• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.761-766
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• 2010

This study was aimed to propose La(III)-zeolite composite which can effectively and simultaneously remove ammonia and phosphate in confined water bodies such as lakes and ponds. The optimum ratio of La(III):zeolite for the simultaneous removal of ammonia and phosphate was 0.0048 La(III) g:1 zeolite g. The drying temperature of La(III)-zeolite composite severely affected phosphate adsorption showing optimum condition at room temperature. It was revealed that the optimum dosage of La(III)-zeolite composite was 4.052 g/L at adsorption time of 90 min. The presence of alkalinity in aqueous solution brought positive effect on phosphate adsorption. Detachment of La(III) from La(III)-zeolite composite, which was dried at room temperature, was not observed in aquous solution. It indicates that La(III)-zeolite composite could effectively block phosphate released from sediment.

• The Journal of Engineering Geology
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• v.23 no.2
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• pp.95-104
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• 2013

This study proposes an efficient management plan for improving the water quality of agricultural reservoirs. Hongdong reservoir is located in an area that includes farmland, forest, residential housing, and livestock farms. The levels of pollutants in Hongdong reservoir were investigated with the aim of improving the water quality in the reservoir. The potential concentrations of total nitrogen (T-N) and total phosphorus (T-P) in Hongdong reservoir were 1.06-3.67 and 0.52-1.12 $g/m^2-d$, respectively. An analysis of leaching characteristics was performed under anaerobic conditions for 72 hours at $20^{\circ}C$. The concentrations of T-P and $PO_4$-P were measured by general leaching for a set period. In the case of T-P, the leaching was measured by irregular leaching due to denitrification of nitrite nitrogen ($NO_2$-N) and nitrate nitrogen ($NO_3$-N). A very small amount of $NH_3$-N on nitrogen ($N_2$) was measured due to the low pH in the column, as a consequence of the anaerobic conditions.

• Journal of the Mineralogical Society of Korea
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• v.28 no.3
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• pp.233-244
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• 2015

In order to study the phase transformation of pyrite and to determine the maximum Fe leaching factors, pyrite samples were an electric furnace and microwave oven and then ammonia leaching was carried out. The rim structure of hematite was observed in the sample exposed in an electric furnace, whereas a rim structure consisting of hematite and pyrrhotite were found in the microwave treated sample. Numerous interconnected cracks were only formed in the microwave treated sample due to the arcing effect, and these cracks were not found in the electric furnace treated sample. Under XRD analysis, pyrite and hematite were observed in the electric furnace treated sample, whereas pyrite, hematite and pyrrhotite were found in the microwave treated sample. The results of the pyrite sample leaching experiments showed that the Fe leaching was maximized with the particle size of -325 mesh, sulfuric acid of 2.0 M, ammonium sulfate of 1.0 M, and hydrogen peroxide of 1.0 M. The electric furnace and microwave treated samples were tested under the maximum leaching conditions, the Fe leaching rate was much greater in the microwave treated sample than in the electric furnace treated sample and the maximum Fe leaching time was also faster in the microwave treated sample than in the electric furnace treated sample. Accordingly, it is expected that the microwave heating can enhance (or improve) Fe leaching in industrial minerals as well as pyrite decomposition in gold ores.

• Resources Recycling
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• v.25 no.6
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• pp.65-72
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• 2016

We studied a selective recovery condition of vanadium (V) from FALL (Fly Ash Leach Liquor) produced at a fossil fuel power station using heavy oil. By applying a spectroscopy to quantify the V in a sample, we identified a concentration range V interfered by on presence of metals such as Ni, Fe Also, the optimal vanadium precipitation rate according to the amount of 5.0M $NH_3$ loaded to the sample, solution pH and stirring time. As a result of the experiment, the maximum selective recovery ratio of V was achieved to be higher than 91.5% when the stirring duration was less than 1 minute at pH 7.0, and $25^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.24 no.6
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• pp.434-443
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• 1980

The purpose of this work was to separate Ce, Pr, Nd and Sm from rare-earth oxides by column chromatography. Rare earth solution were adsorbed into the Amberlite IR-120 resin and were eluted by the ammonia alkali solution of the EDTA. As a result of determinating rare earth metals of each fraction, Ce was separated very effectively and Nd and Sm partially separaed but Pr never separated.

