• Title/Summary/Keyword: anaerobic

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Anaerobic Biotreatment of Animal Manure - A review of current knowledge and direction for future research -

  • Hong, Jihyung
    • Journal of Animal Environmental Science
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    • v.11 no.2
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    • pp.97-102
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    • 2005
  • Anaerobic decomposition is one of the most common processes in nature and has been extensively used in waste and wastewater treatment for several centuries. New applications and system modifications continue to be adapted making the process either more effective, less expensive, or suited to the particular waste in question and the operation to which it is to be applied. Animal manure is a highly biodegradable organic material and will naturally undergo anaerobic fermentation, resulting in release of noxious odors, such as in manure storage pits. Depending on the presence or absence of oxygen in the manure, biological treatment process may be either aerobic or anaerobic. Under anaerobic conditions, bacteria carry on fermentative metabolisms to break down the complex organic substances into simpler organic acids and then convert them to ultimately formed methane and carbon dioxide. Anaerobic biological systems for animal manure treatment include anaerobic lagoons and anaerobic digesters. Methane and carbon dioxide are the principal end products of controlled anaerobic digestion. These two gases are collectively called biogas. The biogas contains $60\~70\%$ methane and can be used directly as a fuel for heating or electrical power generation. Trace amounts of ammonia and hydrogen sulfide ($100\~300\;ppm$) are always present in the biogas stream. Anaerobic lagoons have found widespread application in the treatment of animal manure because of their low initial costs, ease of operation and convenience of loading by gravity flow from the animal buildings. The main disadvantage is the release of odors from the open surfaces of the lagoons, especially during the spring warm-up or if the lagoons are overloaded. However, if the lagoons are covered and gases are collected, the odor problems can be solved and the methane collected can be used as a fuel. Anaerobic digesters are air-tight, enclosed vessels and are used to digest manure in a well-controlled environment, thus resulting in higher digestion rates and smaller space requirements than anaerobic lagoons. Anaerobic digesters are usually heated and mixed to maximize treatment efficiency and biogas production. The objective of this work was to review a current anaerobic biological treatment of animal manure for effective new technologies in the future.

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Effect of anaerobic digestate on seed germination of perennial ryegrass seeds

  • Byun, Ji Eun;Choi, Min Su;Seo, Un Kab;Ryoo, Jong Won
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.211-211
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    • 2017
  • This experiments were conducted to investigate seed germination to evaluate the influence of anaerobic digestate on seed germination of perennial ryegrass seeds. The study conducted a germination experiment in petri-dishes, using perennial ryegrass seeds. The treatments were compared: non-treated control treated with distilled water, different concentration of anaerobic digestate. The germination percentage of perennial ryegrass seeds was highest in the fermented anaerobic digestate treatment. Root length of perennial ryegrass seeds was long by 4~5cm in the fermented anaerobic digestate with unfermented anaerobic digestate. In the relative root length ratio was by 30% higher in the in the fermented anaerobic digestate with unfermented anaerobic digestate. The germination index of perennial ryegrass seeds was high by 113% in the fermented anaerobic digestate compared to no treatment. The fermented anaerobic digestate have shown stimulatory effects in germination and development of root. Use of fermented anaerobic digestate can be recommended to farmers as a ecofriendly practice for better germination and growth.

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Clinical and Bacteriological Evaluation of the Patients with Anaerobic Bacteria Isolation from Blood (혈액에서 혐기성 세균이 분리된 환자의 임상 및 세균학적 검토)

  • Kim, Jin-Ju;Chong, Yun-Sop;Lee, Samuel Y.
    • The Journal of the Korean Society for Microbiology
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    • v.20 no.1
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    • pp.35-44
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    • 1985
  • Isolation and identification of anaerobic bacteria from blood cultures are still technically demanding procedures. Recently, with the use of gas liquid chromatography, the accuracy of identification is much improved. However, there has never been a satisfactory data analysis on anaerobic bacteremia in Korea. The authors evaluated both the clinical and the bacteriological data of 129 anaerobic bacteremias found at the Yonsei Medical Center during the period of 1973 to 1984. The most frequently isolated anaerobic bacteria were Bacteroides (52.7%), among which the major species was B. fragilis (38.7%). Incidence of anaerobic bacteremia by sex was 57% in male and 43% in female. Mortality was higg in groups below 1-year old and above 50-year old. The cause of death seemed closely correlated with the patient's age, general condition and the severity of the underlying disease. Various neoplasms were the most common (20%) underlying diseases predisposing the anaerobic bacteremia. Biliary tract was considered the most frequent route of infection in anaerobic bacteremia. The frequent clinical signs in anaerobic bacteremia were fever (65%), followed by liver function abnormality (29%), jaundice (20%) and hypotention(18%). When analysis of positive rate of blood culture was made on the patients from whom 4 cultures were done within 24 hours, it was found that 33% of the samples were positive. Isolation rate of anaerobic bacteria in thioglycollate medium was 83.8%, while it was 44% in Tryptic soy broth. Among the anaerobic bacteremia, 25.4% were polymicrobial infections with aerobic bacteria (92.5%), such as E. coli(33.3%). From these studies, it is concluded that B. fragilis is the most important causative organism in anaerobic bacteremia, with high fatality, particularly in those who have underlying diseases. The ports of entry are mainly biliary, gastrointestinal and female genital tract. Fever is the most frequent clinical sign. Single blood culture is not sufficient to detect all anaerobic bacteremia, therefore more cultures with optimal time interval are needed. The incidence of polymicrobial infection in anaerobic bacteremia is higher than that in overall bacteremia.

