• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.358-363
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• 2006

KSMBR process is dynamic state advanced wastewater treatment applied with Trisectional Aeration (TSA) mode combined with membrane. TSA was remodeled conventional intermittent aeration which was operated nonaeration-aeration. TSA operates nonaeration ($N_1$) - aeration (A) - nonaeration ($N_2$) in Trisectional Aeration Reactor (TAR). Organics of influent could be nearly consumed to denitrification without influence by remained DO in TAR and it could be operated about sludge return ratio of 1Q (influent base). The purpose of this study was to apply KSMBR to the full-scale plant and to evaluate efficiency of nitrogen and phosphorus removal and TSA operation. The result of this study, average CODcr/T-N and CODcr/T-P ratio were 7.8 and 59.6, respectively. BOD, TCODcr, SS, T-N, T-P, E-coli removal efficiency were 98.4, 95.2, 73.0, 69.6, 99.95 %, respectively. KSMBR obtained high removal efficiencies of C, N and P when it applied full-scale plant.

• Fire Science and Engineering
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• v.30 no.3
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• pp.1-6
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• 2016

More than five thousands transportation fires occurannually in Korea and the resulting destruction of property and loss of life is huge and results in traffic and environmental pollution. The recent development of automobile technology such as the hybrid concept and use of bio fuels makes fire protection even more difficult due to a lack of understanding of the new adapted system including vehicle engines. In this study, a numerical simulation was performed on a PSR (perfectly Stirred Reactor) to simulate an automobile engine and to clarify the effect of gasoline/ethanol surrogates as a fuel. The temperature, NOx and soot emissions were predicted to decrease with increasing ethanol content, but that of unburned hydrocarbons was found to increase dramatically. The result will provide not only the basic thermal characteristics for engines and their after-treatment systems, but also make it possible to assess the potential for fire events in these systems when an ethanol mixed fuel is used in gasoline vehicles.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.407-414
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• 2016

Ex-situ catalytic pyrolysis of a Korean native oak tree over microporous zeolites (HZSM-5, HBeta, and HY) was performed by using a fixed bed reactor. The effect of sample to catalyst ratio and reaction temperature was also investigated to optimize production conditions of high quality bio-oil. Among three catalysts, HZSM-5 showed the highest aromatic formation due to its proper pore size and strong acidity. Although HY and HBeta also showed the catalytic activity, they produced larger amounts of coke due to their larger pore size. The smaller ratio of the sample to the catalyst and higher reaction temperature were also required to maximize the yields of aromatic hydrocarbons via the catalytic pyrolysis of oak tree over HZSM-5.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.15-20
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• 2012

Processing of organic waste is converted to anaerobic digestion for environmental friendly and sustainable energy recovery and reduction of sludge. In this study, ECOPAD (ECOdays' Plug-flow Anaerobic Digster)design for a high solids content and high organic matter content were used to investigate an applicability and efficiency of food waste treatment and poultry wastewater treatment. Case-by-case analysis of treatment efficiency of ECOPAD using food waste of city "P" and city "S". Volatile Solids basis organic removal efficiency of city "P" and city "S" was 84% and 88% respectively. And, the content of methane (P City: 70%, S City: 71%) was measured similarly. In the case of poultry waste bio-gas production was measured to $1.6Nm^3/kg$-VSrem, and methane content was measured to 69%.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.506-510
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• 2009

The effects of various organic wastes on anaerobic fermentative hydrogen production were studied using enriched mixed microflora in batch tests. Rotten fruit, corn powder and organic wastewater enriched with sulfate (up to 1,000 mg/L) were used for experiments. Maximum hydrogen production (547.1 mL) was observed from rotten apple with initial substrate concentration of 132.2 g COD/L. The experimental result on sulfate enriched organic wastewater indicated that hydrogen production is not adversely influenced by relatively high sulfate concentration. Residual sulfate content remained at 96-98 % after 75 hours of reaction, which showed that no major sulfate reduction was occurred at pH 5.3-5.5 in the reactor. The volatile fatty acid (VFA) fractions produced during the reaction was in the order of butyrate > acetate > propionate in all experiments. The results of this study would be useful for controlling the conditions on fermentative hydrogen production using different feedstocks.