• Environmental Analysis Health and Toxicology
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• v.1 no.1
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• pp.77-80
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• 1986

Radiochemical synthesis of $N^{G}$-mono［$^{14}$ C-methyl］-L-arginine is described. The compound was synthesized from radio-active mono［$^{14}$ C］-methylamine as easily and purified by strong cation-exchange resin (NH form) liquid chromatography using a gradient of ammonium hydroxide, and crystallized as flavianate. The free amino acid was successfully prepared by strirring its flavianate and strong anion-exchange resin (OH- form), which could remove the flavianic acid from its salt in water below room temperature. Purity of the compound was tested by thin-layer chromatography, thin-layer electro-phoresis, and scintillation spectrometry.y.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.398-403
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• 2003

The purpose of this paper is to investigate purification characteristic of soil-bentonite landfill liner and to develop a desirable liner system. In order to clarify the purification characteristics, high pressure column tests using soil-bentonite, reactive soil-bentonite and reactive bentomat were carried out in the presence of water and leachate. The test results indicated that the significant amount of NH$_3$-N, Pb and Cu was removed through the reactive soil-bentonite liner system.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.157-162
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• 2017

Inorganic stiffening agents were prepared by mixing paper sludge incineration ash, blast furnace slag fine powder quicklime, anhydrous gypsum and fly ash. The main components of the solidifying agent developed for sludge treatment were SiO, $Al_2O_3$, $TiO_2$, $Fe_2O_3$, $Mn_2O_3$, CaO, MgO, $Na_2O$, $K_2O$, $P_2O$, and $SO_3$. Unlike cement, the developed solidifying agent did not contain $Cr^{6+}$, which is known as a carcinogen. Heavy metals and oil contaminated soil were mixed with solidifying agent and cured for 7 days and the heavy metal content was below the environmental standard. Sewage sludge cake, food waste and solidifying agent were mixed with each other, and after 7 days curing, soil component test showed that the heavy metal content was below the environmental standard. After mixing the sludge, solidifying agent and additive mixture into the beaker, the ammonia concentration was measured to be 0 after 3 days.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.2
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• pp.63-70
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• 2001

Changes in concentrations of dissolved oxygen, ammonia, nitrate, pH, Fe and Mn were monitored from the laboratory incubation of an benthic chamber. The extent of sedimentary organic carbon and nitrogen decomposition was quantified by applying the concentration data to the chemical reaction equations of early diagenesis. The patterns of the concentration changes, observed during the 237 hr long incubation experiment, made it possible to divide the entire experiment period into four characteristic sub-periods (0-9 hr, 9-45 hr, 45-141hr, 141-237 hr). C/N ratio, estimated for each sub-period, was 6.63, 1.49, 0.81 and 0.02, respectively. This sequential decrease in C/N ratio suggests that during the incubation experiment dissolved nitrogen species diffuse more out of the sediment than dissolved carbon species. Greater diffusion of nitrogen indicates the preferential decomposition of organic nitrogen during early diagenesis of sedimentary organic matter. Comparison of the concentration data (sedimentary organic carbon and nitrogen, porewater organic carbon and ammonia)between the sediment pre and post incubation also indicates the preferential decomposition of nitrogen during early diagenesis of sedimentary organic matter.

• Journal of the Korean Chemical Society
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• v.65 no.4
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• pp.249-253
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• 2021

Litter and manure were obtained at a cow house of a livestock farm in Andondg city. We examined the change of formation of nitrogen and phosphorous from these samples and tried to suggest a more useful and realistic way for removing them. Constituent and its content of sample were identified by XRF. NO₂^-, NO₃^-, and PO₄^3- ions and NH₄⁺, T-P and T-N released from sample were analyzed using ion chromatograph and UV/Vis spectrometry, respectively. As the results of this study, the ammonia nitrogen in the early stage of cow excretion is a need to make an ammonia gas state that can be immediately volatile by increasing the pH. Nitrogen and phosphorous, the main source of nutrition in green algal bloom can be removed by transforming insoluble salts such as calcium phosphate (CaHPO₄·3H₂O) and struvite (NH₄MgPO₄·6H₂O), respectively, with addition of Ca and Mg after stimulating fermentation of manure.