• Title/Summary/Keyword: Residue rate

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A Pilot Study for Microfiltration of Alcohol Stillage Condensate and Permeate Recycle to Fermentation Broth (알코홀 증류폐액의 Pilot Scale 정밀여과와 여과액의 발효 재활용에 대한 연구)

  • 김영범;이기세;남궁견;김종현
    • KSBB Journal
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    • v.16 no.4
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    • pp.403-408
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    • 2001
  • Distillation condensate generated from downstream processing of microbial alcohol fermentation imposes a serious burden to biological wastewater treatment or anaerobic digestion due to its high contents of SS (suspended solids) and TN (total nitrogen), A pilot scale microfiltration of the stillage condensate with a stainless steel SCEPTER membrane of 0.1 ${\mu}$m pore size was carried out to remove SS which was mostly composed of microbial cell residue. A stable permeate flux was achieved when the decanter effluent containing 0.7% of SS was filtered under the conditions of X10 VCR (volume concentration ratio), 2.5 bar of TMP (transmembrane pressure), and 60$^{\circ}C$. When stillage condensate with 2.6% SS was treated directly with microfiltration, VCR below X3 was recommended for a long duration of filtration. The permeate and retentate obtained from microfiltration were recycled to make-up medium of fermentation. Adding permeate or retentate up to 30% of fermentation volume showed no distinguished undesirable influence during the course of alcohol fermentation. Although only slight improvements in the final amount of CO$_2$ evolution and alcohol content were observed, fermentation rate increased so that the required time to reach 450 L/ton of CO$_2$ evolution was shortened to 72% of that with normal media.

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Resistance Mechanisms of Green Peach Aphid, Myzus persicae (Homoptera: Aphididae), to Imidacloprid (복숭아혹진딧물(Myzus persicae)의 imidacloprid에 대한 저항성 기작)

  • 최병렬;이시우;유재기
    • Korean journal of applied entomology
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    • v.40 no.3
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    • pp.265-271
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    • 2001
  • Resistance mechanisms in the green peach aphid (Myzus persicae) resistant to imidacloprid were investigated. Imidacloprid residues on the aphid integuments decreased slowly as time passed with no significant difference between the susceptible and resistant strains. Residue in the aphid body increased in both strains with time elapse, and was slightly more in the susceptible strain. A higher metabolic rate of imidacloprid in the resistant strain can be expected by the fact that more amount of imidacloprid were excreted in the resistant strain than in the susceptible one. The activity of AChE was higher 1.4 times in the resistant strain than in the susceptible one, and imidacloprid did not inhibit AChE at all in both strains. Piperonyl butoxide (PBO) and iprobenfos (IBP) synergized imidacloprid activity. The mixtures of imidacloprid and PBO (1 : 1 and 1 : 5) caused 69.4- and 250-fold increase of imidacloprid toxicity against the aphid. Insecticide toxicity of the mixtures of IBP and imidacloprid (1 : 1 and 1 : 5) was also increased 227 and 80.6 times. Esterase activity when $\alpha$-naphtyl butyrate and $\beta$-naphtyl acetate were used as substrates was higher in the resistance strain than in the susceptible one. This means that P450 monooxygenase and esterase are responsible for the resistance to imidacloprid in this aphid strain.

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Effect of Legume Cover Crops and Nitrogen Fertilization Rates on Yield and Nitrogen Use Efficiency of Waxy Corn (Zea mays L.) in No-Tillage System