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In situ Analysis of Methanogenic Bacteria in the Anaerobic Mesophilic and Thermophilic Sludge Digestion (중온 및 고온 혐기성 소화에서 메탄생성균 군집 분석에 관한 연구)

  • Hwang, Sun-Jin;Jang, Hyun-Sup;Eom, Hyoung-Choon;Jang, Kwang-Un
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.4
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    • pp.515-521
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    • 2004
  • Anaerobic digestion has many advantages over the more conventional aerobic treatment processes such as low levels of excess sludge production, low space (area) requirements, and the production of valuable biogas. The purpose of this study was to evaluate the effect of organic loading rate of anaerobic digestion on thermophilic($55^{\circ}C$) and mesophilic($35^{\circ}C$) conditions. Fluorescent in situ hybridization (FISH) method was also used to study the microbial community in the reactors. The stabilizing time in mesophilic anaerobic reactors was shorter as approximately 20 days than 40 days in the thermophilic anaerobic reactors. The amount of methane production rate in anaerobic reactors was independent of the concentrations of supplied substrates and the amount of methanogens. When the microbial diversity in the mesophilic and thermophilic reactors, which had been treated with acetate-based artificial wastewater, were compared, it was found that methanogenesis was carried out by microbial consortia consisting of bacteria and archaea such as methanogens. To investigate the activity of bacterial and archaeal populations in all anaerobic reactors, the amount of acetate was measured. Archaea were predominant in all reactors. Interestingly, Methanothrix-like methanogens appeared in mesophilic anaerobic reactors with high feed substrate concentrations, whereas it was not observed in thermophilic anaerobic reactors.

Biological Treatemnt of Dye Wastewater Using an Anaerobic-Aerobic System (혐기-호기 공정을 이용한 염료페수의 생물학적 처리)

  • 박영식;문정현;안갑환
    • Journal of Environmental Science International
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    • v.11 no.6
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    • pp.569-576
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    • 2002
  • Anaerobic/aerobic reactor system was used to treat a synthetic wastewater with glucose as carbon sources(0.38~2.29 kg COD/m3.day) and Acid Red 14(1.05 "24.00 g Acid Red 141m3.day, color degree of 570 ~ 1710). COD removal efficiency by the anaerobic stage in operation period were above 90 % organic loading rate of 0.38 ~ 2.29 kg COD/m3.day(except, adaptation period) and the removal efficiency of the whole system were above 96 %. The decolorization of the Acid Red 14 was through the alteration of the dye structure(or cleavage of the Azo bond) during the anaerobic treatment. In the A/A system, the anaerobic stage played an essential role in removing both color and COD. In addition it also improves biodegradability of dye f3r further aerobic treatment. After operation, average MLSS concentration of anaerobic sludge reactor, anaerobic fixed-bed reactor and aerobic fixed-bed reactor were 17100mg/L, 20000mg/L, and 10000mg/L, respectively.

Comparative Analysis of Performance and Microbial Characteristics Between High-Solid and Low-Solid Anaerobic Digestion of Sewage Sludge Under Mesophilic Conditions

  • Lu, Qin;Yi, Jing;Yang, Dianhai
    • Journal of Microbiology and Biotechnology
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    • v.26 no.1
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    • pp.110-119
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    • 2016
  • High-solid anaerobic digestion of sewage sludge achieves highly efficient volatile solid reduction, and production of volatile fatty acid (VFA) and methane compared with conventional low-solid anaerobic digestion. In this study, the potential mechanisms of the better performance in high-solid anaerobic digestion of sewage sludge were investigated by using 454 high-throughput pyrosequencing and real-time PCR to analyze the microbial characteristics in sewage sludge fermentation reactors. The results obtained by 454 highthroughput pyrosequencing revealed that the phyla Chloroflexi, Bacteroidetes, and Firmicutes were the dominant functional microorganisms in high-solid and low-solid anaerobic systems. Meanwhile, the real-time PCR assays showed that high-solid anaerobic digestion significantly increased the number of total bacteria, which enhanced the hydrolysis and acidification of sewage sludge. Further study indicated that the number of total archaea (dominated by Methanosarcina) in a high-solid anaerobic fermentation reactor was also higher than that in a low-solid reactor, resulting in higher VFA consumption and methane production. Hence, the increased key bacteria and methanogenic archaea involved in sewage sludge hydrolysis, acidification, and methanogenesis resulted in the better performance of high-solid anaerobic sewage sludge fermentation.

