• Textile Coloration and Finishing
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• v.27 no.1
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• pp.96-104
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• 2015

This study examined the pretreatment effect, appropriate dyeing conditions, color fastness and functionality of cotton fabrics dyed with Zizania latifolia Turcz. Dye uptake was substantially increased by pretreatment and chitosan pretreatment was much more effective than tannic acid pretreatment. Optimal dyeing conditions were colorant concentration of 100%, dyeing temperature of $100^{\circ}C$, dyeing time of 80 minutes and dyebath pH of 5.5. Color fastness of chitosan pretreatment and dyed cotton to washing, rubbing, perspiration and light was 4, 5, 3-4(acidic), 3(alkaline) and 3 respectively. Color fastness of tannic acid pretreatment and dyed cotton to washing, rubbing, perspiration and light was 4, 5, 3-4(acidic), 4-5(alkaline) and 4 respectively. Deodorization rates of ammonia(NH3) were 99.9% in both cases. UV protection rate were 98.3% of UV-A and 98.5% of UV-B in case of chitosan pretreatment. UV protection rate were 98.2% of UV-A and 98.5% of UV-B in case of tannic acid pretreatment. UV protection factor(UPF) was 50+ in both cases. Reduction rate of Staphyloccus aureus were 99.9% in both cases. Therefore Zizania latifolia Turcz. could be used a new functional colorant.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.387-394
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• 2002

The efficiency variation of UF(tubular)/RO(spiral wound) process using acrylic wastewater treated by photo-catalyst pretreatment and coagulant-filter-neutralization pretreatment processes were discussed wit the variation of appled pressure and temperature. Ultrafiltration tubular module using acrylic wastewater treated by photo-catalyst pretreatment and coagulant-filter-neutralization pretreatment processes was shown that COD and T-N were not highly affected with the variation of appled pressure and temperature. It was shown that removal efficiency of COD and T-N was low. Removal efficiency of TDS and turbidity with ultrafiltration tubular module was better with the acrylic wastewater by photo-catalyst pretreatment than acrylic wastewater by coagulant-filter-neutralization pretreatment. T-N and TDS were shown high removal efficiency in reverse osmosis membrane process.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.578-590
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• 2015

The present study examines the influence of slurry composting and biofiltration liquid fertilizer (SCBLF) treatment on the biomass characteristics of yellow poplar, and the optimization of organosolv pretreatment for sugar production. After SCBLF treatment, total exchangeable cation contents of yellow poplar was increased from $3.1g\;kg^{-1}$ to $4.4g\;kg^{-1}$, and as a result, biomass production of yellow poplar was also enhanced by 82.3%. Organosolv pretreatment was conducted with three independent variables: 1) reaction temperature: $133.2^{\circ}C$ to $166.8^{\circ}C$; 2) acid concentration: 0.2% to 1.8%; and 3) reaction time: 1.6 min to 18.4 min. Reaction temperature was the most significant variable in water insoluble solid (WIS) recovery rate. High overall sugar yield was attained from pretreatment conditions approximately 50% of WIS recovery rate, and the highest overall glucose yield (44.0%) was achieved from pretreatment at $140^{\circ}C$ with 1.5% acid concentration for 5 min. Consequently, 21.1% of glucose and 5.8% of xylose were produced from the organosolv pretreatment of SCBLF-treated 8-year-old yellow poplar.

• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.78-90
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• 2012

Soybean hull is an attractive feedstock for glucose production. To increase the glucose conversion in acid hydrolysis, a pretreatment method combined steam explosion with alkali pretreatment for soybean hull was studied. For first step pretreatment, steam explosion conditions (log Ro 2.45) were optimized to obtain maximum solid recovery and cellulose content. In the second step pretreatment, the conditions for potassium hydroxide pretreatment of steam exploded soybean hull were optimized by using RSM (response surface methodology). The optimum conditions for minimum lignin content were determined to be 0.6% potassium hydroxide concentration, $70^{\circ}C$ reaction temperature and 198 min reaction time. The predicted lignin content was 2.2% at the optimum conditions. Experimental verification of the optimum conditions gave the lignin content in similar value with the estimated value of the model. Finally, glucose conversion of pretreated soybean hull using acid hydrolysis resulted in $97.1{\pm}0.4%$. This research of two-step pretreatment was a promising method for increasing the glucose conversion in the cellulose-to-glucose process.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.261-266
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• 2011