  • Choi, Jong-Seo;Kim, Min-Tae;Ryu, Jin-Hee;Kim, Kwang Seop;Kim, Sook-Jin;Park, Ki-Do
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.5
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    • pp.531-540
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    • 2016
  • The adoption of legume cover crops in no-tillage system can contribute to improve soil fertility by providing several benefits, including reduction in soil erosion, suppression of weed growth and N supply to subsequent crops. We conducted a field study to investigate the effect of cover crops and nitrogen fertilization rates on yield and nitrogen use efficiency of waxy corn (Zea mays L.) in no-tillage upland field. Two legume cover crops, hairy vetch (Vicia villosa Roth) and crimson clover (Trifolium incarnuturn L.) were mechanically terminated with roller in early June. For each cover crop treatment, nitrogen (N) fertilizer was applied at three different rates (145, 72.5 and $0kg\;N\;ha^{-1}$). The growth and yield characteristics of corn were significantly affected by the N fertilization rates in crimson clover plots, which suggest N mineralization from the cover crop residue was not sufficient. In contrast, N fertilization rates had no significant effect on growth and yield of corn in hairy vetch plots, indicating that the amount of N released from the cover crop is large enough to meet most of the N requirement of corn. However, the application of N fertilizer in hairy vetch cover plots resulted in slight increase of crop yield, though not statically significant, and high levels of N concentration in corn plant tissue possibly due to luxury consumption of N. Organic residues on the soil surface in hairy vetch cover plots had substantial amounts of N after harvest, ranging from 100 to $116kg\;N\;ha^{-1}$, which is presumably retained during winter season and released by microbial mineralization in subsequent year. The highest nitrogen yield efficiency was achieved in the plot with hairy vetch cover and no N fertilizer application, followed by the plot with hairy vetch cover and $72.5kg\;N\;ha^{-1}$ fertilization rate. In conclusion, hairy vetch showed better performance in corn productivity as compared with crimson clover. In addition, it was concluded that the application of N fertilizer between 0 and $72.5kg\;N\;ha^{-1}$ in combination with hairy vetch cover crop might be most efficient for corn yield under no-tillage system with climatic and soil characteristics similar to those of the experimental site.

A Study on the Hydrolysis of p-Nitrophenyl Carboxylates by Micellar Surfactants Catalysts Involving Histidyl Residue (히스티딜기등을 포함하는 미셀성 계면활성제를 촉매로 사용한 파라니트로페닐 에스테르의 가수분해반응에 관한 연구)

  • Won Fae Koo;Choon Pyo Hong
    • Journal of the Korean Chemical Society
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    • v.33 no.1
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    • pp.3-10
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    • 1989
  • In order to obtain a clue in understanding enzymatic hydrolysis in which the His-Cys moieties of papain protease is involved, we prepared cationic peptide-sufactants bearing histidyl, cysteinyl, and both histydyl and cysteinyl residues. Their catalytic efficiency toward the hydrolysis of PNPL were investigated in comicellar phases formed with $N^{+}C_{2}CysC_{12}$, $N^{+}C_{2}HisC_{12}$, $N^{+}C_{2}HisCysC_{12}$ increased markedly in the same order compared with that of $N^{+}C_{2}AlaC_{12}$. The markedly increased catalytic effects are attributed to the imidazole groups of $N^{+}C_{2}HisC_{12}$ and the thiol groups of $N^{+}C_{2}CysC_{12}$, and the large catalytic efficiency of $N^{+}C_{2}HisCysC_{12}$, is considered due to the interaction of the imidazole and the thiol groups. In order to investigate catalytic activities, rate constants for the functional groups, km* and dissociation constants, pKa have been determined. The results showed that $k^{\ast}_m$ and pKa of the imidazole groups were $7.91{\times}10^{-4}S^{-1}$ and 6.49, and those of the thiol groups were $6.00{\times}10^{-4}S^{-1}$ and 10.50. The catalytic effects of comicellar systems on the hydrolysis of p-nitrophenyl esters has increased according to the increasing size of the alkyl carbon number. Therefore, the catalytic effects have been increasing by the interaction of micellar hydrophobic parts and substrates as well as action of the functional groups.

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The Exposure Risk Assessment of Residual Pesticides in Tea (다류에 존재하는 잔류농약 노출 안전성 평가)

  • Kim, Jae-Kwan;Oh, Moon-Seog;Kim, Ki-Yu;Kim, Yeong-Su;Son, Mi-Hee;Bae, Ho-Jung;Kang, Chung-Won;Park, Young-Bok;Yoon, Mi-Hye;Lee, Jong-Bok;Jeong, Ju-Yeon
    • The Korean Journal of Pesticide Science
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    • v.15 no.1
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    • pp.28-35
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    • 2011
  • The investigation of 218 residual pesticides for 19 types of tea (persimmon leaf tea, chrysanthemum tea, green tea, lavender tea, rosemary tea, dandelion leaf tea, puer tea, mulberry leaf tea, hydrangea leaf tea, jasmine tea, nuomixiang tea, buckwheat tea, mugwort tea, lotus leaf tea, oolong tea, longjing tea, rose tea, tiehkwanyin tea and huoguo tea) obtained from markets in Ansan and Suwon was carried out to assess the risk for residual pesticides in tea. The detection rate was 23.1 % (19 samples of total 65 tea samples) and the detected pesticides were 15 pesticides, such as bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon and triazophos. The range of concentrations for the detected residual pesticides was 0.01 to 1.24 mg/kg which showed below their maximum residue limits (MRL), but the residual concentration of bifenthrin in a puer tea showed above the legal limit of 0.3 mg/kg. The result of risk assessment of residual pesticides for the detected 15 samples showed that EDI (estimated daily intake) of the pesticides detected ranged 0.0001~0.0844% of their ADI (acceptable daily intake).

