(49e) An Efficient Degradation of Perchloroethylene By Nano Zero Valent Iron (nZVI) and Nzvi Activated Sodium Percarbonate with and without Addition of Ethylenediaminetetraacetic Acid Disodium Salt Dehydrate

An efficient degradation of perchloroethylene by nano zero valent iron (nZVI) and nZVI activated sodium percarbonate with and without addition of ethylenediaminetetraacetic acid disodium salt dehydrate
Muhammad Danish^1,2, Shuguang Lu¹, Usman Farooq¹, Sadiq Hussain², Ayyaz Ahmad³, Muhammad Naqvi⁴, Mujtaba Ashraf ²,  Abdul Sattar Qureshi⁵,Xiaori Fu^1
1State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
²Department of Chemical Engineering, NFC-Institute of Engineering and Technology, Multan, Pakistan
³Department of Chemical Engineering, Muhammad Nawaz Sharif University of Engineering and Technology, Multan, Pakistan
⁴Department of Energy, Building and Environment, Mälardalen University, Västerås 72123, Sweden
⁵Institute of Biotechnology and Genetic Engineering, University of Sindh, Jamshoro 76080, Pakistan

Abstract
This study primarily focused on the degradation of perchloroethylene (PCE) by using nano zero valent iron (nZVI) without sodium percarbonate (SPC) in the absence and presence of ethylenediaminetetraacetic acid disodium salt dehydrate (EDTA-Na₂). The degradation of PCE followed pseudo-first-order kinetic behavior in the absence of EDTA-Na₂. The rate constants increased exponentially with the increasing molar ratios of SPC and nZVI. Main by-products found were formic acid and ethylene in both nZVI alone as well as in the nZVI-SPC system. The PCE degradation significantly enhanced over a shorter reaction time of 3 hours in the presence of EDTA-Na₂ by using nZVI system alone whereas, the PCE degradation ceased after 20 hours in long term experiment (120 hours) showing low degradation of PCE than that of no addition of EDTA-Na₂. However, the PCE degradation severely decreased in the nZVI-SPC system. The advantageous aspect of the EDTA-Na₂ can be attributed to the possible prevention of Fe⁺² and Fe⁺³ precipitation that could minimize the nZVI surface passivation. On the contrary, rapid corrosion of nZVI by EDTA-Na₂ and larger generation of Fe⁺² ions in a short span of time that can possibly consume the reactive oxygen species at a faster rate as compared to PCE could be the adverse characteristics of the EDTA-Na₂.