Oxidizing Capacity of Periodate Activated with Iron-Based Bimetallic Nanoparticles

Lee, Hongshin,Yoo, Ha-Young,Choi, Jihyun,Nam, In-Hyun,Lee, Sanghyup,Lee, Seunghak,Kim, Jae-Hong,Lee, Changha,Lee, Jaesang American Chemical Society 2014 Environmental science & technology Vol.48 No.14

<P>Nanosized zerovalent iron (nFe<SUP>0</SUP>) loaded with a secondary metal such as Ni or Cu on its surface was demonstrated to effectively activate periodate (IO<SUB>4</SUB><SUP>–</SUP>) and degrade selected organic compounds at neutral pH. The degradation was accompanied by a stoichiometric conversion of IO<SUB>4</SUB><SUP>–</SUP> to iodate (IO<SUB>3</SUB><SUP>–</SUP>). nFe<SUP>0</SUP> without bimetallic loading led to similar IO<SUB>4</SUB><SUP>–</SUP> reduction but no organic degradation, suggesting the production of reactive iodine intermediate only when IO<SUB>4</SUB><SUP>–</SUP> is activated by bimetallic nFe<SUP>0</SUP> (e.g., nFe<SUP>0</SUP>–Ni and nFe<SUP>0</SUP>–Cu). The organic degradation kinetics in the nFe<SUP>0</SUP>–Ni(or Cu)/IO<SUB>4</SUB><SUP>–</SUP> system was substrate dependent: 4-chlorophenol, phenol, and bisphenol A were effectively degraded, whereas little or no degradation was observed with benzoic acid, carbamazepine, and 2,4,6-trichlorophenol. The substrate specificity, further confirmed by little kinetic inhibition with background organic matter, implies the selective nature of oxidant in the nFe<SUP>0</SUP>–Ni(or Cu)/IO<SUB>4</SUB><SUP>–</SUP> system. The comparison with the photoactivated IO<SUB>4</SUB><SUP>–</SUP> system, in which iodyl radical (IO<SUB>3</SUB><SUP>•</SUP>) is a predominant oxidant in the presence of methanol, suggests IO<SUB>3</SUB><SUP>•</SUP> also as primary oxidant in the nFe<SUP>0</SUP>–Ni(or Cu)/IO<SUB>4</SUB><SUP>–</SUP> system.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2014/esthag.2014.48.issue-14/es5002902/production/images/medium/es-2014-002902_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es5002902'>ACS Electronic Supporting Info</A></P>

Reply to comment on “Combination of cupric ion with hydroxylamine and hydrogen peroxide for the control of bacterial biofilms on RO membranes by Hye-Jin Lee, Hyung-Eun Kim, Changha Lee [Water Research 110, 2017, 83–90]”

Lee, Hye-Jin,Lee, Changha Pergamon Press 2017 Water research Vol.118 No.-

<P><B>Highlights</B></P> <P> <UL> <LI> Procedures for reaction quenching used in our recent study were clarified. </LI> <LI> Bacterial inactivation by the pH drop was negligible in our experiments. </LI> <LI> Bacterial inactivation by Cu(II)/sulfite was prevented in the presence of EDTA. </LI> </UL> </P>

Combination of cupric ion with hydroxylamine and hydrogen peroxide for the control of bacterial biofilms on RO membranes

Lee, Hye-Jin,Kim, Hyung-Eun,Lee, Changha Pergamon Press 2017 Water research Vol.110 No.-

