• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.297-300
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• 1986

A trial paste fertilizer for rice was manufactured by a developed process using major raw materials of waste liquid from glutamic acid fermentation, urea, phosphoric acid, diammomium phosphate and potassium chloride with potassium hydroxide for pH adjust and both glycerin and $HB_4O$ for enhancing and maintaining dispersion of paste. The ratios of N, $P_2O_5$ and $K_2O$ for trial products of paste fertilizer were 10:15:13 for Japonica var., and 12.5:15:13 for Indica var., and it was 6.0 in pH and 1.45g/cc in specific gravity.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.129-133
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• 2020

The concentration of remaining formaldehyde contained in waste liquid emitted from the process of urea-formaldehyde microcapsule synthesis was analyzed by gas chromatography-mass spectrometry (GC-MS). Three factors that can affect on the reaction of formaldehyde were selected including pH, ammonium chloride input and temperature. The effect of these factors on the concentration of remaining formaldehyde was studied. When ammonium chloride input was 0.025g, microcapsules could not be obtained or core substance leaked out because of weak shell, and therefore this reaction condition would be inadequate. It was confirmed that the concentration of remaining formaldehyde could be minimized when the microencapsulation was conducted at 70℃ and pH 2.5 by using a ammonium chloride input of 0.050g. This study can make contribution to UF microencapsulation in safer working environment.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.123-129
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• 1999

The utilization methods of algae biomass have been studied constantly in whole world. These are $\circled1$the wastewater treatment if waste stabilization pond and oxidation ditch etc. and $\circled2$the biosorption of heavy metals and recovery of strategic' precious metals and $\circled3$the single-celled protein production and the production of chemicals like coloring agent and $\circled4$the production of electric energy through methane gasification. The culture system also has been developed constantly in relation with such utilization method developments. In the result of experimental operation under continuous and cyclic irradiation of light, using high rate algae biomass culture pond(HRABCP), which had been made so as to be an association system with the various items which had been managed to have high efficiency for algae culture, the algae production of the 12 hours-irradiance pond was 41.48 Chlorophyll-a ${\mu}g/L$ only in spite of having the more chance of $CO_2$ synthesis to algae cell than the 24 hours-irradiance pond. This means that the energy supply required for dark-reaction of photosynthesis is very important like this. The difference of algae production between continuous and cyclc irradiation explains that the dark-reaction of photosynthesis acts on algae production as the biggest primary factor. The continuous irradiance on HRABCP made the good algae-production($1403.97{\;}{\mu}g$ Chlorophyll-a/mg) and the good oxygen-production(5.8 mg $O_2/L$) and the good solid-liquid seperation. especially, DO concentration through the oxygen-production was enough to fishes' survival.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.39-45
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• 2009

An experimental research with 2.0 liter 4-cylinder turbocharged diesel engine was carried out to investigate the combustion and emission characteristics for various alternative fuels. The conventional diesel fuel, neat GTL, blends of 80% of GTL and 20% of biodiesel derived from waste cooking oil are utilized without any modification of engine hardware and ECU data. For GTL and blends of GTL/biodiesel fuel, the ignition delay decreased at the same operating conditions, and overall combustion duration increased slightly. Also, the peak cylinder pressure increased for blends of GTL/biodiesel compared to diesel and GTL fuel. THC and CO emissions with blends of GTL/biodiesel compared to other fuels decreased for the low and middle load conditions. But NOx emission increased due to oxygen content in biodiesel. The number concentrations of PM are higher for blends of GTL/biodiesel than other test fuels in the nucleation mode, while it had an opposite tendency in the accumulation mode, which implies more reduction of PM for blends of GTL/biodiesel on the base of mass concentration.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1114-1119
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• 2004

The biofilms on pipe walls in water distribution systems are of interest since they can lead to chlorine demand, coliform growth, pipe corrosion, and water taste and odor problems. As such, the study described in this paper is part of an AWWARF and Tampa Bay Water tailored collaboration project to determine the effect of blending different source waters on the water quality in various distribution systems. The project was based on 18 independent pilot distribution systems (PDS), each being fed by a different water blend (7 finished waters blended in different proportions). The source waters compared were groundwater, surface water, and brackish water, which were treated in a variety of pilot distribution systems, including reverse osmosis (RO) (desalination), both membrane and chemical softening, and ozonation-biological activated carbon (BAC), resulting in a total of 7 different finished waters. The observations from this study consistently demonstrated that unlined ductile iron was more heavily colonized by a biomass than galvanized steel, lined ductile iron, and PVC (in that order) and that the fixed biomass accumulation was more influenced by the nature of the supporting material than by the water quality (including the secondary residual levels). However, although the bulk liquid water cultivable bacterial counts (i.e. heterotrophic plate counts or HPCs) did not increase with a greater biofilm accumulation, the results also suggested that high HPCs corresponded to a low disinfectant residual more than a high biofilm inventory. Furthermore, temperature was found to affect the biofilms, plus the AOC was important when the residual was between 0.6 and 2.0 mg $Cl_2/l$. An additional aspect of the current study was that the potential of the exoproteolytic activity (PEPA) technique was used along with a traditional so-called destructive technique in which the biofilm was scrapped off the coupon surface, resuspended, and cultivated on an R2A agar. Both techniques indicated similar trends and relative comparisons among the PDSs, yet the culturable biofilm values for the traditional method were several orders of magnitude lower than the PEPA values.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.4
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• pp.99-104
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• 2001

