• Title/Summary/Keyword: digestion

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Characteristics of Anaerobic Methane Production by Ultrasonic Treatment of Excess Sludge (잉여슬러지의 초음파 처리에 의한 혐기성 소화에서의 메탄생성 특성 연구)

  • Lee, Jonghak;Jeong, Tae-Young;Roh, Hyun-Seog;Kim, Dongjin
    • Journal of Korean Society on Water Environment
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    • v.26 no.5
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    • pp.810-815
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    • 2010
  • Ultrasonic sludge pre-treatment has been studied to enhance the performance of anaerobic digestion by increasing sludge hydrolysis which is regarded as the rate-limiting-step of anaerobic digestion. In this study, the effect of ultrasonic pre-treatment on sludge hydrolysis (solubilization) and methane production was investigated. Sludge solubilization efficiency increased with ultrasonic energy input. However, it is uneconomical to apply more than 720 kJ/L as the solubilization efficiency per energy input declines afterwards. Volatile fatty acids concentration increased after the ultrasonic sludge hydrolysis. Anaerobic batch digestion showed that methane volume reached 64.7 and 84.5 mL after 18 days of incubation with the control sludge and ultrasonically hydrolyzed sludge, respectively. Methane production potential, maximum methane production rate, and the lag time of modified Gompertz equation were changed from 70 mL, 6.4 mL/day, and 1.2 days to 89 mL, 9.6 mL/day, and 0.5 day, respectively, after the ultrasonic sludge treatment. The results proved that ultrasonic pre-treatment contributed significantly not only for the methane production but also for the reduction of anaerobic digestion time which is critical for the performance of anaerobic sludge digestion.

A Study on the Improvement of Sludge Digestion Efficiency by Solubilization Equipment and Gas Purification System (가용화장치 및 가스정제 설비에 의한 슬러지 소화 효율 향상에 관한 연구)

  • Jang, Seong-Ho;Yi, Pyong-In;Lee, Yong-Dea;Kim, Han-Soo;Cho, Han-Jin;Ryu, Jae-Young;Kim, Sang-Woo
    • Journal of Environmental Science International
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    • v.23 no.5
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    • pp.853-859
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    • 2014
  • The purpose of this study was to improve low digestibility in anaerobic digestion facility of the sewage treatment plant. To perform this research, sludge digestion and digestion gas purification facilities in sewage treatment plant was applied. In the result of this study, it was very effective for sludge reduction from the improvement of digestive efficiency. In addition, it was confirmed that high purity $CH_4$ (methane) was produced. This results can be useful as basic data to improve the low digestibility in anaerobic digestion processes.

Investigation of the Effects of Environment Friendly Digestion Process on the Rice Hull (왕겨의 고도활용을 위한 친환경 고온고압 증해처리 효과)

  • Lee, Young-Ju;Jung, Woong-Ki;Sung, Yong-Joo
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2011.04a
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    • pp.139-150
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    • 2011
  • The effects of the high pressure and the high temperature digesting process with water on the properties of rice hull were investigated in this work. Two temperature condition such as $160^{\circ}C$ and $180^{\circ}C$ and thee treatment time such as 15 min, 30 min and 45 min were applied for this treatment. The pH of extract after the digestion process decreased as the temperature and the treatment time of the digestion were increased. The ash content and lignin content were not decreased by the the digestion. The structure of rice hull after digestion treatment became more weak, the better efficiency of the fiberization with PFI-Mill was shown for the digestion treated rice hull with the higher temperature and the longer treatment time.

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Anaerobic co-digestion of food waste leachate with microalgae for improvement of methane production (메탄생산 향상을 위한 음폐수와 미세조류의 혐기성 통합소화)

  • Lee, Kwanyong;Chantrasakdakul, Phrompol;Kim, Daegi;Park, Jongjin;Choi, Jang-Seung;Park, Ki Young
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.1
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    • pp.55-60
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    • 2014
  • Food waste leachate (FWL) is a serious pollutant waste coming from the food waste recycling facilities in Korea. FWL has a high organic matter content and high COD to nitrogen (COD/N) ratio, which can disturb efficient methane production in the anaerobic digestion of FWL. In the present study a microalga, Clorella vulgaris (C.V), was used as co-substrate for the FWL anaerobic digestion in order to supply nutrients, decrease the COD/N ratio and increase its methane yield. Different co-digestion mixtures (COD/N ratios) were studied by using biochemical methane potential test and modified Gompertz equation for kinetic study. Mixed substrate of FWL and C. vulgaris in the co-digestion clearly showed more the biomethane yield than the sole substrates. The maximum methane production, 827.7 mL-$CH_4$/g-VS added, was obtained for COD/N ratio of 24/1, whereas the highest improvement of methane yield was found for COD/N ratio of 15/1.

