• Journal of the Korea Organic Resources Recycling Association
• /
• v.19 no.1
• /
• pp.64-78
• /
• 2011

Surface of hydrophobic polyethylene membrane was modified to become hydrophilic by ion beam irradiation. Submerged membrane filtration reactors contained pristine membrane or surface-modified membrane and the influent to reactors was pickled radish wastewater. The objectives of this study was to investigate the variation of flux and pressure and the characteristics of pollutant removal such as organics, suspended solids and nutrients with time. The result of experiments using intermittent pristine membrane showed the occurrence of severe fouling by increasing permeate pressure rapidly in case of pickled radish wastewater but in synthetic wastewater, this phenomenon was not occurred. In experiments of variation flux after chemical cleaning and water cleaning in pristine membrane, chemical cleaning must be necessary for renewals of pollutant membrane. Performance of intermittent operation is higher than that of continuous operation. Reaching fouling time in the case of surface-modified membrane is 6 times as long as pristine membrane. According this reason, replacement expense of surface-modified membrane could be 1/6 of that of pristine membrane. Effluent from this process was relatively good water quality and performance in the removal efficiency of SS, nitrogen and phosphorus was particularly higher.

• Korean Chemical Engineering Research
• /
• v.57 no.3
• /
• pp.420-424
• /
• 2019

In SNG (synthetic natural gas) process by proposed RIST(Research Institute of Industrial Science & Technology)-IAE(Institute for Advanced Engineering) (including three adiabatic reactors and one isothermal reactor), the methanation reaction and water gas shift (WGS) reaction take place simultaneously, and the supply of steam with syngas might control the temperature in catalyst bed and deactivate the catalyst. In this study for development of SNG process, the characteristics of the methanation reaction with a Ni-based catalyst by prepared RIST and using a low $H_2/CO$ mole ratio (including $CO_2$ 22%) are evaluated. The operating conditions ($H_2O/CO$ ratio of the $1^{st}$ adiabatic reactor, operating temperature range of $4^{th}$ isothermal reactor, etc.) were reflected the results from previous studies and in the same condition a pilot scale SNG process is carried out. As a results, the pilot scale SNG process is stable and the CO conversion and $CH_4$ selectivity are 100% and 96.9%, respectively, while the maximum $CH_4$ productivity is $660ml/g_{cat}{\cdot}h$.

• Clean Technology
• /
• v.16 no.3
• /
• pp.172-181
• /
• 2010

Hydrofluoroethers (HFEs) with fluoride molecules in their structure which are evaluated as the third generation replacement alternatives to chlorofluorocarbons (CFCs) are known to be excellent for removal of nanoparticles and fluoride-type soils due to their low surface tension and high wetting index. In addition, HFEs have good physical properties with no flash point and excellent drying characteristics. But, HFEs also have shortcomings in that they are not effective for removal of organic soils due to their poor solubility in soil. In this study, $C_5$ HFE-based cleaning agents were formulated through addition of solvents such as isopropyl alcohol (IPA), ethyleneglycol monoether (EG), propyleneglycol monoethylether (PM) to HFE-7100 [$CF_3CF_2CF_2CF_2OCH_3$] or HFE-mec-f [$CF_3CHF=CF_2OCH_2CF_3$] with its maximum amount, respectively, in order to have no flash point for the safety in the working environment. These solvents are known to be excellent for dissolving organics in soil. Their physical properties and cleaning abilities for fluxes, water-insoluble cutting oils, and fluoride-type oils were evaluated and compared with those of other cleaning agents with single components. The experimental results show that the HFE-based formulated cleaning agents have various good physical properties which are almost similar to those of a single type of HFE cleaner. They show excellent cleaning ability for fluxes, water-insoluble cutting oils, and fluoride-type oils. These results indicate that the HFE-based formulated cleaning agents can be applicable to various industrial cleaning fields because of their good physical properties and cleaning abilities for various soils.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.11 no.1
• /
• pp.55-61
• /
• 2023

