纳米零价铁耦合氢自养反硝化去除水中硝酸盐
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摘要
首先采用液相还原法制备纳米零价铁粒子,然后将制得的纳米零价铁与氢自养反硝化菌进行耦合,组成纳米零价铁-氢自养反硝化耦合体系,考察了不同温度、pH值、Fe/N值、初始硝酸盐浓度和H_2对耦合体系去除硝酸盐的影响,并对硝酸盐去除机理进行了讨论。结果表明,纳米零价铁-氢自养反硝化耦合体系对硝酸盐有很好的去除作用,反应速率高于单一的化学还原或生物反硝化过程。Fe/N值对硝酸盐还原速率的影响不大,却对反应产物影响显著,试验条件下,纳米零价铁的最佳投量为10 mL。不同pH值条件下耦合体系对硝酸盐的去除趋势非常接近。温度对耦合体系降解硝酸盐的速率有一定影响,温度越高,硝酸盐的去除速率越快,但整体差别不大。初始硝酸盐浓度为25、65、105和150 mg/L时,对硝酸盐的平均去除速率分别为13. 64、11. 63、16. 55和13. 73 mg/(L·h)。给予耦合体系充足氢气的情况下,硝酸盐的降解速率较快,高于不额外供给氢气的耦合体系。
Nanoscale zero-valent iron was prepared using the liquid reduction method. The nitrate removal process by the coupled nanoscale zero-valent iron and autohydrogenotrophic denitrifying bacteria (nZVI-AB) system was investigated. Influences of temperature, p H, Fe/N ratio, initial nitrate concentration,and H_2 on nitrate removal effect were investigated. The results showed that n ZVI-AB system had excellent efficiency in nitrate removal,and the reaction rate was much higher than uncoupled systems. The effect of Fe/N ratio on the reaction reduction rate was insignificant,but was significant on the nitrate reaction products. Under the experimental conditions,the optimal dosage of nanoscale zerovalent iron was 10 mL. The removal patterns of nitrate by the coupled system under different pH values were very close. Temperature had a partial effect on the degradation rate of nitrate in the coupled system.The higher the temperature was,the faster the removal rate of nitrate was,but the difference was mild overall. When the initial nitrate concentration was 25 mg/L,65 mg/L,105 mg/L,and 150 mg/L,the average removal rates of nitrate were 13. 64 mg/ (L·h),11. 63 mg/ (L·h),16. 55 mg/ (L·h),and 13. 73 mg/ (L· h),respectively. When sufficient hydrogen was provided to the coupled system,the degradation rate of nitrate was faster than that without additional hydrogen supply.
Nanoscale zero-valent iron was prepared using the liquid reduction method. The nitrate removal process by the coupled nanoscale zero-valent iron and autohydrogenotrophic denitrifying bacteria (nZVI-AB) system was investigated. Influences of temperature, p H, Fe/N ratio, initial nitrate concentration,and H_2 on nitrate removal effect were investigated. The results showed that n ZVI-AB system had excellent efficiency in nitrate removal,and the reaction rate was much higher than uncoupled systems. The effect of Fe/N ratio on the reaction reduction rate was insignificant,but was significant on the nitrate reaction products. Under the experimental conditions,the optimal dosage of nanoscale zerovalent iron was 10 mL. The removal patterns of nitrate by the coupled system under different pH values were very close. Temperature had a partial effect on the degradation rate of nitrate in the coupled system.The higher the temperature was,the faster the removal rate of nitrate was,but the difference was mild overall. When the initial nitrate concentration was 25 mg/L,65 mg/L,105 mg/L,and 150 mg/L,the average removal rates of nitrate were 13. 64 mg/ (L·h),11. 63 mg/ (L·h),16. 55 mg/ (L·h),and 13. 73 mg/ (L· h),respectively. When sufficient hydrogen was provided to the coupled system,the degradation rate of nitrate was faster than that without additional hydrogen supply.
