• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.31-34
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• 2004

Feasibility of electrokinetic(EK)-Fenton process and Ozone chemical oxidation were investigated for tile removal of organic contaminants and heavy metals from the contaminated soil. In EK-Fenton process, accumulated electroosmotic flow(EOF) was 80 L for 26 days. Removal efficiency of TPH, As, and Ni were 61%, 36%, and 47%, respectively. The concentration of As was high near the anode due to the transport of anionic As toward the anode, while the concentration of Ni was high near the cathode by the movement of cationic Ni to the cathode. Field scale application of in-situ ozonation was carried out for removal of TPH in 3-D test cell (3 m$\times$2 m$\times$2 m). After 25 days of ozone injection, more than 80% of removal rate was observed through the test cell.

• Advances in nano research
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• v.10 no.1
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• pp.77-90
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• 2021

In the present study, novel chitosan coated magnetic magnetite (Fe3O4) nanoparticles were successfully biosynthesized from mushroom, Agaricus campestris, extract. The obtained bio-nanocomposite material was used to investigate ultra-fast and highly efficient for removal of Ni2+ ions in a fixed-bed column. Chitosan was treated as polyelectrolyte complex with Fe3O4 nanoparticles and a Fungal Bio-Nanocomposite Material (FBNM) was derived. The FBNM was characterized by using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infrared spectra (FTIR) and Thermogravimetric Analysis (TGA) techniques and under varied experimental conditions. The influence of some important operating conditions including pH, flow rate and initial Ni2+ concentration on the uptake of Ni2+ solution was also optimized using a synthetic water sample. A Central Composite Design (CCD) combined with Response Surface Modeling (RSM) was carried out to maximize Ni2+ removal using FBNM for adsorption process. A regression model was derived using CCD to predict the responses and analysis of variance (ANOVA) and lack of fit test was used to check model adequacy. It was observed that the quadratic model, which was controlled and proposed, was originated from experimental design data. The FBNM maximum adsorption capacity was determined as 59.8 mg g-1. Finally, developed method was applied to soft drinks to determine Ni2+ levels. Reusability of FBNM was tested, and the adsorption and desorption capacities were not affected after eight cycles. The paper suggests that the FBNM is a promising recyclable nanoadsorbent for the removal of Ni2+ from various soft drinks.

• Journal of environmental and Sanitary engineering
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• v.24 no.2
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• pp.31-39
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• 2009

In this research, I carried out the adsorption and removal test of Pb, Ni, Co and Cu ions using organic substances spread out any where in the nature which can be obtained easily from our neighbor-such as Paulownia coreana, Pinus densiflora, Juniperus chinesis, Quercus dentata, Magnolia kobus, Platanus occidentalis, Gingko biloba, Diospyros kaki leaves. As the result of the research to find the best optional condition for the adsorption and removal, shows that the adsorption and removal ratio of Pb ion by a Paulownia coreana raw leaves is 99% at $70^{\circ}C$, those of Ni ion and Co ion by Magnolia kobus formalin treatment leaves are 79% at $70^{\circ}C$, 97% at $40^{\circ}C$ respectively. And that of Cu ion by Platanus occidentalis treatment leaves is 97% at $50^{\circ}C$ in mixed solution. As the result of comparing the removal ratio by raw leaves and formalin treatment leaves, the removal ratio of treatment is 30~90% more effective than raw leaves in most cases. And I concluded Pb > Cu > Co > Ni ion in multiple solution and Co > Ni > Cu >Pb ion in single solution after testing adsorption and removal ratio of mixed solution separately as time goes by. In general, the reactions were completed within first 5 minutes. The test result of measuring the hydrolysable tannin content of each leaf shows that an overcup Quercus dentata is 11.36%, a Diospyros kaki is 10.81% and the rest of them are 2.49~4.12% in raw leaves cases. In treatment leaves cases, an overcup Quercus dentata is 3.23% and the others are less than 1%.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3063-3070
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• 2014

In this study, poly(N-methylol methacrylamide) (NMMAAm) and poly(N-methylol methacrylamide/vinyl sulphonic acid) (NMMAAm-VSA) hydrogels were synthesized by $^{60}Co-{\gamma}$ ray irradiation at an ambient temperature. The graphs belonging to the gelation percent- percent-dose and swelling curves were drawn by using data which were obtained from water and different pH solutions. Characterization of hydrogels was performed by FTIR and DSC-TGA analysis. Heavy metal ion ($Ni^{2+}$, $Co^{2+}$) removal capacities of hydrogels were investigated in aqueous solutions, which had different concentrations (100-1500 mg/L). In metal ion removal studies, pH value of aqueous medium was kept constant at 5.0. Maximum metal ion removal values were obtained for NMMAAm-VSA (1:3 mole ratio) hydrogels. Metal ion removal capacities of NMMAAm-VSA (1:3 mole ratio) hydrogels were found as 82 mg/g and 98 mg/g for $Ni^{2+}$ and $Co^{2+}$ ions, respectively.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.239-244
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• 2019

Plating wastewater containing various heavy metals can be produced by several industries. Specifically, we focused on the removal of copper (Cu2+) and nickel (Ni+) ions from the plating wastewater because all these ions are strictly regulated when discharged into watershed in Korea. The application of both nanofiltration (NF) and reverse osmosis (RO) technologies for the treatment of wastewater containing copper and nickel ions to reduce fresh water consumption and environmental degradation was investigated. In this work, the removal of copper (Cu2+) and nickel (Ni+) ions from synthetic water was studied on pilot scale remove by before using two commercial nanofiltration (NF) and reverse osmosis(RO) spiral-wound membrane modules (NE2521-90 and RE2521-FEN by Toray Chemical). The influence of main operating parameters such as feed concentration on the heavy metals rejection and permeate flux of both membranes, was investigated. Synthetic plating wastewater samples containing copper ($Cu^{2+}$) and nickel ($Ni^{2+}$) ions at various concentrations(1, 20, 100, 400 mg/L) were prepared and subjected to treatment by NF and RO in the pilot plant. The results showed that NF, RO process, with 98% and 99% removal for copper and nickel, respectively, could achieve high removal efficiency of the heavy metals.

