本文選題：微生物絮凝劑 + 粉煤灰�。� 參考：《內(nèi)蒙古工業(yè)大學(xué)》2017年碩士論文

【摘要】：隨著社會經(jīng)濟(jì)的快速發(fā)展,重金屬污染情況越來越嚴(yán)重,而作為毒性最大的重金屬之一的Pb~(2+),主要來源于工業(yè)廢水中,其可以通過呼吸道、消化道甚至皮膚進(jìn)入到人體內(nèi),且不斷蓄積,從而對人體各系統(tǒng)造成傷害。如何選擇一種高效且環(huán)保的方法成為研究熱點(diǎn)。微生物絮凝劑具有可生物降解、無毒、安全、高效、且沒有二次污染等特點(diǎn),但生產(chǎn)成本高等局限性限制了其規(guī)�；a(chǎn)應(yīng)用。粉煤灰因?yàn)槠潆x子交換容量高、比表面積大等特點(diǎn)逐步代替天然沸石應(yīng)用于廢水處理等領(lǐng)域,但粉煤灰的利用效率較低。因此,本研究提出利用粉煤灰與微生物絮凝劑協(xié)同作用去除水中重金屬Pb~(2+),從而提高水處理效率。首先,分別單獨(dú)優(yōu)化粉煤灰及微生物絮凝劑處理Pb~(2+)的最佳條件,同時(shí)根據(jù)動力學(xué)及熱力學(xué)模型,揭示反應(yīng)機(jī)制。在此基礎(chǔ)上,通過采用響應(yīng)曲面優(yōu)化法確定粉煤灰與微生物絮凝劑聯(lián)合后的最優(yōu)組合。研究的主要內(nèi)容和結(jié)果如下:采用分離純化技術(shù)從內(nèi)蒙古地區(qū)鹽堿地中篩選出一株高效絮凝劑產(chǎn)生菌,編號為HG6,16S rDNA鑒定為Oceanobacillus polygoni。研究優(yōu)化了這種新型的耐鹽,嗜堿型微生物絮凝劑MBF-HG6的生產(chǎn)制備。該微生物絮凝劑產(chǎn)生菌的最佳培養(yǎng)基的碳源,氮源,金屬離子和初始pH分別為淀粉,尿素,Fe~(2+)和pH 9.0。所得微生物絮凝劑在0℃至60℃的溫度范圍內(nèi)顯示出良好的熱穩(wěn)定性。純化的MBF-HG6含有81.53%多糖和9.98%蛋白質(zhì)。傅里葉變換紅外光譜表明,MBF-HG6中含有羧基,羥基和氨基。通過響應(yīng)曲面優(yōu)化法發(fā)現(xiàn)當(dāng)投加6.96 m L MBF-HG6,4.77 mL CaCl2(1%,m/v)和19.24 g/L NaCl時(shí)其絮凝活性可以達(dá)到90.25%。分別考察粉煤灰與微生物絮凝劑MBF-HG6在不同影響因素下對Pb~(2+)的去除效果,以及研究粉煤灰及MBF-HG6去除Pb~(2+)的過程中的吸附行為等溫模型、動力學(xué)、熱力學(xué),并對粉煤灰及MBF-HG6吸附Pb~(2+)的機(jī)理進(jìn)行了初步探討。再此基礎(chǔ)上,采用BBD法研究了粉煤灰與微生物絮凝劑聯(lián)合去除廢水中Pb~(2+)的最佳條件組合,設(shè)定響應(yīng)值為Pb~(2+)的去除率,方差分析顯示,模型F值為17.30,P=0.0005,相關(guān)系數(shù)R=0.9017,擬合模型極顯著。在最優(yōu)條件下:粉煤灰投加量1.46 g/L,MBF-HG6投加量0.888 g/L,CaCl2投加量15.6 mL/L(1%,w/v),測定Pb~(2+)的去除率達(dá)到99.75%。與單獨(dú)使用粉煤灰去除Pb~(2+)及單獨(dú)使用MBF-HG6去除Pb~(2+)時(shí)相比,節(jié)省了粉煤灰及MBF-HG6的投加量。通過Zeta電位分析發(fā)現(xiàn),粉煤灰與MBF-HG6對Pb~(2+)的去除過程中存在電中和作用及吸附架橋機(jī)理,在粉煤灰中加入MBF-HG6及助凝劑CaCl_2,對于膠體顆粒脫穩(wěn)后的絮凝和吸附架橋具有鞏固作用,能夠?qū)崿F(xiàn)最大限度地去除含鉛廢水中的重金屬。
[Abstract]:With the rapid development of social economy, the pollution of heavy metals becomes more and more serious. As one of the most toxic heavy metals, Pb~(2 mainly comes from industrial wastewater, which can enter human body through respiratory tract, digestive tract and even skin. And continue to accumulate, thus causing harm to the human body system. How to choose an efficient and environmentally friendly method has become a research hotspot. Microbial flocculants are biodegradable, non-toxic, safe, efficient and have no secondary pollution, but the high production cost and other limitations limit its large-scale production applications. Because of its high ion exchange capacity and large specific surface area, fly ash is gradually replaced by natural zeolite in wastewater treatment, but the utilization efficiency of fly ash is low. Therefore, in this study, the synergistic action of fly ash and microbial flocculant was put forward to remove the heavy metal Pb~(2 in water to improve the water treatment efficiency. Firstly, the optimal conditions of treating Pb~(2 with fly ash and microbial flocculant were optimized separately, and the reaction mechanism was revealed according to the kinetic and thermodynamic models. On this basis, the optimal combination of fly ash and microbial flocculant was determined by using response surface optimization method. The main contents and results are as follows: a strain of high efficiency flocculant producing bacteria was isolated from saline and alkali soil in Inner Mongolia by separation and purification technique, and identified as Oceanobacillus polygoni by rDNA. The production and preparation of this new salt-tolerant and alkalophilic microbial flocculant MBF-HG6 were studied and optimized. The carbon source, nitrogen source, metal ion and initial pH of the microbial flocculant producing strain were starch, urea ferritin 2) and pH 9.0, respectively. The obtained microbial flocculant shows good thermal stability in the range of 0 鈩，

本文編號：1852421