本文關(guān)鍵詞：河流脫氮微生物的篩選及脫氮特性研究　出處：《鄭州大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

  更多相關(guān)文章： 氨氮 菌種鑒定 脫氮效率 菌種馴化

【摘要】：河流、湖泊等水體中氨氮濃度超標(biāo)是引發(fā)我國(guó)水體污染的主要因素之一,氨氮超標(biāo)引起的諸多問(wèn)題成為近年來(lái)研究的熱點(diǎn)。本文從鄭州市賈魯河主干流及上游支流采集水樣,分析水體污染特點(diǎn)。通過(guò)富集、分離、純化等手段從樣品中篩選出來(lái)7株脫氮菌,檢驗(yàn)菌株的脫氮特性,選擇其中3株考察其對(duì)河水中氨氮的去除效果。對(duì)賈魯河水體污染特點(diǎn)分析,結(jié)果顯示:賈魯河水體氨氮濃度超標(biāo)是最主要的污染問(wèn)題;研究區(qū)域內(nèi)COD濃度沿程變化不規(guī)律,DO值上游高于下游,各形態(tài)氮含量沿程基本呈現(xiàn)上升趨勢(shì)。根據(jù)COD、各形態(tài)氮以及DO值變化等分別選擇各批次部分點(diǎn)位的樣品作為微生物篩選重點(diǎn)研究對(duì)象。利用銨鹽有機(jī)和無(wú)機(jī)培養(yǎng)基富集3個(gè)批次的水樣,經(jīng)過(guò)1月左右富集完成,春、夏季批次樣品富集情況良好,PCR-DGGE分析結(jié)果顯示:富集液中Thermomonas brevis strain(反硝化細(xì)菌熱單胞菌)、Pseudomonadaceae bacterium(假單胞桿菌科細(xì)菌)等明顯占優(yōu)勢(shì),且存在可能具有異養(yǎng)硝化作用的Pseudomonas sp.(假單胞桿菌)、Flavobacterium Bergey(黃桿菌)、Rhizobium(根瘤菌),未發(fā)現(xiàn)自養(yǎng)型脫氮菌。從3個(gè)批次的富集液中分離出純菌共110株,比較其對(duì)氨氮的去除效率,初步篩選出脫氮效率較高的22株菌,結(jié)合16S r DNA測(cè)序分結(jié)果,并查閱文獻(xiàn),選取其中可能具有異養(yǎng)硝化作用的C2、C30、C31、C42、C49、NC13、NC63共7菌種鑒定,結(jié)果表明:C2、C30、C31、C42、C49為假單胞桿菌,分別與Pseudomonas putida(惡臭假單胞桿菌)、Pseudomonas mendocina(門(mén)多薩假單胞桿菌)、Pseudomonas mendocina、Pseudomonas chengduensis、Pseudomonas oleovorans(石油假單胞桿菌)表現(xiàn)出較小差異性;其余2株菌NC13和NC63可基本確定為Diaphorobacter nitroreducens和Pseudoxanthomonas mexicana。所篩選出的7株菌對(duì)氨氮均具有較高的去除率,24h內(nèi)對(duì)培養(yǎng)基內(nèi)氨氮的去除率最高達(dá)91.8%,但去除方式多為細(xì)菌的同化作用,約20%~25%的氨氮在5株假單胞桿菌體內(nèi)通過(guò)異養(yǎng)硝化作用被還原成氣體逸出。7株菌最適生長(zhǎng)溫度在30℃左右;菌株C2、C30為中性菌,中性條件便可生長(zhǎng)很好,菌株C31和C42更易于在偏堿性的條件下生長(zhǎng)。菌株C42能利用不同的碳源,以檸檬酸鈉為碳源時(shí)脫氮效果最佳,其余菌株更易利用丁二酸鈉。通過(guò)培養(yǎng)條件優(yōu)化發(fā)現(xiàn),轉(zhuǎn)速的提升最有利于菌株提高脫氮效率。選取C2、NC13、NC63研究其對(duì)河水中氨氮的去除效果,發(fā)現(xiàn)將菌株直接投加于河水時(shí),菌株易因營(yíng)養(yǎng)條件不足而死亡,對(duì)河水中氨氮無(wú)去除效果;因此采取逐漸降低外加碳源和氮源濃度的方式逐步進(jìn)行菌種馴化,經(jīng)過(guò)兩個(gè)周期馴化,假單胞桿菌C2馴化初見(jiàn)效果,對(duì)環(huán)境中氨氮去除后殘余量達(dá)4.53mg/L,其余2株菌能適應(yīng)馴化過(guò)程,但去除氨氮效果不明顯。
[Abstract]:The concentration of ammonia nitrogen in rivers, lakes and other water bodies is one of the main factors causing water pollution in China. In recent years, many problems caused by excessive ammonia nitrogen have become a hot topic. In this paper, water samples are collected from the main stream and upstream tributaries of the Jaru River in Zhengzhou City, and the characteristics of water pollution are analyzed, and the characteristics of water pollution are analyzed through enrichment and separation. Seven strains of denitrifying bacteria were screened out from the samples by purification methods. The denitrification characteristics of the strains were tested, and three of them were selected to study the removal effect of ammonia nitrogen in the river water, and the characteristics of water pollution in the Jaru River were analyzed. The results show that the concentration of ammonia and nitrogen in the water of the Jaru River is the most important pollution problem. The variation of COD concentration in the study area was irregular. The do value in upstream was higher than that in downstream, and the nitrogen content in all forms showed an upward trend along the course. According to COD. Each nitrogen form and do value were selected as the main research object of microbial screening. The three batches of water samples were enriched with ammonium salt organic and inorganic medium. The samples were enriched well in spring and summer after enrichment on January. PCR-DGGE analysis showed that Thermomonas brevis strain (denitrifying bacteria) was found in the enriched solution. Pseudomonadaceae bacteria (Pseudomonas bacteria) and other obvious advantages. And there is Pseudomonas sp. (Pseudomonas pseudomonas) that may have heterotrophic nitrification (Flavobacterium Bergeyium). Rhizobium (Rhizobium, no autotrophic denitrifying bacteria) was isolated from three batches of enrichment solution, and 110 strains of pure bacteria were isolated, and the removal efficiency of ammonia nitrogen was compared. 22 strains with high denitrification efficiency were preliminarily screened. The results of 16s r DNA sequencing were used to select C2C30C31C42, which may have heterotrophic nitrification. Seven strains of C49-NC13NC63 were identified. The results showed that C31C42C49 was Pseudomonas spp. And Pseudomonas putida (Pseudomonas mendocina). Pseudomonas mendocina,Pseudomonas chengduensis. Pseudomonas oleovorans (Pseudomonas petroleum) showed a small difference; The other two strains, NC13 and NC63, can be basically identified as Diaphorobacter nitroreducens and Pseudoxanthomonas. The 7 strains screened by mexicana. all had high removal rate of ammonia nitrogen. The highest removal rate of ammonia nitrogen in culture medium was 91.8% within 24 hours, but most of the removal methods were bacteria assimilation. About 20% of ammonia nitrogen was reduced to gas escape by heterotrophic nitrification in 5 strains of Pseudomonas spp. The optimum growth temperature was about 30 鈩，

本文編號(hào)：1401948