• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.253-253
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• 2010

Rice straw was pretreated with aqueous ammonia in order to enhance enzyme digestibility. Soaking in ammonia aqueous (SAA) was conducted with 15% ammonia, at $60^{\circ}C$. for 24 h. Optimization of both saccharification conditions and enzyme loading of SAA rice straw was carried out. Especially enzyme loading test was performed using statistical method. Moreover proton beam irradiation (PBI) was also performed to overcome the problem which inhibit the enzyme digestibility at 1-25 kGy doses with 45 MeV of beam energy. Optimal condition for enzymatic saccharification was follows; pH 4.8, $50^{\circ}C$, 60 FPU of enzyme activity, 1:4 ratio of celluase and ${\beta}$-glucosidase. Also, optimal doses of PBI on rice straw and SAA-treated rice straw for efficient sugar recovery were found to be 3 kGy, respectively. When saccharification was performed with optimal condition, glucose conversion yield was 89% of theocratical maximum in 48 h, and 3 kGy of PBI was applied to SAA-treated rice straw, approximately 90% of the theoretical glucose yield was obtained in 12 h. The results of X-ray diffractometry (XRD) support the effect of both SAA and PBI on sugar recovery, and scanning electron microscopy (SEM) images unveiled the physical change of the rice straw surface since rugged rice straw surface was observed.

• KSBB Journal
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• v.14 no.3
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• pp.358-364
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• 1999

The effect of hydrogen peroxide on pretreatment of oakwood was investigated. Reaction temperature was $170^{\circ}C$ and reaction solutions used in pretreatment were aqueous ammonia, sulfuric acid and pure water. When 10% ammonia solution was used, the extents of delignification and hemicellulose recovery were 55% and 26%, respectively. These values were significantly higher as delinigfication and lower as hemicellulose recovery than those of acid hydrolysis. To overcome this problem, hydrogen peroxide was added into ammonia solution stream to increase hemicellulose recovery. But delignification and hemicellulose recovery were not increased as much as hydrogen peroxide loading was increased. And as hydrogen peroxide loading was increased, the decomposition of sugars solubilized from hemicellulose and cellulose were increased. So there were significant differences between the total amount in solid residue and liquid hydrolyzate, and the total amount in the original biomass. It was found that hydrogen peroxide added was reacted with substrate packed mostly in the front part of reactor. In order to increase hemicellulose recovery, it was necessary to treat with acidic solution than with alkali solution. Effect of hydrogen peroxide was higher in water than acid solution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.32-40
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• 2024

The aim of this research was to apply a method designed to derive the factors influencing total ammonia removal when operating an additional pretreatment system at Aquaponics. The Box-Behnken method, among response surface analysis methods was used to characterize and determine the optimal nitrification conditions when operating the pretreatment system. Among the mathematically and statistically calculated prediction equations, the total ammonia nitrogen concentration Y1 measured on day 8 was derived as Y₁=-195.8+2.23X₁+42.9X₂+47.5X₃+0.1856X₁²-1.380X₁X₂-1.770X₁X₃, and the time taken to reach the maximum total ammonia nitrogen concentration during the experiment period was derived as Y₂=271-5.04X₁+60.5X₂-64.8X₃+0.1654X₁²+6.54X₃²-0.600X₁X₃-9.00X₂X₃. The coefficients of determination of the regression models of Y₁ and Y₂ were 93.99% and 94.46%, respectively. The modified coefficients of determination were also high, at 89.48% and 88.91%, respectively. The prediction coefficients of determination of Y₁ and Y₂, were 70.68% and 62.11%, respectively, which was relatively lower than that of Y1, but still indicated a reliable prediction performance.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.45-51
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• 2014

This is to study the effects of various pretreatment methods of agricultural residue, corn stover, and to compare the feature and pros and cons of each method including dilute sulfuric acid (DSA), soaking in aqueous ammonia (SAA), and ammonia recycle percolation (ARP). In order to convert corn stover to ethanol, various pretreatments followed by simultaneous saccharification and co-fermentation (SSCF) were tested and evaluated in terms of ethanol yield. With 3%, w/w of glucan loading using ARP-, DSA-, and SAA-treated solids, SSCFs using recombinant E. coli strain (ATCC$^{(R)}$ 55124) with commercial enzymes (15 FPU of Spezyme CP/g-glucan and 30 CBU/g-glucan enzyme loading) were tested. In the SSCF tests, 87, 90, and 78% of theoretical maximum ethanol yield were observed using ARP-, DSA-, and SAA-treated solids, respectively, which were 69, 58, and 74% on the basis of total carbohydrates (glucan + xylan) in the untreated corn stover. Ethanol yield of SAA-treated solid was higher than those of ARP- and DSA-treated solids. In addition, SSCF test using treated solids plus pretreated hydrolysate indicated that the DSA-treated hydrolysate showed the strongest inhibition effect on the KO11 strain, whereas the ARP-treated hydrolysate was found to have the second strongest inhibition effect. Bioconversion scheme using SAA pretreatment and SSCF can make the downstream process simple, which is suggested to produce ethanol economically because utilization of hemicellulose in the hydrolysate is not necessary.

