• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.5
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• pp.119-130
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• 2013

The objective of this study was to analyze an availability of green roof soil based on the bottom ash soil and compost using sludge derived from food factory as comparing and analysing the growth of native plants. Analysing the physical properties and chemical resistance of 12 different type mixing soils which is mainly used in green roof, selected 4 types of soil, experiments were conducted to compare plant growth. The growth status of the plant showed the most superior of the soil 13(control), next soil 9(Pearlite : Bottom Ash : Compost = 20 : 60 : 20) and soil 10(Pearlite : Zeolite : Compost = 60 : 20 : 20) This result showed that native plants grow well in the soil based on the bottom ash and compost using sludge derived from food factory, and this soil type is determined that is available the green roof soil.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.75-81
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• 1993

The thermochemical stability of $Ni^{2+}-faujasite$ was studied by differential thermal analysis(DTA), thermal gravitational analysis(TGA), X-ray diffraction analysis(XRD) and quantum chemical calculations. Dehydration of $Ni^{2+}-faujasite$ was observed at 373-773K. A CNDO/2 calculations have been applied on cluster models for the representative T sites in faujasite to get total energy and wiberg bond orders. It has proved that the decrease of zeolitic crystallinity is directly related to the weakening of Al-O bonds in framework.

• Journal of the Korean Chemical Society
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• v.25 no.1
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• pp.26-29
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• 1981

Reactions of m-xylene were studied in a fixed-bed type micropulse reactor over cation-exchanged dealuminated mordenite and zeolite Y catalysts. Over H-mordenite catalysts higher catalyst pretreatment temperature as well as dealumination resulted in the increase of the formation of disproportionation product. $Ba^{2+}- and Mg^{2+}-$exchanged mordenite catalysts showed the shape selectivity in the disproportionation reaction of m-xylene, that is, the formation of trimethylbenzene decreasing sharply as the degree of cation exchange increased.

• Clean Technology
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• v.23 no.2
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• pp.213-220
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• 2017

Dry reforming of methane to synthesis gas was investigated over a series of Ni/HY catalysts promoted by Mg, Ca, K and Mn. These catalysts were characterized by XRD, BET, SEM, and TGA analyses before and after the reaction. Conversions and product yields were increased with increasing nickel loading up to 13 wt%. Among the catalysts tested in this work, the Ni-Mg/HY catalyst showed the highest carbon resistance and the most stable catalytic performance. It was revealed that the addition of Mg promoter reduced the nickel particle size and produced the highly dispersed nickel particles, and consequently, retarded the catalyst deactivation.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.66-73
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• 2006

The purpose of this study was done to evaluate degradation characteristics of non-biodegradable organic matters including aromatic compounds in livestock wastewater using CFZ process. The CFZ process is consisted of coagulation/sedimentation, Fenton oxidation and zeolite adsoption process. degradation charateristics of each treatment water including livestock wastewater were analyzed by UV scanning, FT-IR and GC/MS. After coagulation/sedimentation process as 1st treatment, non-biodegradable matters remained after 1st treatment were removed by using OH radical produced in Fenton oxidation process. As a result of treatment using these processes, NBDCOD removal efficiency was over 90%. Increase of $E_2/E_3$ ratio (absorbance at 250 and 365 nm) in each treatment water means that aromaticity of livestock wastewater decreased. In case of GC/MS, most aromatics or polynuclear aromatics like benzene, phenol and scatol in livestock wastewater almost wasn't detected after oxidation using OH radical.

• Membrane Journal
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• v.26 no.5
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• pp.351-364
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• 2016

In recent decades, many researchers have tried to improve desalination performances of polyamide (PA) thin-film composite membranes (TFCs) by incorporating nanomaterials into a selective PA layer. This review focuses on PA-based nanocomposite membranes with high performances for energy-effective desalination in reverse osmosis. Carbon based nanomaterial (e.g., graphene oxide (GO), carbon nanotubes (CNT)) and/or other nanoparticles (e.g., zeolite, silica and etc.,) were applied to overcome the trade-off correlation between water permeability and salt rejection of current polymeric desalination membranes. Here, this brief review will discuss current studies of PA-based nanocomposite membranes with enhanced separation characteristics and provide the future research direction to achieve further improved desalination performances.

