發(fā)布時(shí)間：2018-04-23 17:29

  本文選題：稻殼 + 電磁波吸收��； 參考：《浙江大學(xué)》2017年博士論文

【摘要】：稻殼是一種產(chǎn)量巨大的農(nóng)業(yè)廢棄物,常被直接丟棄或焚燒處理,不僅占用土地、污染環(huán)境,更造成資源浪費(fèi)。稻殼中含有豐富的二氧化硅、纖維素和木質(zhì)素成分,是廉價(jià)又來源穩(wěn)定的可再生生物資源。因此,對稻殼進(jìn)行資源化利用、提高其附加值以及提高其綜合利用率顯得尤為重要。本文以稻殼及稻殼灰為基礎(chǔ),研究了其對染料廢水的吸附性能。通過鎂熱還原開發(fā)制備了稻殼基吸波材料。利用原位復(fù)合技術(shù),制備了稻殼鐵氧體納米復(fù)合材料,并協(xié)同微波誘導(dǎo)技術(shù),研究了其對染料廢水的處理。此外,考察了微波誘導(dǎo)技術(shù)對傳統(tǒng)芬頓體系處理染料廢水增強(qiáng)作用,拓寬了芬頓體系在廢水處理中的應(yīng)用。通過研究,得到了以下結(jié)論:(1)制得的稻殼灰的主要成分為碳和二氧化硅,具有低密度(0.4gcm-3)、低成本和介電損耗高等優(yōu)勢(見第二章)。其吸波機(jī)理主要是介電損耗,其中有效吸波成分為碳。煅燒溫度和氣氛均會(huì)對稻殼灰的吸波性能造成影響,700℃以上制備得到的稻殼灰吸波性能較好,原因是高溫下無定形碳的石墨化和K2O等雜質(zhì)引起的表面熔融,從而增大其復(fù)介電常數(shù)的實(shí)部和虛部。在2-18GHz測試頻段范圍內(nèi),最大反射率最大可達(dá)-21dB,RL-10dB處的頻寬為5 GHz。與傳統(tǒng)電損耗型吸波材料相比,具有相當(dāng)?shù)男詢r(jià)比優(yōu)勢和應(yīng)用潛力。(2)通過鎂熱還原反應(yīng)從稻殼灰中制備了稻殼基吸波材料(見第三章),吸波成分主要為碳和碳化硅,其機(jī)理為電損耗。因此,氮?dú)鈿夥障蚂褵玫牡練せ医?jīng)鎂熱還原后制備的SiC/C復(fù)合物樣品吸波性能更好,表現(xiàn)出較高的介電損耗和較寬的帶寬。所得樣品在RL-5 dB和-10 dB處的最大帶寬隨碳含量減少而減小,而最佳厚度隨碳化硅含量增加而減小。樣品的電磁波吸收最佳厚度為1.5-2.0mm,最大RL為-28.9-68.4dB,當(dāng)RL-5 dB時(shí)帶寬范圍為 6.7-13 GHz,當(dāng)RL-10 dB 時(shí)帶寬為 3.2-6.2 GHz。(3)稻殼灰可作為廉價(jià)吸附劑處理染料廢水(見第四章)。煅燒氣氛和溫度直接影響稻殼灰的成分形貌和孔隙結(jié)構(gòu)等物性特征。在氮?dú)庵徐褵玫降牡練?BRHA)具有更大的比表面積、微孔體積以及碳含量�？諝庵徐褵玫降牡練�(WRHA)則含有更高的中孔比例和二氧化硅含量。600℃下煅燒得到的BRHA比表面積最大,為347 m2g-1。中孔是吸附亞甲基藍(lán)(MB)的有效結(jié)構(gòu)類型,因此稻殼灰的吸附性能與其中孔體積成線性相關(guān)。其最大亞甲基藍(lán)吸附量q0為50.51 mgg-1。吸附過程符合準(zhǔn)二級動(dòng)力學(xué)方程,吸附平衡符合langmuir等溫線模型。(4)制備了具有高比表面積和孔體積的多孔稻殼鐵氧體納米復(fù)合材料:RHA/MnFe204(RMN)和RHA/CoFe204(RCN)(見第五章)。在微波輔助作用下能快速高效處理MB。MB脫除過程符合準(zhǔn)二級動(dòng)力動(dòng)力學(xué)方程。其脫除效率與樣品用量、微波功率以及初始pH值呈正比。對比反應(yīng)前后pH值發(fā)現(xiàn),反應(yīng)后pH值趨于中性。MB的發(fā)色基團(tuán)最先被RMN和RCN脫除。根據(jù)反應(yīng)后MB溶液溶度、NO3-和SO42-離子濃度,可以計(jì)算出推算出反應(yīng)后MB分子的最低礦化度:在RMN和RCN分別達(dá)到的最大MB去除率55.0%和99.7%的反應(yīng)中,分別有超過22.1%和46.8%的MB分子被完全降解。(5)研究了將微波誘導(dǎo)技術(shù)與芬頓體系協(xié)同作用脫除MB(見第六章)。結(jié)果表明,微波的引入大大強(qiáng)化了芬頓體系的對MB的脫除效率。僅微波輻照1min,可達(dá)到93.0%的脫除率,高于傳統(tǒng)芬頓體系65 min的脫除效果。羥基自由基的產(chǎn)生是脫除效率的關(guān)鍵,因此隨Fe2+和H202濃度的增加,則MB去除率也相應(yīng)增大。MB的脫除率在pH小于7時(shí)變化不大,當(dāng)pH達(dá)到8時(shí),脫除效率急劇下降,最佳pH為3左右。在微波輔助芬頓氧化過程中,664 nm處特征峰削弱較另兩處肩峰更為明顯,且產(chǎn)生藍(lán)移現(xiàn)象,說明664nm對應(yīng)的二甲氨基發(fā)色團(tuán)被氧化分解。
[Abstract]:Rice husk is a kind of large agricultural waste, which is often discarded or burned directly. It not only occupies land, pollutes the environment, but also causes the waste of resources. The rice husk contains rich silica, cellulose and lignin, which is a cheap and stable renewable biological resource. Therefore, the utilization of rice husk is used to improve its attachment. It is particularly important to add value and improve its comprehensive utilization rate. In this paper, the adsorption properties of rice husk waste water are studied on the basis of rice husk and rice husk ash. The rice husk base absorbing material is prepared by the development of magnesium heat reduction. The nanocomposite material of rice husk ferrite is prepared by in situ composite technology, and the microwave induction technology is used to study its microwave induction technology. In addition to the treatment of dye wastewater, the enhancement of the traditional Fenton system on the treatment of dye wastewater by the traditional Fenton system was investigated, and the application of the Fenton system in the wastewater treatment was widened. The following conclusions were obtained: (1) the main components of the rice husk ash are carbon and two silicon oxide, with low density (0.4gcm-3), low cost and dielectric. The high loss advantage (see chapter second). Its absorption mechanism is mainly dielectric loss, in which the effective absorption component is carbon. The calcining temperature and atmosphere will affect the absorption properties of the rice husk ash. The performance of the rice husk ash is better