• Title, Summary, Keyword: Digestion

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Comparison of Anaerobic Digestion Efficiency with Different Temperature of Food Wastes (음식물류폐기물의 성상별 온도변화에 따른 혐기성소화 효율 비교 연구)

  • Hwang, Kwanghyun;Kim, Dongik
    • Journal of Korean Society on Water Environment
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    • v.35 no.4
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    • pp.332-339
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    • 2019
  • A comparative study on the anaerobic digestion efficiency according to the temperature change was conducted considering the characteristics of domestic food wastes with high water content of about 80 % or more. The substrate was tested for anaerobic digestion efficiency in two substrates, a liquid component separated naturally from food waste and food waste itself. In the anaerobic digestion experiments, the digestion efficiency was the highest at $55^{\circ}C$ (thermophilic temperature). However, the digestion efficiency at $45^{\circ}C$(middle high temperature) was lower than that at $35^{\circ}C$(mesophilic temperature). The comparison of general food wastes anaerobic digestion requiring 30 days of hydraulic retention time to the liquid component indicated a stable digestion efficiency even after 15 days of hydraulic retention time.In the experiments conducted on food waste, the digestion efficiency at $55^{\circ}C$ was higher than that at $35^{\circ}C$. When the food waste, especially the liquid component originating from food waste, is treated by anaerobic digestion method, the mesophilic temperature and thermophilic temperature conditions are more favorable in the digestion efficiency than the middle high temperature ($45^{\circ}C$). However, when applying thermophilic or mesophilic temperature anaerobic digestion process operation in the field, the amount of energy input should be considered.

Mesophilic and Thermophilic Anaerobic Digestion of Swine Manure (中溫및 高溫嫌氣性消化에 의한 豚糞處理)

  • Kim, Nam Cheon;Min, Kyung Sok;Chung, Paul Gene
    • Journal of Environmental Health Sciences
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    • v.10 no.1
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    • pp.107-117
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    • 1984
  • This study was made to evaluate the temperature effects on anaerobic digestion of swine manure. A laboratory single-stage, high-rate, anaerobic digester was operated at 10, 20 and 30 day's HRT at the temperature of 35$\circ$C or 55$\circ$C. The conclusions from this study are as follows: (1) COD and BOD reductions were similar in both the mesophilic and thermophilic digestions. (2) With thermophilic digestion, volatile reduction increased to 67%, as compared with 60% of mesophilic digestion. With thermophilic digestion, the pH increased to 8.5 as compared with 8.0 of mesophilic digestion. With thermophilic digestion, the concentration of volatile acid increased to 763 mg/l, as compared with 250 mg/l of mesophilic digestion. While the gas was produced by mesophilic digestion at 0.74m$^3$/kg of VS fed, it increased to 0.87 m$^3$/kg VS fed by thermophilic digestion. The refractory VS was about 25% of the infiuent VS.

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The Comparision of the Characteristics of Water Quality in Alternative Aerobic-Anoxic and Aerobic Sludge Digestion (선택적인 Aerobic-Anoxic과 Aerobic 슬러지소화에서의 수질특성 비교)

  • Lim, Bong-Su
    • Journal of Korean Society of Water and Wastewater
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    • v.11 no.1
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    • pp.74-80
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    • 1997
  • The objectives of this study were to compare the characteristics of water quality in alternative Aerobic-Anoxic(A/A) and Aerobic(Control) sludge digestion. The A/A process control parameter as the pH signal(dpH/dt) was used. Comparison of the result of A/A digestion with those of Aerobic digestion indicated a 54% saving in aeration compared to Aerobic digestion. TN removal efficiency rates of A/A and Aerobic digestion were 45% and 4%, respectively. The concentration of COD(64 mg/l and 268 mg/l for the A/A and Aerobic digestion, respectively) and Ortho-P in the supernatant were also less with A/A digestion. MLVSS and Coliform destructions were noticed similar for both digestion, but better dewatering charateristics were noted for the A/A digestion.

