Ferric ion promoted degradation of acetaminophen with zero − valent copper activated peroxymonosulfate process

Zero − valent copper activated peroxymonosulfate (Cu(0)/PMS) system had widely studied for degrading contaminant due to being highly efficient. However, the weak reactivity and easy dismutation of Cu(I) in acid condition restrained its efficiency. In our study, ferric ion (Fe(III)) significantly enhanced Cu(0)/PMS system for acetaminophen degradation and total organic carbon removal. Multiple reactive oxidants including Fe(IV), Cu(III) and hydroxyl radical (•OH) were generated in the Fe(III)/Cu(0)/PMS system. In the Fe(III)/Cu(0)/PMS system, Cu(0) generated Cu(I) by hydrogen corrosion and PMS oxidation, and then Fe(III) reacted with Cu(I) and Cu(0) producing Fe(II). At the same time, PMS reduced Cu(II) to Cu(I), and Cu(I) reacted with oxygen with forming hydrogen peroxide (H2O2). Finally, both Cu(I) and Fe(II) induced H2O2 and PMS producing reactive oxidants, and meanwhile H2O2 was formed by the reaction of Fe(IV) and •OH. Thereinto, Fe(IV) and •OH made main contribution on the degradation of acetaminophen, while Fe(IV), Cu(III) and •OH were responsible for orange II degradation. Common water matrix including sulfate ion, nitrate ion and carbonate ion had inapparent impact on acetaminophen degradation, but chloride ion and humic acid limited slightly the degradation of acetaminophen. There had a good degradation of acetaminophen in tap water, lake water and well water with the Fe(III)/Cu(0)/PMS system. Adjusting the final reaction solution to pH 8.0 and subsiding, the discharge of total copper was within the II-level environmental quality standards for surface water in China (1 mg/L). The study might provide a new and promising idea based on Cu(0) activated PMS system for enhanced degradation of contaminants.