• Advances in nano research
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• v.9 no.3
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• pp.173-181
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• 2020

Adsorption and heterogeneous electro-Fenton process using iron-loaded ZSM-5 nano-zeolite were investigated for the removal of Tetracycline (TC) from wastewater. The nano-zeolite was synthesized hydrothermally and modified through impregnation. The zeolite was characterized by XRD, FT-IR, FE-SEM, N₂ adsorption-desorption, and NH₃-TPD techniques. The equilibrium data were best represented by the Freundlich isotherm. The pseudo-second-order kinetic model was the most accurate model for the adsorption of TC on the modified nano-zeolite. The effect of parameters such as pH of solution and current density were investigated for the heterogeneous electro-Fenton process. The results showed that the current density of 150 mA and pH of 3 led to the highest TC removal (90.35%) at 50 min. The nano-zeolite showed the appropriate reusability. Furthermore, the developed kinetic model was in good agreement with the removal data of TC through the electro-Fenton process.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.318-321
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• 2003

This study explored the feasibility of applying Electrokinetic-Fenton process(EK-Fenton process) to remediation of contaminant sorbed on the soil possessed low-permeability. The addition of 0.01 N H$_2$SO$_4$ in the anode reservoir for the $H_2O$$_2$stabilization improved the stabilization of $H_2O$$_2$and the treatment effect of phenanthrene across the entire soil specimen. The use of $H_2O$$_2$and dilute acid as anode purging solution is a promising method treating of HOCs in low-permeability subsurface environments.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_4
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• pp.165-172
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• 2001

We investigated the optimal experimental conditions and reaction kinetics for the decompositions of PCE, TCE, naphthalene, and chloroform using conventional Fenton oxidation process. Additionally, the influence of pH on the decompositions of PCE was also evaluated. The results indicated that the optimal pH value was around 3. The dosage of Fenton's reagent and the molar ratio of hydrogen peroxide to ferrous ion for an approximately complete decomposition was found to depend on the properties of the organic compound. Due to their unsaturated structures, the results show that PCE, TCE, and naphthalene could be all effectively decomposed by Fenton's reagent oxidation. Their unsaturated structures could be mostly destoyed within first 1-2 minutes at a low dosage with an certain molar ratio of hydrogen peroxide to ferrous ion. However the saturated compound such as chloroform was more difficult to decompose even with a relatively high dosage of Fenton's reagent.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.250-256
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• 2005

This study was aimed to investigate treatment feasibility of leachate from D landfill that is located in gyr대ungbuk. From the analytical results of leachate, organic and nonbiodegradable matters were contained in high concentration. Thus chemical treatment was introduced to degrade nonbiodegradable matters in pre or post biological process. Two types of Fenton oxidation were adapted in this study. The first one is pre treatment process before biological treatment. The second one is post treatment process after biological treatment. The optimal conditions of both treatment methods were investigated as follows. In case of pre treatment process, the optimal conditions appeared in $Fe^{+2}/H_2O_2$(mmol/mmol): 0.1, $H_2O_2/CODcr$(mg/mg): 27.0, pH: 3 and reaction time: 2hrs. On the other hand, in case of post treatment process, the optimal conditions appeared in $Fe^{2+}$(mmol/mmol): 0.14, $H_2O_2/COD_{cr}$(mg/mg): 57.4, pH: 3 and reaction time: 1.25hrs. In the above optimal conditions, high COD removal was obtained in pre and post treatment process. Also it can expect that Fenton oxidation converted nonbiodegradable matters into biodegradable matters.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.34-42
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• 1997

A laboratory experiments were performed to investigate the treatment of photographic processing wastewater by chemical oxidation and biological treatment system. The effect of reaction conditions such as hydrogen peroxide dosage, ferrous sulfate dosage and pH on the COD removal in Fenton oxidation were investigated. The optimal dosage of hydrogen peroxide was 2.58 M and 3.87 M for the developing and fixing process wastewater, respectively. The Fenton oxidation was most efficient in the pH range of 3-5 and the optimal condition for initial reaction pH was 5 for a developing process wastewater. With iron powder catalyst, the COD for a developing process wastewater was removed in lower pH than with ferrous sulfate catalyst. The removal efficiency of COD for refractory compounds such as Diethyleneglycol, Benzylalcohol, Hydroxylamine Sulfate, Ammonium Thiosulfate, Ammonium Ferric EDTA and Disodium EDTA in the photogaphic wastewater was found than 90% except Potassium Carbonate. When the photographic processing wastewater after pretreatment by Fenton oxidation was treated with batch activated sludge process, the addition of $KH_2PO_4$ as a phosphorous compound improved the removal efficiency of COD. During the continuous biological treatment of developing and fixing process wastewater after pretreatment by Fenton oxidation, the effluent COD concentration less than 100 mg/l was obtained at 0.425 and 0.25 kgCOD/m$^3$.d, respectively.

