本文關(guān)鍵詞： 重金屬污染水體 農(nóng)林廢棄物 耐性真菌 復(fù)合生物吸附劑 等溫吸附 吸附動力學(xué) 固定吸附床　出處：《中南林業(yè)科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：生物吸附法是一種利用生物質(zhì)材料自身吸附性能去除污染物質(zhì)的有效方法。利用農(nóng)林廢棄生物質(zhì)材料和微生物菌體為原料制備的生物吸附劑去除重金屬,具有廣闊的應(yīng)用前景。但是單一農(nóng)林類廢棄生物質(zhì)材料在實際應(yīng)用中存在吸附容量低、密度小、易漂浮等缺點,而單一微生物菌體在吸附應(yīng)用中也存在造粒困難、固液分離困難等問題,導(dǎo)致兩者難以大規(guī)模單獨應(yīng)用于重金屬污染治理中。近年來,有關(guān)改進生物質(zhì)材料吸附容量和性能方面的報道很多,但采用農(nóng)林廢棄物接種耐重金屬菌體制備復(fù)合生物吸附劑方面的研究甚少。本研究針對農(nóng)林廢棄生物質(zhì)材料與耐鉛真菌,利用兩類不同材料制備復(fù)合生物吸附劑,通過耐性菌株和農(nóng)林廢棄物材料的生化復(fù)合過程,提升材料吸附性能。采用農(nóng)林廢棄物花生殼(PS)、粟米糠(MC)等為原料,與鉛鋅礦區(qū)尾礦渣中篩選出的耐性菌株米曲霉菌(Aspergillus oryae,HA)通過復(fù)合培養(yǎng)方式,制備花生殼-米曲霉(PSH)、粟米糠-米曲霉(MCH)等復(fù)合吸附劑,通過靜態(tài)批量試驗考察pH值、吸附劑濃度、Pb~(2+)離子濃度和吸附時間對吸附效果的影響,通過動態(tài)連續(xù)流固定床吸附試驗研究不同操作條件下固定床系統(tǒng)的吸附穿透曲線并分析其動態(tài)吸附特性,應(yīng)用等溫吸附模型、吸附動力學(xué)模型、穿透曲線擬合模型、掃描電鏡和傅里葉紅外光譜分析生物吸附劑對Pb~(2+)離子的吸附機理。主要研究結(jié)果如下:①引入HA改變了玉米秸稈、小麥秸稈、花生殼和粟米糠的吸附容量,四種復(fù)合吸附劑的吸附能力存在較大差異,吸附容量增大順序為粟米糠花生殼小麥秸稈玉米秸稈。②靜態(tài)Pb~(2+)吸附試驗結(jié)果表明,與MC和PS相比,MCH和PSH具有吸附容量大,吸附速率快,pH值適用范圍廣的特點。③相比于Freundlich和D-R等溫吸附模型,Langmuir模型可以更好的描述不同吸附劑對Pb~(2+)離子的等溫吸附過程,PS、PSH、MC、MCH的理論吸附容量由qm分別為:14.62、20.92、11.89、21.79mg/g。Lagergren準二級動力學(xué)模型較準一級和顆粒內(nèi)擴散模型可以更好的描述復(fù)合吸附劑對Pb~(2+)的吸附過程,說明化學(xué)吸附為該過程的主要作用和限速步驟。④FTIR和SEM分析表明,復(fù)合后吸附劑表面形態(tài)和官能團均發(fā)生顯著改變,活性官能團中以羧基、胺基的變化最為明顯,羥基、羧基、氨基和羰基在吸附Pb~(2+)過程中起主要作用。MCH相比PSH具有更多樣的吸附活性官能團且表面形態(tài)變化更為明顯。⑤ 動態(tài)連續(xù)流吸附試驗結(jié)果表明,復(fù)合吸附劑PSH、MCH的穿透時間tb和飽和點時間te分別比單一吸附劑PS、MC明顯推遲。復(fù)合后吸附劑PSH、MCH的動態(tài)吸附容量qexp分別由復(fù)合前的4.62、7.13 mg/g提升至6.49、8.30 mg/g。復(fù)合后吸附劑穿透曲線傳質(zhì)區(qū)長度縮短,系統(tǒng)的整體吸附能力提升。⑥動態(tài)連續(xù)流不同操作條件試驗結(jié)果表明,系統(tǒng)的穿透時間tb隨柱高的增加或者流速、初始Pb~(2+)濃度的減小而增加,傳質(zhì)區(qū)長度H則隨柱高的減小或者流速、初始濃度的增加而增加,其中流速變化對穿透時間和傳質(zhì)區(qū)長度影響最大,初始濃度變化對穿透時間和傳質(zhì)區(qū)長度影響最小。⑦Thomas 模型較好的擬合了 PSH(R2=0.9532～0.9828)和MCH(R2=0.9410～0.9681)對Pb~(2+)的動態(tài)吸附過程,說明該過程中的內(nèi)部擴散和外部擴散并非限速步驟,模型較好地預(yù)測了不同操作條件下吸附劑動態(tài)吸附性能,可以用于描述PSH為填料的吸附固定床系統(tǒng)。BDST模型較好的描述了 PSH和MCH系統(tǒng)的不同吸附柱高度與不同ct/co下的的穿透時間關(guān)系,對不同流速和初始濃度條件下的穿透時間進行了較為精確的預(yù)測,對吸附劑為PSH時的預(yù)測效果優(yōu)于MCH。⑧相比單一材料,復(fù)合吸附劑對復(fù)合重金屬離子的去除效果均有了明顯提升,復(fù)合后PSH相比PS對Pb3~(2+)、Zn~(2+)、Cd~(2+)、Cu~(2+)離子的的除率分別提升了75.55、123.56、119.39、95.15%,MCH 相比 MC 對 Pb~(2+)、Zn~(2+)、Cd~(2+)、Cu~(2+)離子的去除率分別提升了 188.26、135.50、139.49、173.92%,MCH對不同重金屬離子的吸附效果提升更為明顯。
[Abstract]:Biosorption is an effective method for the utilization of biomass materials adsorption properties to remove pollutants. The removal of heavy metal biosorbent waste biomass materials and microbial as raw material prepared by agriculture and forestry, has a wide application prospect. But the single agricultural waste biomass materials in practical applications of low adsorption capacity and low density, easy to floating the disadvantages of single microbial adsorption on the application also exists in the granulation difficulty, solid-liquid separation difficulties, resulting in two difficult large-scale applied to heavy metal pollution. In recent years, the improvement of biomass materials adsorption capacity and performance of many reports, but the study of agricultural and forestry waste inoculation composite biosorbent resistant the heavy metal is very little. This study was made for the agricultural waste biomass materials