This study aims to develop CLSM fill material for emergency restoration using landfill coal ash. As a result of examining physical properties such as particle size distribution and fines content of landfill coal ash, bottom ash, fly ash, and general soil were mixed, and SP was found to have a density of 2.03 and a residual particle pass rate of 7.8 %. CLSM materials that secure fluidity in unit quantities without using chemical admixtures such as glidants and water reducing agents have a high risk of material separation due to bleeding. As a result of this experiment, it was found that the bleeding ratio did not satisfy the standard in the case of the specimen with a large amount of fly ash and a lot of addition of mixing water. As a result of the compressive strength test, the strength development of 0.5 MPa or more for 4 hours was found to be satisfactory for the specimens using hemihydrate gypsum with a unit binder amount of 200 or more, and the remaining gypsum showed poor strength development. Although it is judged that landfill coal ash can be used as a CLSM material, it is necessary to identify and apply the physical and chemical characteristics of coal ash buried in the ash treatment plant of each power generation company.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.3
• /
• pp.330-338
• /
• 2010

In this study, removal characteristics of nitrogen oxides $(NO_x)$ from road transport by using peat as the packing media for biodegradation have been investigated in the long term. Physicochemical and biological treatment of peatmixed media eliminates any requirement to use chemical substances and also facilitates the biodegradable actions of microorganism. Safe biodegradation of pollutants, no need to apply additional microbes owing to their active growth, and no generation of secondary pollutants were found in this experiment. It was concluded that average removal efficiencies of nitric oxide (NO) and nitrogen dioxide $(NO_2)$ were 80% and 97% respectively with respect to the linear velocity 35~40 mm/s and 0.3 ppm ozone concentration in the long period operation. Inflow concentration of nitric oxide over 0.05 ppm was suitable when pretreated with ozone. Non-ozone stage was performed with linear velocity 20~100 mm/s and then the average removal efficiency of nitric oxide and nitrogen dioxide were 38% and 94% respectively. Other results showed that the apparent static pressure was raised with increases in applied water content and aerial velocity in mixed media during fan operation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.2
• /
• pp.201-208
• /
• 2014

This study was conducted to evaluate the ensiling characteristics and the in situ degradability of a by-product feed (BF)-based silage. Before ensilation, the BF-based mixture was composed of 50% spent mushroom substrate, 21% recycled poultry bedding, 15% ryegrass straw, 10.8% rice bran, 2% molasses, 0.6% bentonite, and 0.6% microbial inoculant on a wet basis and ensiled for up to 4 weeks. The BF-based silage contained on average 39.3% moisture, 13.4% crude protein (CP), and 52.2% neutral detergent fiber (NDF), 49% total digestible nutrient, and 37.8% physically effective $NDF_{1.18}$ on a dry matter (DM) basis. Ensiling the BF-based silage for up to 4 weeks affected (p<0.01) the chemical composition to a small extent, increased (p<0.05) the lactic acid and $NH_3$-N content, and decreased (p<0.05) both the total bacterial and lactic acid bacterial counts from $10^9$ to $10^8$ cfu/g when compared to that before ensiling. These parameters indicated that the silage was fermented and stored well during the 4-week ensiling period. Compared with rice or ryegrass straws, the BF-based silage had a higher (p<0.05) water-soluble and filterable fraction, a lower insoluble degradable DM and CP fraction (p<0.05), a lower digestible NDF (p<0.05) fraction, a higher (p<0.05) DM and CP disappearance and degradability rate, and a lower (p<0.05) NDF disappearance and degradability rate. These results indicated that cheap, good-quality BF-based roughage could be produced by ensiling SMS, RPB, rice bran, and a minimal amount of straw.

• Food Science of Animal Resources
• /
• v.40 no.1
• /
• pp.55-73
• /
• 2020

Poultry meat is generally exposed to quality deterioration due to lipid oxidation during storage. Oxidative stability of meat can be increased by feed supplementation. Aim of the current study was to investigate the effect of dietary supplementation of fish waste derived bioactive peptides on antioxidant potential of broiler breast meat and physico-chemical characteristics and quality parameters of nuggets prepared from breast meat. 180 broiler birds (six groups of 30 birds) were purchased. Each group was given different concentrations of bioactive peptides i.e. 0, 50, 100, 150, 200, and 250 mg/kg feed. After completion of six weeks birds were slaughtered and breast meat was stored at -18℃ for six months. Nuggets were prepared and stored at -18℃ for 45 days. Meat samples were analyzed for antioxidant activity [total phenolic contents (TPC), DPPH^· scavenging activity, and ferric reducing antioxidant power] and lipid oxidation assay at regular intervals of 1, 2, 3, 4, 5, and 6 months while nuggets were analyzed for quality (pH, color, texture and water holding capacity) parameters after regular interval of 15 days. A significant (p<0.05) effect of feed supplementation was observed on antioxidant status such as TPC, DPPH^· scavenging activity, and FRAP of broiler breast meat. Dietary interventions of bioactive peptides significantly (p<0.05) delayed lipid oxidation of breast meat than control. All the quality parameters were also significantly affected due to dietary bioactive peptides and storage duration. Thus, dietary interventions of bioactive peptides can increase the antioxidant and shelf stability of broiler breast meat and nuggets.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.1
• /
• pp.32-37
• /
• 1985

