In order to improve the quality of reclaimed water, a comparative study was conducted under different C/N and HRT conditions to examine the effect on advanced nitrogen and phosphorus removal by using sponge iron/sulfur composite fillers and low electrical current. The results indicated that both the sponge iron/sulfur composite fillers and low electrical current treatment can strengthen the removal efficiency of nitrogen and phosphorus, and their combination can further stabilize the pH value of 7.2~8.5 in the denitrification system. It was found that the removal of total nitrogen (TN) was mainly depended on the process of heterotrophic denitrification, hydrogen autotrophic denitrification and sulfur autotrophic denitrification, while 94.04% of the total phosphorus (TP) were removed in the form of iron-phosphate precipitation. Furthermore, biofilm was taken from the fillers to build the bacterial 16S rRNA gene clone library by adopting the high-throughput sequencing technologies. The results showed that the bacteria which can use both organic carbon and elemental hydrogen as its electron donor for denitrification accounted for 29.47% of the bacterial community in the sponge iron fillers system. The proportion of Thiobacillus bacteria which can use elemental sulfur as its electron donor reached 60.47% and 40.62% of the bacterial community in the system of sponge iron/sulfur composite fillers and the combined system of composite fillers with low electrical current, respectively.Therefore, there are obvious advantages of employing sponge iron/sulfur composite fillers and low electrical current to enhance the effect of advanced nitrogen and phosphorus removal from reclaimed water.
徐忠强, 郝瑞霞, 徐鹏程, 张娅. 硫铁填料和微电流强化再生水脱氮除磷的研究[J]. 中国环境科学, 2016, 36(2): 406-413.
XU Zhong-qiang, HAO Rui-xia, XU Peng-cheng, ZHANG Ya. Research on enhanced denitrification and phosphorus removal from reclaimed water by useing sponge iron/sulfur composite fillers and low electrical current. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(2): 406-413.
ZHAO Y X, FENG C P, WANG Q H, et al. Nitrate removal from groundwater by cooperating heterotrophic with autotrophic denitrification in a biofilm-electrode reactor[J]. Journal of Hazardous Materials, 2011,192(3):1033-1039.
Hao R X, Li S M, Li J B, et al. Denitrification of simulated municipal wastewater treatment plant effluent using a three-dimensional biofilm-electrode reactor:operating performance and bacterial community[J]. Bioresource Technology, 2013,143:178-186.
Zhou M, Fu W, Gu H, et al. Nitrate removal from groundwater by a novel three-dimensional electrode biofilm reactor. Electrochimica Acta, 2007,52(19):6052-6059.
Sun Y M, Nemati M. Evaluation of sulfur-based autotrophic denitrification and denitritation for biological removal of nitrate and nitrite from contaminated waters. BIORESOURCE TECHNOLOGY, 2012,114:207-216.
Chaganti S R, Lalman J A, Heath D D. 16S rRNA gene based analysis of the microbial diversity and hydrogen production in three mixed anaerobic cultures[J]. International Journal of Hydrogen Energy, 2012,37(11):9002-9017.
Magurran A E,张峰主,译.生物多样性测度[M]. 北京:科学出版社, 2011,70-71.
Shinoda Y, Sakai Y, Uenishi H, et al. Aerobic and anaerobic toluene degradation by a newly isolated denitrifying bacterium, Thauerasp strain DNT-1[J]. AppliedAnd Environmental Microbiology, 2004,70(3):1385-1392.
Letain T E, Kane S R, Legler T C, et al. Development of a genetic system for the chemolithoautotrophic bacterium Thiobacillus denitrificans[J]. Applied and Environmental Microbiology, 2007,73(10):3265-3271.
Shao M F, Zhang T, Fang H. Sulfur-driven autotrophic denitrification:diversity, biochemistry, and engineering applications[J]. Applied Microbiology and Biotechnology, 2010, 88(5):1027-1042.
Wang H Y, Zhou Y X, Yuan Q, et al. Bacteria morphology and diversity of the combined autotrophic nitritation and sulfurcarbon three-dimensional-electrode denitrification process[J]. Journal of Environmental Science and Health Part A-Toxic/hazardous Substances & Environmental Engineering, 2014,49(1):39-51.