Laboratory Study on the Factors Affecting on Initial Anaerobic Biomass Development (혐기성 부착미생물의 초기성장에 미치는 영향인자에 관한 연구)

  • 허준무;박종안;손부순
    • Journal of environmental and Sanitary engineering
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    • v.13 no.1
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    • pp.185-194
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    • 1998
  • Laboratory-scale investigation into initial anaerobic biofilm development was carried out by circulating mixed liquor from a steady-state anaerobic reactor through silicone tubing and then rerurning the mixed liquor to the reactor. The wall of the silicone tubing was the surface upon which anaerobic biofilm accumulation or development was monitored. Methanogenic bacteria accumulation was monitored by F$_{420}$ fluorescence (picomoles F$_{420}$/cm$^{2}$) of the extracted biofilm material. Biofilm accumulation was measured by the increase in COD of the extracted material ($\mu $g COD/cm$^{2}$). Experiments were conducted for 25 days, and biofilm analyses were performed at 5 days intervals. The results indicated that the initial rates of methangen and anaerobic biofilm accumulation increased with increasing organic loading rate and higher initial rates were observed for 15 days than 15 day liquid HRT or SRT. When the initial rates were plotted against the corresponding mixed liquor volatile suspended solids the difference between the results at the two HRT's became much less significant. Thus, the concentration of mixed liquor volatile suspended solids was found to be a very important parameter affecting initial anaerobic biofilm development. The ratio of methanogens to anaerobic biofilm was also investigated. The results showed that the ratio remained constant through the 25 days of each experiment and for high organic loading rates. Based on the results of this research, a reduction, a reduction of start-up period of anaerobic fixed film reactors might be achieved by maintaining a high organic loading and a large concentration of anaerobic microorganisms in the mixed liquor during the start-up period.

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Developments and future potentials of anaerobic membrane bioreactors (AnMBRs)

  • Visvanathan, Chettiyappan;Abeynayaka, Amila
    • Membrane and Water Treatment
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    • v.3 no.1
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    • pp.1-23
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    • 2012
  • The coupling of anaerobic biological process and membrane separation could provide excellent suspended solids removal and better biomass retention for wastewater treatment. This coupling improves the biological treatment process while allowing for the recovery of energy through biogas. This review gives a basic description of the anaerobic wastewater treatment process, summarizes the state of the art of anaerobic membrane bioreactors (AnMBRs), and describes the current research trends and needs for the development of AnMBRs. The research interest on AnMBR has grown over the conventional anaerobic processes such as upflow anaerobic sludge blanket (UASB). Studies on AnMBRs have developed different reactor configurations to enhance performances. The AnMBR performances have achieved comparable status to other high rate anaerobic reactors. AnMBR is highly suitable for application with thermophilic anaerobic process to enhance performances. Studies indicate that the applications of AnMBR are not only limited to the high strength industrial wastewater treatment, but also for the municipal wastewater treatment. In recent years, there is a significant progress in the membrane fouling studies, which is a major concern in AnMBR application.

Experimental Evaluation of Intermittent Leachate Recirculation Anaerobic System to digest Source from Separated Food Waste (단속식 침출수 순환형 음식물류 폐기물 혐기성 소화 공법에 대한 실험적 특성 파악)

  • Lee, Je-Seung;Lee, Byong-Hi
    • Journal of the Korea Organic Resources Recycling Association
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    • v.22 no.2
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    • pp.57-66
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    • 2014
  • The leachate recirculation anaerobic digestion system has the advantage of stable methane gas generation compared with existing one phase systems. In this study, an anaerobic digestion system fed with source separated food waste from school cafeteria was studied with different food waste/inoculum anaerobic sludge volume ratios (8:2, 3:7, 2:8). From this study, leachate recirculation anaerobic reactor with food waste/inoculum anaerobic sludge volume ratio of 2:8 that is 9 gVS/L of OLR(Organic Loading Rate) had the highest gas production. Also this anaerobic reactor showed daily decrease of H2S and NH3 contents in produced gas. Average biogas yield was 1.395 m3 Biogas/kg VS added. Other anaerobic reactors with food waste/inoculum anaerobic sludge volume ratio of 8:2 and 3:7 stopped methane gas production.

The effects of immune response on maximal aerobic and anaerobic exercise (급성적인 최대 유·무산소 운동이 면역반응에 미치는 영향)

  • Kim, Kwon-Sup
    • Journal of the Korean Society of Industry Convergence
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    • v.5 no.3
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    • pp.269-275
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    • 2002
  • The purpose of this study is to examine the effect of the acute aerobic and anaerobic exercise on immune response. Fourteen university soccer players are sampled and divided into two groups -- one group of seven for aerobic exercise, the other for anaerobic exercise. The one group of aerobic exercise went through the Graded Exercise Test of Bruce protocol, using Treadmill, and were driven to be all-out ; the other of anaerobic exercise took the Wingate Test. Blood the respective periods of rest, post exercise, and recovery for ten minutes. The results are as follows. (1) The acute aerobic and anaerobic exercise don't affect monocyte and granulocyte. (2) The change in lymphocyte and NK cell resulting from the acute aerobic and anaerobic exercise shows a significant differences in the three different periods, but not significant differences between the two groups.

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