Supercritical $CO_2$ pretreatment before dehydration leads to a faster dehydration rate. The best supercritical $CO_2$ pretreatment conditions for the most effective dehydration were $45^{\circ}C$, 25 MPa and $55^{\circ}C$, 25 MPa. Increasing pressure of the supercritical $CO_2$ pretreatment system tended to accelerate the dehydration rate more than increasing temperature did. Samples pretreated at higher temperatures and pressures showed greater shrinking and pore distribution on scanning electron microscopy. Control samples maintained their cell walls, whereas samples pretreated at higher temperatures and pressures showed more cell disruption, and more pores were observed. Pore sizes of control and pretreated samples were about 100 and $70{\sim}80\;{\mu}m$, respectively. Samples pretreated at higher temperatures and pressures had smaller pores and a denser distribution.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.3
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• pp.179-182
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• 2003

Anaerobic fermentation was attempted to produce methane from the wood chip (Eucalyptus globulus). By the pretreatment of the wood chip using hot water with high temperature, NaOH, and steam explosion, the production of methane gas was enhanced. The pretreatment using Steam explosion resulted in more amount of methane gas produced than the treatment using either hot water or 1% (w/w) NaOH with high temperature, and the steam explosion at a steam pressure of 25 atm and a steaming time of 3 min was the most effective for the methane production. The amount of methane gas produced depended on the ratio of weight of Klason lignin, a high molecular weight lignin, in the treated wood chip.

• Journal of the Korean Wood Science and Technology
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• v.45 no.2
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• pp.182-194
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• 2017

The optimum alkali pretreatment parameters (reaction time, reaction temperature and potassium hydroxide concentration) for facilitate the conversion into fermentable sugar (glucose) from steam exploded (severity log Ro 2.45) barley husk were determined using Response Surface Methodology (RSM) based on a factorial Central Composite Design (CCD). The prediction of the response was carried out by a second-order polynomial model and regression analysis revealed that more than 88% of the variation can be explained by the models. The optimum conditions for maximum cellulose content were determined to be 201 min reaction time, $124^{\circ}C$ reaction temperature and 0.9% potassium hydroxide concentration. This data shows that the actual value obtained was similar to the predicted value calculated from the model. The pretreated barley husk using acid hydrolysis resulted in a glucose conversion of 94.6%. This research of steam explosion and alkali pretreatment was a promising method to improve cellulose-rich residue for lignocellulosic biomass.

• Journal of Welding and Joining
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• v.34 no.4
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• pp.40-47
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• 2016

The Zn coating on automotive galvanized steel sheets can improve corrosion resistance. However, the boiling temperature of Zn is lower than the melting temperature of steel and it causes well-known spatter and porosity problem. One of most prominent solutions is a pretreatment of Zn coating by an additional welding arc prior to the main welding process. In this research, GTA and GMA are selected as heat sources for pretreatment and main welding processes, respectively. The authors suggested three possible mechanisms to reduce weld defects by the GTA pretreatment: (1) Formation of gap between the sheets; (2) Evaporation of Zn layer; (3) Oxidation of Zn layer. Among them, Zn Oxidation is the most important mechanism to reduce weld defects in the GTA-GMA hybrid process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.1018-1023
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• 2010

This study was conducted to investigate quality changes of apple slab after pretreating with supercritical $CO_2$. L, a, b and color difference values were little changed at increasing temperature and pressure. Polyphenol oxidase was inhibited according to increment of supercritical $CO_2$ temperature and pressure. Springiness and hardness were increased at increasing pressure and temperature condition of pretreatment but hardness showed lower value than untreatment. The texture like sponge of dried apple slab was probably due to channels which were made during penetration and release of carbon dioxide.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2413-2420
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• 2018

Sida acuta, a common type of weed in Thailand, contains relatively high cellulose (42.7%) content. We pretreated NaOH to improve glucose recovery from S. acuta. The effect of pretreatment temperature and NaOH concentration was fundamentally investigated based on hydrolysis efficiency with recovery of solid fraction. The pretreatment condition was determined to be 3% NaOH at $60^{\circ}C$ for 9 h, which showed the highest glucose recovery. The hydrolysates obtained by enzymatic hydrolysis of S. acuta were applied to the fermentation of Saccharomyces cerevisiae K35, and a theoretical yield of 97.6% was achieved at 18 h. This indicated that the hydrolysates medium without detoxification had no negative effects on the fermentation. The production of biomass into bioethanol was evaluated based on the material balance of 1,000 g basis. Following this estimation, approximately 28 g and 110 g bioethanol could be produced by untreated and pretreated S. acuta, respectively, and this production was improved about 3.9-fold by NaOH pretreatment. These results again show the importance of pretreatment in biorefinery process.