• KSBB Journal
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• v.27 no.3
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• pp.145-150
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• 2012

This study was accomplished using packed bed column reactors that contain nonsurface-modified polypropylene media and surface-modified media from hydrophobic surface property into hydrophilic property by ion beam irradiation. The objectives of this research was investigated the characteristics of organic compounds removal and microbe attachment from sewage of school cafeteria in these reactors. In 736.8 mg/L of the average inflow $COD_{Cr}$ concentration the reactors with and without surface modification showed 81.8% and 70.3% of average $COD_{Cr}$ removal efficiencies, respectively, which proves the $COD_{Cr}$ removal efficiency of surface-modified media reactor is higher than that of nonsurface-modified media reactor. After 90 days, there were maximum differences between modified system and non-modified system. In that time the maximum removal efficiency of $COD_{Cr}$ was 96.5% in modified system and was 85.2% in non-modified system that showed removal efficiency of surface-modified media system is 11.3% higher than that of nonsurface-modified media system. The average removal efficiency of SS was 80.4% for the surface modified system and 61.6% for the non-modified system under same condition. Also, the reactor of surface-modified media has advantage on microbe attachment and biofilm formation.

• Food Science and Preservation
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• v.10 no.2
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• pp.136-141
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• 2003

This they was conducted to investigate the surface treated effect of Packaged kimchi on the PH, acidity, total microbe, number of lactic acid bacteria, browning and formation of off-flavor during storage at 10$^{\circ}C$. Kimchi was treated with 70% ethanol(1 time spraying) and attachment of polyethylene film(PE) on the surface of packaged kimchi and stored at 10$^{\circ}C$. pH of the control and ethanol treated kimchi stored for 15 days was decreased to 4.0 level but, the pH of PE-treated kimchi maintained over pH 4.0 until 21 days of storage. The aridity was the same tendency as the pH, which showed delaying of fermentation by PE treatment. Total microbe of PE treated kimchi was lower and number of lactic acid bacteria was higher than those of control and ethanol treated products, respectively. Degree of browning and off-flavor of control and ethanol treated kimchi increased from 13 days of storage, but the degrees of the PE-treated kimchi was lower during all storage periods.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.10
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• pp.561-567
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• 2017

This study focused on estimating the low concentration of $NH_4{^+}-N$ removal by using simultaneous reaction of the adsorption and microbial nitrification with microbe-attached zeolite media. To evaluate the adsorption effect of the zeolite media, the expanded polypropylene (EPP) media which are not able to adsorb $NH_4{^+}-N$ were used as a control media in order to compare the adsorption ability. Each media was used to experiment after aerated 8 hr for attachment of the microbes. The batch experiment shows that nitrification occurred in zeolite media better than EPP media because nitrifiers could consume the relatively enough amount of $NH_4{^+}-N$ adsorbed onto the zeolite media. Compared to the reactor with EPP media, nitrification occurred only in the reactor with zeolite media under continuous operation at the empty bed contact time (EBCT) of 25 min and 3 mg/L of $NH_4{^+}-N$ concentration. As the EBCT of the reactor with zeolite media increased from 10 to 60 min, the nitrification efficiencies increased too. $NH_4{^+}-N$ removal efficiency showed up more than 90% at EBCT 60 min. And the difference in concentration of the total nitrogen between the influent and the effluent was 0.25 mg/L at EBCT 10 min, 0.78 mg/L at EBCT 25 min, 0.59 mg/L at EBCT 40 min and 0.37 mg/L at EBCT 60 min, respectively. This difference was due to between adsorption rate and nitrification rate of $NH_4{^+}-N$, and it was considered that $NH_4{^+}-N$ was adsorbed on the zeolite media by the gap of the concentration.