【導讀】對本文的研究做出重要貢獻的個人和集體均已在文中以明確方式標。本人完全意識到本聲明的法律結(jié)果由本人承擔。隨著電鍍、冶金、制革、化工、印染等工業(yè)的發(fā)展，大量含有重金屬的廢水被排放到自然環(huán)境中，造成了嚴重的環(huán)境污染。在自然環(huán)境，尤其是受到Cr污染的環(huán)境中，不少微生物對Cr具有抗。性或使之解毒，將高毒、易溶于水的Cr還原成低毒、易于沉淀的Cr。目前，已發(fā)現(xiàn)對Cr. 酸鹽等硫氧化物以及元素硫還原形成硫化氫這一生理特性的細菌的統(tǒng)稱。鉻效率高的特點，并且生長范圍廣，性能穩(wěn)定。這些研究結(jié)果可為微生物治理含鉻廢水提供高效功能。具有良好的去除重金屬的功能。為探尋一種綠色環(huán)保。Cr的傳統(tǒng)處理方法。硫酸鹽還原菌代謝機理。不同溫度條件培養(yǎng)對混合菌群SRB還原Cr能力的影響。子最高允許排放濃度為。

　　

【正文】 究采用的用混合硫酸鹽還原菌群 將六價鉻離子還原成低價態(tài)的三價無毒鉻離子，探討了其在不同溫度和 pH 條件下對不同濃度的 Cr（ VI） 的還原性能，力求找到耐受性很高的菌群的最佳溫度范圍和 pH 范圍。為人類的工業(yè)發(fā)展與人和自然的和諧共處掃除 障礙。 22 參考文獻 [1].李新榮，沈德中 .硫酸鹽還原菌的生態(tài)特性及其應用 [N].應用與環(huán)境射干物學報， 1999:10－ 13. [2]Ku. H, J Srgensen, B. B. Microsensor measurements of sulfate reduction and sulfide in pact microbial munities of aerobic biofilm [J]. Appl. Environ. Microbiol 1992, 58:1164－ 1174. [3]馬曉航，賈小明 ，趙宇華，用硫酸鹽還原菌處理重金屬廢水的研究 [J]，微生物學雜志， 2021 ,23 ( 1): 3639. [4]韓懷芬，蒲風蓮，裘娟萍 .生物法修復鉻污染土壤的研究［ J］ .能源環(huán)境保護， 2021， 17(2):7－ 9. 23 [5]王保軍，楊惠芳，李文忠 .真菌還原 Cr（ VI)的研究 [J].微生物學報，1998， (2):108－ 113. [6] 李福德 .微生物治理電鍍廢水力一法［ J］ .電鍍與精飾， 2021,24 2):35－ 37. [7]Li F D, Harris B, Urrutia M M, et al. Reduction of Cr( VI )by a consortium of sulfatereducting bacteria (SRBIII) [J]. Applied Environmental Microbiology, 1994, 60(4 5):1525－ 1531. [8]Smith W L, Gadd G M. Reduction and precipitation ofby mixed culture sulphate 一 reducing bacterial biofilm [J] Journal of Applied Microbiology， 2021， 88:983－ 991. [9]張小里，劉海洪，陳開勛等 .硫酸鹽還原菌生長規(guī)律的研究 [J]。西北大學學報 (自然科學版 )， 1999， 29(5): 397－ 402. [10]李亞新，蘇冰琴 .SRB 和酸性礦山廢水的生物處理 [[J].環(huán)境污染治理技術(shù)與設備， 2021， 1(5): 1－ 11. [11]王明義，梁小兵，鄭婭萍，趙由之，魏中青 .硫酸鹽還原菌鑒定和檢測方法的研究進展 [J].微生物學雜志， 2021， 25(6):81－ 84. [12]咎逢宇， 趙秀蘭 .啤酒酵母吸附去除水中 Cr( VI)的研究［ J］ .云南環(huán)境科學， 2021， 23(增刊 ):146－ 150. [13] 瞿建國，中如香，徐伯興，李福德 .硫酸鹽還原菌還原 Cr(VI)的初步研究 [J].華東師范大學學報 (自然科學版 ),2021,1(3):105－ 10. [14] 劉靖，侯寶利等 .硫酸鹽還原菌腐蝕研究進展 ［ J］ .材料保護， 2021，34(8):8－ 11. 24 [15] 趙宇華，葉央芳，劉學東，硫酸鹽還原菌及其影響因子 [J]，環(huán)境污染與防治， 1997， 19(s):41－ 43. [16]國家環(huán)保局。水的 廢水監(jiān)測分析方法 [S]。北京 :中國環(huán)境科學出 版社， 1989:220－ 250. [17] 王清良段曉恒黃愛武 SRB生物法處理廢水的研究進展與現(xiàn)狀 [J].中國礦業(yè) ,2021,14(2):6－ 8. [18]黃民生，鄭樂平，朱莉，微生物對重金屬的吸附與解吸 [M]，化工裝備技術(shù)， 2021,21(2):17－ 22 . [19]趙宇華，葉央芳，劉學東，硫酸鹽還原菌及其影響因子 [N]，環(huán)境污染與防治， 1997， 19(5):41－ 43. [20]Odom J. M. Singleton R. The sulfate reducing bacteria, Contemporary Perspectives, SpringierVerla［ J］ , New York Inc. 1993:6. [21] 張介馳，田小光，硫酸鹽還原菌凈化含鉻電鍍廢水的中試研究[J]，生物技術(shù)， 1997， 7(1):32－ 34. [22]倪修龍，王毓芳，徐章法 .含鉻廢水的生物治理 [J].上?；?，（ 23]）張小里，陳志聽，劉海洪等，環(huán)境因素對硫酸鹽還原菌生長的影響 [N]，中國腐蝕與防護學報， 2021， 20 (4): 224－ 229. [24]王紹文，姜鳳有，重金屬廢水治理技術(shù) [M]，北京 :冶金工業(yè)出版社， 1993 ， 11:20－ 120. [25]Postage,. The SulfateReducing Bacteria[M] Cambridge:Cambridge University Press,1984. 25 致 謝 在本論文完成和實驗過程中，得到了鄧樂老師和彭智輝老師的悉心指導和熱情幫助 ，在此 在此請允許我兩位我敬愛的老師表示深深的感謝！同時，實驗過程還得到了實驗室各位師兄師姐的友情幫助，特別感 謝賀氣志師姐，她實驗時細致嚴謹?shù)木瘛⒐ぷ魃戏e極熱情的態(tài)度深深感染了我。 最后感謝我的家人對我支持，是他們給了我堅持不懈的勇氣和毅力。這段時間還有很多在來幫助過我、指導過我、鼓勵過我的各位老師、朋友、同學，我在此一并感謝！ 