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Performance Evaluation of Hybrid SBR Aerobic Digestion combined with Ultrasonication by using a Mathematical Model (초음파 결합형 SBR 호기성 소화 모델과 영향 예측)

  • Kim, Sung Hong;Lee, Dong Woo;Kim, Dong Han
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.6
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    • pp.897-905
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    • 2012
  • Based on the activated sludge model, a simple aerobic digestion model which represents the aerobic sludge digestion by sequencing batch reactor(SBR) equipped with ultrasonicator was composed and performed in this study. The results are as follows. Aerobic digestion efficiency can be increased by adopting ultrasonic pretreatment. For the 5 days of SRT, 24 % of particulate component is predicted to be removed by ultrasonic pretreatment and aerobic digestion. This is 7 %p higher than that of conventional aerobic digestion. A Hybrid SBR aerobic digestion combined with ultrasonication shows higher digestion efficiency than aerobic digestion and ultrasonic pretreatment system. In case of this hybrid system, the digestion efficiency was predicted up to 49 % when the ultrasonication was performed every 2 hours, repeatedly. However, excessive treatment like every hours of ultrasonication in an aerobic digestion process results in adverse effect on TCOD removal because biomass disintegrated completely and the solubilized COD can not be used for the biomass synthesis again.

Microwave-assisted Protein Digestion on Various Locations of a Microplate

  • Lee, Ji-Hye;Park, Se-Hwan;Lee, Sun-Young;Hong, Jang-Mi;Park, Kyu-Hwan;Kim, Hyun-Sik;Kim, Jeong-Kwon
    • Mass Spectrometry Letters
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    • v.2 no.4
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    • pp.84-87
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    • 2011
  • The effectiveness of microwave-assisted protein digestion in different well positions of a 96-well microplate was investigated where microwave-assisted protein digestion of bovine serum albumin was performed in 10 different wells of a 96-well microplate in a microwave oven. Similarly increased sequence coverages (~70%) were generally observed for the 10 microwave-assisted protein digestion samples compared to conventional overnight digestion (63%), which is possibly due to higher miscleavage ratios (~53%) of the samples from microwave-assisted protein digestion than conventional overnight digestion (42.1%). The reproducible results of microwave-assisted digestions from different well positions demonstrate the potential of high-throughput analysis of proteins using microwave-assisted protein digestion.

Comparison of Microwave with Conventional Wet-Digestion Methods for the Element Analysis of Plant and Compost (식물체 및 퇴비 성분 분석을 위한 마이크로웨이브 분해법과 기존 습식 분해법의 비교)

  • Nam, Jae-Jak;Cho, Nam-Jun;Jeong, Yee-Guen;Lee, Sang-Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.31 no.3
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    • pp.253-258
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    • 1998
  • To verify the suitability of microwave digestion method for analyzing macro nutrients and metals. K, Ca, Mg, Cu, Zn, and Mn contents in plant and composts were investigated comparing with conventional wet digestion method. Because it takes short time to digest metal samples by using microwave method compared with conventional wet digestion method. Digestion time for metal samples was four to six hours long for wet digestion, while one hour long for microwave digestion. Determinant coefficients of Cu, Mn, Zn, Ca, K, and Mg contents between two analyzing methods were 0.99, 0.99, 0.94. 0.97, 0.98, and 0.91, respectively. In the case of Ca and K, microwave digestion method analyzed their contents relatively low compared with wet digestion method. Meanwhile, microwave digestion method analyzed the contents for Cu, Ma, and Zn relatively high compared with wet digestion method. This study results in that microwave digestion method could be an alternative to replacing conventional wet digestion method.

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Evaluation of Acid Digestion Procedures to Estimate Mineral Contents in Materials from Animal Trials

  • Palma, M.N.N.;Rocha, G.C.;Valadares Filho, S.C.;Detmann, E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.11
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    • pp.1624-1628
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    • 2015
  • Rigorously standardized laboratory protocols are essential for meaningful comparison of data from multiple sites. Considering that interactions of minerals with organic matrices may vary depending on the material nature, there could be peculiar demands for each material with respect to digestion procedure. Acid digestion procedures were evaluated using different nitric to perchloric acid ratios and one- or two-step digestion to estimate the concentration of calcium, phosphorus, magnesium, and zinc in samples of carcass, bone, excreta, concentrate, forage, and feces. Six procedures were evaluated: ratio of nitric to perchloric acid at 2:1, 3:1, and 4:1 v/v in a one- or two-step digestion. There were no direct or interaction effects (p>0.01) of nitric to perchloric acid ratio or number of digestion steps on magnesium and zinc contents. Calcium and phosphorus contents presented a significant (p<0.01) interaction between sample type and nitric to perchloric acid ratio. Digestion solution of 2:1 v/v provided greater (p<0.01) recovery of calcium and phosphorus from bone samples than 3:1 and 4:1 v/v ratio. Different acid ratios did not affect (p>0.01) calcium or phosphorus contents in carcass, excreta, concentrate, forage, and feces. Number of digestion steps did not affect mineral content (p>0.01). Estimated concentration of calcium, phosphorus, magnesium, and zinc in carcass, excreta, concentrated, forage, and feces samples can be performed using digestion solution of nitric to perchloric acid 4:1 v/v in a one-step digestion. However, samples of bones demand a stronger digestion solution to analyze the mineral contents, which is represented by an increased proportion of perchloric acid, being recommended a digestion solution of nitric to perchloric acid 2:1 v/v in a one-step digestion.