<P><B>Abstract</B></P> <P>Combinations of Cu(II) with hydroxylamine (HA) and hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) (i.e., Cu(II)/HA, Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB>, and Cu(II)/HA/H<SUB>2</SUB>O<SUB>2</SUB> systems) were investigated for the control of <I>P. aeruginosa</I> biofilms on reverse osmosis (RO) membranes. These Cu(II)-based disinfection systems effectively inactivated <I>P. aeruginosa</I> cells, exhibiting different behaviors depending on the state of bacterial cells (planktonic or biofilm) and the condition of biofilm growth and treatment (normal or pressurized condition). The Cu(II)/HA and Cu(II)/HA/H<SUB>2</SUB>O<SUB>2</SUB> systems were the most effective reagents for the inactivation of planktonic cells. However, these systems were not effective in inactivating cells in biofilms on the RO membranes possibly due to the interactions of Cu(I) with extracellular polymeric substances (EPS), where biofilms were grown and treated in center for disease control (CDC) reactors. Different from the results using CDC reactors, in a pressurized cross-flow RO filtration unit, the Cu(II)/HA/H<SUB>2</SUB>O<SUB>2</SUB> treatment significantly inactivated biofilm cells formed on the RO membranes, successfully recovering the permeate flux reduced by the biofouling. The pretreatment of feed solutions by Cu(II)/HA and Cu(II)/HA/H<SUB>2</SUB>O<SUB>2</SUB> systems (applied before the biofilm formation) effectively mitigated the permeate flux decline by preventing the biofilm growth on the RO membranes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Cu(II)-based combined disinfectants effectively inactivated <I>P. aeruginosa</I> cells. </LI> <LI> Different inactivation behaviors were observed in planktonic and biofilm cells. </LI> <LI> The Cu(II)/HA/H<SUB>2</SUB>O<SUB>2</SUB> treatment cleaned fouled RO membranes, recovering the flux. </LI> <LI> Pre-treatments using the combined disinfectants prevented biofouling on RO membranes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Chloride-enhanced oxidation of organic contaminants by Cu(II)-catalyzed Fenton-like reaction at neutral pH

Lee, Hongshin,Seong, Juhee,Lee, Ki-Myeong,Kim, Hak-Hyeon,Choi, Jaemin,Kim, Jae-Hong,Lee, Changha Elsevier 2018 Journal of hazardous materials Vol.344 No.-

<P><B>Abstract</B></P> <P>The Cu(II)-catalyzed Fenton-like reaction was found to be significantly accelerated in the presence of chloride ion (i.e., the Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB>/Cl<SUP>−</SUP> system), enhancing the oxidative degradation of organic contaminants at neutral pH. The degradation of carbamazepine (a select target contaminant) by the Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB> system using 1μM Cu(II) and 10mM H<SUB>2</SUB>O<SUB>2</SUB> was accelerated by 28-fold in the presence of 10,000mg/L Cl<SUP>−</SUP> at pH 7. The observed rate of carbamazepine degradation generally increased with increasing doses of Cu(II), H<SUB>2</SUB>O<SUB>2</SUB>, and Cl<SUP>−</SUP>, and exhibited an optimal value at around pH 7.5. Various other organic contaminants such as propranolol, phenol, acetaminophen, 4-chlorophenol, benzoic acid, and caffeine were also effectively degraded by the Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB>/Cl<SUP>−</SUP> system. Experiments using oxidant probe compounds and electron paramagnetic spectroscopy suggested that cupryl (Cu(III)) species are the major reactive oxidants responsible for the degradation of these organic contaminants. The enhanced kinetics was further confirmed in natural seawater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Cu(II)-catalyzed Fenton-like reaction was accelerated in the presence of Cl<SUP>−</SUP>. </LI> <LI> The Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB>/Cl<SUP>−</SUP> system was optimized at neutral pH. </LI> <LI> Cu(III)-chloro complexes were suggested as major reactive oxidants. </LI> <LI> The Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB>/Cl<SUP>−</SUP> system can be a useful approach to treat saline wastewater. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Analysis on Characteristics of Tunnel Field Effect Transistor with Elevated Drain by Changing Drain Underlap Length

Changha Kim,Kitae Lee,Junil Lee,Ryoongbin Lee,Byung-Gook Park 대한전자공학회 2019 대한전자공학회 학술대회 Vol.2019 No.6

Chemistry of persulfates for the oxidation of organic contaminants in water

Lee, Changha,Kim, Hak-Hyeon,Park, Noh-Back Techno-Press 2018 Membrane water treatment Vol.9 No.6

