• Journal of Korean Society of Water and Wastewater
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• v.31 no.3
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• pp.229-236
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• 2017

In this study, a direct contact membrane module was manufactured to be used in a pilot scale membrane distillation process to treat $3m^3/day$ of the digestate produced from anaerobic digestion of livestock manure. In order to investigate the performance of the membrane module, permeate flux was measured with and without spacer inside the module under various condition of temperature difference and cross flow velocity (CFV) through the membrane surfaces. Flux recovery rate after chemical cleaning was also investigated by applying three different cleaning methods. Additionally, thermal energy consumption was theoretically simulated based on actual pilot plant operation conditions. As results, we observed flux of the module with spacer was almost similar to the theoretically predicted value because the installation of spacer reduced the channeling effect inside the module. Under the same operating condition, the permeate flux also increased with increasing temperature difference and CFV. As a result of chemical in-line cleaning using NaOCl and citric acid for the fouled membranes, the recovery rate was 83.7% compared to the initial flux when NaOCl was used alone, and 87% recovery rate was observed when only citric acid was used. However, in the case of using only citric acid, the permeate flux was decreased at a rapid rate. It seemed that a cleaning by NaOCl was more effective to recover the flux of membrane contaminated by the organic matter as compared to a cleaning by citric acid. The total heat energy consumption increased with increasing CFV and temperature difference across the membrane. Thus, further studies should be intensively conducted to obtain a high permeate flux while keeping the energy consumption to a minimum for a practical application of membrane distillation process to treat wastewater.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.839-845
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• 2007

Temperature dependence of kinetic constants in the anaerobic acidogenesis was investigated using anaerobic chemostat-type reactor. Glucose was used as a substrate in this experiment. Temperature ranging from 15 to $30^{\circ}C$ were studied. The saturation constant$(k_s\upsilon)$ and growth yield(Y) decreased with increasing temperature, while the maximum specific substrate utilization rate$(\upsilon_{max})$ increased. A temperature correction factor$(Q_{10})$ values of the substrate utilization rate and bacteria growth rate were the range from 1.3 to 2.2 and 1.5 to 2.2, respectively. The growth yield(Y) for the acidogenesis process was less sensitive to temperature changes than the maximum specific substrate utilization rate$(\upsilon_{max})$. The simulation model of the relationship between the substrate and sludge retention time(SRT) at the temperature range of 20 to $30^{\circ}C$ is obtained as the following ; $1/SRT={(6.53){\cdot}(1.038)^{T-20}{\cdot}(S/X)}/{(1.38){\cdot}(0.983)^{T-20}+(S/X)}$.

• KSBB Journal
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• v.23 no.1
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• pp.90-95
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• 2008

In this study, a combined process of sequential anaerobic-aerobic digestion (SAAD), fluidized-bed bioreactor (FBBR), and ultrafiltration (UF) for the treatment of small scale food waste leachate was developed and evaluated. The SAAD process was tested for performance and stability by subjecting leachate from food waste to a two-phase anaerobic digestion. The main process used FBBR composed of aerators for oxygen supply and fluidization, three 5 ton reaction chambers containing an aerobic mesophilic microorganism immobilized in PE (polyethylene), and a sedimentation chamber. The HRTs (hydraulic retention time) of the combined SAAD-FBBR-UF process were 30, 7, and 1 day, and the operation temperature was set to the optimal one for microbial growth. The pilot process maintained its performance even when the CODcr of input leachate fluctuated largely. During the operation, average CODcr, TKN, TP, and salt of the effluent were 1,207mg/L, 100mg/L, 50 mg/L, and 0.01 %, which corresponded to the removal efficiencies of 99.4%, 98.6%, 89.6%, and 98.5%, respectively. These results show that the developed process is able to manage high concentration leachate from food waste and remove CODcr, TKN, TP, and salt effectively.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.749-755
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• 2021

The objective of this study was to investigate the physicochemical properties of rice starch extracted from stale rice using alkaline steeping (AKL) and improved enzymatic digestion (iENZ) methods. The crude protein content (0.5-0.7%) of stale rice starch (SRS) was less than 1% by iENZ, but not so when measured by the existing ENZ methods. SRS is an intermediate amylose rice starch. AKL-SRS and iENZ-SRS exhibited typical A-type crystal packing arrangements with similar relative crystallinities. iENZ-SRS showed higher gelatinization onset and peak temperatures with a narrower gelatinization temperature range, compared to those of AKL-SRS, indicating that iENZ annealed SRS. Thus, iENZ-SRS exhibited lower swelling power and solubility, and higher pasting viscosities with delayed viscosity development. Overall, the use of stale rice as a rice starch source could make economical production of rice starch possible, and iENZ may diversify rice starch characteristics, which expands the utilization of rice starch in food and non-food industries.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.516-519
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• 2000

Generally pancreas consist of lipid, water and protein, digestion enzyme complex (pro-tease, lipase, amylase). The sample used in this work was frozen dry and treated by a semi-batch flow type. In order to develop a supercritical fluid extraction process to rem-ove lipid from the pancreas, experiments were conducted at various operating conditions(pressure range $1500{\sim}2800psi$, temperature range $25{\sim}40^{cdot}C$, particle size$(0.25{\sim}1.0mm$, flow rate $20{\sim}80m{\ell}/min)$. Also cholesterol in the pancreas was removed. The highest extraction efficiency was 2500psi, $35^{\cdot}C$, 0.25mm of pancreas size. The enzyme activity of the pancreas produced from this work showed high value compared with imported pancreas.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.282-286
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• 1990