than that of the amorphous carbon at high temperature. The reason is the surface melting caused by the impurities such as K2O and other impurities at high temperature. In the range of 2-18GHz test band, the maximum reflectivity is up to -21dB, and the width of RL-10dB is 5 GHz.. Compared with the traditional electric lossless wave absorbing material, it has a considerable price ratio and application potential. (2) the absorption of rice husk based on the MgO heat reduction reaction from rice husk ash The material (see Chapter third) is mainly carbon and silicon carbide, and its mechanism is electrical loss. Therefore, the SiC/C composite sample prepared by magnesium heat reduction under nitrogen atmosphere is better at absorbing wave performance, showing high dielectric loss and wider bandwidth. The maximum bandwidth of the samples at RL-5 dB and -10 dB is with carbon content. The optimum thickness decreases with the increase of SiC content. The optimum thickness of electromagnetic wave absorption is 1.5-2.0mm and the maximum RL is -28.9-68.4dB. When RL-5 dB is 6.7-13 GHz, when RL-10 dB is 3.2-6.2 GHz. (3), rice husk ash can be used as a cheap adsorbent to treat dyestuff wastewater (fourth chapter). Calcining atmosphere And the temperature directly affects the physical properties of the composition and pore structure of the rice husk ash. The rice husk (BRHA) calcined in nitrogen has a larger specific surface area, micropore volume and carbon content. The rice husk (WRHA) calcined in the air contains higher mesoporous ratio and the BRHA specific surface area of the calcined two silicon oxide content at.600 C. The maximum, 347 m2g-1. mesopore is an effective structure type for adsorbing methylene blue (MB), so the adsorption properties of the rice husk ash are linearly related to the pore volume. The maximum methylene blue adsorption capacity of Q0 is 50.51 mgg-1., which conforms to the quasi two kinetic equation, and the adsorption equilibrium conforms to the Langmuir isotherm model. (4) the high specific surface has been prepared. RHA/MnFe204 (RMN) and RHA/CoFe204 (RCN) (see fifth). The process of rapid and efficient treatment of MB.MB removal under microwave assisted action meets the quasi two stage dynamic dynamic equation. The removal efficiency is proportional to the sample dosage, microwave power and initial pH value. PH before and after the reaction is compared. It is found that the chromophore of neutral.MB after reaction pH is first removed by RMN and RCN. According to the solubility of MB solution, NO3- and SO42- ion concentration after reaction, the minimum mineralization degree of MB molecules can be calculated after the reaction: the MB with the maximum MB removal rate of 55% and 99.7% of RMN and RCN respectively, there are more than 22.1% and 46.8% MB, respectively. The molecules were completely degraded. (5) the synergistic effect of microwave induction and Fenton system was studied to remove MB (see sixth chapter). The results showed that the introduction of microwave greatly enhanced the removal efficiency of the Fenton system. The removal rate of 93% was achieved by only microwave irradiation of 1min, which was higher than that of the 65 min of the traditional Fenton system. With the increase of the concentration of Fe2+ and H202, the removal rate of MB also increases with the increase of the concentration of MB, and the removal efficiency of.MB is little changed when pH is less than 7. When pH reaches 8, the removal efficiency decreases sharply and the best pH is about 3. In the process of microwave assisted Fenton oxidation, the characteristic peak of 664 nm is more obvious than the other two acromion. The blue shift phenomenon indicates that the two methylamino chromophores corresponding to 664nm are oxidized and decomposed.

