• Title, Summary, Keyword: Digestion

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Correlation of Heavy Metal Concentrations between Total Digestion and Aqua Regia Digestion for Sediments from Yeongsan and Seomjin Watersheds (완전분해와 전분해 방법에 의한 영산강.섬진강수계 퇴적물의 중금속농도 상관관계)

  • Oh, Da-Yeon;Choi, Kyoung-Kyoon;Huh, In-Ae;Hwang, In-Seong;Kim, Young-Hoon;Hur, Jin;Shin, Hyun-Sang;Oh, Jeong-Eun;Shin, Won-Sik;Park, Jeong-Hun
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.1
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    • pp.32-38
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    • 2011
  • In this study, the correlations of concentrations in sediment heavy metals between two pretreatment methods, total digestion and aqua regia digestion, have been investigated. Total 43 samples had been collected from streams and lakes in Yeongsan and Seomjin watersheds. They were decomposed in two pretreatment methods and five metal components (Cd, Cr, Ni, Pb, Zn) were analyzed. Overall average concentrations of heavy metals were Zn>Cr>Pb>Ni>Cd in the order. The concentrations of aqua regia digestion were 35.0% (Cd), 53.8% (Cr), 66.2% (Ni), 64.4% (Pb) and 76.4% (Zn) of the concentrations of total digestion and heavy metal concentrations of total digestion were higher. Heavy metal concentrations in sediments from lakes were higher than those from streams. The correlation equations between the concentrations of total digestion and aqua regia digestion were obtained. The concentrations of Zn and Ni, which showed strong linear correlations, increased in aqua regia digestion as the concentration in total digestion increased. The linear correlation coefficients between two digestion methods for most analyzed metals were above the average correlation. However, these results can be applied with limitations due to heterogeneity of sediments.

Automated On-Line Digestion System for the Determination of Total Phosphorus (총 인 분석을 위한 자동 전처리 시스템)

  • 정형근;조영일;김범식;박주형
    • Journal of Environmental Science International
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    • v.10 no.1
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    • pp.13-19
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    • 2001
  • An on-line digestion system based on the flow injection analysis technique was presented for the determination of total phosphorus. The system converts condensed and organic phosphoruses into orthophosphate that can be analyzed spectrophotometically. The reaction between orthophosphate and ammonium molybdate in a strong acid medium forms the yellow complex of phosphomolybdate which is next reduced to a molybdic blue complex by stannous chloride. The quantitation of orthophosphate is based on the absorbance of the molybdic blue. To determine total phosphorus, the digestion system was installed between the sample injector and the reaction coil with the added lines of digestion solution(potassium persulfate+sulfuric acid) and the $H_2O$ carrier. The system has shown that the digestion efficiencies were greater than 95% for the typical condensed and organic phosphoruses. When tripolyphosphate standards were used, the calibration data showed that the linear dynamic range extended to a concentration of 1.5ppm with the detection limit of 25ppb total phosphorus. The typical relative standard deviation was less than 2%. The proposed system was successfully applied to lake water, wastewater, and streamwater. The analytical variables such as digestion efficiency, analysis time, and reproducibility were evaluated and compared with the manual digestion method.

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Co-digestion of Thermophilic Acid-fermented Food Wastes and Sewage Sludge (음식물찌꺼기 고온산발효산물과 하수슬러지의 혼합처리)

  • Ahn, Chul-Woo;Jang, Seong-Ho;Park, Jin-Sik
    • Journal of Environmental Science International
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    • v.15 no.9
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    • pp.897-905
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    • 2006
  • This study has been conducted to investigate biodegradation characteristics and optimum mixing ratio for co-digestion with thermophilic acid-fermented food waste and sewage sludge using batch anaerobic digester. As the basis operating conditions for anaerobic digestion, the reaction temperature was controlled $35{\pm}1^{\circ}C$ and stirrer was set 70rpm. Thermophilic acid-fermented food waste and sewage sludge were mixed at the ratio of 10:0, 7:3, 5:5, 3:7, 0:10 and 5;5(food waste : sewage sludge) as the influent substrates. In results of co-digestion according to mixing ratio of thermophilic fermented food wastes and sewage sludge in batch mesophilic anaerobic digestion reactor, $385mL\;CH_4/g\;VS_{added}$ of methane production rate at 1:1 mixing ratio was more than that of any other mixing ratios. Compared with $293mL\;CH_4/g\;VS_{added}$ of methane production rate at 1:1 mixing ratio of food wastes and sewage sludge, pretreatment of food wastes by thermophilic acid fermentation was more effective in co-digestion with sewage sludge.

