硫酸鹽還原菌的脫硫性能和鐵還原性能

陳明翔，周集體，路達,2，張玉

(1.大連理工大學 環境學院,工業生態與環境工程教育部重點實驗室，遼寧 大連 116024； 2.河北大學 化學與環境科學學院,河北 保定 071002)

隨著工業的發展，化石燃料的大量燃燒所產生的二氧化硫(SO2)和一氧化氮(NO)，造成了酸雨、臭氧層破壞、光化學煙霧等環境污染，并嚴重威脅人類的健康[1].SO2和NO一體化脫除技術，作為大氣污染治理的發展趨勢之一，已經得到廣泛研究[2-3].目前，比較常見的煙氣同時脫硫脫硝技術主要包括等離子體法、液相氧化法、光催化氧化法、絡合吸收法、吸附法等[4-8].盡管這些方法有著諸多的優點，但仍有許多方面需要改進，如高能耗、高成本、存在二次污染等問題.生物法工業廢氣凈化技術因其設備簡單、投資及運行費用低、且無二次污染等優點日益受到人們的關注[1].目前，多數研究采用生物法單獨脫除SO2或NO，而生物法同步脫硫脫硝尚處于實驗探索階段[3].

1 材料和方法

1.1 菌種

實驗采用的SRB是由大連市春柳河污水處理廠的厭氧污泥經富集、馴化、反復稀釋涂布而得.經16S rDNA測序和Blast分析表明，菌株與脫硫弧菌屬(Desulfovibriosp.)的同源性最高，故命名為Desulfovibriosp.CMX.在GenBank上登錄，其序列號為GU584224.在廣東省微生物菌種保藏中心的保藏號為GIM1.765.

1.2 培養基

富集培養基：K2HPO4,0.50 g；NH4Cl,1.00 g；MgSO4·7H2O,2.00 g；Na2SO4,0.86 g；CaCl2,0.10 g；酵母浸粉，1.00 g；乳酸鈉(質量分數為70%～80%)，5 mL；蒸餾水，1 000 mL，pH值調至7.00±0.20.在0.1 MPa，121 ℃下滅菌20 min.在培養基使用前用濾膜過濾滅菌加入0.10 g的維生素C.

基礎培養基：Na2HPO4·12H2O，5.00 g；NaH2PO4·2H2O，2.20 g；酵母浸粉，1.00 g；乳酸鈉(質量分數為70%～80%)，5 mL；蒸餾水，1 000 mL.在0.1 MPa，121 ℃下滅菌20 min.在培養基使用前用濾膜過濾滅菌加入0.10 g的維生素C.

1.3 菌株脫硫性能的優化

1.3.1 pH值對D.sp.CMX的脫硫性能的影響

1.3.2 不同碳源對D.sp.CMX脫硫性能的影響

1.4 菌株Fe(Ⅲ)EDTA還原能力的考察

分別將0，5，15，25 mmol/L的Fe(Ⅲ)EDTA加入100 mL基礎培養基中，并將D.sp.CMX(細胞蛋白質量濃度為20.00 mg/L)分別厭氧接種于初始Fe(Ⅲ)EDTA濃度不同的培養基中，在pH=7、溫度為30 ℃的條件下厭氧培養，并定期取樣測定其蛋白生長量、亞鐵(Fe2+)和總鐵含量.

1.5 分析方法

2 結果和討論

2.1 pH對D.sp.CMX的脫硫性能的影響

圖1 pH值不同時D.sp.CMX的脫硫性能Fig.1 Sulfate reducing performances of D.sp.CMX at different pH values

圖2 不同碳源時D.sp.CMX的脫硫性能Fig.2 Sulfate reducing performances of D.sp.CMX at different carbon sources

2.2 碳源對D.sp.CMX的脫硫性能的影響

2.3 初始質量濃度對D.sp.CMX的脫硫性能的影響

ρ/(g·L-1)圖3 初始的質量濃度不同時D.sp.CMX的脫硫性能Fig.3 Sulfate reducing performances of D.sp.CMX at different sulfate concentrations