Persulfates (i.e., peroxymonosulfate and peroxydisulfate) are capable of oxidizing a wide range of organic compounds via direct reactions, as well as by indirect reactions by the radical intermediates. In aqueous solution, persulfates undergo self-decomposition, which is accelerated by thermal, photochemical and metal-catalyzed methods, which usually involve the generation of various radical species. The chemistry of persulfates has been studied since the early twentieth century. However, its environmental application has recently gained attention, as persulfates show promise in in situ chemical oxidation (ISCO) for soil and groundwater remediation. Persulfates are known to have both reactivity and persistence in the subsurface, which can provide advantages over other oxidants inclined toward either of the two properties. Besides the ISCO applications, recent studies have shown that the persulfate oxidation also has the potential for wastewater treatment and disinfection. This article reviews the chemistry regarding the hydrolysis, photolysis and catalysis of persulfates and the reactions of persulfates with organic compounds in aqueous solution. This article is intended to provide insight into interpreting the behaviors of the contaminant oxidation by persulfates, as well as developing new persulfate-based oxidation technologies.

Activation of Persulfates by Graphitized Nanodiamonds for Removal of Organic Compounds

Lee, Hongshin,Kim, Hyoung-il,Weon, Seunghyun,Choi, Wonyong,Hwang, Yu Sik,Seo, Jiwon,Lee, Changha,Kim, Jae-Hong American Chemical Society 2016 Environmental science & technology Vol.50 No.18

<P>This study introduces graphited nanodiamond (G-ND) as an environmentally friendly, easy-to-regenerate, and cost-effective alternative catalyst to activate persulfate (i.e., peroxymonosulfate (PMS) and peroxydisulfate (PDS)) and oxidize organic compounds in water. The G-ND was found to be superior for persulfate activation to other benchmark carbon materials such as graphite, graphene, fullerene, and carbon nanotubes. The G-ND/persulfate showed selective reactivity toward phenolic compounds and some pharmaceuticals, and the degradation kinetics were not inhibited by the presence of oxidant scavengers and natural organic matter. These results indicate that radical intermediates such as sulfate radical anion and hydroxyl radical are not majorly responsible for this persulfate-driven oxidation of organic compounds. The findings from linear sweep voltammetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and electron paramagnetic resonance spectroscopy analyses suggest that the both persulfate and phenol effectively bind to G-ND surface and are likely to form charge transfer complex, in which G-ND plays a critical role in mediating facile electron transfer from phenol to persulfate.</P>

Bacterial inactivation by visible light-activated ZIF-8: Bactericidal mechanism revisited

Changha Lee(이창하),Doyeon Park(박도연) 대한환경공학회 2022 대한환경공학회 학술발표논문집 Vol.2022 No.11

Oxidative treatment of waste activated sludge by different activated persulfate systems for enhancing sludge dewaterability

Lee, Ki-Myeong,Kim, Min Sik,Lee, Changha Springer (Biomed Central Ltd.) 2016 Sustainable environment research Vol.26 No.4

Oxidation of organic contaminants in water by iron-induced oxygen activation: A short review

Changha Lee 대한환경공학회 2015 Environmental Engineering Research Vol.20 No.3

Reduced forms of iron, such as zero-valent ion (ZVI) and ferrous ion (Fe[II]), can activate dissolved oxygen in water into reactive oxidants capable of oxidative water treatment. The corrosion of ZVI (or the oxidation of (Fe[II]) forms a hydrogen peroxide (H₂O₂) intermediate and the subsequent Fenton reaction generates reactive oxidants such as hydroxyl radical (●OH) and ferryl ion (Fe[IV]). However, the production of reactive oxidants is limited by multiple factors that restrict the electron transfer from iron to oxygen or that lead the reaction of H₂O₂ to undesired pathways. Several efforts have been made to enhance the production of reactive oxidants by iron-induced oxygen activation, such as the use of iron-chelating agents, electron-shuttles, and surface modification on ZVI. This article reviews the chemistry of oxygen activation by ZVI and Fe(II) and its application in oxidative degradation of organic contaminants. Also discussed are the issues which require further investigation to better understand the chemistry and develop practical environmental technologies.