磁性壳聚糖凝胶微球固定反硝化菌去除地下水中硝酸盐氮
Removal of nitrate nitrogen in groundwater by denitrifying bacteria immobilized on magnetic chitosan gel microspheres
-
摘要: 本研究从活性污泥中分离出氢自养反硝化细菌,在厌氧条件下利用氢气作为电子受体,将硝酸盐氮污染物彻底还原为氮气.通过原位共沉淀/柠檬酸钠交联法制备了一种磁性壳聚糖微球,将氢自养反硝化菌固定于磁性壳聚糖微球上组成固定化微生物反硝化体系.利用16SrDNA菌种鉴定、扫描电镜(SEM)、傅里叶红外光谱(FTIR)对固定化前后的材料进行了表征,并与游离的氢自养反硝化菌进行对比,同时进行静态批实验考察了在不同影响因素下硝酸盐去除效果.结果表明,分离出的氢自养反硝化菌属于陶厄氏菌属(MK928401),且被成功固定在磁性壳聚糖微球上;相同时间内,固定化氢自养反硝化菌对硝酸盐氮去除率高出游离细菌59%,说明固定化菌克服了由于游离菌易团聚而限制反硝化速率的缺点;磁性壳聚糖微球的加入,在一定程度上拓宽了氢自养反硝化菌对硝酸盐氮浓度的适应范围,同时拓宽了氢自养反硝化菌对pH的耐受范围;固定化氢自养反硝化菌经5次重复利用后,仍能高效还原硝酸盐氮,相比于游离细菌具有可回收和循环利用性.以上结果得出,以磁性壳聚糖微球固定氢自养反硝化菌,为高效去除地下水中的硝酸盐氮提供了一种更有效的途径.Abstract: In this study, hydrogen autotrophic denitrifying bacteria were isolated from activated sludge, and hydrogen was used as an electron acceptor under anaerobic conditions to completely reduce nitrate nitrogen to nitrogen. Magnetic chitosan microspheres were prepared by in-situ coprecipitation/sodium citrate cross-linking method, and hydrogen autotrophic denitrifying bacteria were immobilized on the magnetic chitosan microspheres to form an immobilized microbial denitrification system. The 16SrDNA strains were identified by SEM and FTIR. The materials before and after immobilization were characterized and compared with free hydrogen autotrophic denitrifying bacteria. Nitrate removal was evaluated in static batch experiments under different influencing factors. The results show that the isolated autotrophic denitrifying bacteria belonged to the genus Teueus (MK928401) and were successfully immobilized on the magnetic chitosan microspheres. The nitrogen removal rate was 59% higher than that of free bacteria, indicating that the immobilized bacteria overcame the disadvantage of limited denitrification rate due to the easy agglomeration of free bacteria. The addition of magnetic chitosan microspheres broadened the adaptation range of hydrogen autotrophic denitrifying bacteria to nitrate nitrogen concentration as well as their tolerance to pH. The immobilized hydrogen autotrophic denitrifying bacteria could still efficiently reduce nitrate nitrogen after 5 repeated uses. It is recyclable compared to free bacteria. The above results show that the immobilization of hydrogen autotrophic denitrifying bacteria on magnetic chitosan microspheres provides a more effective way to efficiently remove nitrate nitrogen from groundwater.
-
[1] MULDER A, VAN DE GRAAF A A, ROBERTSON L A, et al. Anaerobic ammonium oxidation discovered in a denitrifying fluidized bed reactor[J]. Fems Microbiology Ecology, 1995, 16(3):177-184. [2] MUNEOKA T, YAMAZAKI Y, WAKOU S, et al. Evaluation of nitrate pollution in river water at agricultural watershed[J]. International Journal of Environmental & Rural Development, 2014, 5(2):51-56. [3] SU J F, LUO X X, WEI L, et al. Performance and microbial communities of Mn(Ⅱ)-based autotrophic denitrification in a moving bed biofilm reactor (MBBR)[J]. Bioresource Technology, 2016, 211:743-750. [4] 王家宏, 毛敏. 磁性聚吡咯的合成及其快速去除水中硝酸盐[J]. 环境化学, 2017,36(4):915-923. WANG J H,MAO M.Preparation of magnetic polypyrrole adsorbent and its rapid removal of nitrate from aqueous solution[J]. Environmental Chemistry, 2017,36(4):915-923(in Chinese).