2.4 D.sp.CMX的鐵還原能力的考察

圖4 D.sp.CMX的鐵還原能力Fig.4 Ferric reducing capacity of D.sp.CMX

圖5 D.sp.CMX在Fe(Ⅲ)EDTA中的生長情況Fig.5 Growth of D.sp.CMX in Fe(Ⅲ)EDTA solution

SRB可以直接將Fe(Ⅲ)、尤其是水溶態的Fe(Ⅲ)生物還原，但是，又有研究表明，25 mmol/L的Fe(Ⅲ)EDTA不是一個合適的電子受體，大部分的異養鐵還原微生物無法還原25 mmol/L的Fe(Ⅲ)EDTA[23-25].而在本實驗中，菌株D.sp.CMX在25 mmol/L的Fe(Ⅲ)EDTA溶液中，也可以發生異養的鐵還原.隨著Fe(Ⅲ)EDTA濃度的升高，D.sp.CMX在22 h時的蛋白濃度反而降低，這可能是由絡合劑對SRB的毒性導致的，已有研究證明，EDTA、檸檬酸都對SRB的活性有一定的抑制作用[26].

3 結論

參 考 文 獻：

[1] 謝志榮,魏在山,曾貴華,等.生物法同時脫硫脫硝試驗研究[J].環境工程學報,2009,3(9):1648-1652.

XIE Zhirong,WEI Zaishan,ZENG Guihua,et al.Simultaneous desulfurization and denitrification by a biological method[J].Chinese Journal of Environmental Engineering,2009,3(9):1648-1652.

[2] 趙榮志,梁寶瑞,宋存義,等.密相半干法低溫同時脫硫脫硝影響因素[J].環境工程學報,2013,7(12):4945-4950.

ZHAO Rongzhi,LIANG Baorui,SONG Cunyi,et al.Influencing factors during simultaneous removal of NOxand SO2in semi-dry dense bed at low temperature[J].Chinese Journal of Environmental Engineering,2013,7(12):4945-4950.

[3] 徐姣,張衛江,田桂林.生物法同步脫除SO2和NO的實驗研究[J].化學工程,2010,38(3):61-64.

XU Jiao,ZHANG Weijiang,TIAN Guilin.Experimental study on biological simultaneous removal of SO2-containing and NO-containing waste gases[J].Chemical Engineering(China),2010,38(3):61-64.

[4] ZHAO Yi,GUO Tianxiang,CHEN Zhouyan,et al.Simultaneous removal of SO2and NO using M/NaClO2complex absorbent[J].Chem Eng J,2010,160(1):42-47.

[5] YUAN Yuan,ZHANG Junying,LI Hailong,et al.Simultaneous removal of SO2,NO and mercury using TiO2-aluminum silicate fiber by phohotocatalysis[J].Chem Eng J,2012,192:21-28.

[6] HUANG Liwei,DANG Yongxia.Removal of SO2and NOx by pulsed corona combined with in situ Ca(OH)2absorption[J].Chinese J Chem Eng,2011,19(3):518-522.

[7] MENENDEZ J A,ARENILLAS A,FIDALGO B,et a1.Microwave heating processes involving carbon materials[J].Fuel Process Technol,2010,91(1):1-8．

[8] 曲兵,劉盛余,徐園園,等.鼓泡反應器中液相絡合催化同時脫硫脫硝的研究[J].環境工程學報,2012,6(2):555-560.

QU Bing,LIU Shengyu,XU Yuanyuan,et al.Simultaneous desulfurization and denitrification by complex catalysis in bubbing reactor[J].Chinese Journal of Environmental Engineering,2012,6(2):555-560.

[9] CHEN Mingxiang,ZHANG Yu,ZHOU Jiti,et al.Sulfate removal by Desulfovibrio sp.CMX in chelate scrubbing solutions for NO removal[J].Bioresour Technol,2013,143:455-460.

[10] DONG Xiyang,ZHANG Yu,ZHOU Jiti,et al.Fe(II)EDTA-NO reduction coupled with Fe(II)EDTA oxidation by a nitrate-and Fe(II)-reducing bacterium[J].Bioresour Technol,2013,138:339-344.

