• Environmental Engineering Research
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• v.25 no.4
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• pp.554-560
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• 2020

This study focuses on nitrification through a biological aerated filter (BAF) that is filled with a zeolite medium at low concentrations of ammonia. The zeolite medium consists of natural zeolite powder. The BAF is operated under two types of media, which are a ball-type zeolite medium and expanded poly propylene (EPP) medium. Nitrification occurred in the zeolite BAF (ZBAF) when the influent concentration of ammonia nitrogen was 3 mg L-1, but the BAF that was filled with an EPP medium did not experience nitrification. The ammonia nitrogen removal efficiency of ZBAF was 63.38% and the average nitrate nitrogen concentration was 1.746 mg/L. The ZBAF was tested again after a comparison experiment to treat pond water, and municipal wastewater mixed pond water. The ZBAF showed remarkable ammonia-nitrogen treatment at low concentration and low temperature. During this period, the average ammonia nitrogen removal efficiency was 64.56%. Especially, when water temperature decreased to 4.7℃, ammonia nitrogen removal efficiency remained 79%. On the other hand, the chemical-oxygen demand (COD) and phosphorus-removal trends were different. The COD and phosphorus did not show as efficient treatment as the ammonia-nitrogen treatment.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.93-100
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• 2001

To study the possibility of agricultural utilization of seafood processing wastewater sludges, the change of temperature, decreasing ratio of weight generation quantity of $CO_2$ and $NH_3$, and contents of inorganic elements for composting by adding different rates of zeolite and livestock manure to seafood processing wastewater sludges were investigated. Changes of temperature, decreasing ratio of total weight and generation quantity of $CO_2$ were not little different with increasing addition rates of zeolite for composting. But the less addition quantity of livestock manure is, the higher were temperature and decreasing ratio weight for composting. Ceneration quantity of $NH_3$ in composting materials as adding zeolite ti 5, 10 and 20% and livestock manure to 50, 65 and 80% were 68, 61 and $46mg/kgvs{\cdot}hr$, respectively, for composting periods. So, $NH_3$ generated little quantity as much as possible addition of zeolite and manure. Contents of T-C and T-N little decreased and C/N ratio little increased after composting than before. Content of $P_2O_5$, $K_2O$, CaO also increased a little, that of MgO is not different and that of Mn decreased very sharply in all conditions after composting than before.

• Polymer(Korea)
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• v.28 no.5
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• pp.374-381
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• 2004

Gas permeability of low density polyethylene (LDPE) film containing zeolite powder for $CO_2,\;O_2$ and $N_2$ were investigated. Zeolite powders modified by cations or surfactant were compounded with LDPE to produce $20 wt\%$ masterbatch. After blending the masterbatch with LDPE, zeolite filled films were prepared by the blown film process. Finally, the composite films containing zeolite loadings of 0, 3,5, and $10 wt\%$ were produced. A gas permeability apparatus based on the variable volume principle was designed to analyze the characteristics of films. Experiments showed a general trend that gas permeabilities first decreased and then increased as the zeolite content was increased. Surfactant modified zeolite showed a better interfacial adhesion with the matrix, but the film did not show a discernible difference in gas permeability compared with the other modified films. The difference of temperature dependences in the gas permeabilities of composite films was slightly smaller than that of LDPE film.

• Journal of Radiation Industry
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• v.2 no.1
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• pp.9-14
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• 2008

Livestock wastewater containing high concentrations of organic matters and ammonia-nitrogen has been known as one of the recalcitrant wastewater. It is difficult to treat by conventional wastewater treatment techniques. This study was carried out to evaluate the feasibility of zeolite ion exchange and gamma-ray irradiation treatment of livestock wastewater. The removal efficiencies of $SCOD_{Cr}$ and $NH_3-N$ were significantly enhanced by gamma-ray irradiation after zeolite ion exchange as a pre-treatment. However, the effects of zeolite particle size on the $SCOD_{Cr}$ and $NH_3-N$ removal efficiencies were insignificant. These results indicate that the combined process of zeolite ion exchange and gamma-ray irradiation has potential for the treatment of livestock wastewater.

• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.223-229
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• 2007

The mechanism of hydrothermally synthesizing Na-A zeolite from siliceous mudstone at a $Na_2O/SiO_2$ ratio of 0.6, a $SiO_2/Al_2O_3$ 2.0 and a $H_2O/Na_2O$ 119 has been observed by IR, DTA, XRD and SEM. This mudstone is a tertiary periodic sedimentary rock and widely spreads around the Pohang area. In the early hydrothermal synthesis at $80^{\circ}C$ in an autoclave, sodium silicate and sodium aluminate were found to be preferentially reacted to generate Na-A type zeolite. Gibbsite and bayerite were also formed due to the presence of extra aluminum oxide in the feedstock. As reaction time in-creased up to 50 h, residual sodium aluminatewas reacted with siliceous mudstone, causing the Na-A zeolite crystal to grow and the hydroxylsodalite to generate. Therefore, in the $14{\sim}50\;h$ synthetic time, Na-A zeolite and hydroxylsodalite were formed. Also, if reaction time passed over 50 h, a part of the Na-A zeolite was finally redissolved and reacted with hydroxylsodalite to synthesize Na-P zeolite, generating porous surface of Na-A zeolite and disappearing hydroxylsodalite.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.443-463
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• 2024

