• 유기물자원화
• /
• 제12권3호
• /
• pp.76-85
• /
• 2004

폐기물의 혐기성 분해반응은 메탄 발생 및 건강 위해성 등과 같은 악영향을 줄 수 있다. 폐기물을 호기적인 조건에서 분해하는 것은 메탄발생 억제 및 폐기물의 조기 안정화를 촉진하는 것으로 알려져 있다. 본 연구에서는 굴착폐기물을 충전한 모의 매립조를 호기 및 혐기 조건으로 운전함으로써 공기주입이 매립지의 조기안정화에 미치는 영향을 살펴보았다. 본 연구에서는 전주 S 비위생 매립지(매립기간: 1991. 11~1994. 11)에서 폐기물을 굴착하여 시료로 이용하였다. 굴착폐기물은 물리적 조성은 토사류, 비닐/플라스틱류의 난분해성 및 비분해성 물질이 대부분이었다. 호기성 매립조의 발생가스 조성에서 비교적 높은 산소와 이산화탄소 농도가 나타나 미생물에 의한 호기성 분해가 활발하게 일어나고 있는 것을 알 수 있었다. 굴착폐기물의 혐기성 분해는 매우 미미하여 혐기성 매립조에서는 저농도의 $CH_4$ 가스가 발생하였다. 모의매립조의 침출수 pH는 혐기성 매립조 7.7~8.9, 호기성 매립조 7.3~8.5로 약알카리성을 나타내었다. BOD, COD, $NH_4-N$, $NO_3-N$의 농도변화를 관찰해 보았을 때, 굴착폐기물에 공기를 주입하여 호기성 조건을 만들어 주는 것은 유기물의 생물학적 분해를 가속화하여 침출수의 수질 개선에 큰 도움을 주는 것으로 나타났다.

• 청정기술
• /
• 제25권4호
• /
• pp.302-310
• /
• 2019

호기조와 혐기/무산소조를 직렬로 연결한 인공습지를 이용하여 크게 오염된 하천수를 처리하였다. 호기조는 자연 공기 배출 시스템을 통하여 공기가 연속적으로 공급되어 호기성 상태가 유지되었다. 인공습지의 성능에 영향을 미치는 최적의 영향인자를 조사하기 위하여 체류시간을 다르게 한 5개의 파일럿 플랜트를 사용하였다. 호기조에서 BOD (biochemical oxygen demand)와 COD (chemical oxygen demand)의 제거율은 1차 반응 속도식을 나타내었고, COD 제거 속도 상수는 BOD보다 약간 낮았다. 온도 의존성은 COD (θ = 1.0079)와 BOD (θ = 1.0083)제거에 대한 값이 거의 동일했으나 T-N 제거의 온도 의존성(θ_N)은 1.0189로 다소 높게 나타났다. SS제거율은 98%로 높았고 수력학적 부하 속도(Q/A)가 증가함에 따라 제거 효율이 증가하는 경향을 보였다. 혐기/무산소조에서 BOD와 COD 제거의 주요 메커니즘은 호기조와 완전히 다르게 나타났다. 혐기/무산소조에서 COD와 COD는 생물학적 탈질을 위한 탄소원으로 공급되었고 T-P는 혐기/무산소조 내의 orthophosphate와 자갈 사이의 양이온 교환에 의해 제거되는 것으로 조사되었다. 인공습지는 여과된 고형물에 의해 막힘 없이 성공적으로 운영되었고 고형물들은 매우 빠르게 연속적으로 분해되었다.