Characteristic of Decomposition of Residual Pesticides on Diazinon and Endosulfan in Young Radish (시설 열무 중 diazinon 및 endosulfan에 대한 잔류농약 분해특성)

  • Choi, Geun-Young;Kim, Jun-Hyoung;Han, Byung-Jae;Jeong, Yang-Mo;Seo, Hye-Young;Shim, Sung-Lye;Kim, Kyong-Su
    • Applied Biological Chemistry
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    • v.47 no.2
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    • pp.238-243
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    • 2004
  • To investigate the changes in content of residual pesticides for safety production of young radishes in the production steps in greenhouse and to evaluate the safety of young radishes in the final consuming step, biological half-life of pesticides (diazinon, endosulfan) in packaging products was studied. Samples were collected regularly from 2 hours to 10 days after the distribution of pesticides in young radishes. The contents of residual pesticides in young radishes during cultivating in greenhouse as the levels of distribution concentrations reduced with time. During 10 days of pesticides distribution, decomposition rate of pesticides were diazinon > endosulfan. A half-life of endosulfan was 0.6 day longer than diazinon because endosulfan derived persistent endosulfan sulfate. To produce the safe young radish, after the distribution of the pesticides the desirable harvest time based on maximum residue limit (MRL) was 6th day diazinon for and 10th day for endosulfan.

Leaching Behavior of Gold from CPU chip Grinding Products in Iodide/Iodine Solution (Iodide/Iodine용액에서 CPU chip 분쇄물의 금 침출특성)

  • Jung, Insang;Joe, Aram;Choi, Joonchul;Song, Youjin;Park, Poongwon;Park, Kyungho;Lee, Sujeong;Park, Jaikoo
    • Resources Recycling
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    • v.25 no.1
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    • pp.3-9
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    • 2016
  • The leaching behavior of gold from waste CPU chip using Iodide/Iodine solution was studied. The direct leaching of gold with Iodide/Iodine solution for CPU chip under the size of 150 mesh showed leaching ratio of 20%. It was assumed that the copper film was produced on the gold particle during grinding process and the copper film prevents lodine/Iodide solution from contacting with leachable gold. Meanwhile, the extraction of gold was improved to 90% by pretreatment process with $HNO_3$ solution. In order to explain the result, EDS and ICP analysis for the leaching residue were conducted. It was found that the copper coated on the surface of the gold particle was removed about 80% by $HNO_3$, resulting in the increment of gold leaching rate.

Determination of residual novobiocin in livestock products and fisheries products by HPLC (HPLC를 이용한 축·수산 식품 중 잔류 노보비오신의 분석)

  • Lee, Byung Kyu;Lee, Cheol-Woo;Lee, Sang-Ju;Jung, Eun Ha;Lim, Hyun Kyun;Han, Sang Beom
    • Analytical Science and Technology
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    • v.20 no.4
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    • pp.347-354
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    • 2007
  • A simple and rapid high-performance liquid chromatography assay for the determination of residual novobiocin levels in bovine, porcine, chicken, flatfish and japanese eel muscle has been developed and validated. The separation condition for HPLC/UV was optimized with phenyl hexyl ($4.6{\times}150mm$, $5{\mu}m$) column with 10 mM monobasic sodium phosphate buffer (pH 2.5)/acetonitrile (50/50, v/v) as the mobile phase at a flow rate of 1.0 mL/min and detection wavelength was set at 254 nm. Residues were extracted from tissue by blending with methanol and lipid materials were removed with n-hexane. Then, the methanol extract was evaporated to dryness under a nitrogen stream, reconstituted in the mobile phase. Aliquot of the organic extract was decanted and filtered through $0.45{\mu}m$ syringe filter. The $20{\mu}L$ of the resulting solution was injected into the HPLC system. The calibration ranges were $0.5{\sim}5{\mu}g/g$ and calibration curves were linear with coefficients of correlation better than 0.95. The limits of quantification were $0.5{\mu}g/g$ for all muscles. The recoveries of bovine, porcine, chicken, flatfish and japaneseel muscles were 99.8%, 102.4%, 91.0%, 104.0% and 93.0%, respectively. The procedures were validated according to the CODEX guideline, determining specificity, linearity, accuracy, precision, quantitation limit and recovery.