【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TB332

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 趙曉明;劉元軍;;雙層涂層復(fù)合材料的介電性能[J];航空材料學(xué)報(bào);2016年02期

2 侯敏;鄧先倫;孫康;肖鳳龍;楊華;;超級電容器用活性炭電極材料研究進(jìn)展[J];生物質(zhì)化學(xué)工程;2015年03期

3 趙路陽;任濱僑;金玉;宋曉曉;;木質(zhì)素吸附劑對重金屬和有機(jī)物吸附研究進(jìn)展[J];黑龍江科學(xué);2014年02期

4 陳雪剛;葉瑛;程繼鵬;;電磁波吸收材料的研究進(jìn)展[J];無機(jī)材料學(xué)報(bào);2011年05期

5 黃寶祥;;稻殼利用現(xiàn)狀綜述[J];現(xiàn)代農(nóng)業(yè)科技;2007年06期

6 肖華,周榮豐;電芬頓法的研究現(xiàn)狀與發(fā)展[J];上海環(huán)境科學(xué);2004年06期

7 閻鑫,胡小玲,岳紅,盧錦花;納米級尖晶石型鐵氧體制備進(jìn)展[J];材料導(dǎo)報(bào);2002年08期

8 楊伯倫,賀擁軍;微波加熱在化學(xué)反應(yīng)中的應(yīng)用進(jìn)展[J];現(xiàn)代化工;2001年04期

9 盧芳儀,盧愛軍;稻殼的綜合利用[J];糧食與飼料工業(yè);1997年12期

，

本文編號：1792917