Effect of centrifugation on tryptic protein digestion

  • Kim, Soohwan;Kim, Yeoseon;Lee, Dabin;Kim, Inyoung;Paek, Jihyun;Shin, Dongwon;Kim, Jeongkwon
    • Analytical Science and Technology
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    • v.30 no.2
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    • pp.96-101
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    • 2017
  • This study investigated the effect of centrifugation on tryptic digestion. This was done by applying different centrifugation speeds (6,000, 8,000, 10,000, 20,000, and $30,000{\times}g$) over various durations (0, 10, 20, 30, 40, 50, and 60 min) to digest two model proteins - cytochrome c and myoglobin. The intact proteins and resulting peptides were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Centrifugation greatly improved the tryptic digestion efficiency of cytochrome c, where either an increase in centrifugation speed or in digestion duration significantly improved the digestion of cytochrome c. However, centrifugation did not noticeably improve the digestion of myoglobin; 16 h of centrifuge-assisted tryptic digestion at $30,000{\times}g$ barely removed the myoglobin protein peak. Similar results were also obtained when using conventional tryptic digestion with gentle mixing. When acetonitrile (ACN) was added to make 10% ACN buffer solutions, the myoglobin protein peak disappeared after 6 h of digestion using both centrifuge-assisted and conventional tryptic digestions.

Determination of Metallic Elements in Urban Particulate Matter (SRM 1648) by ICP-MS and AAS (ICP-MS와 AAS를 이용한 대기 입자상 표준물질 (SRM 1648) 금속성분의 정량에 관한 연구)

  • Yoo Su-Young;Choi Kum-Chan;Kim Ki-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.4
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    • pp.423-430
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    • 2005
  • This study was investigated with sample digestion techniques and a reliability of the analytical results for a quantitative analysis of a standard reference material ('urban particulate matter', SRM 1648). The metallic elements were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) with closed vessel microwave acid digestion method and atomic absorption spectroscopy (AAS). Quality control of the overall analytical procedures for metallic element determinations of standard reference material were estimated by analysis of a SRM 1648. Three digestion solutions $(type\;1:\;HNO_3,\;type\;2:\;HNO_3\;and\;H2O_2(4'1)\;mixture,\;type\;3:5.55\%\; HNO_3\;and\;16.75\%\;HCI\;mixture)$ were applied to SRM 1648. As a result, three digestion solutions used in this study are completely unable to digest Cr of SRM 1648. Reliability of Cr and As showed some errors in the digestion with digestion solution type (3) due to the influence of chlorides. Type (3) digestion solutions are sufficient to fulfill the digestion of As as well as Se in SRM 1648. ICP-MS results showed the improvement in accurate and precise determination of some trace elements like Cd, V and Pb in SRM 1648. It is important to use the proper digestion solution for each element to qualify analytical precision.

Grain Processing on Feed Efficiency for Beef Production (비육용 곡물사료의 가공방법과 증체효율)

  • 김영길
    • Journal of Life Science
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    • v.5 no.3
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    • pp.126-136
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    • 1995
  • The studies had been conducted to evaluate the grain processing effects for ruminants on starch digestion, body weight gain and feed efficiency since 1970. This research deals with experimental results on chemical structure, gelatinization, microbial starch digestion in rumen, intestinal starch digestion in rumen, roles of protozoa, intestinal starch digestion of bypass starch, limits to starch digestion in small intestine. The grain processing has different effects on digestion, weight gain and feed efficiency when different grain sources and contents is used, and the quality and quantity of roughage is different. The economical and efficient method of grain processing should be selected considering weight gain and feed efficiency enhancement than digestibility.

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