and lead tolerant fungus, using two different Preparation of composite materials by composite biosorbent, biochemical process tolerance strains and agricultural and forestry waste materials, enhance the adsorption properties of materials. The agricultural and forestry waste peanut shell (PS), corn bran (MC) as raw materials, and the resistance strain of Aspergillus oryzae were selected by lead-zinc mine tailings in (Aspergillus oryae, HA) by composite cultivation, preparation of peanut shell Aspergillus oryzae (PSH), corn bran and Aspergillus oryzae (MCH) composite adsorbent, through static batch test pH value, adsorbent concentration, Pb~ (2+) effect of ion concentration and adsorption time on the adsorption effect, through the dynamic continuous flow fixed bed adsorption adsorption experiment fixed bed system under different operating conditions of the breakthrough curve and analyze its dynamic adsorption characteristics, application of adsorption isotherm, adsorption kinetics model, through curve fitting model, analysis of adsorption of Pb scanning electron microscope and infrared spectra of Fu Li leaves ~ (2+) ion adsorption mechanism. The main results are as follows: the introduction of HA changed the corn straw, wheat straw, corn bran and peanut shell adsorption capacity, there is a big difference between the four kinds of adsorption capacity, adsorption capacity increases the order of millet rice bran peanut shell wheat straw corn straw. The static Pb~ (2+) adsorption test results show that, compared with MC and PS, MCH and PSH have high adsorption capacity, adsorption speed, pH value is applicable to a wide range of characteristics. Compared to the Freundlich and D-R isotherm model, Langmuir model can better describe the adsorption of Pb~ (2+) adsorption isotherm, ion PS, PSH, MC, the theory of the adsorption capacity of MCH by QM were 14.62,20.92,11.89,21.79mg/g.Lagergren quasi description composite adsorbent kinetic model is a quasi two level and intra particle diffusion model is better for Pb~ (2+) adsorption process, explains Study of adsorption as the main function and the rate limiting step of the process. The FTIR and SEM analysis showed that the adsorbent surface morphology and functional groups changed significantly after compound, active functional groups with carboxyl, amino change is the most obvious, hydroxyl, carboxyl, amino and carbonyl groups in the adsorption of Pb~ (2 +) in the process of the main.MCH PSH has more than the adsorption of reactive functional groups and surface morphology change is more obvious. The dynamic continuous adsorption test results show that the composite adsorbent PSH TB MCH, the breakthrough time and saturation time te respectively than single adsorbent PS, MC significantly delayed. The composite adsorbent PSH, the dynamic adsorption capacity of qexp MCH 4.62,7.13 mg/g respectively by the composite before the upgrade to 6.49,8.30 mg/g. composite adsorbent penetration length curve of mass transfer zone is shortened, enhance the overall adsorption ability of the system. The dynamic continuous different operating conditions, the results of the test show that, 緋葷粺鐨勭┛閫忔椂闂磘b闅忔煴楂樼殑澧炲姞鎴栬，

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