Studies on the reactivity activation of zero-valent iron (ZVI) with hydrogen peroxide for nitrate reduction in mine water

Abstract

The emission of mining wastewater with high concentration of nitrate leads to the risk of the aquatic ecosystem, being detrimental to human health and excess nutrients of water bodies. The aim of this thesis work was to improve the reactivity of zero-valent iron (ZVI) on the reduction of nitrate to ammonium in mine water.The selected method for the reactivity improvement of ZVI surface wasa ZVI/H2O2 system. Preliminary tests were performed to demonstrate the feasibility of ZVI/H2O2 system. The effect of pH value, iron mass and hydrogen peroxide concentration on nitrate reduction were evaluated by batch experiments. The effect of adding iron oxide waste with ZVI was tested as well.The result of this thesis indicated that nitrate reduction rate achieved 99.5% with the experimental setups in optimized conditions.Thus, it was possible to increase the nitrate reduction rate at near neutral pH conditions by adding a strong oxidant, H2O2.