The influence of agitation speed on the yeast growth was investigated in the production of probiotic feed from pulverized liquified food wastes by aerobic fermentation. A yeast Kluyvermyces marxianus was selected through a preliminary screening. The yeast was cultured by 2liter jar fermenter. in 10% solid(w/v) substrate of liquified food waste at $35^{\circ}C$ with each different agitation speed of 500, 900 and 1200 rpm. For the acceleration of enzyme excretion mixed culture with Aspergillus oryzae was also attempted and the results were compared to those of single culture. As results the viable cell number was increased by increasing agitation speed. But it showed highest value in 900rpm and then decreased in 1200rpm. The mixed culture increased amylase activity and growth rate, but did not seem to enhance the highest viable cell count in the final fermentation stage.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.679-687
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• 2018

Korean red pine (Pinus densiflora) is one of the major Pinus species in Korea. Red pine bark is removed prior to the chipping process in the wood industry and discarded as waste. However, red pine bark contains a considerable amount of naturally occurring phenolics, including flavonoids, and therefore may have a variety of biological effects. In this study, we investigated if Korean red pine bark extract (KRPBE) could protect neuronal PC-12 cells from oxidative stress and inhibit cholinesterase activity. Analysis of reversed-phase high-performance liquid chromatography results revealed four phenolics in KRPBE: vanillin, protocatechuic acid, catechin, and taxifolin. The total phenolic and flavonoid contents of KRPBE were 397.9 mg gallic acid equivalents/g dry weight (DW) and 248.7 mg catechin equivalents/g DW, respectively. The antioxidant capacities of KRPBE measured using ABTS, DPPH, and ORAC assays were 697.3, 521.8, and 2,627.7 mg vitamin C equivalents/g DW, respectively. KRPBE and its identified phenolics protected against $H_2O_2$-induced oxidative cell death in a dose-dependent manner. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission in synaptic clefts, were inhibited by treatment with KRPBE and its identified phenolics. Taken together, these results suggest that KRPBE and its constituent antioxidative phenolics are potent neuroprotective agents that can maintain cell viability under oxidative stress and inhibit cholinesterase activity.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.683-687
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• 2008

When suspended solids are removed by natural sedimentation, it is necessary to use mainly huge equipments and waste great cost. This is a problem that must be solved certainly as soon as possible. In this study, suspended solids of yellow soil water were rapidly removed by controlling pH and amounts of magnetic powder, organic and inorganic flocculants. In the case of the suspended solids of 0.3% yellow soil water, the most excellent turbidity was achieved at pH between 7 and 7.5.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.660-667
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• 2016

Conventional decontamination methods utilize water-based systems, which generate high amounts of secondary wastes. Herein, we describe an environmentally benign decontamination method using liquid and supercritical $CO_2$. The use of $CO_2$ as a solvent affords effective waste reduction by its ability to be recycled, thereby leaving be hind only the contaminants upon its evaporation. In this study, a $CO_2$ solution process was assessed using t-salen(t-butylsalen), DC18C6 (dicyclohexano-18Crown6), 8-HQN(8-hydroxyquinoline), NEt4PFOSA(perfluoro-1-octanesulfonic acid tetra-ethyl ammonium salt), and NEt4PFOA(pentadecafluorooctanoic acid ammonium salt) to extract spiked radioactive contaminants(Nb,Zr,Co,Sr) from an inert sample matrix, namely filter paper. With the static extraction method, Sr was extracted with a maximum extraction rate of 97%, and Nb was extracted with a maximum extraction rate of 75%. Additionally, we were also able to extract Co and Zr with maximum extract ion ratesof 73% and 64%, respectively.

• Resources Recycling
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• v.24 no.3
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• pp.27-33
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• 2015

EAFD (Electric Arc Furnace Dust) is considered as pernicious pollutant, assigned hazardous waste. Since this dust is a by-product of industry, it contains valuable metals such as Fe, Zn, Ni, Cu which can be turned into resources by recycling process. In this study, hydrometallurgical process was applied to recover Zn from Electric Arc Furnace Dusts. The result showed 95% Zn recovery at 3M $H_2SO_4$, Solids/Liquid ratio 1:2 and aeration of 1.8L/min for 2hr. However there was 80% Zn recovery at lower $H_2SO_4$ concentration apply for pilot scale plant.