“…Especially, nitrate and its metabolic by-product nitrite are the main cause of methemoglobinemia which is also named the blue baby syndrome, tissue hypoxia and cancer. [11][12][13] To minimize the harm caused by nitrate, the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA) have stipulated that nitrate concentration should be limited to 10 mg N L À1 in drinking water. [14][15][16] In order to remove excess nitrate from the drinking water to meet the requirements of human health, various technologies have been applied to eliminate nitrates, such as biological denitrication, [17][18][19] chemical reduction, 20,21 reverse osmosis, [22][23][24][25] electrodialysis, [26][27][28][29][30] ion exchange, [31][32][33] electrocatalysis 34 and photocatalysis.…”