• Journal of Ginseng Research
• /
• 제19권2호
• /
• pp.93-100
• /
• 1995

This study was undertaken to determine whether administration of a standardized gindeng extract at 300 mg.$d^1$ for 8 weeks could enhance maximum aerobic and anaerobic exercise capabilities and whether any changes of such effects can be occurred when exercise training was added. Forty-one male university students were randomly divided into four groups as ginseng-untrained (GU, n=10), ginseng-trained (GT, n=10), placebo-untrained (PU, n=10), and placebo-trained (PT, n=11). The trained groups underwent 8 weeks of aerobic exercise at 65% of individual's maximum oxygen consumption ($Vo_2$ max) for 30 min.$d^1$, 3d.$wk^1$. Prior to and at the end of experiment, $Vo_2$ max, anaerobic power (AP), anaerobic capacity (AC), and leg muscle strength were determined and some physiological parameters related to $Vo_2$ max were measured. Initially, all subject groups did not differ in average $Vo_2$ max (range 45.9 to 47.9 ml/.kg-1.min-1). After 8 weeks, the $Vo_2$ max increased significantly from the initial level by 12.6% in group GU, 14.5% in group PT, and 24.5% in group GU which was significantly higher than group GU but not group PT. Changes in all measured parameters related to $Vo_2$ max were similar among the subject groups except group PU. Both the AP and the AC were significantly increased in all subject groups (range +3.6 to +13.1% above initial for the AP and +4.4 to) 8.955 above initial for the AC) but the higher changes were found for the AP in groups PT and GU, and for the AC in grouts PT, when compared with group PU. No significant differences in the two anaerobic variables were observed between group GT and the other groups of subjects. Leg strength was also significantly enhanced over group PU in groups PT, GU and GT. There were no significant differences among the latter three subject groups. As a result of these findings, it was concluded that under the conditions of this study ginseng administration at the prescribed dose exhibited the training-like effects on $Vo_2$ max as well as anaerobic power and leg muscle strength but no clear synergistic action on these physical fitness variables occurred when both g inseng administration and exercise training were combined.

• 한국전문물리치료학회지
• /
• 제18권1호
• /
• pp.74-82
• /
• 2011

The purpose of this study was to compare the anaerobic threshold (AT) between subjects with and without non-specific chronic low back pain (NCLBP). The patient group included 15 women with NCLBP. The normal group included 15 women without NCLBP who were age-, height-, weight-, and activity level-matched. The subjects performed a Balke treadmill protocol which was symptom-limited progressive loading test. Their heart rate (HR), ventilatory gas and metabolic equivalents (METs) were measured using the automatic breath gas analyzing system. After the test, each subjects' ratings of perceived exertion (RPE) were evaluated. The visual analog scale (VAS) was assessed pre- and post-test. The independent t-test and Wilcoxon's signed-rank test were used for analysis of the data. Time, HR, the volume of oxygen consumption ($VO_2$), relative $VO_2$, and METs at the AT level of the patient group were significantly lower than those of the healthy group (p<.05). However, there were no significant differences in RPE, VAS, and breathing frequency at the AT level (p>.05). The findings of this study indicate that patients with NCLBP had a lower aerobic fitness than healthy subjects. Thus, implementation of rehabilitation program to increase aerobic fitness may be considered in patietns with NCLBP, and further studies are required to determine the etiological factors of decreased aerobic fitness.

• 미생물학회지
• /
• 제6권2호
• /
• pp.41-53
• /
• 1968

Studies on the carbohydrate metabolism of yeast as influenced by gamma-irradiation from cobalt-60 have been carried, then the mechanisms of radiation effect on respiration and fermentation were discussed under considerations of permeable changes of irradiated cell membrane. The cells of baker's yeast (Saccharomyces cerevisiae) which had been gamma-irradiated of 240 k.r. doses for an hour, then were put into aerobic oxidation and anaerobic fermentation without substrate. Total and fractionated carbohydrates of irradiated yeast cells were determined by calorimetric method with anthrone and orcinol reagents, the amounts of total carbohydrate, trehalose, RNA-ribose, PCA-soluble glycogen, alkali-soluble glycogen, acetic acid-soluble glycogen, mannan and glucan were determined according to the course of aerobic oxidation and anaerobic fermentation. It is found that the carbohydrates of irradiated cells leak out and amount of the losses teaches eleven times more than that of control, the volume of losses are seems to be replaced by water, it can be suggested the damage of gamma-irradiation occurs in the site of passive transport of cell membrane. The endogeneous aerobic respiration of irradiated cells are increased much more than control, the synthesis of reserve glycogen, glucan and RNA-ribose promoted much more than control. The anaerobic fermentation of irradiated cells are also increased than that of control, but the breakdown of carbohydrate is less than endogeneous respiration of irradiated cells. The synthetic rate is also less than that of aerobic oxidation. In irradiated yeast cells, trehalose is revealed to be primary substrate for endogeneous carbohydrate metabolism, so it is proved that the enzymic patterns are not changed but the activities of enzymes relating endogeneous respiration and autofermentation is activated. It is to be considerable to distiguish endogeneous respiration and autofermentation from exogeneous respiration and fermentation on irradiation, for membrane permeability changes and loses out carbohydrate by ionizing radiation.