The controversial points and a remedy on evaluation of heavy metal contamination in standard method for examination of soil in Korea. (국내 토양오염 공정시험방법중 중금속 관련 오염평가의 문제점과 개선책)

  • 오창환;유연희;이평구;박성원;이영엽
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.298-301
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    • 2000
  • Heavy metals are extracted from stream sediments, roadside soils and sediments and soils and tailings from mining area using partial extraction, acid digestion and HF-digestion. Compared to amounts of heavy metals extracted using partial extraction, those extracted using acid digestion are higher by 2.0∼220.9 times in Cu, 2.4∼2806.1 times in Pb, 1.3∼121 times in Cd, 14.1∼1300885 times in Fe, 1.2∼271.5 times in Mn, 1.3∼372.5 times in Zn, 2.2∼1734.5 times in Cr. Although partial extraction, which extracts less amounts of heavy metals from soil compared to acid digestion, is used in domestic standard method for examination of soil, domestic soil standard for heavy metals in non-agricultural and industrial areas is higher than soil standard in foreign countries which use acid digestion, For improvement of the domestic standard method for assessment of soil, it is suggested to lower the domestic soil standard for heavy metals or to change pretreatment method for extracting heavy metals from partial extraction to acid digestion with modifying the soil standard.

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Improved Detection of Multi-phosphorylated Peptides by LC-MS/MS without Phosphopeptide Enrichment

  • Kim, Suwha;Choi, Hyunwoo;Park, Zee-Yong
    • Molecules and Cells
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    • v.23 no.3
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    • pp.340-348
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    • 2007
  • Although considerable effort has been devoted in the mass spectrometric analysis of phosphorylated peptides, successful identification of multi-phosphorylated peptides in enzymatically digested protein samples still remains challenging. The ionization behavior of multi-phosphorylated peptides appears to be somewhat different from that of mono- or di-phosphorylated peptides. In this study, we demonstrate increased sensitivity of detection of multi-phosphorylated peptides of beta casein without using phosphopeptide enrichment techniques. Proteinase K digestion alone increased the detection limit of beta casein multi-phosphorylated peptides in the LC-MS analysis almost 500 fold, compared to conventional trypsin digestion (~50 pmol). In order to understand this effect, various factors affecting the ionization of phosphopeptides were investigated. Unlike ionizations of phosphopeptides with minor modifications, those of multi-phosphorylated peptides appeared to be subject to effects such as selectively suppressed ionization by more ionizable peptides and decreased ionization efficiency by multi-phosphorylation. The enhanced detection limit of multi-phosphorylated peptides resulting from proteinase K digestion was validated using a complex protein sample, namely a lysate of HEK 293 cells. Compared to trypsin digestion, the numbers of phosphopeptides identified and modification sites per peptide were noticeably increased by proteinase K digestion. Non-specific proteases such as proteinase K and elastase have been used in the past to increase detection of phosphorylation sites but the effectiveness of proteinase K digestion for multi-phosphorylated peptides has not been reported.

Revisit of the Digestion-related Items for Diagnosing Soeumin (소음인 진단지표로서 소화 관련 항목에 대한 고찰 - 음식불선화는 소음인의 진단지표인가)

  • Kim, Sang-Hyuk
    • Journal of Sasang Constitutional Medicine
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    • v.34 no.2
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    • pp.15-35
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    • 2022
  • Objectives Recent studies have reported that the digestion-related items contribute significantly to the diagnosis of constitution, though these were not described as the indicator for diagnosing Sasang constitution in 『Donguisusebowon(東醫壽世保元)』 「Sasanginbyeonjeunglon(四象人辨證論)」. The purpose of this study was to explore the reasons why such a gap appeared. Methods The digestion-related items and their rationales to be shown in eleven studies on the Questionnaire for Sasang Constitution Diagnosis were reviewed. Thirty primary studies included in two systematic reviews were also reviewed to reconsider the significance of digestion-related items as an indicator for diagnosing Soeumin. Results & Conclusions A few pathways were found in studies on the Questionnaire for Sasang Constitution Diagnosis, which could overestimate the significance of digestion-related items more than actual. Besides, in the primary studies included in two systematic reviews, there was also a possibility of overestimating the importance of digestion-related items due to some biases in the selection of subjects and the conducting of the study. Therefore, there might be room for reconsideration that indigestion was necessarily an indicator for diagnosing Soeumin.

A Strength on the Properties of Non-Cement Mortar containing Rice Husk Powder extracted from Digestion (증해 추출 왕겨 분말을 혼입한 무시멘트 모르타르의 강도 특성)

  • Cho, Sung-Eun;Cho, Sung-Won;Kim, Young-Su
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.225-226
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    • 2021
  • Recently, environmental problems have emerged as a major issue all over the world due to an increase in carbon dioxide(CO2). The amount of CO2 generated during cement production accounts for 6% to 8% of domestic CO2 emissions and a solution to reduce CO2 emissions the construction industry is trying to use mineral admixtures to reduce cement. Since digestion has no firing process the advantage of it is that there is no air pollution to occur. In this study, we studied the compressive strength of binary non-cement mortar containing rice husk powder extracted from digestion by the ratio of 10%, 20%, 30%, 40%. As a result, the table flow was increased when the mixing rate of rice husk powder extracted from digestion was higher, and the highest compressive strength was shown when the rice husk powder extracted from digestion mixing rate was 10%.