To extract insoluble proteins of soymilk residue by microorganism the soymilk residue was treated with crude enzyme solution from Bacillus subtilis IAM 1071 natto. Optimum conditions of pH, temperature, and digestion time were determined, and amino acid composition of the extract was obtained at $45^{\circ}C$. Under optimum conditions, the extractability with natto reached to 65% in 15hrs. The contents of essential amino acids of extract were high and specially, S-containing amino acids including methonine and cysteine and Lysine content were high.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.945-949
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• 1994

Chondroitin sulfate (Chs) contents in edible snail , Achatina fulica Bowdich , andits processed meat extracts were determined by high-performance liquid chormatogrpahy(HPLC) and spectrophotometric method. Spectrophotometric method was based on the precipitation of acriflavine by ChS, and HPLC method was based on the detection of two unsaturated disaccharides, 2-acetamido-2-deoxy-3-O-($\beta$ -D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose($\Delta$Di-4S) and 2-acetamido-2deoxy-3-O-($\beta$-D-gluco-4-eepyranosyluronic acid)-6-O-sulfo-D-galactose ($\Delta$야-6S) librated from ChS byenzymeatic digestion with chondroitinase ABc. the ratio of 125$\mu$mol of sodium hydroxide to mg of ChS and 8$0^{\circ}C$ of reaction temperature were proper for alkaline hydrolysis to remove protein residue form ChS. In assay preparation for HPLC ethod, the iptimum concentration of the enzyme chondroitinase ABc was 0.15 unit per 50 $\mu\textrm{g}$ of ChS at a fixed reaction time (30 min) and pH 8.0 using Tris buffer. ChS content in edible snail was 177.6mg% by spectrophotometric method and 153.5mg% by HPLC method and those in the processed meat extract was 71.3mg% by spectrometric method ad 62.8mg% by HPLC method, respectively.

• Journal of Animal Environmental Science
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• v.21 no.1
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• pp.21-28
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• 2015

We studied the possibility on the application of the Thermophilic Aerobic Oxidation (TAO) process to anaerobic digestate stabilization. In treating digestate with TAO reactor the internal temperature of the reactor was increasing higher and $51^{\circ}C$ and over was maintained after 6 days on. The physiochemical compositions of liquids increased from pH 8.1 to 9.8 and EC decreased from 29.8 to 12.0 mS/cm in treating process of digestate with TAO reactor. CODcr decreased from 22,654 to 18,843 mg/L, showed about 16.82% of remove efficiency. TN and $NH_4-N$ decreased from 4,813 to 1,733 mg/L, from 3,815 to 812 mg/L respectively, which showed about 64.0% and 78.7% of removal efficiency respectively.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1665-1671
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• 2009

Anaerobic digestion sludge was cultivated in an electrochemical bioreactor (ECB) to enrich the hydrogenotrophic methanogens. A modified graphite felt cathode with neutral red (NR-cathode) was charged with electrochemical reducing power generated from a solar cell. The methane and carbon dioxide collected in a Teflon bag from the ECB were more than 80 ml/l of reactant/day and less than 20 ml/l of reactant/day, respectively, whereas the methane and carbon dioxide collected from a conventional bioreactor (CB) was around 40 ml/l of reactant/day, respectively. Moreover, the maximal volume ratios of methane to carbon dioxide (M/C ratio) collected in the Teflon bag from the ECB and CB were 7 and 1, respectively. The most predominant methanogens isolated from the CB on the $20^{th}$, $80^{th}$, and $150^{th}$ days of incubation were hydrogenotrophs. The methanogenic diversity analyzed by temperature gradient gel electrophoresis (TGGE) of the 16S rDNA variable region was higher in the ECB than in the CB. The DNA extracted from the TGGE bands was more than 95% homologous with hydrogenotrophic methanogens in the ECB, but was an aceticlastic methanogen in the CB. In conclusion, the ECB was demonstrated as a useful system for enriching hydrogenotrophic methanogens and increasing the M/C ratio of the gas product.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.64-69
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• 1999

Gelatinization characteristics of 111 glutinous rice varieties were evaluated by Rapid Visco Analyzer. Gelatinization viscosity of glutinous rice tested varied with ecotypes or varietal groups: indica, japonica, and Tongil type. Indica rice showed the highest average value of initial pasting temperature. The average values for peak, hot, and cool viscosities were highest in Tongil-type rice, and lowest in japonica rice. Japonica showed the lowest breakdown and consistency, but the highest setback value. Indica was lower in alkali digestion value (ADV), and shorter in gel length after gelatinization thanjaponica and Tongil-type. Glutinous rices tested could be divided into six groups by cluster analysis based on their gelatinization characteristics. Group I-A was mostly early maturing japonica varieties while I-B was mostly indica and Tongil-type rices. Groups II-A and II-B were consisted of very early maturingjaponica, and III-A and III-B included medium or medium late maturingjaponica varieties. Group III-A showed the lowest average values of peak, hot, cool, and consistency viscosities, and also in breakdown and setback ratios. Group I-B revealed the highest values in peak, hot, cool, breakdown, and consistency viscosities. ADV was low in groups I-A, I-B, and II-B, and gel consistency was not different among the six varietal groups. Principal component analysis using seven traits related with gelatinization produced four effective components, and the first and second components were highly correlated with all the gelatinization characters evaluated.