相關博士學位論文 前5條

1 許醒;陽離子型生物質(zhì)吸附劑的研制及其去除水中陰離子的效能及再生研究[D];山東大學;2014年

2 曹威;改性稻草去除水中SO_4~(2-)和Cr(Ⅵ)的特性和機理研究[D];華南理工大學;2012年

3 陳素紅;玉米秸稈的改性及其對六價鉻離子吸附性能的研究[D];山東大學;2012年

4 王宇;利用農(nóng)業(yè)秸稈制備陰離子吸附劑及其性能的研究[D];山東大學;2007年

5 唐光臨;焦化廢水亞硝化反硝化生物脫氮的研究[D];重慶大學;2002年

相關碩士學位論文 前6條

1 譚心;改性農(nóng)作物秸稈吸附聯(lián)用生物還原去除水體中高氯酸根的效果研究[D];山東大學;2013年

2 李敏;電化學方法深度去除水中硝酸鹽氮[D];北京化工大學;2011年

3 楊德成;Pd-Cu/TiO_2催化還原水中的硝酸根和亞硝酸根[D];南開大學;2011年

4 許醒;麥草陰離子吸附劑的研制及對磷酸根的吸附性能研究[D];山東大學;2009年

5 張紹浩;富營養(yǎng)化湖泊藻類控制技術比較及新方法的研究[D];華中科技大學;2006年

6 高志堅;玉米秸稈厭氧消化試驗研究[D];北京化工大學;2004年

，

本文編號：1893018