Analysis of coenzyme Q10 in human plasma by high performance liquid chromatography (고성능액체크로마토그라피를 이용한 혈장 내 코엔자임 큐텐 분석)

  • Park, Yong-Sun;Park, Sang-Boem;Song, Sean-Mi;Kim, Yong-Woo;Lee, Kyoung-Ryul
    • Analytical Science and Technology
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    • v.22 no.6
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    • pp.514-518
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    • 2009
  • Coenzyme $Q_{10}$($CoQ_{10}$), a vitamin E-like substance, represents a components of the complex antioxidant system of the human organism. $CoQ_{10}$ levels in human plasma were determined by high performance liquid chromatography (HPLC) with UV detection. It was dissociated from lipoproteins by methanol and extracted into n-hexane with liquid-liquid extraction procedure, after centrifugation, the supernatant was dried under nitrogen gas stream. The residue was dissolved in the absolute ethanol. Determination of $CoQ_{10}$ was performed on a $C_{18}$ reversed-phase analytical column with ultraviolet detection at 275 nm and the mobile phase containing 15% (v/v) ethanol in methanol at a flow rate of 1.7 mL/min. The low limit of quantitation was 0.02 mg/L (S/N=10), the linearity between the concentration and peak height is from 0.1 to 2.0 mg/L. Twenty-four randomly selected plasma samples from apparently healthy, 27 to 44 year old individuals (males and females) were analyzed for total $CoQ_{10}$. The average level in these subjects was $0.62{\pm}0.13mg/L$ with the range of 0.41-0.98 mg/L. This method has a specific and a sufficient limit of quantitation (LOQ) for analysis of $CoQ_{10}$ in human plasma in both a clinical study and research at laboratories.

Analysis of Four Pesticides, Isoproturon, Phenmedipham, Pyridate and Nitenpyram Residues by High-Performance Liquid Chromatography with Diode-Array Detector (HPLC를 이용한 Isoproturon, Phenmedipham, Pyridate 및 Nitenpyram 4종 성분의 잔류농약 분석법 개발)

  • Yang, Sung-Yong;Koo, Yun-Chang;Wang, Zeng;Heo, Kyeong;Kim, Hyeong-Kook;An, Eun-Mi;Shin, Han-Seung;Lee, Jin-Won;Lee, Kwang-Won
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.8
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    • pp.1165-1170
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    • 2010
  • A method for the determination of four pesticide compounds, urea (isoproturon), bis-carbamate (phenmedipham), thiocarbamate (pyridate) and vinyllidenediamine (nitenpyram) were examined and analyzed by HPLC with C-18 column ($250\;mm{\times}4.6\;mm$, $5\;{\mu}m$ diameter particle size). Mobile phase consisted of deionized water, acetonitrile and 50 mM $KH_2PO_4$ (pH 2.5). Isoproturon and phenmedipham analytical condition was isocratic elution of the column with 50% solvent A (acetonitrile) and 50% solvent B (deionized water); pyridate was 85% solvent A (acetonitrile) and 15% solvent B (deionized water) at a flow rate of 1 mL/min; and nitenpyram analytical condition was 90% solvent A (50 mM $KH_2PO_4$, pH 2.5) and 10% solvent B (acetonitrile) at a flow rate of 1 mL/min. In results, retention times were 6.12, 8.63, 9.40 and 12.76 min for isoproturon, phenmedipham, pyridate and nitenpyram, respectively. All injection volumes were $10\;{\mu}L$ and the limit of quantitation was 0.05 mg/kg for four pesticide compounds, respectively. Recovery rate test was performed with three farm products, rice, apple and soybean. Four pesticide compounds were spiked at concentrations of 0.05, 0.1 and 0.5 mg/kg. The recovery rates were ranged from 70.18% to 118.08% and the standard deviations of all experiments were within 10%.