• Title/Summary/Keyword: waste rate

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Effect of Enzymatic Pretreatment on Acid Fermentation of Food Waste (효소 전처리가 음식물 쓰레기의 산발효에 미치는 영향)

  • Kim, H.J.;Kim, S.H.;Choi, Y.G.
    • Journal of Environmental Health Sciences
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    • v.31 no.4 s.85
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    • pp.294-300
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    • 2005
  • Food waste can be a valuable carbon source in biological nutrient removal (BNR) systems because of high C/N and C/P ratios. However, food waste should be pretreated to promote its hydrolysis rate because hydrolysis reaction would be a rate-limiting step. This study investigates the influence of the enzymatic pretreatment on acid fermentation of food waste. Solubilization of particulate matter in food waste by using commercial enzymes was examined. The acidification efficiency and the volatile fatty acids (VFAs) production potential of enzymatically pretreated food waste were also examined. The highest volatile suspended solids (VSS) reduction was obtained with an enzyme mixture ratio of 1:2:1 of carbohydrase:protease:lipase. An optimum enzyme dosage for solubilization of food waste was $0.1\%$(V/V) with the enzyme mixture ratio of 1:2:1. In the acid fermentation of enzymatically pretreated food waste, $0.1\%$(V/V) enzyme mixture dosage for pretreatment result in the maximum VFAs production and the best VFAs fraction in soluble COD(SCOD). The VFAs production at this addition level was 3.3 times higher than that of no-enzyme added fermenter. The dominant VFAs present was n-butyrate followed by acetate.

Evaluation on Resource Recovery Potential by Landfill Gas Production (매립가스 발생량에 따른 자원화 가능성 평가)

  • Lee, Hae-Seung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.10
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    • pp.4679-4688
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    • 2011
  • This study was performed to the municipal waste generation amounts and characteristics for B city in Gangwon province, predicted the methane gas generation rate emitted from landfill, and analyzed the possibility of energy recovery to RDF(Refuse Derived Fuel) using combustible waste. The study results showed that the average bulk density of municipal waste for B city was 144.0 kg/$m^3$, and the average ratios of combustible waste were 36.0 % of paper, 21.6 % of vinyl, and 19.7 % of food waste. respectively. In the experiment for heating value, high and low heating value(moisture) was measured to 3,471 $kca{\ell}$/kg and 2,941 $kca{\ell}$/kg, respectively. After the prohibition of burying of food waste in landfill, the heating value of municipal waste was dramatically increased due to increase of the ratio of paper, vinyl, and plastic waste. The prediction results of methane gas generation rate emitted from landfill showed that the gas generation rate is increasing to 2,505.7 CH4 ton/year in 2021. After then, the rate is decreasing gradually. When the RDF facility is installed, the rate is decreasing after peaking at 1,956.9 CH4 ton/year in 2013. The generation rate of LFG emitted from waste landfill of B city was analyzed to 9.92 $m^3$/min, similar to 10.11 $m^3$/min for other city.

A fundmental Study on Vermistavilization of Foodwaste (Vermistabilization에 의한 음식물쓰레기 처리에 관한 기초연구)

  • 손희정;김형석
    • Journal of environmental and Sanitary engineering
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    • v.15 no.4
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    • pp.91-97
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    • 2000
  • The objective of this study was to evaluate the possiblity of Foodwaste and co-treatment with other waste for vermistabilization. The value of oxidation-reduction potential(Eh) of the dewaterized foodwaste by a plant of subatmospheric evaporation was a possitive(+) value indicating, but the values of pH, salinity was idicating an unfavorable condition for earthworm life. The paper mill mixing waste properties by ripening for 20days were changed into the favorable range for earthworm. The growth of earthworms in foodwaste and mixing waste of paper mill 30% was found to be 68%, 84% for the survival rate, 227%, 275% for the liveweight increasing rate, respectively. The ingestion rate of foodwaste and mixing waste of paper mill 30% indicate 0.72g/g·d, 0.81g/g·d, respectively. About 62∼75% of ingestion amount produce cast and characteristics of cast indicate pH 6.1∼6.5 organic component 34∼42%, salinity 0.35∼0.4, CEC 73∼94 me/100g, N, P, K concentration 0.8∼1.2%, 0.4∼1.6%, 0.43∼0.5% respectively. Therefore it can be evaluated that the casts are good soil condition and organic fertilizer.

