【摘要】：近年來,由于含氮廢水的大量排放,造成水環(huán)境污染日益嚴(yán)重和復(fù)雜。生物脫氮是目前廢水脫氮中最經(jīng)濟有效的方法之一,而傳統(tǒng)的生物脫氮工藝即自養(yǎng)硝化 厭氧反硝化工藝,存在工藝流程長、脫氮效率低的問題。近年越來越多異養(yǎng)硝化菌被發(fā)現(xiàn),這類細(xì)菌生長快、活性高、增殖底物廣泛、大多能同時進(jìn)行異養(yǎng)硝化和好氧反硝化作用,因此異養(yǎng)硝化生物脫氮成為廢水脫氮領(lǐng)域的研究熱點之一。本研究從馴化成熟且具有高效同步硝化反硝化作用的SBR反應(yīng)器中篩得一株高效異養(yǎng)硝化菌YL,并通過單因子試驗和正交試驗對其異養(yǎng)硝化和好氧反硝化特性進(jìn)行了研究。此外,考察了菌株YL應(yīng)用于模擬廢水的處理效果,為今后的實際應(yīng)用提供理論依據(jù)。主要試驗和研究結(jié)果如下:(1)篩得一株異養(yǎng)硝化菌,命名為YL。經(jīng)形態(tài)學(xué)觀察、生理生化試驗和分子生物學(xué)鑒定,為銅綠假單胞菌(Pseudomonas aeruginosa)。(2)菌株YL進(jìn)行異養(yǎng)硝化作用的最適條件為:碳源為琥珀酸鈉、C/N為10、pH為7.0、溫度為30℃、轉(zhuǎn)速為160~200 r/min。且菌株YL具有很強的高氨氮濃度耐受力。菌株YL能夠以羥胺作為氮源進(jìn)行生長和代謝,反應(yīng)中間產(chǎn)物為亞硝氮和硝氮,48 h后羥胺去除率為94.8%,總氮去除率為90.4%。(3)菌株YL能夠轉(zhuǎn)化起始濃度為200 mg/L的亞硝氮和硝氮。轉(zhuǎn)化亞硝氮過程的中間產(chǎn)物為氨氮和硝氮,48 h后亞硝氮和總氮去除率分別為92.7%和91.9%;轉(zhuǎn)化硝氮過程有中間產(chǎn)物亞硝氮的積累,48 h后硝氮和總氮去除率分別為93.6%和63.4%。影響菌株YL好氧反硝化性能最主要的因素是C/N,在優(yōu)化條件(C/N=10,T=30℃,r=200 r/min,pH=7.0)下,硝氮去除率為94.6%,總氮去除率76.3%。(4)在碳源為琥珀酸鈉、C/N為10、pH為7.0、溫度30℃及轉(zhuǎn)速160 r/min條件下,相比于其它氮源,以氨氮為增殖底物時菌株YL的增殖速率最大,最大比生長速率為0.19 h-1,氨氧化速率為5.05 mg/g/h,TOC轉(zhuǎn)化速率為45.95 mg/g/h,氨氮和TOC去除率分別為100%和90.8%,且反應(yīng)過程無亞硝氮和硝氮的積累。(5)采用純菌YL為種源形成的活性污泥處理模擬廢水,反應(yīng)器運行的8~20 d期間,菌株YL的數(shù)量約占細(xì)菌總數(shù)的43%以上,系統(tǒng)相對穩(wěn)定,TOC去除率保持在85%左右,氨氮去除率高達(dá)96%~100%,總氮去除率始終在90%左右。系統(tǒng)的脫氮除碳效果顯著優(yōu)于菌株篩選所用的SBR中的硝化污泥(P=0.005、0.0020.05)。說明在該系統(tǒng)中菌株YL具有很強的競爭優(yōu)勢,能夠穩(wěn)定地存活于系統(tǒng)中,有助于維持系統(tǒng)長期高效脫氮運行。
[Abstract]:In recent years, due to the discharge of a large number of nitrogen-containing wastewater, the pollution of water environment is becoming more and more serious and complex. Biological denitrification is one of the most economical and effective methods in wastewater denitrification at present, while the traditional biological denitrification process, autotrophic nitrification / anaerobic denitrification process, has the problems of long process flow and low denitrification efficiency. In recent years, more and more heterotrophic nitrifying bacteria have been found. These bacteria grow fast, have high activity and proliferate a wide range of substrate, and most of them can carry out heterotrophic nitrification and aerobic denitrification at the same time. Therefore, heterotrophic nitrification biological denitrification has become one of the research hotspots in the field of wastewater denitrification. In this study, a strain of highly efficient heterotrophic nitrifying bacteria YL, was screened from a SBR reactor with mature domestication and high efficiency simultaneous nitrification and denitrification, and its heterotrophic nitrification and aerobic denitrification characteristics were studied by single factor test and orthogonal test. In addition, the effect of strain YL on the treatment of simulated wastewater was investigated, which provided a theoretical basis for its practical application in the future. The main results are as follows: (1) A strain of heterotrophic nitrifying bacteria named YL. was screened. The optimum conditions for heterotrophic nitrification of Pseudomonas aeruginosa (Pseudomonas aeruginosa). (2) strain YL were as follows: carbon source was sodium succinate, C 鈮，

本文編號：2481141