This study investigated the impact of activated carbon, palm activated carbon, and zeolite on horse oil (HO) extracted from horse neck fat using supercritical fluid extraction with deodorant-untreated HO (CON) as a comparison. The yield and lipid oxidation of deodorant untreated HO (CON) were not significantly affected by the three deodorants. However, deodorant-treated HOs exhibited significantly elevated levels of α-linolenic acid (C18:3n3) and eicosenoic acid (C20:1n9) compared to CON (p<0.05), while other fatty acids remained consistent. Zeolite-purified HO demonstrated significantly lower levels of volatile organic compounds (VOCs) than other treatments (p<0.05). Remarkably, zeolite decreased the concentration of pentane, 2,3-dimethyl (gasoline odor), by over 90%, from 177.17 A.U. ×10⁶ in CON to 15.91 A.U. ×10⁶. Zeolite also effectively eliminates sec-butylamine (ammonia and fishy odor) as compared to other deodorant-treated HOs (p<0.05). Additionally, zeolite reduced VOCs associated with the fruity citrus flavor, such as nonanal, octanal, and D-limonene in HO (p<0.05). This study suggests that integrating zeolite in supercritical fluid extraction enhances HO purification by effectively eliminating undesirable VOCs, presenting a valuable approach for producing high-quality HO production in the cosmetic and functional food industries.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.303-309
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• 2009

The effects of zeolite type catalysts addition on the thermal decomposition of low density polyethylene(LDPE) and ethylene vinyl acetate(EVA) resin have been studied in a thermal analyzer(TGA, DSC) and a small batch reactor. The zeolite type catalysts tested were natural zeolite, FCC catalyst, used FCC catalyst, and catalyst A. As the results of TGA experiments, addition of antifogging-agent decreased the pyrolysis point to $250^{\circ}C$, but addition of longevity-agent and clay reduced the pyrolysis rate in EVA resin. Addition of the zeolite type catalysts in the LDPE resin increased the pyrolysis rate in the order of catalyst A > used FCC catalyst > natural zeolite > LDPE resin. Addition of the zeolite type catalysts in the EVA resin increased the pyrolysis rate in the order of used FCC catalyst > natural zeolite > catalyst A > EVA resin. In the DSC experiments for LDPE resin, addition of zeolite type catalysts decreased the melting point and the heat of pyrolysis reaction in the order of catalyst A > used FCC catalyst > natural zeolite> LDPE resin. In the batch system experiments, the mixing of natural zeolite enhanced the yield of liquid fuel oil.

• Journal of Environmental Health Sciences
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• v.33 no.4
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• pp.317-324
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• 2007

The sewage treatment sludge disposal has become a serious environmental problem because of restricted direct land-filling and oceandumping in spite of their large amounts discharged. So the recycling of sewage treatment sludge is very useful alternative for waste management. Here, we studied the feasibility of zeolite synthesis in open system from the sewage treatment sludge incinerator fly ash by means of hydrothermal synthesis. We considered the concentration of NaOH, reaction time, reaction temperature and reaction step as synthesis variables. The phase of zeolite products was identified by X-ray diffractometer(XRD) and ammonium ion exchange test was performed for the raw fly ash and two zeolite products(Z-3 and Z-5). In leaching test of the raw fly ash, hazard metal is detected very low level compared with regulatory leaching test standard. But in total recoverable test, the total contents of the fly ash were very high in terms of the standard for waste-derived fertilizer. Through hydrothermal reaction, small amount of zeolite P was synthesied in 1 N of NaOH solution and relatively large amount of hydroxysodalite was synthesied in 3 N and 5 N of NaOH solution with similar peak intensity. Addition of an aging step in the synthesis didn't increase the amount of zeolite phase. Maximum $NE_4^+-N$ exchange capacity is 1.49 mg $NH_4^+-N/g$ in Z-3 and 1.38 mg $NH_4^+-N/g$ in Z-5. Most of the ammonium ion is exchanged in 30 minutes and disorption did not occur until 5 hours.

• Nuclear Engineering and Technology
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• v.40 no.3
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• pp.175-182
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• 2008

The results of process development for the blending of waste salt from the electrorefining of spent fuel with zeolite-A are presented. This blending is a key step in the ceramic waste process being used for treatment of EBR-II spent fuel and is accomplished using a high-temperature v-blender. A labscale system was used with non-radioactive surrogate salts to determine optimal particle size distributions and time at temperature. An engineering-scale system was then installed in the Hot Fuel Examination Facility hot cell and used to demonstrate blending of actual electrorefiner salt with zeolite. In those tests, it was shown that the results are still favorable with actinide-loaded salt and that batch size of this v-blender could be increased to a level consistent with efficient production operations for EBR-II spent fuel treatment. One technical challenge that remains for this technology is to mitigate the problem of material retention in the v-blender due to formation of caked patches of salt/zeolite on the inner v-blender walls.

• Journal of Environmental Science International
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• v.28 no.6
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• pp.553-559
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• 2019

In this study, zeolitic materials at $Na_2CO_3/CFA$ ratio of 0.6 - 1.8 were synthesized from coal fly ash from a thermal power plant using a fusion/hydrothermal method. The zeolitic materials were found to have cubic crystals structure and X-ray diffraction (XRD) peaks of Na-A zeolite by XRD and SEM analysis. When the zeolitic materials were synthesized from the coal fly ash, the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratios of 0.9-1.8 had the same location as the XRD peaks of commercial Na-A zeolite. The XRD peaks of the Na-A zeolite ($Na_{12}Al_{12}Si_{12}O_{48}27.4H_2O$) were confirmed in the $2{\theta}$ in the range of 7.18-34.18. However, it was also confirmed that peaks of $CaCO_3$, an impurity inhibiting synthesis of Na-A zeolite from CaO and $Na_2CO_3$ in the coal fly ash, occurred in the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratio of 1.5-1.8. The crystallinities of the zeolitic materials tended to increase gradually within the $Na_2CO_3/CFA$ ratio range of 0.6-1.8.