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Determination of Forward Dissolution Rate of Glass by a Single-Pass Flow-Through Test (Single-Pass Flow-Through Test방법에 의한 유리의 정용해율 측정)

  • Kim Seung-Soo;Chun Kwan-Sik;Choi Jong-Won;Kim Sung-Ki;Hahn Pil-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.4
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    • pp.335-340
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    • 2005
  • The forward dissolution rate of a borosilicate waste glass was determined as an interlaboratory study(ILS) testing program for the evaluation of precision in the measurement of the dissolution rate or a waste glass using a single-pass flow-through(SPFT) test, whose conducting practice has been written for standardization through American Society for Testing and Materials (ASTM). A simulated low-activity waste glass powder with a size of 100/200 mesh was dissolved by lithium buffer solution (pH=10) at 70? under Ar atmosphere. By plotting the dissolution rates as a function of silicon and boron concentration in eluate, the forward dissolution rate of the glass was obtained as about $2.7\times10^{-5}g{\cdot}m{\cdot}s^{-1}$ in our laboratory.

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Performance Evaluation of Eco-friendly Permeable Block Using Basalt Waste Rock (현무암 폐석을 이용한 친환경 투수블록의 성능평가)

  • Sang-Soo Lee;Hyeong-Soon Kwon;Jae-Hwan Kim
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.4
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    • pp.299-306
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    • 2023
  • Environmental pollution problems are occurring due to the negative treatment of basalt waste in Jeju Island. This study identifies the characteristics of permeable block with basalt with physical and chemical adsorption mechanisms and examines their applicability and functionality as building materials. This experiment is basic data for evaluating the functionality of the permeable block by analyzing flexural strength, compressive strength, permeability coefficient, carbon dioxide, and fine dust adsorption rate by producing a permeable block using a basalt waste rock. As the basalt waste stone replacement rate increased, the flexural strength and compressive strength tended to decrease, and as the replacement rate increased, the water permeability coefficient, absorption rate, carbon dioxide, and fine dust adsorption rate tended to increase. Therefore, it is judged that the permeable block using the basalt waste rock is superior to the existing permeable block.

Anaerobic Hydrogen Fermentation of Food Waste Treated by Food Waste Disposer (주방용 오물분쇄기로 처리된 음식물류 폐기물의 혐기성 수소 발효)

  • Choi, Jae Min;Lee, Chae Young
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.5
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    • pp.468-474
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    • 2014
  • This study was conducted to evaluate the characteristics of mesophilic fermentative $H_2$ production from food waste which was treated by food waste disposer. It was found that $H_2$ yield and lag phase were affected by particle size of food waste. The $H_2$ yield decreased with increasing particle size while lag phase increased. The maximum $H_2$ yield was found $0.584{\pm}0.03$ mol $H_2$/mol hexose at particle size smaller than 0.30 mm. The $H_2$ production rate was also affected by chemical composition of food waste. The $H_2$ production rate linearly decreased with increasing proteins to carbohydrates ratio(P/C ratio) where the maximum value was $0.031{\pm}0.006$ mol $H_2$/mol hexose h at 0.17.

Operating Characteristics of Composting Facility during Composting of Food Waste and Co-composting of Food Waste and Sewage Sludge (음식물쓰레기 단독 퇴비화 및 음식물쓰레기와 하수 슬러지의 혼합 퇴비화에 따른 퇴비화시설의 운전특성)

  • 남궁완;이노섭;박준석;인병훈;허준무;박종안
    • Journal of Environmental Health Sciences
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    • v.28 no.5
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    • pp.86-92
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    • 2002
  • This study was performed to assets the operating characteristics of food waste composting and co-composting (food waste + sewage sludge) at a compelling facility. The facility was being operated successfully without being affected by kind of composting feed materials. Partial anaerobic condition was detected during food waste composting and co-com-posting, but these two composting systems were proven to be operated successfully under aerobic condition from the monitoring results of $O_2$, volatile solids reduction rate, temperature, and other parameters. The conductivity and chloride concentrations of compost were gradually increased during two composting periods, but the conductivity and chloride concentrations of co-compelling indicated lower values than those of food waste composting at final point(40 m). As a result, co-composting was turned out to be more desirable than food waste composting, considering salt problem. High correlations ($R^2$= 0.9265 for food waste composting and $R^2$= 0.9685 for co-composting) between CEC and volatile organic matter were found. Quality of composts produced from two composting process satisfied Korean heavy metal standard.

