Novel Cu(II)–EDTA Decomplexation by Discharge Plasma Oxidation and Coupled Cu Removal by Alkaline Precipitation: Underneath Mechanisms

Abstract

Strong complexation between heavy metals and organic complexing agents makes the heavy metals difficult to be removed by classical chemical precipitation. In this study, a novel decomplexation method was developed using discharge plasma oxidation, which was followed by alkaline precipitation to treat water containing heavy metal-organic complex, that is, Cu-ethylenediaminetetraacetic acid (Cu-EDTA). The decomplexation efficiency of Cu complex reached up to nearly 100% after 60 min's oxidation by discharge plasma, which was accompanied by 82.1% of total organic carbon removal and energy efficiency of 0.62 g kWh. Presence of free Cu favored Cu-EDTA decomplexation, whereas the presence of excessive EDTA depressed this process. Cu-EDTA decomplexation was mainly driven by the produced O, O, O, and •OH by discharge plasma. Cu-EDTA decomplexation process was characterized by UV-vis, ATR-FTIR, total organic carbon, and three-dimensional fluorescence diagnosis. The main intermediates including Cu-EDDA, Cu-IDA, Cu-NTA, small organic acids, NH, and NO were identified, accompanied by Cu releasing. The followed precipitation process removed 78.1% of Cu, and Cu-associated precipitates included CuCO, CuCO(OH), CuO, and Cu(OH). A possible pathway of Cu complex decomplexation and Cu removal in such a system was proposed.

Mechanisms of Active Substances in a Dielectric Barrier Discharge Reactor: Species Determination, Interaction Analysis, and Contribution to Chlorobenzene Removal

“…CB removal efficiency increased with increasing SIE from 22.64, 76.68, and 30.80 to 78.16, 87.45, and 76.76% in air, N 2 , and O 2 atmospheres, respectively. The generation of energetic electrons also increased because of the increase in SIE. , Such a phenomenon was advantageous for breaking up the CB molecules. However, because of the low concentration of CB in the reaction atmosphere, the main energy of the electric field acted on the background gas (N 2 , O 2 , and H 2 O).…”

“…The generation of energetic electrons also increased because of the increase in SIE. 53,54 Such a phenomenon was advantageous for breaking up the CB molecules. However, because of the low concentration of CB in the reaction atmosphere, the main energy of the electric field acted on the background gas (N 2 , O 2 , and H 2 O).…”

Preparation of Cysteine‐Functionalized Fe3O4 Magnetic Nanoparticles for Determination of Cu2+

“…Among different types of magnetic nanomateriales, iron oxide nanoparticles (Fe 3 O 4 NPs) have attracted much attention because of its large specific surface, non‐toxicity, super paramagnetic behavior, easy functionalization, and biocompatibility [8b] . However, the non‐modified magnetic nanoparticles are difficult to recycle in practical application because they tend to agglomerate and form clusters [8a] .…”

C-dot doping for enhanced catalytic performance of TiO2/5A for toluene degradation in non-thermal plasma-catalyst system

“…Recently, the combination of NTP (e.g., DBD and corona discharge) with catalysts has been regarded as a novel and efficient technology for the removal of VOCs at atmospheric pressure and room temperature, especially for low concentrations of VOCs (< 1000 ppm) (Hossain et al 2021;Jiang et al 2019;Lee et al 2019;Li et al 2020a;Vandenbroucke et al 2011;Wang et al 2018a). The plasmacatalyst hybrid system can efficiently take advantage of the plasma's ability to reduce the activation energy of catalytic reactions and the high selectivity of the catalyst (Stasiulaitiene et al 2016;Tang et al 2019;Wang et al 2018b).…”