• Analytical Science and Technology
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• v.30 no.4
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• pp.174-181
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• 2017

Bio-liquid is a liquid by-product of the hydrothermal carbonization (HTC) reaction, converting wet biomass into solid hydrochar, bio-liquid, and bio-gas. Since bio-liquid contains various compounds, it requires efficient sampling method to extract the target compounds from bio-liquid. In this research, fatty acid methyl ester (FAME) in bio-liquid was extracted based on hollow fiber supported liquid phase microextraction (HF-LPME) and determined by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography/Mass Spectrometry (GC/MS). The well-known major components of biodiesel, including methyl myristate, palmitate, methyl palmitoleate, methyl stearate, methyl oleate, and methyl linoleate had been selected as standard materials for FAME analysis using HF-LPME. Physicochemical properties of bio-liquid was measured that the acidity was 3.30 (${\pm}0.01$) and the moisture content was 100.84 (${\pm}3.02$)%. The optimization of HF-LPME method had been investigated by varying the experimental parameters such as extraction solvent, extraction time, stirring speed, and the length of HF at the fixed concentration of NaCl salt. As a result, optimal conditions of HF-LPME for FAMEs were; n-octanol for extraction solvent, 30 min for extraction time, 1200 rpm for stirring speed, 20 mm for the HF length, and 0.5 w/v% for the concentration of NaCl. Validation of HF-LPME was performed with limit of detection (LOD), limit of quantitation (LOQ), dynamic range, reproducibility, and recovery. The results obtained from this study indicated that HF-LPME was suitable for the preconcentration method and the quantitative analysis to characterize FAMEs in bio-liquid generated from food waste via HTC reaction.

• Korean Journal of Environmental Biology
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• v.22 no.4
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• pp.501-506
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• 2004

In organic agriculture, choose of effective and cheap bio-pesticide is very important. The authors developed an insecticidal extract from neem cake, waste of neem oil from kernel, and applied as a bio-pesticide. Bio-pesticide neem cake extracts experiment on cabbage pest was carried out at Wonju Agricultural Technology and Extension Center from 11 March to 30 May 2003. There were six treatments with three replications, using completely randomized design. Treatments involved three and six sprays of synthetic pyrethroid pesticide cypermethrin 10 EC at the dilution rate of 2.2 mL $L^{-1}$ of distilled water and four, five and six sprays of bio-pesticide neem at the dilution rate of 13.3 mL $L^{-1}$ of distilled water, and untreated control. For each treatment, designated sprayings were done at 7 days interval. Pre-spray data showed that the plants in all the experimental plots were already infested with aphid (Aphis gossypii), and diamondback moth (Pluetella xylostella). The results indicated that all neem pesticide treatments were more effective in insecticidal activity than the untreated control and the chemical treatments in controlling aphids and diamondback moth. Among the three neem treatments, there were no significant differences between them.

• Journal of Environmental Science International
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• v.17 no.11
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• pp.1265-1271
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• 2008

Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.57-66
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• 2019

This study carried out on-site investigation and precision monitoring to prepare proper design and operation technical guidelines for the use of bio gas in organic waste resources (fertilizing urine, food waste, food waste, food waste, etc.). According to the government's mid- and long-term policy on bio gasification, the expansion of waste resources is actively being pushed forward. However, facilities that use the biogas produced for urban gas and transportation are still under-efficient. Precision monitoring was carried out for biogasification facilities of organic waste resources in seven locations nationwide. When the results of precision monitoring were summarized with the four-season average, the efficiency analysis of each organic waste resource showed that the organic breakdown rate was 66.3% on average on VS basis. Analysis of biogas characteristics before and after pretreatment revealed that the $H_2S$ average of the entire facility was measured at 949.7 ppm using iron salts and desulfurization (dry, wet) and that the quality refining facility shearing and rear end was 29.0 ppm and 0.3 ppm. The methane content was found to be reduced by 65.6% at the rear of the fire tank, 63.5% at the back and 97.5% at the rear.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.188.2-188.2
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• 2011

The use of renewable energy sources is becoming increasingly necessary to minimize the problems derived from the global warming impacts caused by the utilization of fossil fuels as well as their limited supply and reservoir. Also, localized heavy rain has occurred in many areas. As a result, suspended wood waste is being inflow into the dam and the problem of waste disposal has occurred. It is a unique renewable and alternative source for the production of energy. The experiment using wood waste (dry weight 25.0g) was conducted for extraction sugars such as xylose, lactose and glucose. For the sugar extraction from wood waste, hydrolysis experiment using wood waste was conducted by two steps. First step was reacted with 72% sulfuric acid (24.0N and 37.5 ml) for 1hr at $30^{\circ}C$ and second step was reacted at $105^{\circ}C$ for one hour after adding 2.45times of hot water. Extracted sugar was used in the experiment of sugar consumption to estimate feasibility of ethanol production using yeast(P. Stipitis and S cerevisiae). As a result, sugar extracted from wood waste was effective consumed by yeast(P. Stipitis and S cerevisiae). The consumption rate by yeast was S. cerevisiae was faster than that of P. stipitis. It can be confirmed that resource as ethanol production using wood waste was available.

• Environmental Engineering Research
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• v.24 no.2
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• pp.191-201
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• 2019

Petroleum industry produces one of the popular hazardous waste known as Petroleum Sludge. The treatment and disposal of petroleum sludge has created a major challenge in recent years. This review provides insights into various approaches involved in the treatment, and disposal of petroleum sludge. Various methods used in the treatment and disposal of petroleum sludge such as incineration, stabilization/solidification, oxidation, and bio-degradation are explained fully and other techniques utilized in oil recovery from petroleum sludge such as solvent extraction, centrifugation, surfactant EOR, freeze/thaw, pyrolysis, microwave irradiation, electro-kinetic method, ultrasonic irradiation and froth flotation were discussed. The pros and cons of these methods were critically considered and a recommendation for economically useful alternatives to disposal of this unfriendly material was presented.

• Journal of the Korean Professional Engineers Association
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• v.39 no.5 s.188
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• pp.20-24
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• 2006

The energy of 97% consumed by our country depends on it's import from foreign market. This article covers hydrogen, fuel-cell, coal liquefaction gasification energy, and solar, wind, photovoltaic, hydro power, ocean, waste, geothermal, bio energy that is renewable energy, and so on, which are new-generation energy sources, increasing the concern on new & renewable source of enenrgy in future.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.313-313
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• 2015

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.1
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• pp.13-19
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• 2010

Four waste paper mills in Korea, where multifractors, devices for fiber fractionation, were installed, were selected to investigate how effectively and how differently the multifractors were used. They all used slot-type screens. Effective fiber fractionations by fiber length were expected by the multifractors, but in reality, they were used for selecting fiber furnishes that were flexible and hydrated. Flakes, which meant large fiber bundles, were rejected effectively by the multifractors. There existed a high regression coefficient between the fiber length differences and the freeness differences of the accepted and the rejected fiber furnishes.

• Environmental Engineering Research
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• v.11 no.2
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• pp.106-125
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• 2006

Cesium and strontium are two important fission products and the removal/speciation of these two cations with several inorganic/bio-materials is an interesting topic to discuss. It is to be noted that inorganic materials are found to be fairly effective and efficient in the removal/speciation of these cations. Moreover, these solids are to be found promising as they show fairly good radiation and temperature stability. Hence, they play an important role in the radioactive waste management studies. However, various studies reveal that in addition to inorganic materials various biosorbents can also be employed in the removal/speciation of these ions. But the radiation and temperature stability of these bio-sorbents and dead biomasses are still the topic lying among the researchers to be investigated.