摘要：To address the environmental and health hazards of nitrate(NO_(3)^(-))in water,a denitrification advanced reduction process(ARP)using only formic acid(HCOOH)activated by ultraviolet(UV)light was *** efficiency,influencing factors,mechanism,and kinetics of the reduction were investigated through component analysis and radical *** show that,after 90 min of UV illumination,the reduction and gas conversion ratios of 50 mg/L NO_(3)^(-)-N reach 99.9%and 99.8%,respectively,under 9 mM of C_(0)(HCOOH),pH=3.0,and N_(2) ***,96.7%of HCOOH is consumed and converted into *** NO_(3)^(-)-N conversion process includes the transformation to NO_(2)^(-)-N,followed by a further reduction to gas and a direct conversion into gas,introducing small amounts of nitrite and *** carbon dioxide anion radical(·CO_(2)^(-))from HCOOH/HCOO^(-)is the principal cause of NO_(3)^(-)-N reduction by UV/HCOOH/N 2 *** contrast,·CO_(2)^(-)production is caused by the hydroxyl radical(·OH).The NO_(3)^(-)-N reduction efficiency is enhanced by the increase in the light intensity,considerably affected by the initial pH,and less affected by inorganic anions,including Cl^(-),H_(2)PO_(4)^(-),and HCO_(3)^(-)/CO_(3)^(2-).The initial HCOOH concentration and light intensity are the main factors that influence the NO_(3)^(-)-N reduction rate.