引文
[1]刘雨．纳米铁的制备及去除水中硝酸盐氮研究[D]．合肥:合肥工业大学，2009.Liu Yu.Preparation of Nanoscale Zero-valent Iron and Research on Nitrate and Nitrite Removal[D].Hefei:Hefei University of Technology,2009(in Chinese)．
[2]Huang Y H,Zhang T C.Effects of low p H on nitrate reduction by iron powder[J].Water Res,2004,38(11):2631-2642．
[3]张环，金朝晖，韩璐，等．负载型纳米铁化学反硝化法去除硝酸盐氮的研究[J]．中国给水排水，2006,22(15):83-87.Zhang Huan,Jin Zhaohui,Han Lu,et al.Study on nitrate nitrogen removal in chemical denitrification by supported nano zero-valent iron[J].China Water&Wastewater,2006,22(15):83-87(in Chinese)．
[4]Siantar D P,Schreier C G,Chou C S,et al.Treatment of1,2-dibromo-3-chloropropane and nitrate-contaminated water with zero-valent iron or hydrogen/palladium catalysts[J].Water Research,1996,30(10):2315-2322．
[5]陈曦．纳米零价铁及其与微生物联合修复多氯联苯污染土壤[D]．杭州:浙江大学，2014.Chen Xi.Remediation of Polychlorinated Biphenyls Contaminated Soil by Nanoscale Zerovalent Iron or n ZVI-microorganism Integrated Treatment[D].Hangzhou:Zhejiang University,2014(in Chinese)．
[6]Yang G,Lee H L.Chemical reduction of nitrate by nanosized iron:Kinetics and pathways[J].Water Res,2005,39(5):884-894．
[7]Kapoor A,Viraraghavan T.Nitrate removal from drinking water-review[J].J Environ Eng,1997,123(4):371-380．
[8]Hu H Y,Goto N,Fujie K,et al.Reductive treatment characteristics of nitrate by metallic iron in aquatic solution[J].Journal of Chemical Engineering of Japan,2001,34(9):1097-1102．
[9]Choe S H,Liljestrand H M,Khim J.Nitrate reduction by zero-valent iron under different p H regimes[J].Appl Geochem,2004,19(3):335-342．
[10]Chen D,Yang K,Wang H Y,et al.Nitrate removal from groundwater by hydrogen-fed autotrophic denitrification in a bio-ceramsite reactor[J].Water Sci Technol,2014,69(12):2417-2422．
[11]高树梅，王晓栋，秦良，等．改进液相还原法制备纳米零价铁颗粒[J]．南京大学学报:自然科学版，2007,43(4):358-364.Gao Shumei,Wang Xiaodong,Qin Liang,et al.Preparation of nano zero-valent iron particles by modified liquid phase reduction method[J].Journal of Nanjing University:Natural Sciences,2007,43(4):358-364(in Chinese)．
[12]Lee K C,Rittmann B E.Effects of p H and precipitation on autohydrogenotrophic denitrification using the hollowfiber membrane-biofilm reactor[J].Water Res,2003,37(7):1551-1556．
[13]东美英，安毅，李倩倩，等．纳米铁-微生物耦合体系去除硝酸盐的影响因素研究[J]．环境工程学报，2010,4(11):2449-2454.Dong Meiying,An Yi,Li Qianqian,et al.Study of influential elements on nitrate reduction by nanoscale iron particles integrated with microorganisms[J].Chinese Journal of Environmental Engineering,2010,4(11):2449-2454(in Chinese).
[2]Huang Y H,Zhang T C.Effects of low p H on nitrate reduction by iron powder[J].Water Res,2004,38(11):2631-2642．
[3]张环，金朝晖，韩璐，等．负载型纳米铁化学反硝化法去除硝酸盐氮的研究[J]．中国给水排水，2006,22(15):83-87.Zhang Huan,Jin Zhaohui,Han Lu,et al.Study on nitrate nitrogen removal in chemical denitrification by supported nano zero-valent iron[J].China Water&Wastewater,2006,22(15):83-87(in Chinese)．
[4]Siantar D P,Schreier C G,Chou C S,et al.Treatment of1,2-dibromo-3-chloropropane and nitrate-contaminated water with zero-valent iron or hydrogen/palladium catalysts[J].Water Research,1996,30(10):2315-2322．
[5]陈曦．纳米零价铁及其与微生物联合修复多氯联苯污染土壤[D]．杭州:浙江大学，2014.Chen Xi.Remediation of Polychlorinated Biphenyls Contaminated Soil by Nanoscale Zerovalent Iron or n ZVI-microorganism Integrated Treatment[D].Hangzhou:Zhejiang University,2014(in Chinese)．
[6]Yang G,Lee H L.Chemical reduction of nitrate by nanosized iron:Kinetics and pathways[J].Water Res,2005,39(5):884-894．
[7]Kapoor A,Viraraghavan T.Nitrate removal from drinking water-review[J].J Environ Eng,1997,123(4):371-380．
[8]Hu H Y,Goto N,Fujie K,et al.Reductive treatment characteristics of nitrate by metallic iron in aquatic solution[J].Journal of Chemical Engineering of Japan,2001,34(9):1097-1102．
[9]Choe S H,Liljestrand H M,Khim J.Nitrate reduction by zero-valent iron under different p H regimes[J].Appl Geochem,2004,19(3):335-342．
[10]Chen D,Yang K,Wang H Y,et al.Nitrate removal from groundwater by hydrogen-fed autotrophic denitrification in a bio-ceramsite reactor[J].Water Sci Technol,2014,69(12):2417-2422．
[11]高树梅，王晓栋，秦良，等．改进液相还原法制备纳米零价铁颗粒[J]．南京大学学报:自然科学版，2007,43(4):358-364.Gao Shumei,Wang Xiaodong,Qin Liang,et al.Preparation of nano zero-valent iron particles by modified liquid phase reduction method[J].Journal of Nanjing University:Natural Sciences,2007,43(4):358-364(in Chinese)．
[12]Lee K C,Rittmann B E.Effects of p H and precipitation on autohydrogenotrophic denitrification using the hollowfiber membrane-biofilm reactor[J].Water Res,2003,37(7):1551-1556．
[13]东美英，安毅，李倩倩，等．纳米铁-微生物耦合体系去除硝酸盐的影响因素研究[J]．环境工程学报，2010,4(11):2449-2454.Dong Meiying,An Yi,Li Qianqian,et al.Study of influential elements on nitrate reduction by nanoscale iron particles integrated with microorganisms[J].Chinese Journal of Environmental Engineering,2010,4(11):2449-2454(in Chinese).
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