• 대한환경공학회지
• /
• 제22권5호
• /
• pp.861-867
• /
• 2000

무산소 조건에서의 인섭취를 이용한 질소, 인 화합물의 동시 제거 가능성을 연속회분식반응기(SBR)를 사용하여 고찰하였다. 혐기-호기상의 AO SBR 반응기에 점차적으로 무산소상을 도입함으로써 질산염을 전자수용체로 사용하여 탈질이 가능한 인섭취 미생물들(DPAOs)을 다량으로 축적하였다.(혐기-호기-무산소-호기상의 $(AO)_2$ SBR). 무산소상과 호기상에서의 인섭취율을 비교해 보았을 때, 전체 인제거 미생물 내에서 DPAOs의 비율이 약 10%에서 64%까지 증가하였다. $(AO)_2$ SBR은 안정된 질소, 인제거 성능을 보였으며, 유기물질, 질소, 인 화합물의 제거율은 각각 92%, 88%, 100%였다. $(AO)_2$ SBR의 운전결과와 회분식 실험으로 부터 아질산염은 무산소상에서의 인제거 반응에 어떠한 악영향도 미치지 않으며, 오히려 질산염과 함께 전자 수용체로 사용되어짐을 알 수 있었다.

• 유기물자원화
• /
• 제23권4호
• /
• pp.40-51
• /
• 2015

본 연구에서는 국내 폐기물매립지에서 배출되는 온실가스를 저감하기 위한 호기성 안정화 기술의 적용 가능성을 평가하였다. 대상매립지는 국내 Y 매립지로 LandGEM 모델을 이용하여 메탄 배출량을 산정하였으며, 온실가스 저감량($CO_2eq$)은 혐기성 조건(베이스라인)과 호기성 조건에서의 배출량을 비교하여 산정하였다. 호기성 조건에서의 온실가스 저감은 폐기물매립지 내부로 공기를 주입 시 혐기성에서 호기성으로 전환되면서 부산물로 메탄대신 이산화탄소가 발생되기 때문이다. 평가결과 호기성 안정화 기술은 기존 혐기성 대비 86.6%의 온실가스를 감축하는 것으로 나타났으며, 이는 조기안정화를 통한 주변 환경오염 저감과 동시에 온실가스를 대폭 저감시킬 수 있는 것을 의미한다. 따라서 호기성 안정화 기술은 지속가능한 매립관점에서 보았을 때 국내 폐기물매립지에 적용할 수 있는 가장 적합한 기술 중 하나로 판단된다.

• 산업기술연구
• /
• 제39권1호
• /
• pp.21-25
• /
• 2019

This work experimentally determined the effect of microaerobic condition on anaerobic digestion of thickened waste activated sludge in semi-continuous mesophilic digesters at hydraulic retention time of 20 days. The concentration of hydrogen sulfide was $7{\pm}2ppm$ at the microaerobic condition and $14{\pm}2ppm$ at the anaerobic condition. Removal efficiency of volatile solid was not significantly different between microaerobic ($40{\pm}8%$) and anaerobic ($38{\pm}8%$) conditions. There was no important difference between microaerobic ($1,352{\pm}98ml/d$) and anaerobic ($1,362{\pm}104ml/d$) conditions in the biogas production, either. Therefore, it could be concluded that the application of the microaerobic condition was an efficient method of the hydrogen sulfide removal from the biogas.

• 한국미생물학회:학술대회논문집
• /
• 한국미생물학회 2003년도 International Meeting of the Microbiological Society of Korea
• /
• pp.10-12
• /
• 2003

• 상하수도학회지
• /
• 제18권4호
• /
• pp.515-521
• /
• 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.