• Clean Technology
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• v.29 no.4
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• pp.313-320
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• 2023

In order to increase the usability of H₂-SCR, the NOx removal characteristics with catalyst powder of PtNi/CeO₂-W-TiO₂ using Ce as a co-catalyst was synthesized and coated on a porous metal structure (PMS) were evaluated. Catalyst powder of PtNi/CeO₂-W-TiO₂(PtNi nanoparticles onto W-TiO₂, with the incorporation of ceria (CeO₂) as a co-catalysts) was synthesized and coated onto a porous metal structure (PMS) to produce a Selective Catalytic Reduction (SCR) catalyst. H₂-SCR with CeO₂ as a co-catalyst exhibited higher NOx removal efficiency compared to H₂-SCR without CeO₂. Particularly, at a 10wt% CeO₂ loading ratio, the NOx removal efficiency was highest at 90℃. As the amount of catalyst coating on PMS increased, the NOx removal efficiency was improved below 90℃, but it was decreased above 120℃. When the space velocity was changed from 4,000 h^-1 to 20,000 h^-1, the NOx removal efficiency improved at temperatures above 120℃. It was expected that the use of the catalyst could be reduced by applying the PMS with excellent specific surface area as a support.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.979-983
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• 2009

The mean pH of wastewater discharged from the plating process is 2, so a less amount of alkali is required to raise pH 2 to 5. In addition, if sodium sulfite is used to raise pH 5 to 9 in the secondary treatment, caustic soda or slaked lime is not necessary or only a small amount is necessary because sodium sulfite is alkali. Thus, it is considered desirable to use only $FeSO_4{\cdot}7H_2O$ in the primary treatment. At that time, the free cyanide removal rate was highest as around 99.3%, and among heavy metals, Ni showed the highest removal rate as around 92%, but zinc and chrome showed a low removal rate. In addition, the optimal amount of $FeSO_4{\cdot}7H_2O$ was 0.3g/L, at which the cyanide removal rate was highest. Besides, the free cyanide removal rate was highest when pH value was 5. Of cyanide removed in the primary treatment, the largest part was removed through the precipitation of ferric ferrocyanide: $[Fe_4(Fe(CN)_6]_3$, and the rest was precipitated and removed through the production of $Cu_2[Fe(CN)_6]$, $Ni_2[Fe(CN)_6]$, CuCN, etc. Furthermore, it appeared more effective in removing residual cyanide in wastewater to mix $Na_2SO_3$ and $Na_2S_2O_5$ at an optimal ratio and put the mixture than to put them separately, and the optimal weight ratio of $Na_2SO_3$ to $Na_2S_2O_5$ was 1:2, at which the oxidative decomposition of residual cyanide was the most active. However, further research is required on the simultaneous removal of heavy metals such as chrome and zinc.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.36-43
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• 2009

The feasibility of electrokinetic remediation was investigated in the laboratory to treat contaminated soil with Zn, Ni and F. Electro-migration and electro-osmosis are the major removal mechanisms because fluorines desorbed from soil exist as an anionic form in soil pores, and Zn and Ni exist as a cationic form. Desorption of fluorine was enhanced under the alkaline condition, but that of Zn and Ni increased under the acidic condition. Sequential pH control was effective to control the mixed wastes from contaminated soil. 2 V/cm was applied to reactor to evaluate the effect of constant voltage gradient, after two weeks, the removal efficiency of Zn, Ni and F was 20.5%, 2.5% and 57.4%, respectively. Even though the removal of Zn and Ni was very low, the pH control enhanced transport of Zn and Ni significantly. As a result, sequential pH control is a effective method to remediate mixed waste-contaminated soil.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.271-275
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• 2005

Pine bark, chinese cabbage, crap shell which are used for removing metal ions from aqueous solutions. The removal of metal ions from aqueous solution by adsorption and ion exchange on bio residues was studied. Biosorption of $Cu^{2+},\;Ni^{2+},\;Pb^{2+}$ were compared. Adsorption ability different for the factors [adsorption time, adsorbent weight, initial concentration] and all experiments pH variation were investigated. It was shown that chinese cabbage has higher metal removal ability than other materials The pH variation of metal solution were investigated according to the influences of the initial concentration and weight adsorbents.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.189-196
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• 2010

The removal of phosphorus (P) in the wastewater is essential for the prevention of eutrophication in the river and stream. This study was initiated to evaluate the effect of the various heavy metals on the growth and P removal capacity of Pseudomonas sp., which was well known as phosphorus accumulating microorganism(PAO's) in the EBPR(Enhanced Biological Phosphorus Removal) process. The five heavy metals used in the study were Cu, As, Zn, Ni, and Cd. The growth rate of Pseudomonas sp. was the greatest at $25^{\circ}C$, but the removal efficiency of P was the highest at $30^{\circ}C$. The $IC_{50}$ (median Inhibition Concentration) values of Pseudomonas sp. for the Cu, As, Zn, Ni, and Cd were 2.35, 11.04, 1.80, 4.92, and 0.24 mg/L, respectively. Therefore, it appears that the sensitivity of the heavy metals to Pseudomonas sp. was in the following order: Cd> Zn> Cu> Ni> AS. Also, the P removal efficiencies by Pseudomonas sp. were correspondingly decreased as the concentrations of heavy metals were increased.