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Effect of Replacing Corn and Wheat Bran With Soyhulls in Lactation Cow Diets on In Situ Digestion Characteristics of Dietary Dry Matter and Fiber and Lactation Performance

  • Meng, Qingxiang;Lu, Lin;Min, Xiaomei;McKinnon, P.J.;Xiong, Yiqiang
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.12
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    • pp.1691-1698
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    • 2000
  • An in situ digestion trial (Experiment 1) and a lactation trial (Experiment 2) were conducted to determine the effects of replacing corn and wheat bran with soyhulls (SH) in lactating dairy cow diets on the extent and kinetics of digestion of DM and NDF, and lactation performance. In experiment 1, five mixed feeds consisting of mixed concentrate and roughages (50:50 on a DM basis) were formulated on isonitrogenous and isoenergetic bases to produce five levels (0, 25, 50, 75 and 100%) of SH replacement for corn and wheat bran. SH had high in situ digestion (92 and 89% for potentially digestible DM and NDF) and fairly fast digestion rate (7.2 and 6.3 %/h for DM and NDF). Increasing level of SH replacement resulted in increased NDF digestibility (linear, p=0.001-0.04) and similar DM digestibility (beyond 12 h incubation, p=0.10-0.41). As level of SH replacement increased, percentage of slowly digestible fraction (b) of DM increased (linear, p=0.03), percentage of rapidly digestible fraction (a) of DM tended to decrease (linear, p=0.14), and DM digestion lag time tended to be longer (linear, p=0.13). Percentage of potentially digestible fraction (a+b) and digestion rate (c) of slowly digestible fraction of dietary DM remained unaltered (p=0.36-0.90) with increasing SH in the diet. Increasing level of SH for replacing corn and wheat bran in the diet resulted in increases in percentages of b (quadratic, p<0.001), a (linear, p=0.08), a+b (quadratic, p=0.001) and a tendency to increase in c for NDF (linear, p<0.19). It was also observed that there was a satisfactory fit of a non-linear regression model to NDF digestion data ($R^2=0.986-0.998$), but a relatively poor fit of the model to DM digestion data ($R^2=0.915-0.968$). In experiment 2, 42 lactating Holstein cows were used in a randomized complete block design. SH replaced corn and wheat bran in mixed concentrates at 0, 25, and 50%, respectively. These mixed concentrates were mixed with roughages and fed ad libitum as complete diets. Replacing corn and wheat bran with SH at 0, 25 and 50% levels did not influence (p=0.56-0.95) DM intakes (18.4, 18.6, and 18.5 kg/d), milk yields (27.7, 28.4 and 27.6 kg/d), 4% fat-corrected-milk (FCM) yields (26.2, 27.6, and 27.3 kg/d) and percentages of milk protein (3.12, 3.17 and 3.18%), milk lactose (4.69, 4.76 and 4.68%) and SNF (8.50, 8.64, and 8.54%). On the other hand, milk fat percentges linearly increased (3.63, 3.85 and 3.90% for SH replacement rates of 0, 25 and 50% in the diet, p=0.08), while feed costs per kg FCM production were reduced.

Analysis of Nutrient Content by Digestion Phase of Legumes using an In Vitro Digestion Model (In Vitro Digestion Model을 활용한 두류 소화 단계별 영양성분 변화 분석)

  • Da Bin Lee;Kyeong A Jang;In Seon Hwang;Min Sook Kang;Mi-Kyung Seo;Haeng Ran Kim;Seon Mi Yoo
    • The Korean Journal of Food And Nutrition
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    • v.36 no.5
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    • pp.368-378
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    • 2023
  • Changes in contents of free sugars, amino acids, and fatty acids of legumes were analyzed for each phase of in vitro digestion. In addition, contents of resistant starch in raw and digested pulses were compared. Soybeans, kidney beans, cowpeas, and chickpeas were analyzed. An in vitro digestion model was used to analyze contents of nutrients using LC-MS and GC-MS. Stachyose in kidneybean, cowpea, and chickpea increased as the digestion phase progressed. In four types of legumes, raffinose slightly decreased or showed no significant difference between the Oral phase and the BBMV phase. Content of glucose, a monosaccharide, increased during the BBMV phase. During the digestion phase, levels of free amino acids and free fatty acids also increased. Content of resistant starch was reduced compared to that in the raw material. It was 0.01g/100 g food in soybean, 1.06 g/100 g food in red kidney bean, 0.77g/ 100g food in cowpea, and 0.76 g/100 g food in chickpea. It was confirmed that nutrients in the in vitro digestion model were liberated at each digestion phase with changes in the content of resistant starch. These results are expected to be used as fundamental data for obtaining bioavailability of nutrients.