Zhang Yang, Li Haokang, Li Shuo, Li Yifan, Ding Yuanhong
College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
Department of Environmental Design, Qingdao University of Science and Technology, Qingdao, 266061, China.
Sci Rep. 2024 Sep 17;14(1):21649. doi: 10.1038/s41598-024-72529-2.
Nitrate can be electrolyzed mainly into N, but the generated ammonia, as its secondary intermediate, is soluble and remained in the wastewater yet, which affects negatively the degradation of nitrate and total nitrogen. In this work, an electrolytic reactor constructed with Ti/RuSn anode and Fe cathode, was applied to electrolyze nitrate, and magnesium chloride was used as electrolyte and precipitant simultaneously, while disodium hydrogen phosphate (DSP) was added only as precipitant of ammonia. The results indicated that, most part of generated ammonia could be precipitated as magnesium ammonium phosphate (MAP) and some residual ammonia may be transformed into N by breakpoint chlorination. Thus, the nitrate and total nitrogen (TN) degradation efficiencies could be enhanced obviously by the combined electrolysis precipitation process.
硝酸盐主要可被电解为氮气，但生成的氨作为其二级中间产物，可溶且仍留在废水中，这对硝酸盐和总氮的降解产生负面影响。在本研究中，采用以钛钌锡阳极和铁阴极构建的电解反应器来电解硝酸盐，同时使用氯化镁作为电解质和沉淀剂，而仅添加磷酸氢二钠（DSP）作为氨的沉淀剂。结果表明，生成的氨大部分可沉淀为磷酸铵镁（MAP），部分残留氨可通过折点加氯转化为氮气。因此，联合电解沉淀工艺可显著提高硝酸盐和总氮（TN）的降解效率。
