• Journal of the Korean GEO-environmental Society
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• v.15 no.12
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• pp.25-34
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• 2014

The objective of this study was to investigate the removal characteristics and the elimination mechanism of heavy metals in Acid Mine Drainage (AMD) using spherical-type porous Zeolite-StarFish ceramics (porous ZSF ceramics) packed in a continuous column reactor system. The average removal efficiencies of heavy metals in AMD were Al 98.7, As 98.7, Cd 96.0, Cu 89.1, Fe 99.5, Mn 94.4, Pb 96.3 and Zn 80.8 % during 110 days of operation time. The average removal capacity of porous ZSF ceramics for heavy metals were measured to be Al 21.76, As 1.52, Cd 1.27, Cu 3.41, Fe 44.83, Mn 3.48, Pb 2.36 and Zn $3.76mg/kg{\cdot}day$. The analysis results of mechanism using SEM, EDS and XRD exhibited that the porous ZSF ceramics could act as a multi-functional ceramics for the removal of heavy metals in AMD through the reactions of precipitation, adsorption and ion-exchange. The experimental results of column reactor system displayed that the porous ZSF ceramics would be a consistently efficient agent for the removal of heavy metals in AMD for a long term.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.131-136
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• 2013

The aim of this study was to investigate the removal of fluoride using thermally treated pyrophyllite as adsorbent. Sorption experiments were conducted under batch conditions to examine the effects of adsorbent dose, reaction time, initial fluoride concentration and solution pH on fluoride removal. In the experiments, the pyrophyllite thermally treated at different temperatures [untreated (P-U), $400^{\circ}C$ (P-400), $600^{\circ}C$ (P-600)] were used. Results showed that the adsorption capacity was in the order of P-400 > P-U > P-600. The XRD analysis indicated that both P-U and P-400 were composed of quartz, dickite and pyrophyllite while P-600 was quartz. The BET analysis showed that the specific surface area was in the order of P-600 > P-400 > P-U. Kinetic data showed that fluoride sorption to P-400 arrived at equilibrium around 24 h. Equilibrium test demonstrated that the maximum sorption capacity of P-400 was 0.957 mg/g. In addition, fluoride removal by P-400 was not sensitive to solution pH between 4 and 10. However, fluoride removal decreased considerably at highly acidic (pH < 4) and alkaline (pH > 10) conditions. This study demonstrates that pyrophyllite could be used as a low-cost adsorbent for fluoride removal from aqueous solution.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.473-482
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• 2009

In this study, iron and manganese coated sand (IMCS) was prepared by mixing Joomoonjin sand with solutions having different molar ratio of manganese ($Mn^{2+}$) and iron ($Fe^{3+}$). Mineral type of IMCS was analyzed by X-ray diffraction spectroscopy. Removal efficiency of arsenic through As(III) oxidation and As(V) adsorption by IMCS having different ratio of Mn/Fe was evaluated. The coated amount of total Mn and Fe on all IMCS samples was less than that on sand coated with iron-oxide alone (ICS) or manganese-oxide alone (MCS). The mineral type of the manganese oxide on MCS and iron oxides on ICS were identified as ${\gamma}-MnO_2$ and mixture of goethite and magnetite, respectively. The same mineral type was appeared on IMCS. Removed amount As(V) by IMCS was greatly affected by the content of Fe rather than by the content of Mn. Adsorption of As(V) by IMCS was little affected by the presence of monovalent and divalent electrolytes. However a greatly reduced As(V) adsorption as observed in the presence of trivalent electrolyte such as $PO_4\;^{3-}$. As(III) oxidation efficiency by MCS in the presence of NaCl or $NaNO_3$ was two times greater than that in the presence of $PO_4\;^{3-}$. Meanwhile a greater As(III) oxidation efficiency was observed by IMCS in the presence of $PO_4\;^{3-}$. This was explained by the competitive adsorption between phosphate and arsenate on the surface of IMCS.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.73-79
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• 2009

As waste-water disposal plants and oxidative biodegradation for the removal of waste polyaromatic dyes are proved to be ineffective due to the chemical stability of dyes, we studied various strains of mushroom fungi for the removal of these dyes. 100 fungi were isolated from the mushroom samples of 230 species collected in Korea. The growth medium containing a dye (Bromophenol Blue, Congo Red, or Methylene Blue) was inoculated to 10% and incubated for 7 days without shaking. The six strains which removed dyes effectively were selected for further studies with respect to removal of polycyclic aromatic dyes. For all strains, the rate of decoloration of dyes was increasing with Methylene Blue, Bromophenol Blue and Congo Red. The rate of decoloration was higher with stationary culture than with shaking culture. Adsorption of the dyes was the highest with Congo Red.

• Membrane Journal
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• v.25 no.6
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• pp.503-514
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• 2015

In this study, water purification system without coagulant was consisted of F/A and membrane to produce purified water which only uses physical treatment without coagulant. Because the use of coagulant has a possibility remaining of hazardous aluminum with our health. Especially, the Filtralite was reviewed the possibility to remove turbidity and organic material. It was found that the turbidity removal rate of Filtralite was 83~84%. It show that Filtralite has similar efficiency to sand-filter. But Filtralite has higher 50% removal rate of organic material than sand-filter due to well-developed pore on the surface of it. So, Filtralite could be used to substitute the sand-filter for the F/A process due to higher removal rate. And also coupled with activated carbon in F/A process, TMP was increased by TOC value. To prevent increasing TMP, media that has outstanding organic adsorption ability should be used.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.169-178
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• 2012

This study was aimed at providing optimal water treatment processes based on various required water quality for utilization of the Saemangeum lake water as water supply alternatives to this area. Various water treatment methods were considered for investigation there characteristics, pollution removal rate, pros and cons in order to select appropriate water treatment processes satisfying the required water quality for different purposes. As results, the FDA system for SS, turbidity, BOD removals, UV treatment for coliform, BOD removals, FNR process for T-N, T-P removals, and ECRS process for desalination purpose were found to be better methods in senses of removal efficiency, operation and maintenance. Case studies were provided with cost analysis for field applications in the Saemangeum area.