[5] 李铁龙, 康海彦, 刘海水, 等. 纳米铁的制备及其还原硝酸盐氮的产物与机理[J]. 环境化学, 2006, 25(3):294-296. LI T L,KANG H Y,LIU H S, et al. Preparation of nano-iron and its product and mechanism of reducing nitrate nitrogen[J]. Environmental Chemistry, 2006, 25(3):294-296(in Chinese).
[6] YANG L, REN Y X, LIANG X, et al. Nitrogen removal characteristics of a heterotrophic nitrifier Acinetobacter junii, YB and its potential application for the treatment of high-strength nitrogenous wastewater[J]. Bioresource Technology, 2015, 193:227-233. [7] 李文超, 石寒松, 王琦,等. 硫自养反硝化技术在污废水处理中应用研究进展[J]. 水处理技术, 2017,43(8):6-11. LI W C,SHI H S,WANG Q, et al.Advances in application of sulfur autotrophic denitrification technology in wastewater treatment[J]. Water T reatment Technology, 2017,43(8):6-11(in Chinese).
[8] 张环, 金朝晖, 韩璐,等. 负载型纳米铁还原硝酸盐氮的反应机理探讨[C]//第三届全国环境化学学术大会论文集. 2005. ZHANG H,JIN C H,HAN L, et al. Discussion on reaction mechanism of supported nano-iron reducing nitrate nitrogen[C]. Proceedings of the 3rd National Conference on Environmental Chemistry,2005(in Chinese). [9] LEE K C, RITTMANN B E. Applying a novel autohdrogenotrophic hollow-fiber membrane biofilm reactor for denitrification of drinking water[J]. Water Research, 2002, 36:2040-2052. [10] 黄文斌. 自养反硝化细菌去除地下水硝酸盐的试验研究[D]. 西安:西安建筑科技大学, 2013. HUANG W B. Experimental research about hydrogenotrophic denitrification for the removal of nitrate in groundwater[D]. Xi'an:Xi'an University of Architecture and Technology,2013(in Chinese). [11] KURT M, DUNN I J, BOURNE J R. Biological denitrification of drinking water using autotrophic organisms with H2 in a fluidized-bed biofilm reactor[J]. Biotechnology & Bioengineering, 1987, 29(4):493-501 [12] 王可. 以菌丝球为载体强化去除含酚废水效能研究[D]. 哈尔滨:哈尔滨工业大学, 2017. WANG K. Research on enhanced phenol distribution treatment by mycelium pellet as carrier[D]. Harbin:Harbin Institute of Technology, 2017(in Chinese). [13] 张松, 侯彬, 纪婷婷,等. 生物质炭固定化融合菌株F14方法的研究及其对芘的去除[J]. 农业环境科学学报, 2018, 37(3):464-470. ZHANG S,HOU B, JI T T, et al. Degradation of pyrene by immobilized cells of fusant bacterial strain F14 using biochar[J]. Journal of Agro-Environment Science,2018, 37(3):464-470(in Chinese).
[14] 黄茜, 蒋梦莹, 王丽晓,等. 竹炭固定化微生物对水中壬基酚的降解效率[J]. 应用生态学报, 2018, 29(5):1677-1685. HUANG Q, JIANG M Y, WANG L X, et al. Degradation of nonylphenol in water by microorganisms immobilized on bamboo charcoal[J]. Chinese Journal of Applied Ecology, 2018, 29(5):1677-1685(in Chinese).
[15] CHEN D, CHEN J, ZHONG W, et al. Degradation of methyl tert-butyl ether by gel immobilized Methylibium petroleiphilum PM1[J]. Bioresource Technology, 2008, 99(11):4702-4708. [16] MUZZARELLI R A A. Potential of chitin/chitosan-bearing materials for uranium recovery:An interdisciplinary review[J]. Carbohydrate Polymers, 2011, 84(1):54-63. [17] HELANDER I M, NURMIAHO-LASSILA E L, AHVENAINEN R, et al. Chitosan disrupts the barrier properties of the outer membrane of Gram-negative bacteria[J]. International Journal of Food Microbiology, 2001, 71(2-3):235-244. [18] 蒲生彦,王可心,马慧,等. 磁性壳聚糖凝胶微球对水中Pb(Ⅱ)的吸附性能[J]. 中国环境科学, 2018, 38(4):1364-1370. PU S Y, WANG K X, MA H, et al. Adsorption properties ofmagnetic chitosan hydrogelmicrospheres to Pb(Ⅱ) from aqueous solutions[J]. China Environmental Science, 2018, 38(4):1364-1370(in Chinese).
