• KSBB Journal
• /
• v.5 no.3
• /
• pp.279-291
• /
• 1990

Partial hydrolysed and deacetylated chitin, CHITA and CHITB as supports of immobilized enzyme were obtained by treatment of acid and base respectively. Glutaraldehyde, bifunctional reagent, was employed for crosslinking between $\beta$-glucosidase and support. Immobilized enzyme activities of CHITA-Gase and CHITB-Gase were determined with the reaction of p-nitrophenol-$\beta$-D-glucopyranoside(PNG) in batch reactor, CSTR and PFR. Their optimum temperature, pH and enzymatic characteristics including Km and Vmax values were observed with variation of the flow rates. Mass transfer coefficient(h), effectiveness factor(η), deactivation rate(kd ) of two immobilized enzymes were also examined to compare efficiency of reactors.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.4
• /
• pp.228-233
• /
• 2015

This study was performed to examine the effect of zinc on the biodegradability, nitrification, denitrification and oxygen uptake rate (OUR) using batch reactor and continuous flow stirred tank reactor (CSTR) of anaerobic/anoxic/oxic ($A^2/O$). The results of this study can be summarized as follows. In the case of the effect of zinc on organic treatment, zinc had no effect up to 12 mg/L with batch reactor but biodegradability was lowered when it was above 3.0 mg/L with CSTR. Concerning the case on nitrification and removal of nitrogen, nitrification rate was lowered when zinc was above 6.0 mg/L with batch reactor and removal rate of nitrogen was lowered when zinc was above 3.0 mg/L with CSTR. Removal rate of phosphorus was lowered when it was above 6.0 mg/L zinc with batch reactor and above 3.0 mg/L zinc with CSTR. In the case of OUR, it decreased as microbial activity was affected when zinc concentration was above 3.0 mg/L in CSTR.

• Applied Biological Chemistry
• /
• v.25 no.3
• /
• pp.150-154
• /
• 1982

Top-dressing pot experiment with $^{15}N$ urea was carried out by using three varieties. Two-split application was much better for Tongil line than 4-split. Fertilization efficiency (Fe), use efficiency (Eu) and absorbed fertilizer nitrogen efficiency (Ef) were much greater in 2-split than in 4-split. The order of Fe followed that of Ef. Grain yield and $^{15}N$ excess % among plant parts suggest that Tonsil line uptakes fertilizer nitrogen much in early stage and retranslocated well later. The order of soil nitrogen increment in plant per fertilizer nitrogen in plant $({\Delta}Ns/Nf)$ might be an index of soil nitrogen use efficiency due to fertilizer.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.6
• /
• pp.1292-1297
• /
• 2009

This study was performed to investigate solubility, dissolution rate and ash content of solid type fuel additive in gasoline and diesel in order to set up manufacturing standards. From the results, the unfiltered impurities were increased when the fuel additive was added on gasoline and diesel. Also, the unfiltered fuel additive was decreased with respect to increasing the pore size of the filter paper. When one gram of the fuel additive was dissolved in one liter of gasoline at room temperature, the best dissolution rate was about 2 hours. But, almost nothing was dissolved in diesel during 72 hours at $20^{\circ}C$ below zero. At the experiment of ash content, the gasoline which the fuel additive was melted in was showing 28 times more ash content than that was not including the fuel additive. Therefore, it seemed that almost all of ash content was caused by the fuel additive.

• Korean Journal of Food Science and Technology
• /
• v.27 no.3
• /
• pp.313-317
• /
• 1995

Ion exchange process was optimized to purify ultrafiltrated bean cooking water(BCW) for the production of soy-oligosaccharides. The ultrafiltrated BCW with cutoff MW(COMW) 20,000 membrane was treated with various ion exchange resins. Protein and ash were mostly removed by anion and cation exchange resins, respectively. Based upon removing capabilities for ash and protein, a cation exchange resin(SK1B) and an anion exchange resin(WA30) were selected. Protein and ash were more efficiently removed at low extract/resin ratios(ERR), but part of the oligosaccharides were concomitantly lost. When 2-step-ultrafiltrated BCW first with COMW 20,000 membrane and successively with COMW 5,000 membrane was treated with a mixed resin(SK1B : WA30 =1 : 2) at ERR 5.0, most oligosaccharides were recovered in a clear protein- and ash-free liquid.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.2
• /
• pp.102-108
• /
• 2009