• Korean Journal of Veterinary Service
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• v.30 no.2
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• pp.259-267
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• 2007

A study on the relation between some husbandry practices and brucellosis in goats in Bangladesh was conducted at selected areas of Mymensingh and Dhaka district, Bangladesh, from March 2005 to May 2006. Sera from 300 goats were tested by Rose bengal test (RBT), plate agglutination test (PAT), tube agglutination test (TAT) and mercaptoethanol test (MET). Out of the 300 goats, 1.670% (n=5) were positive to RBT and PAT respectively, and 2.0% (n=6) were positive to TAT and 2.33% (n=7) were positive to MET. The prevalence of brucellosis was bigger in goats reared collectively (n=2, 4%) than reared individually (n=5, 2%), and bigger in goats housed with concrete floor (n=2, 4%) than that of bare floor (n=5, 2%). The rate of brucellosis was higher in goats keep separately (n=6, 2.61%) than that of kept with other animals (n=1, 1.43%) especially with cattle. Out of 290 goats from free grazing, 7 were positive but no positive reactor(n=10) was found in non grazing goats. In conclusion, however, seroprevalence of brucellosis had no statistically significant association with rearing type, housing type and grazing or not.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.76-82
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• 2012

Biomass and coal are great potential energy sources for gasification process. These solids can be gasified to produce syngas and bio-oil which can be upgraded further to transportation fuel. Two biomass and three coals have been gasified with steam in a thermobalance reactor under atmospheric pressure in order to evaluate their kinetic rate information The effects of gasification temperature ($600{\sim}850^{\circ}C$) and partial pressure of steam (30~90 kPa) on the gasification rate have been investigated. The three different types of gas-solids reaction models have been applied to the experimental data to compare their predictions of reaction behavior. The modified volumetric reaction model predicts the conversion data well, thus that model was used to evaluate kinetic parameters in this study. The gasification reactivity of five solids has been compared. The obtained activation energy of coal and biomass gasification were well in the reasonable range. The expression of apparent reaction rates for steam gasification of five solids have been proposed as basic information for the design of coal gasification processes.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.410-414
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• 1992

Endoinulase from Streptomyces sp. S56 was immobilized by adsorption on DEAE-cellulose in 0.01 M citrate-sodium phosphate buffer, pH 6.0 and the properties of immobilized and free enzymes were investigated. The immobilized enzyme preparation, having 40 inulase activity units per dried matrix, revealed the maximal activity at $pH\;4.5{\sim}5.5$ and $55{\sim}60^{\circ}C$ and were most stable at pH 6 and 45^{\circ}C$. The immobilization caused a drop in optimum pH and affinity toward inulin, a slight increase in optimum temperature, an important increase in thermal stability and maximum reaction velocity. The immobilized endoinulase hydrolyzed the tuber extract of jerusalem artichoke and inulin, mainly into fructose and inulobise, degrading 63 and 78% of the total sugar respectively, within 48 hrs in batch reactor.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.205-213
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• 2021

The present study aimed to determine the effect of co-pyrolysis of sawdust biomass and scrap tyre waste employing different blending ratios of sawdust to waste tyre such as 100:0, 75:25, 50:50, 25:75, and 0:100. The thermochemical characterization of feedstocks was carried out by employing the proximate, ultimate analysis, and thermogravimetric (TGA) analyses, calorific values, and scanning electron microscope coupled with energy dispersive x-ray analysis (SEM-EDX) to select the blending ratio having better bioenergy potential amongst the studied ratios. The blending ratio of 25:75 (sawdust to waste tyre) was selected for the co-pyrolysis study in a fixed-bed pyrolysis reactor system based on its solid biofuels properties such as heating value (30.18 MJ/kg), and carbon (71.81 wt%) and volatile matter (63.82 wt%) contents. The pyrolysis temperatures were varied as 500, 600 and 700 ℃ while the other parameters such as heating rate and nitrogen flowrate were maintained at 30 ℃/min and 0.5 L/min respectively. The bio-oil yields as 31.9, 47.1 and 61.2 wt%, bio-char yields as 34.5, 34.2 and 31.4 wt% and gaseous product yields as 33.6, 18.60 and 7.3 wt% at the pyrolysis temperatures of 500, 600 and 700 ℃ respectively were obtained. The blends of sawdust and waste tyres showed the improved energy characteristics which could provide the solution for the beneficial management of sawdust and scrape tyre wastes via co-pyrolysis processing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.870-877
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• 2023

The purpose of this study was to assess the efficiency of nitrification based on ammonia loading rates and hydraulic air-loading rates in a moving bed bioreactor (MBBR) under seawater conditions. The goal was to provide foundational data for the design of these bio reactors. At an ammonia loading rate of 0.2 g TAN·m^-2 surface area·day^-1, the influent TAN concentration was determined to be 1.76±0.33 mg·L^-1, which is below the safe concentration for fish survival (2 mg·L^-1). Considering operational aspects, the optimal ammonia-loading rate was derived. Subsequently, experimental results for nitrification efficiency at the optimal ammonia-loading rate revealed that the optimum hydraulic air-loading rate was 1.8 L·air·m^-2 surface area·min^-1. This condition resulted in the lowest concentrations of TAN and NO₂-N in the influent water, thus establishing the optimal hydraulic air-loading rate. A regression equation was derived for the ammonia-removal rate (Y) based on the ammonia-loading rate (x) and expressed as a 0.5-order equation (Y=ax^0.5+b). Specifically, for TAN concentrations of 0-6 mg·L-1, the regression equation Y=0.1683x^0.5-0.13628, was established.