• Journal of Environmental Health Sciences
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• v.34 no.2
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• pp.175-182
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• 2008

This study investigates the optimal conditions for electrogenerated hydrogen peroxide production and the application of the electro-Fenton process using DSA electrodes. The influences of parameters for the hydrogen peroxide generation such as electrode materials, electrolyte concentration, current, pH, air flow rate and electrode distance were investigated using a laboratory scale batch reactor. The relative performance for hydrogen peroxide generation of each of the six electrodes is : Ru-Sn-Ti > Ru-Sn-Sb > Ru > Ir > Pt > Sn-Sb. Optimum NaCl dosage, current and air flow rate were 2.0 g/l, 12.5 A and 2 l/min, respectively. When the pH is low, hydrogen peroxide concentration was high. Electrode distance dos not effect to a hydrogen peroxide generation. A complete color removal was obtained for RhB (200 mg/l) at the 8 min mark of the electro-Fenton process under optimum operation conditions of $Fe^{2+}$ 0.105 g/l and 5.0 A. The electro-Fenton process increased initial reaction and decreased final reaction time. However the effect was not high.

• Journal of Korean Society on Water Environment
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• v.21 no.3
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• pp.284-288
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• 2005

In this study, photochemical advanced oxidation processes (AOPs) utilizing the Photo Fenton reaction ($Fe^{2+}+H_2O_2+UV$) were investigated in lab-scale experiments for the treatment of livestock wastewater. For the experimets, the livestock wastewater was pretreated by coagulation with $3,000mg/L\;FeCl_3$. The optimal conditions for Photo-Fenton processes were determined: pH was 5, the concentration of ferrous ion (Fe II) was 0.01 M. The concentration of hydrogen peroxide was 0.1 M, and molar ratio ($Fe^{2+}/H_2O_2$) was 0.1. The optimal reaction time was 80 min. Under the optimal condition of Photo-Fenton process, chemical oxygen demand (COD), color and fecal coliform removal efficiencies were about 79, 70, and 99.4%, respectively and sludge production was 7.5 mL from 100 mL of solution.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.76-83
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• 2000

This research is about wastewater containing non-biodegradable TDI(Toluene Diisocyanate) that is treated by the activated carbon adsorption method. In the case of the Fenton oxidation process being applied to the existing process, optimal pH, reaction time, chemical dosing amount, removal rate, and cost were investigated. A pilot plant test was applied after finding optimal conditions with lab experiments. The optimal conditions were pH 3~5(COD removal rate 84~88%) and reaction time 30min~1hr. In higher $H_2O_2$ dosing amount, COD removal rate was a little higher. But there was little difference in the removal rate according to $FeSO_4{\cdot}7H_2O$ dosing amount. Treatment cost was economical in the case of the Fenton oxidation process being operated earlier than activated carbon adsorption system. But chemical dosing point, chemical mixing effect, chemical dosing amount, removal rate, and the cost of facility and others must be considered in practical process.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.395-406
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• 2010

In this study, anaerobic digestion, electro-oxidation and electro-fenton oxidation processes were investigated to reduce oily refinery sludge. Anaerobic digestion process was not suitable for oily activated sludge reduction because of characteristics itself and, as experimental results revealed, reduction efficiency was low for electro-oxidation process. However, 40% total suspended solid reduction of oily activated sludge was obtained by electro-fenton oxidation process, operating at pH=1, 0.5 A and $Fe^{2+}$:$H_2O_2$ ratio = 1:30. In addition, higher reduction efficiency was obtained as reaction time was increased (30, 60, 90, 120 min) despite of low $H_2O_2$ concentration. From the results, it has been investigated that electro-fenton oxidation is efficient process for oily activated sludge reduction.

• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.169-187
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• 2002

The effects of important parameters such as reaction time and pH on the Fenton's process were evaluated using a batch reactor. It was proven that organic materials and heavy metals in leachate could be successfully removed by Fenton's reagent. Favorable operation conditions were investigated. It was observed that the reaction between ferrous iron and hydrogen peroxide with the production of hydroxyl radical was almost complete in 10 minutes. That is, the oxidation of organic materials by Fenton's reagent was so fast that it was complete in 30 minutes with batch experiments. With the formation of carbonic acid, pH of the batch reactor decreased to favorable acidic conditions without acid addition. The oxidation of organic materials in the leachate showed a pH dependence and was most efficient in the pH range of 2-3.