DO, ORP and pH values measured during SBR operation can provide information about removal reaction of organic contaminants and nutrient materials in the reactor. It is already generalized control strategy to control reaction phase time using their special patterns indicating the end of the removal reactions. However, those informations are limited to point out the end time of oxidative reaction in the aerobic phase or reductive reaction in the anoxic phase without giving quantitative value of influent loading level. In this research, a diagnosis algorithm which can estimate the loading level of carbon and ammonia as high, medium and low was developed using the basic measurements like DO, ORP, and pH. It will be possible to know the level of influent loading rate from those online measurements without experimental analysis.

• Microbiology and Biotechnology Letters
• /
• v.48 no.4
• /
• pp.525-532
• /
• 2020

A continuous fermentation process was carried out to enhance hyaluronic acid (HA) production using Streptococcus zooepidemicus cells. During the 1st stage continuous operation from 8 h with a dilution rate of 0.029/h (D1), HA was produced in the range of 7.5-10 g/l. During the 2nd stage from 44 h with a dilution rate of 0.036/h (D2), HA production (8.28 g/l) was initially reduced to a small extent due to increase of dilution rate from D1 to D2, and then a new pseudo-steady state was formed within a few hours with a concurrent small variations of HA production. The HA amount produced during the latter part of the 2nd stage was stably maintained in the range of 8.28-9.48 g/l, about 4.7% less amount compared to the 1st stage. Due to 24% increase of dilution rate from D1 to D2, however, maximum volumetric productivity (DP) amounting to 0.341 g/l/h was obtained at 96 h during the 2nd stage. This maximum productivity obtained from the continuous culture turned out only a small increase (3%) as compared to the corresponding batch fermentation. However, it should be noted that, in the case of batch process, one run typically consists of serial stages of growth culture plus one final production culture. This implies that, if the continuous fermentation that practically needs no dead time necessary for the multi-stage growth cultures is run for longer period, the total amount of the accumulated HA would be far greater than the amount obtained from the corresponding batch culture performed for the identical period.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.287-290
• /
• 2000

To examine effects of agitation and aeration as well as adding of glucose and yeast extract on cell growth and polysaccharide production by Paecilomyces japonica, batch culture was carried out at 5L jar fermenter at $27^{\circ}C$ with the initial pH 7 for 7 days cultivation(innoculum size 2%, working volume 3L). Media compositions(g/L) were 30 glucose, 20 yeast extract, 0.5 $KH_2PO_4$, $0.1\;CuCl_2\;{\cdot}\;2H_2O$. Optimum culture conditions of agitation and aeration in batch culture were 400 rpm and 1.0 vvm, resulting in 23.1 g/L biomass and 2.5 g/L polysaccharide. Additional feeding of glucose and yeast extract with a pulse mode conferred an advantage on cell growth and polysaccharide production with showing the results of 29.2 g/L and 3.3 g/L, respectively.

• KSBB Journal
• /
• v.7 no.3
• /
• pp.179-185
• /
• 1992

An anion-charged membrane was used for selective retention of coenzyme NAD(H) in reactor without any chemical modification. The membrane could reject permeation of NAD (H) (80.9%) but not reject permeation of product. The retention ratio was enhanced in the presence of albumin and Tris-maleate buffer. A bioreactor equipped with a membrane, NTR 7410 was constructed and used in the repeated batch production of sorbitol. NADH-dependent sorbitol dehydrogenase from sheep liver was used for the production of sorbitol from fructose. The coenzyme oxidized was regenerated with alcohol dehydrogenase. 47g/L sorbitol was produced for 198 hr with a substrate conversion ratio of 70%. The retention ratio was almost maintained throughout the entire reaction.

• Resources Recycling
• /
• v.11 no.2
• /
• pp.20-27
• /
• 2002

This study was to develop the triboelectrostatic separation technique to recycle the coal from about 20% of mill reject products remained by grinding process in the coal thermoelectric power plant. In this study, we get a test results that can product the cleaned coal of 15% ash content and 66.23% recovery from mill reject of 47% ash content. And then, from the result of the releases analysis, we proved the excellence of treatment method, after showing the treament processing which is able to get 80% of recovery of coal from 20% of ash content demanded in the power plant.