• Journal of Wetlands Research
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• v.17 no.3
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• pp.228-236
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• 2015

Urbanization causes many environmental, hydrological and ecological problems such as distortion of the natural water circulation system, increase in nonpoint source pollutants in stormwater runoff, degradation of surface water quality, and damage to the ecosystem. Due to the increase in impervious surface by urbanization, developed countries apply low impact development (LID) techniques as important alternatives to reduce the impacts of urbanization. In Korea, LID techniques were employed since 2012 in order to manage nonpoint source pollutants. LID technology is a technique for removing pollutants using a variety of physical, chemical and biological mechanisms in plants, microorganisms and filter media with the reduced effluence of stormwater runoff by mimicking natural water circulation system. These LID facilities are used in a variety of filter media, but an assessment has not been carried out for the comprehensive comparison evaluation of adsorption and desorption characteristics for the pollutant removal capacity. Therefore, this study was conducted to analyze the adsorption and desorption characteristics of various filter media used in the LID facilities such as sand, gravel, bioceramic, wood chips and bottom ash etc. in reducing heavy metals(Pb, Cu). In this study, the adsorption affinity for Pb in all filter media was higher than Cu. Pseudo second order equation and Langmuir-3 isotherm are more applicable in the adsorption kinetic model and adsorption isotherm model, respectively. As a result of the desorption experiment, the filter media does not exceed KSLT which is the hazardous substance leaching limit, showing the capability of the filter media in LID. The bioceramic and woodchip as filter medias were evaluated and exhibited excellent adsorption capacity for Pb.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.587-592
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• 2013

In this study, we prepared pelletized porous carbon adsorbent (PCA) according to the different pyrolysis temperature using activated carbon and polyvinyl alcohol (PVA) as a binder for the removal of toluene, which is one of the representative volatile organic compounds (VOCs). We investigated physical characteristics of PCA using FE-SEM, BET, TGA and evaluated their adsorption capacity for toluene using GC. It was confirmed that the formability of pellets composed of the activated carbon, PVA and solvent of mass mixing ratio was 1 : 0.2 : 0.8 was the most outstanding. Toluene adsorption capacity was evaluated by measuring the maximum time when more than 99% of toluene adsorbed on the pellet. The specific surface area of the adsorbent pyrolyzed at $300^{\circ}C$ was measured as 4.7 times in $941.9m^2/g$ compared to that of the unpyrolyzed pellet. Micropore volume and toluene adsorption capacity of PCA increased fivefold to be 0.30 cc/g and thirteenfold to be 26 hours compared to that of the unpyrolyzed pellet, respectively. These results were attributed to the change of pore size and specific surface area due to the PVA content and the different pyrolysis temperature.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.150-154
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• 2000

In order to increase biological activities of Co~nebacteriumpseudodipI~t~~eriticum W3712 which degrades achemical softener (organopolysiloxane), the cells were immobilized on four immobilizing carriers by physicaladsorption. The cells immobilized on bentonite had higher removal efficiency than those immobilized onthe other carriers, and physical adsorption of organopolysiloxane on bentonite was 62.5%. The immobilizedcells were produced by 16 ml of culture broth with 20 g of bentonite, and 100 ml of the standard wastewatercontaining 12.000 mgll COD," with organopolysiloxane was removed 95.0% by 10.0 g of the immobilizedcells treatment at room temperature for 10 days by static culture.y static culture.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.386-392
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• 1989

The adsorption of $NH_4\;^+$ and $Zn^{2+}$ by four Korean zeolites, the major species of which are clinoptilolite, clinoptilolite with mordenite, mordenite with clinoptilolite, and mordenite was measured in different concentrations of solutions of $NH_4\;^+$ and $Zn^{2+}$, and their mixtures. The adsorption of $NH_4\;^+$ was greater than that $Zn^{2+}$ far all samples at the concentrations of the added solutions from $1\;to\;7{\times}10^{-3}N$ and this difference was greater at the higher concentrations. Also, $Zn^{2+}$ adsorption by samples was decreased by the presence of $NH_4\;^+$, but that of $NH_4\;^+$ by the presence of $Zn^{2+}$ was not. The extent of $NH_4\;^+$ selectivity among samples was increased in order of clinoptilolite with mordenite$NH_4\;^+$ adsorbed by six successive equilibrations with the solution containing both $NH_4\;^+$ and $Zn^{2+}$ each at a concentration of $3{\times}10^{-3}N$ were in range from 43.7 to 50.4 me/100g, whereas those amounts of $Zn^{2+}$ were in the range from 6.6 to 17.0 me/100g. It was suggested from these results that mordenite and clinoptilolite, particularly the former, can be used for removal of $NH_4\;^+$ from municipal wastewater and those zeolites treated with wastewater can be applied to agricultural land.