Food waste treatment using Bacillus species isolated from food wastes and production of air-dried Bacillus cell starters

  • An, Byungryul;Park, Mi-Kyung;Oh, Jun-Hyun
    • Environmental Engineering Research
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    • v.23 no.3
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    • pp.258-264
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    • 2018
  • The objectives of this research were to 1) isolate and identify thermophilic bacteria for food waste treatment; 2) investigate the capability of food waste treatment using Bacillus species; and 3) develop air-dried Bacillus starters for food waste treatment. Five Bacillus species were isolated from food wastes and identified as Bacillus licheniformis (B. licheniformis) G1, Bacillus circulans C2, Bacillus subtilis (B. subtilis) E1, Bacillus vanillea F1, and Bacillus atrophaeus G2 based on 16S rDNA sequencing. Each identified Bacillus and the mixture of Bacillus species were cultivated in the standard food waste at $45^{\circ}C$ for 8 d. Changes in cell count, solid contents, and pH of the food waste were monitored during cultivation. Air-dried Bacillus cell powders were prepared using wheat flour and lactomil as excipients, and the cell count and survival rate were determined. The cell count of B. licheniformis G1 exhibited the highest number among the tested Bacillus (${\sim}10^8CFU/mL$). The greatest reduction in solid contents of food waste was achieved by B. subtilis E1 (22.6%). The mixture of B. licheniformis G1 and B. subtilis E1 exhibited a synergistic effect on the reduction of solid contents. Lactomil was determined as better excipient than wheat flour based on the greatest survival rate of 95%.

Using Coffee-Derived Hard Carbon as a Cost-Effective and Eco-Friendly Anode Material for Li-Ion Batteries

  • Hong, Sung Joo;Kim, Seong Su;Nam, Seunghoon
    • Corrosion Science and Technology
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    • v.20 no.1
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    • pp.15-21
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    • 2021
  • Through a simple filtration process, followed by carbonization within a reductive environment, coffee waste grounds can be transformed into a non-porous hard carbon for use in multiple contexts. This resulting coffee-waste carbon has been evaluated as an eco-friendly and cost-effective replacement for conventional graphite. When compared with different types of carbon, our study found that the coffee-waste carbon fell into the category of hard carbon, as verified from the galvanostatic charge/discharge profiles. The coffee-waste carbon showed a superior rate capability when compared to that of graphite, while compromising smaller capacity at low C rates. During electrochemical reactions, it was also found that the coffee-waste carbon is well exposed to electrolytes, and its disordered characteristic is advantageous for ionic transport which leads to the low tortuosity of Li ions. Finally, the high irreversible capacity (low initial Coulombic efficiency) of the coffee-waste carbon, which if also often observed in amorphous carbon, can be adequately resolved through a solution-based prelithiation process, thereby proving that the coffee-waste carbon material is quite suitable for commercial use as an anode material for quickly-chargeable electrodes.

The characteristics of anaerobic biodegradability by food waste (음식물쓰레기의 혐기성 생분해도 특성)

  • 박남배;길대수;이헌모
    • Journal of environmental and Sanitary engineering
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    • v.16 no.2
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    • pp.24-31
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    • 2001
  • This study was aimed to evaluate biodegradability for various food waste using anaerobic batch digestion. In the anaerobic biodegradability study of each food waste according to occurrence source, the cumulative methane productions of water melon and melon were 375, and 354ml and that of cucumber, fresh cabbage, radish, sprouted bean were 366, 364, 374, 384, 355ml and that of noodle, boiled rice and fish were 432, 409 and 477ml $CH_{4/g}$ VS add, respectively. And methane yield rate was about 84.1~97.2%. The reaction rate coefficiency(k) was $0.00495~0.2022day^{-1}$.

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