WANQiong,SUNDang-dang,CAOYi-xi,et al.Research and Progress on Removing Nitrate from Water by Nano-zero-valent Iron[J].China Water & Wastewater,2023,39(16):21-28.
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Research and Progress on Removing Nitrate from Water by Nano-zero-valent Iron

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第39卷 Number: 第16期 Page: 21-28 Column: Date of publication: 2023-08-17
Author(s):
WAN　Qiong1;  SUN　Dang-dang1;  CAO　Yi-xi2;  JU　Kai1;  YANG　Guo-hong1;  LU　Lin-rui1;  LI　Ling-yi1;  ZHANG　Xin-yan1
（1. School of Architecture and Civil Engineering， Xi’an University of Science and Technology， Xi’an 710054， China； 2. Water Ecology Comprehensive Development Co. Ltd.， Shaanxi Water Affair Group， Xi’an 710082， China）
Keywords:
nano-zero-valent iron;  chemical denitrification;  ferroalloy;  nitrogen removal;  modification
Abstract:
Nitrogen is one of the key factors in eutrophication. Although NO3- could be quickly removed from water by chemical denitrification of nano-zero-valent iron (nZVI), the selectivity for nitrogen is very low. The studies of nZVI reduction to the NO3- were summarized, and the basic principles, the influencing factors of the NO3- reduction by nZVI, and the methods of improving N2 selectivity were also introduced. Some conditions contributed the reduction of NO3- by nZVI, including acidic conditioning, high temperature, low DO, high nZVI/NO3- ratio, Cu2+ and Fe2+-containing environments. In contrast, high DO, the presence of HCO3-, SO32-, Cr(Ⅵ) and organic matter are not conducive to the removal of NO3-. Modifying nZVI with surfactants, loaded nano-materials and nano-iron alloys will promote the removal of NO3- and the N2 selectivity to varying degrees. The N2 selectivity was less than 6%, even though the modification of nZVI by surfactants effectively reduced the oxidation and agglomeration of nZVI. However, the N2 selectivity reached 80% in the nZVI/Cu/TiO2 alloy system. The types of nZVI composite materials and the preparation method of raw materials significantly affected the denitrification. In terms of improving the N2 selectivity, the studies showed that the type of nZVI composite determined the material properties, and the preparation method of raw materials affected the material structure. The selection of composite materials, the optimization of preparation methods and operating conditions will be focuses in the future.
Last Update: 2023-08-17