• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.79-85
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• 2006

Innovated technique to oxidize pollutants has been developed. The technique for this study uses plasma discharge in 2-phase (Air-Water) and is called Discharged Water Generating (DWG) system. It produces electric arc which generates not only the physical decomposing power against the pollutants but also oxidants to sterilize pollutants depending on the inlet gas species. These physical and chemical products play an important role in COD decrease and biodegradability enhancement. The enhancement of biodegradability for the refractory organic substances in aqueous solution was estimated in this study. Argon discharge reduced NBDCOD of EDTA from 58.7mg/L to 38.8mg/L, but oxygen discharge and ozonation reduced it to 37.74mg/L and 38.73mg/L respectively. Furthermore, Argon discharge changed 1181mg/L of NBDCOD of dye effluent into 606mg/L but oxygen discharge and ozonation changed it into 888mg/L and 790mg/L respectively.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.1
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• pp.29-36
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• 2004

Organics may be divided into biodegradable and nonbiodegradable fractions on the basis of biodegradability. Biodegradable organics may be subdivided into readily and slowly biodegradable fractions. As this biodegradability of organics in municipal wastewater has a great influence on the efficiency of a biological nutrient removal process, it has been assessed by respirometry. The respirometer, which consisted of a respiration chamber and a respiration cell, was used to measure the respiration rate of biomass utilizing the readily biodegradable organics. The readily biodegradable organics are about 10% of the COD in municipal wastewater. The adequate ratio of wastewater to sludge volume and the concentration of sludge are required in measuring the respiration rate due to the readily biodegradable organics. By using a biochemical oxygen demand test, the slowly biodegradable organics including biomass are estimated about 66% of COD. The soluble inert organics are about 11% of COD. On the basis of mass balance, the particulate inert organics are estimated about 13% of COD.

• New & Renewable Energy
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• v.1 no.2 s.2
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• pp.60-72
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• 2005

The effect of alkaline pre-treatment on the solubilization of waste activated sludge(WAS) was investigated, and the biodegradability of WAS, pretreated WAS, [PWAS], food waste and two types of mixture were estimated by biochemical methane potential [BMP] test at $35^{\circ}C$. The biodegradability of PWAS and mixture waste were significantly improved due to the effect of alkaline hydrolysis of WAS. An alkaline pre-treatment was identified to be one of the useful pre-treatment for improving biodegradability of WAS and mixture waste. In high-rate anaerobic co-digestion system coordinate with an alkaline pre-treatment in process, the digesters were operated at the HRT of 5, 7, 10 and 13 days with a mixture of FW $50\%\;and\;PWAS\;50\%,\;$In term of $CH_4$ content, VS removal and specific methane production [SMP] which are the parameters in the performance of digester, the optimum operating condition was found to be a HRT of 7 days and a OLR of 4.20g/L-day with the highest SMP of 0.340 L $CH_4/g$ VS.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.702-709
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• 1995

Degradation Of $\kappa $-carrageenan-based film by microorganisms screened from carrageenan source and activated sludge of a carrageenan producing factory was investigated by measuring changes of pH, viscosity, total sugar and total organic carbon (TOC) of the medium containing $\kappa $-carrageenan as a carbon source. Initially fifteen strains of microorganism were isolated from carrageenan source and activated sludge and then three organisms among them were selected based on the ability of growing in the medium including 0.3% $\kappa $-carrageenan as a sole carbon source. They were identified as Escherichia coli, Saccharomyces cerevisiae and Aspergillus niger. As indices of biodegradability Of $\kappa $-carrageenan based film, the changes of pH, viscosity, total sugar, and TOC of the carrageenan film-based medium were tested by the cultivation of single or mixed strains of the identified organisms. Mixed culture showed the highest biodegradability, which resulted in the changes of pH from 6.5 to 3.0, viscosity from 164 cps to 15.6 cps, total sugar content from 2.35 g/l to 0.53 g/l and TOC from 5721 ppm to 232 ppm after 30 days of cultivation. The biodegradability determined as the reduction rate of TOC by pure cultures of Asp. niger, E. coli, Sacch. cerevisiae and mixed culture of the three organisms were 94%, 86%, 80% and 96%, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.517-526
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• 2017

The biodegradation and water absorption properties of lignin/poly(vinyl alcohol) (PVA) nanofibrous webs are investigated. Lignin/PVA nanofibrous webs containing 0, 50, and 85wt% of lignin were prepared via an electrospinning process to observe the effect of the lignin concentration on the biodegradability and water absorption properties of lignin/PVA nanofibrous webs. The morphology of the materials was examined by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). To understand the wetting behavior and hydrophilic nature of the electrospun lignin/PVA nanofibrous webs, the water absorbency, contact angle, and water uptake were examined. The enzymatic degradation of lignin/PVA nanofibrous webs was investigated using laccase by measuring total organic carbon (TOC) concentration over a course of 50 days. Water drops were absorbed immediately into all of the specimens. The water uptake of lignin/PVA nanofibrous webs increased as the amount of PVA in the lignin/PVA hybrid webs increased. The enzymatic degradation experiment indicated that the inherent biodegradability of lignin was retained after its transformation into nanofibers. Our findings imply that blending these two types of polymers is promising because it can lead to the development of a new range of multifunctional materials such as antimicrobial absorbent nanotextiles based on sustainable biopolymers.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.514-517
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• 2009