• Korean Journal of Materials Research
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• v.30 no.5
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• pp.223-230
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• 2020

As a case study on aspect ratio behavior, Kaolin, zeolite, TiO₂, pozzolan and diatomaceous earth minerals are investigated using wet milling with 0.3 mm media. The grinding process using small media of 0.3 pai is suitable for current work processing applications. Primary particles with average particle size distribution D₅₀, ~6 ㎛ are shifted to submicron size, D₅₀ ~0.6 ㎛ after grinding. Grinding of particles is characterized by various size parameters such as sphericity as geometric shape, equivalent diameter, and average particle size distribution. Herein, we systematically provide an overview of factors affecting the primary particle size reduction. Energy consumption for grinding is determined using classical grinding laws, including Rittinger's and Kick's laws. Submicron size is obtained at maximum frictional shear stress. Alterations in properties of wettability, heat resistance, thermal conductivity, and adhesion increase with increasing particle surface area. In the comparison of the aspect ratio of the submicron powder, the air heat conductivity and the total heat release amount increase 68 % and 2 times, respectively.

• Bulletin of the Korean Chemical Society
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• v.13 no.2
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• pp.140-145
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• 1992

The excited state intramolecular proton transfer and physical properties of 7-hydroxyquinoline are studied in various solutions and heterogeneous systems by measuring steady state and time-resolved fluorescence, reflection and NMR spectra. Proton transfer is observed only in protic solvents owing to its requirement of hydrogen-bonded solvent bridge for proton relay transfer. The activation energies of the proton transfer are 2.3 and 5.4 kJ/mol in $CH_3OH$ and in $CH_3OD$, respectively. Dimers of normal molecules are stable in microcrystalline powder form and undergo an extremely fast concerted double proton transfer upon absorption of a photon, consequently forming dimers of tautomer molecules. In the supercage of zeolite NaY, its tautomeric form is stable in the ground state and does not show any proton transfer.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.196-208
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• 2018

The effect of channel-system of zeolite on methanol-to-DME reaction was studied. Results revealed that channels size and topology affect catalyst lifetime, type and location of coke precursors. FER and MFI showed the best resistance towards coke deposition, whilst fast deactivation was observed on MOR. Although the higher concentration and strength of acid sites, FER structure formed a lower coke amount, preferably located within the pores, while coke cluster deposited on the external surface of MOR. Analysis of acid sites distribution and strength was performed during deactivation-regeneration process. Coke location assessment was also supported by molecular simulations.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.706-710
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• 2021

In the current research, thermal and catalytic thermogravimetric (TG) analysis of polyethylene terephthalate (PET) over natural zeolite (NZ), olivine, bentonite, HZSM-5, and HAl-MCM-41 were investigated using a TG analyzer and model-free kinetic analysis. Catalytic TG analysis of PET was carried out at multi-heating rates, 10, 20, 30, and 40 ℃/min, under nitrogen atmosphere. Apparent activation energy (Ea) values for the thermal and catalytic pyrolysis of PET were calculated using Flynn-Wall-Ozawa method. Although natural catalysts, NZ, olivine, and bentonite, could not lead the higher PET decomposition efficiency than synthetic zeolites, HZSM-5 and HAl-MCM-41, maximum decomposition temperatures on the differential TG (DTG) curves for the catalytic pyrolysis of PET, 436 ℃ over olivine, 435 ℃ over bentonite, and 434 ℃ over NZ, at 10 ℃/min, were definitely lower than non-catalytic pyrolysis. Calculated Ea values for the catalytic pyrolysis of PET over natural catalysts, 177 kJ/mol over olivine, 168 kJ/mol over bentonite, and 171 kJ/mol over NZ, were also not lower than those over synthetic zeolites, however, those were also much lower than the thermal decomposition, suggesting their feasibility as the proper and cost-effective catalysts on the pyrolysis of PET.