[19] PU S Y, MA H, ZINCHENKO A, et al. Novel highly porous magnetic hydrogel beads composed of chitosan and sodium citrate:An effective adsorbent for the removal of heavy metals from aqueous solutions[J]. Environmental Science & Pollution Research, 2017, 24(19):1-11. [20] LECETA I, GUERRERO P, DE LA CABA K. Functional properties of chitosanbased films[J]. Carbohydrate Polymers, 2013, 93:339-346. [21] ANSARI S A, HUSAIN Q. Potential applications of enzymes immobilized on in nano materials:A review[J]. Biotechnology Advances, 2012, 30:512-523. [22] 吴鹏宇,纪丹凤,苏婧,等.渗透性反应墙技术修复地下水硝酸盐污染的研究进展[J]. 环境工程技术学报,2016,6(3):243-251. WU Z Y, JI D F, SU J, et al. Research progress of permeable ractive barrier in the remediation of nitrate pollution in groundwater[J]. Journal of Environmental Engineering Technology,2016,6(3):243-251(in Chinese).
[23] JING G, ZHOU J, ZHOU Z, et al. Reduction of Fe(Ⅲ)EDTA in a NOx scrubbing solution by magnetic Fe3O4-chitosan microspheres immobilized mixed culture of iron-reducing bacteria[J]. Bioresource Technology, 2012, 108:169-175. [24] 刘志文, 陈琛, 彭晓春, 等. 磁性壳聚糖凝胶球固定厌氧铁氨氧化菌对废水氨氮去除的影响[J]. 环境科学, 2018, 39(10):211-221. LIU Z W, CHEN S, PENG X C, et al. Effect of magnetic chitosan hydrogel beads with immobilized feammox bacteria on the removal of ammonium from wastewater[J]. Environmental Science, 2018, 39(10):211-221(in Chinese).
[25] CASSIDY M B, LEE H, TREVORS J T. Environmental applications of immobilized microbial cells:A review[J]. Journal of Industrial Microbiology, 1996, 16(2):79-101. [26] 余静, 周艳, 颜椿,等. 一株氢自养反硝化菌去除地下水硝酸盐的实验研究[J]. 工业水处理, 2018, 38(10):29-32. YU J, ZHOU Y, YAN C, et al. Experimental research on the removal of nitrate from groundwater by a strain of hydrogen autotrophic denitrification bacterium[J]. Industrial Water Treatment, 2018, 38(10):29-32(in Chinese).
[27] OH J, SILVERSTEIN J. Acetate limitation and nitrite accumulation during denitrification[J]. Journal of Enviromental Engineering, 1999, 125(3):234-242. [28] 苏俊峰, 张凯, 黄廷林,等. 氢自养反硝化细菌SY6的反硝化特性研究[J]. 应用基础与工程科学学报, 2015(3):493-498. SU J F, ZHANG K, HUANG T L, et al. Denitrification characteristics of hydrogen autotrophic denitrifying bacteria SY6 [J]. Journal of Basic Science and Engineering, 2015(3):493-498(in Chinese).
[29] ZHANG Y, XIE K, ZHONG F, et al. Effects of pH on denitrification of hydrogenotrophic denitrifying bacteria[J]. Environmental Pollution & Control, 2010, 32(4):40-43. [30] 李爽, 石珍瑜, 马会强. 氢自养脱氮法去除污染地下水中硝酸盐氮的模拟研究[J]. 环境工程学报, 2017, 11(2):811-817. LI S, SHI Z Y, MA H Q. Simulation studies on removing nitrate-Nitrogen from contaminated groundwater using a hydrogenotrophic denitrification approach[J]. Chinese Journal of Environmental Engineering, 2017, 11(2):811-817(in Chinese).
[31] YANG X, WANG S, ZHOU L. Effect of carbon source, C/N ratio, nitrate and dissolved oxygen concentration on nitrite and ammonium production from denitrification process by Pseudomonas stutzeri, D6[J]. Bioresource Technology, 2012, 104(1):65-72.
计量
- 文章访问数: 2139
- HTML全文浏览数: 2139
- PDF下载数: 50
- 施引文献: 0