[11] BRADFORD M M.A rapid and sensitive method for the quantification of microquantities of protein utilizing the principle of protein-dye binding[J].Anal Biochem,1976,72:248-254.

[12] 彭艷平,余水靜,賴和勁.硫酸鹽還原菌生長條件優化及馴化試驗研究[J].江西理工大學學報,2013,34(3):6-10.

PENG Yanping,YU Shuijing,LAI Hejin.The domestication and optimization of sulfate reducting bacteria growth conditions[J].Journal of Jiangxi University of Science and Technology,2013,34(3):6-10.

[13] BAYOUMY M A E,BEWTRA J K,ALI H I,et al.Sulfide production by sulfate reducing bacteria with lactate as feed in an upflow anaerobic fixed film reactor[J].Water Air Soil Pollut,1999,112:67-84.

[14] 馬巖巖,徐建平.脫硫微生物培養條件及脫硫性能研究[J].安徽工程科技學院學報,2010,25(2):33-35.

MA Yanyan,XU Jianping.On culture condition and desulfurization performance of desulfurization strain[J].Journal of Anhui University of Technology and Science:Natural Science,2010,25(2):33-35.

[15] SMUL A,GOETHALS L,VERSTRAETE W.Effect of COD to sulphate ratio and temperature in expanded-granular-sludge-blanket reactors for sulphate reduction[J].Process Biochem,1999,34:407-416.

[16] VAN DER MAAS P,VAN DER BRINK P,UTOMO S,et al.NO removal in continuous BioDeNOxreactors:Fe(II)EDTA2-regeneration,biomass growth,and EDTA degradation[J].Biotechnol Bioeng,2006,94:575-584.

[17] 徐姣.生物法脫除工業廢氣中SO2和NO的研究[D].天津：天津大學,2008.

[18] LIAMLEAM W,ANNACHHATRE A P.Electron donors for biological sulfate reduction[J].Biotechnol Adv,2007,25:452-463.

[19] 姬玉欣,馬春,金仁村,等.硫酸鹽生物還原中電子供體的選擇[J].化工進展,2011,30(12):2593-2600.

JI Yuxin,MA Chun,JIN Rencun,et al.Selection of electron donors for biological sulfate reduction[J].Chemical Industry and Engineering Progress,2011,30(12):2593-2600.

[20] 蔣永榮,周亶,容翠娟,等.高效硫酸鹽還原菌的分離及特性研究[J].環境科學與技術,2009,32(11):13-17.

JIANG Yongrong,ZHOU Dan,RONG Cuijuan,et al.Isolation of high efficient sulfate-reducing bacteria and its biological desulfurization capability[J].Environmental Science and Technology,2009,32(11):13-17.

[21] OYEKOLA O O,VANHILLE R P,HARRISON S T L.Kinetic analysis of biological sulphate reduction using lactate as carbon source and electron donor:Effect of sulphate concentration[J].Chem Eng Sci,2010,65:4771-4781.

[22] DEMMINK J F,BEENACKERS A A C M.Gas desulfurization with ferric chelates of EDTA and HEDTA:new model for the oxidative absorption of hydrogen sulfide[J].Ind Eng Chem Res,1998,37:1444-1453.

[23] COLEMAN M L,HEDRICK D B,LOVLEY D R,et al.Reduction of Fe(Ⅲ)in sediments by sulphate-reducing bacteria[J].Nat,1993,361:436-438.

[24] LOVLEY D R,RODEN E E,PHILLIPS E J P,et al.Enzymatic iron and uranium reduction by sulphate-reducing bacteria[J].Mar Geol,1993,113:41-53.

[25] FINNERAN K T,FORBUSH H M,VANPRAAGH C G,et al.Desulfitobacterium metallireducens sp.nov.,an anaerobic bacterium that couples growth to the reduction of metals and humic acids[J].J Syst Evol Microbiol,2002,52:1929-1935.

[26] ASBELL M A,EAGON R G.Role of multivalent cations in the organization,structure and assembly of the cell wall of Pseudomonas aeruginosa[J].J Bacteriol,1966,92,380-387.