文獻翻譯 Bioremoval of hexavalent chromium from water by a salt tolerant bacterium, Exiguobacterium sp. GS1 Benedict C. Okeke Abstract Pollution of terrestrial surfaces and aquatic systems by hexavalent chromium, Cr(VI), is a worldwide public health problem. A chromium resistant bacterial isolate identified as Exiguobacterium sp. GS1 by 16S rRNA genesequencing displayed high rate of removal of Cr(VI) from water. Exiguobacterium sp. GS1 is 99% identical to Exiguobacterium acetylicum. The isolate significantly removed Cr(VI) at both high and low concentrations (1–200 ugmL1) within 12h. The Michaelis–Menten Kmand Vmax for Cr(VI) bioremoval were calculated to be ugmL1 and ugmL1h1, respectively. Growth of Exiguobacterium sp. GS1 was indifferent rent at 1–75 ugmL1 Cr(VI) in 12h. At initial concentration of 8,000 ugmL1, Exiguobacterium sp. GS1 displayed rapid bioremoval of Cr(VI) with over 50% bioremoval in 3h and 91% bioremoval in 8h. Kiic analysis of Cr (VI) bioremoval rate revealed zeroorder in 8h. Exiguobacterium grew and significantly 26 reduced Cr (VI) in cultures containing 1–9% salt indicating high salt tolerance. Similarly the isolate substantially reduced Cr (VI) over a wide range of temperature (18–45176。C) and initial pH (–). The Topt and initial pHopt were 35–40176。C and 7–8, respectively. Exiguobacterium sp. GS1 displayed a great potential for bioremediation of Cr(VI) in diverse plex environments. Introduction Hexavalent chromium (Cr (VI)) and trivalent chromium (Cr(III)) are the most prevalent species of chromium in the natural environment . Cr (III) is relatively in soluble in water and exhibits little or no toxicity. In mammals Cr (III) promotes effective glucose, protein, and lipid metabolism. The hexavalent form (Cr(VI)) is, however, highly soluble and mobile in water and displays toxic, mutagenic, and carcinogenic effects to living systems, including microanisms, at low concentrations. Cr(VI) is an irritant at relatively high concentrations [11]. It has also been linked to morphological changes and growth reduction in plants. Major sources of Cr(VI) pollution include effluents from leather tanning, chromium electroplating, wood preservation, alloy preparation and nuclear wastes due to its use as a corrosion inhibitor in nuclear power plants. Although some living anisms require Cr as an essential element, its toxic, mutagenic, and carcinogenic nature render it hazardous. Health problems associated with Cr pollution of terrestrial surfaces and aquatic systems is of increasing worldwide concern. Discharge of Cr(VI) into surface waters is regulated by both the European Union and US EPA to below 50 μgL1. The United States Environmental Protection Authority (US EPA) set the maximum contaminant level (MCL) for total chromium including Cr(VI) and Cr(III) at 100 μgL1 of anthropogenic contamination of water and soils by hexavalent chromium Cr(VI) has spurred the development of physicochemical and bioremediation treatment technologies for Cr(VI) removal or detoxification. Physicochemical treatment technologies include ion exchange adsorption, electrodialyses, precipitation, and chemical reduction. The drawback of these conventional methods include high