Effects of straw mulching on growth of shoot and root of Panax ginseng, soil physical and chemical characteristics were investigated. Straw mulching increased root yield, stem length, leaf area and decreased defoliated plant rate and missing root rate. Percent solid phase and soil hardness decreased, and porosity, percent air phase and percent liquid phase increased under straw mulch. It increased soil water content and decreased soil temperature especially in the rear side of the bed. Available soil phosphorus (very harmfully in some case), exchangeable potassium, organic matter increased while exchangeable calcium decreased and the lowering of pH was retarded under mulch. Straw mulching greatly reduced need population, prevented soil covering on the lower side of leaves and eliminated solings to plants, bed sides and on bed top.

• Food Science of Animal Resources
• /
• v.38 no.2
• /
• pp.403-416
• /
• 2018

In this study, the dietary effects of probiotics with a liquid application system on meat quality and physicochemical characteristics of pigs were evaluated. A total of 80 Landrace${\times}$Yorkshire${\times}$Duroc (LYD) 3-way crossbred pigs (average age $175{\pm}5d$) were assigned to a conventional farm and a probiotics farm equipped with a liquid probiotics application system (40 pigs in each farm). The two treatments were: CON (diet without probiotics) and PRO (diet with probiotics). Dietary probiotics decreased shear force in the longissimus muscle compared to the control group (p<0.05). The treatment diet did not affect backfat thickness, carcass weight, meat color, cooking loss, water holding capacity (WHC), and drip loss. Dietary probiotics significantly reduced ash, salinity, and pH (at 5 and 15 d) (p<0.05). There was no significant effect on thiobarbituric acid reactive substance (TBARS) values. Polyunsaturated fatty acid (PUFA) and omega fatty acids (${\omega}3$ and ${\omega}6$) were significantly (p<0.05) higher in the PRO group, whereas monounsaturated fatty acid (MUFA) was decreased. The free amino acid composition, serine, lysine, histidine, and arginine levels were significantly lower in the PRO than in the control group. The treatment group exhibited higher nucleotide compounds (hypoxanthine, inosine, GMP, IMP) than the controls. Also, levels of ascorbic acid and thiamin were significantly different (p<0.05), while minerals were not significantly different between the groups. In conclusion, feeding of probiotics had effects on shear force, ash, salinity, pH, PUFA, and some amino acids which related to taste and flavor without any negative effects on the pigs' carcass traits.

• Food Science of Animal Resources
• /
• v.38 no.5
• /
• pp.1092-1100
• /
• 2018

The aim of this study was to determine meat quality characteristics and fatty acid composition of Korean native black goats (KNBG) finished on intensive feeding of alfalfa (ALF) and conventional feeding of commercial concentrate pellets (CCP) with low-energy common grasses. Ten KNBG (12 months old) were divided into two groups and subjected to either ALF or CCP treatments. The goats were slaughtered after 6 months of feeding with experimental diets to investigate meat quality characteristics and fatty acid compositions of longissimus lumborum muscle. There were no significant differences in proximate chemical composition, collagen, or myoglobin content between ALF and CCP groups of goats. Meat color, water-holding capacity, or tenderness was not significantly different between the two groups either. However, proportions of monounsaturated fatty acids and polyunsaturated fatty acids were significantly (p<0.05) different between the two groups. The proportion of oleic acid was significantly (p<0.05) higher in ALF goat whereas proportion of linoleic and arachidonic acids were significantly (p<0.05) higher in CCP goat. Results suggest that KNBG finished with intensive feeding of alfalfa could produce goat meat with desirable fatty acids for human diets.