A Study on the Conditioning with Polymer and the Particle Size Distribution of Intermittent Aerobic Digestion Sludge (간헐포기 소화 슬러지의 고분자 응집제에 의한 개량과 입도 분포 변화에 관한 연구)

  • Kim, Hee-Jun;Kim, Seong-Hong;Choi, Jae-Seong
    • Journal of Environmental Health Sciences
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    • v.30 no.3
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    • pp.253-258
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    • 2004
  • Synthetic organic polyelectrolytes can be used to condition sludges to enhance their dewaterability. Intermittent aerobic digestion is an useful digestion technology and has many advantages like neutral pH, low installation cost and easiness to operation. The objectives of this study were to investigate the dewaterability of intemittent aerobic digestion sludge and to find the relationship between dewaterability and particle size distribution change under the conditioning of intermittent aerobic digestion sludge by cationic polyelectrolyte. Digested sludge from intermittent aerobic digestion was used and cationic polyacrylamide polymer was added as a conditioner. CST(capillary suction time), TTF(time-to-filtration) were tested as a dewaterability index and the number of particle distribution was analyzed using particle size analyzer. The results indicate that cationic polyelectrolytes is useful to enhance dewaterability of intermittent aerobic digestion sludge. Mean particle diameter was increased as polymer dosage increased and its value was reached up to 100 mm on the condition of optimal cationic polymer dosage. CST and TTF are well correlated with mean particle diameter when the weighting order is 1.7. By the optimal conditioning with cationic polymer, particles in the filtrate are also reduced significantly and this means that conditioning is helpful to main stream by reducing SS loading from return flow.

Antioxidative Changes of Blueberry Leaf Extracts in Emulsion-Type Sausage during In Vitro Digestion

  • Hur, Sun-Jin;Kim, Doo-Hwan;Chun, Se-Chul;Lee, Si-Kyung
    • Food Science of Animal Resources
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    • v.33 no.6
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    • pp.689-695
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    • 2013
  • This study was conducted to investigate the effects of in vitro human digestion on the antioxidant activity of blueberry leaf extracts (BLE) in emulsion-type sausages (ETS). Leaves from four cultivars of blueberries (Bluecrop, Bluegold, Duke, and Northland) collected from a wild blueberry farm were extracted with 80% ethanol. ETS were prepared with 0.2% BLE. The samples were then passed through an in vitro human digestion system which simulates the composition of the mouth, stomach, and small intestine juice. Only one phenolic compound (chlorogenic acid) was detected in the BLE. Northland BLE had appreciably higher amounts of chlorogenic acid than that of other BLE, both before and after in vitro human digestion. Antioxidant activity of any BLE was not influenced by in vitro human digestion, whereas the antioxidant activity of chlorogenic acid standard increased in response to in vitro human digestion in both 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric-reducing ability of plasma (FRAP). In the present study, the antioxidant activities of the BLE were not strongly influenced by in vitro human digestion, and the antioxidant activity depended on the chlorogenic acid content of ETS. Thus, compounds from blueberry leaves may have important applications in the future as natural antioxidants for meat products.

Digestion of settleable solids from recirculating fish tank as nutrients source for the microalga Scenedesmus sp. cultivation

  • Rotthong, Maneechotiros;Chiemchaisri, Wilai;Tapaneeyaworawong, Paveena;Powtongsook, Sorawit
    • Environmental Engineering Research
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    • v.20 no.4
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    • pp.377-382
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    • 2015
  • The high concentration of nitrogen and phosphorus in wastewater incorporated with the ability to use carbon dioxide as the carbon source make the microalgae become more attractive in wastewater treatment process. This study evaluates the optimal conditions for the digestion of settelable solids from the recirculating aquaculture system to produce the biomass of the green microalga Scenedesmus sp. After solids separation, aerobic digestion of settleable solids under disperse condition produced nitrate as the final product of consequently ammonification and nitrification processes. With the optimal digestion procedure, nitrate concentration during aerobic digestion in 2000 mL vessel increased from $9.63{\pm}0.65mg\;N/L$ to $58.66{\pm}0.06mg\;N/L$ in 10 days. Thereafter, cultivation of Scenedesmus sp. was performed in 1000 mL Duran bottle with air bubbling. The highest Scenedesmus sp. specific growth rate of $0.321{\pm}0.01/d$ was obtained in treatment using liquid fraction after aerobic digestion as the whole culture medium for Scenedesmus sp. cultivation. With this study, digestion of $8,800{\pm}128.12mg\;dry\;weight/L$ of settleable solids from fish pond finally produced $1,235{\pm}21mg\;dry\;weight/L$ of Scenedesmus sp. biomass.