Anaerobic biodegradability(AB), which can be determined with the ultimate methane yield by the decomposition of organic materials, is one of the important parameters for the design and the operation of anaerobic digestion plant. In this study, Biochemical Methane Potential(BMP) test has been carried out to evaluate the methane yield of agro-industrial biomasses such as cattle manure, Italian ryegrass(IRG), Oats, Rye and Barley as the forage crops, Rush, the sludges produced from milling and slaughterhouse wastewater treatment plant(SMWTP, SSWTP). In the condition of thermophilic anaerobic digestion, the ultimate methane yield and anaerobic biodegradability of forage crops ranged from 0.367 to $0.452LCH_4$/gVS of methane yield with AB having the range of about 77.0 to 87.3%. On the other hand, that of other substrate showed low figures compared with the forage crops because of low VS content and C/N ratio. Therefore, the forage crops could be used as a good substrate to produce much more the methane in anaerobic digestion.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.611-616
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• 2011

The impacts of ultrasonic pretreatment on the biodegradability of domestic sewage sludge were evaluated through a series of anaerobic digestion experiments in batch system. The gas and methane production from the sludge samples pretreated by an ultrasonic tool with different durations were measured with time. Although the biogas production increased with the extent of sludge solubilization and the period of ultrasonic pretreatment, the enhancement of sludge biodegradability was much more sensitive to the pretreatment for the relatively short periods. Most of the enhanced biodegradability by the pretreatment was appeared in the early stage of anaerobic digestion, less than 6 days. The maximum biogas production per day was observed between 4 to 6 days when the sludge was pretreated less than 10 minutes while it was obtained in the beginning for the sludge pretreated longer periods. The results suggest that the repeated alternation of low strength ultrasonic pretreatment and anaerobic digestion may be more effective than the combination of one time pretreatment for a relatively long period and following anaerobic digestion.

• Textile Coloration and Finishing
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• v.26 no.3
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• pp.151-158
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• 2014

The oil sorption capacities and biodegradability of nonwoven fabrics(pads) of PP and PP/kapok(10/90wt%) blend prepared in this study and commercial pad(T2COM: 100% PP) were compared. The biodegradability(58.5%) of PP/kapok(10/90wt%) blend pad was about 5times higher than those(11%) of PP and T2COM pads after 45days. The oil sorption rates of oil sorbent pads for various oils(diesel, lubricant and Bunker C oils) were markedly increased with increasing dipping time up to about 5min and then levelled off. The oil sorption rate and oil sorption capacity were found to increase in the order of PP/kapok(10/90wt%) blend>PP>commercial(T2COM) and Bunker C>lubricant>diesel.

• Polymer(Korea)
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• v.26 no.1
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• pp.145-151
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• 2002

Thermoplastic starch(TPS) was prepared from mixing starch and glycerol by twin extruder. The blends were then prepared from high density polyethylene(HDPE) and TPS. Mechanical properties, thermal properties, and morphology of the blends were investigated. Their biodegradability was also studied by using aerobic composting method(ISO14855). Tensile strength, modulus and elongation at break decreased as the content of TPS increased. In particular elongation at break decreased rapidly even at the lower content of TPS. The melting temperatures of the blends were not changed, which showed that HDPE and TPS were immiscible. The morphology of the fractured surface of blend films was investigated by scanning electron microscopy(SEM). It was found that phases were separated. After composting for 45days, the biodegradability of the blends increased as the content of TPS increased.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.155-164
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• 2014

Recently interest on production of biogas from biomass resources has increased because of climate change in worldwide. In this study, anaerobic digestion efficiency of 17 different types of agricultural waste was evaluated using biochemical methane production potential estimated from the International biochemical methane potential standard method (Germany VDI4630). As a result, theoretical biochemical methane potential ($B_{th}$) of agricultural waste biomass ranged from 0.266 to $0.488Nm^3kg^{-1}$-Volatile Solid $(VS)_{added}$. Ultimate biochemical methane potential ($B_u$) of agricultural waste biomass ranged between 0.176 and $0.417Nm^3kg^{-1}-VS_{added}$. The agricultural waste biomass anaerobic biodegradability with $B_u/B_{th}$ and VDI4630 determined by VS contents was 36.0~95.9% and 30.8~91.1%, respectively. Ultimate methane potential and anaerobic biodegradability given by the VS term showed more reasonable results.