• Environmental Engineering Research
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• v.23 no.2
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• pp.136-142
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• 2018

The river water source of Saidabad Surface Water Treatment Plant at Dhaka, Bangladesh, is deteriorated too much to be treated by conventional treatment process due to excessive ammonia pollution. In order to improve the raw water quality before it enters into the main treatment chain, a pilot study was conducted for pre-treatment of the raw water. The objective is to investigate the rate of reduction of ammonia using the Meteor pilot, a biological pretreatment system, which is a laboratory scale Moving Bed Biofilm Reactor with a nominal volume of hundred liters, filled with 50 L of Meteor 660 media. The reduction of ammonia was quite significant on average 73%, while the reduction of COD was in a range from 20 to 60%. The Meteor pilot was able to treat and nitrify the raw water and produce an effluent that respects the guarantee of ammonia < $4.0mg\;NH_3-N/L$ when the raw water ammonia concentration was < $15mg\;NH_3-N/L$. The study identified operating parameters necessary to achieve the desired goal of adequate ammonia removal. The study results would benefit a range of systems across the country by providing guidance on the design and operation of a biological pre-treatment system for ammonia removal.

• 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 the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.5
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• pp.418-423
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• 2010

Carbon nanotubes (CNTs) were synthesized by Fe-catalytic chemical vapor deposition (CVD) method about $800^{\circ}C$. The influence of process parameters such as pretreatment conditions, gas flow ratio, processing time, etc on the growth of CNTs was investigated by field emission scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. Ammonia was added to acetylene source gas before and during the CNT growth. Different types of CNTs formed depending upon the processing condition. It was found that ammonia prevented amorphous carbons from adsorbing to the outer wall of CNT, resulting in purification of CNTs during CNT growth.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.459-462
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• 2000

The pretreatment of used newspaper for the enzymatic digestion preprocess was performed on a percolation reactor and a batch reactor. The test condition of percolation process was $170^{circ}C$, 60min, 1 mL/min, and 400psi, that of batch was $40^{circ}C$, 3hr. and latm Reaction solutions used in pretreatment process were aqueous ammonia, sulfuric acid, water, and hydrogen-peroxide as an oxidizing agent. As a result, the effect of pretreatment was similar to batch and percolation process, but the yield of enzymatic hydrolysis was higher in batch than percolation. This batch pretreatment enhanced enzymatic hydrolysis rate and increased glucose yield from about 15 to 20%. The inhibition factors influenced the rate of enzymatic hydrolysis was investigated, and the ink contented newspaper was the major factor.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.381-387
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• 2009

Enhancing enzymatic saccharification of corn stover by aqueous ammonia soaking pretreatment was investigated on chemical compositional changes and enzymatic hydrolysis characteristics. At three different levels of aqueous ammonia soaking temperature and time ($140^{\circ}C$-1 h, $90^{\circ}C$-16 h and $50^{\circ}C$-6 days), higher temperature and shorter treatment time led to more xylan and lignin removal based on overall composition analysis and carbohydrate compositional analysis. More xylan and lignin removal in higher temperature treatment led to higher enzymatic saccharification of cellulose and xylan to monosaccharide by commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark).

• Journal of the Korean Wood Science and Technology
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• v.38 no.2
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• pp.149-158
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• 2010

Organosolv pretreatments which utilized sulfuric acid, sodium hydroxide and ammonia as catalysts were conducted to screen the effective catalyst for organosolv pretreatment of Liriodendron tulipifera. The enzymatic hydrolysis was achieved effectively with sulfuric acid (74.2%) and sodium hydroxide (63.7%). They were thus considered as effective catalysts for organosolv pretreatment of L. tulipifera. The organosolv pretreatments with sulfuric acid and sodium hydroxide showed a different behavior on the reaction mechanism. The pretreatment with sulfuric acid increased the biomass roughness and pore numbers. On the other hand, the pretreatment with sodium hydroxide enhanced the surface area due to the size reduction and minor defiberization which were caused by hemicellulose degradation at an initial stage and more defiberization by lignin degradation at a later stage. The organosolv pretreatment with sodium hydroxide was performed at several different conditions to evaluate effectiveness of sodium hydroxide as a catalyst for organosolv pretreatment. According to the results of enzymatic digestibility, the changes of chemical composition and the morphological analysis of pretreated biomass, it was suggested that the pretreatment time impacted primarily on enzymatic hydrolysis. Increase in surface area during the pretreatment was a major cause for improvement in enzymatic digestibility when sodium hydroxide was used as a catalyst.