Rapid oxidation of acetaminophen with zero-valent copper induced hydrogen peroxide process in presence of ferric ion and chloride ion
Xin Liu, Peng Xu, Pengfei Zhu, Zhuoyu Yang, Ruoxi Wu, Baolin Hou
Abstract
Zero-valent copper-triggered hydrogen peroxide (Cu 0 /H 2 O 2 ) process was widely used for the degradation of pollutants, while its oxidation efficacy was restrained by the interaction of Cu + with O 2 as well as the dismutation of Cu + . In this study, both ferric ion (Fe 3+ ) and chloride ion (Cl − ) were introduced into the Cu 0 /H 2 O 2 (Fe 3+ /Cl − /Cu 0 /H 2 O 2 ) system, and the removal of acetaminophen was immensely enhanced. In the Fe 3+ /Cl − /Cu 0 /H 2 O 2 , Fe 3+ was converted to Fe 2+ via the reaction of Fe 3+ with Cu 0 and Cu + , and the reaction between Cu + and Fe 3+ receded the reaction of Cu + with O 2 , promoting the formation of reactive oxygen species ; Cl − integrated with Cu + to form the Cu-Cl chelate, and Cl − helped the comproportionation of Cu 0 and Cu 2+ to form CuCl, which decreased the reaction of Cu + with O 2 and promoted the generation of reactive oxygen species. Both the addition of Fe 3+ and Cl − in the Cu 0 /H 2 O 2 process greatly improved the utilization of Cu 0 . •OH, Various reactive oxygen species such as •OH, Fe IV O 2+ and reactive chlorine species were identified in the Fe 3+ /Cl − /Cu 0 /H 2 O 2 process. There into, Fe 2+ stimulated H 2 O 2 to form •OH and Fe IV O 2+ , and Cu + triggered H 2 O 2 to form •OH rather than Cu 3+ , and partial •OH was transferred to reactive chlorine species via the interaction of •OH with Cl − . After increasing the solution pH to > 7.0 and leaching solution, the total copper of reaction solution was below 0.455 mg/L. These results suggested that the Fe 3+ /Cl − /Cu 0 /H 2 O 2 process was feasible, effective and environmentally safe, and the research offered a theory instruction for the application of Fe 3+ and Cl − -enhanced Cu 0 /H 2 O 2 process in pollutants decomposition.