Ultrasonic Pretreatment for Thermophilic Aerobic Digestion in Industrial Waste Activated Sludge Treatment

  • Kim, Young-Kee;Kwak, Myung-Shin;Lee, Won-Hong;Park, Jeong-Woo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.6
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    • pp.469-474
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    • 2000
  • In order to enhance the degradation efficiency of waste activated sludge (WAS) by thermophilic aerobic digestion, an ultrasonic pretreatment was examined. It was observed that ultrasonic pretreatment increased the solubilization of organic matter in the WAS and that the solubilization ratio of the organics increased during the first 30 min but did not extensively increase thereafter. Therefore, a pretreatment time of 30 min was determined to be the economical pretreatment time from the experimental results. From the digestion experiments, which was conducted using the WAS collected from an oil refinery plant in Inchon, Korea, investigating the effects of an ultrasonic pretreatment on thermophilic aerobic digestion, it was confirmed that the proposed ultrasonic pretreatment was effective at enhancing the release of the cellular components in WAS and the degradation of released components in the thermophilic aerobic digestion.

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Development of Continuous Flow Microwave Digestion Procedures for Analysis of Trace Metal in Water Using Ion Chromatography

  • Youn Doo Kim;Gae Ho Lee;Hyung Seung Kim;Dong Soo Kim;Kwang Kyu Park
    • Bulletin of the Korean Chemical Society
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    • v.15 no.9
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    • pp.786-791
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    • 1994
  • A simple and rapid sample pretreatment process necessary for determination of metal oxides in water was proposed. Samples were injected into the continuous-flow tube installed inside the microwave oven and the treated samples were cooled before entered to the Ion Chromatography (IC) or Inductively Coupled Plasma (ICP). By coupling this microwave digestion system with IC or ICP, a fully automatic analytical procedures may be easily established. In this study, two different types of digestion methods were considered; the open tubing method (OTM) and the restraint tubing method (RTM). The RTM was proved to be 3 times faster in digestion period and 10 times higher in detection range than the OTM. Validation of proposed sample digestion system was carried out by using an ICP. The results showed that both of continuous-flow methods, the OTM and the RTM were comparable in accuracies with the conventional batch-type vessel digestion method.

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Aerobic and Anaerobic Digestion of Swine Manure (好氣性 및 嫌氣性 消化에 의한 豚糞處理)

  • Kim, Nam Cheon;Min,, Dal Ki
    • Journal of Environmental Health Sciences
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    • v.14 no.2
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    • pp.43-49
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    • 1988
  • This study was conducted to evaluate the organic removal efficiencies and sludge production in aerobic and anaerobic digestion of swine manure. A laboratory single-stage, high-rate, anaerobic digester was operated at 5, 10, 25 and 30 day's HRT at the temperature of 35$\circ$C, and also aerobic digester operated at 10, 20 and 28.6 day's HRT at the temperature of 20$\circ$C. The conclusions from this study are as follows: 1. While the BOD removal efficiency by anaerobic digestion was 30 to 75%, it was 99% over by aerobic digestion. 2. The sludge production was similar in both aerobic and anaerobic digestion. 3. The gas production was 0.21 to 0.55 m$^3$/kg VS fed by anaerobic digestion.

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A Study on the Treatment of Distillery Wastewater by Single-phase and Two-phase Anaerobic Digestion (단상(單相) 및 2상(相) 혐기성(嫌氣性) 소화(消化)에 의한 주정폐수(酒精廢水) 처리(處理)에 관한 연구(硏究))

  • Choung, Young Kyoo;Rah, Seung Woo;Park, Joon Hwan
    • Journal of Korean Society of Water and Wastewater
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    • v.7 no.1
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    • pp.5-12
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    • 1993
  • The objectives of this paper are to present data to illustrate how an advanced digestion process, two-phase digestion, can provide superior performance in terms of waste stabilization efficiency and net energy recovery. As the result, it is possible to separate enrichment cultures of acidogenic and methanogenic organisms in isolated environments by kinetic control involving manipulation of dilution rates. In single-phase digestion process, HRT and COD loading for effective operation were 14.29 days and 2.33kg $COD/m^3$ day, but two-phase digestion may be conducted efficiently at 7 days of HRT and 5.71kg $COD/m^3$ day of loading. Data from this studies showed that the two-phase process is better than single-phase digestion under all test conditions when compared on the bases of gas yield and production rate, reductions of COD and VS, buffer capacity, and unconverted volatile acids in the effluent.

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