• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.251-255
• /
• 2008

Biogas plant was started in 2007 for the purpose of treatment of $20m^3$/d of wastewater from piggery farm, biogas-production and electricity generation during treatment of the wastewater. The biogas plant is consists of two anaerobic digesters, gas holder and 60 kWe generator. $62,287m^3$ of biogas was produced and 74,745kWh electricity was generated by using the biogas after commencing the biogas plant.

• Journal of Korean Society on Water Environment
• /
• v.29 no.6
• /
• pp.808-812
• /
• 2013

A new type of microbial fuel cell (MFC) with anaerobic membrane filter was designed to produce bioelectricity and to treat domestic sewage at relatively high organic loading rate (OLR) of $6.25kgCOD/m^3/day$ and short hydraulic retention time (HRT) of 1.9 h. A following aeration system was applied to ensure effluent water quality in continuous operation. Glucose was supplemented to increase the influent concentration of domestic sewage. Influent substrate of 95% was removed via the MFC and following aeration system and the corresponding maximum power density was $25.6mW/m^3$. External resistor of $200{\Omega}$ and air-cathode system contributed better MFC performance comparing to $2000{\Omega}$ and dissolved oxygen as a catholyte.

• Journal of Digital Policy
• /
• v.1 no.1
• /
• pp.7-13
• /
• 2022

The purpose of this study was to investigated the effect of taping intervention applied to the diaphragm on the anaerobic performance in 30 seconds. 18 healthy college students were randomly divided into experimental group(KT=9) and control group(Sham=9). In both groups, pre and post measurement was performed by wingate test, and post measurement was performed with taping application after a week rest. The statistics between two groups on the rate of change pre and post were analyzed through Mann-Whitney U test. Statistically, it showed that only the average power(AP) of control group was significantly different. This means that diaphragmatic taping did not affect the performance of anaerobic exercise for 30 seconds. However, considering the increase in aerobic metabolism during long-term anaerobic exercise longer than 30 seconds, further studies on anaerobic exercise performance within various time ranges are needed.

• Environmental Engineering Research
• /
• v.11 no.3
• /
• pp.143-148
• /
• 2006

The ultrasonics is a new technology in waste activated sludge(WAS) treatment. Ultrasonic treatment is well known method for the break up of microbial cells to extract out a variety of intercellular materials inside microorganism cell. This study was done to investigate the effects of the ultrasonic frequency and power on disruption of biosolids in WAS and to examine the effect on methane production of WAS treated by ultrasonics. Biosolids disruption with ultrasound is more effective at ultrasonic frequency of 40 kHz and power of 0.3 watt/mL. In the digestion with WAS pretreated by sonication time for 10 minute at 40 kHz and 0.3 watt/mL, the total quantity of generated methane increased by 75%, as compared with experimental control(non-treatment).

• Proceedings of the Korea Contents Association Conference
• /
• 2005.05a
• /
• pp.191-200
• /
• 2005

The main purpose of the present study was to find the effect of short term creating loading on repeated bouts of kicking, plasma creating phosphokinase and anaerobic power in male taekwondo player from high school. Sixteen male were randomly assigned to two groups. They were tested before and after 6 days of placebo$(4{\times}5g\;glucose\;d^{-1},\;N=11)$ or Creatine monohydrate loading$(consume\;0.3g\;kg^{-1},\;N=11)$. Repeated bouts of kicking was tested through maximal front kicking continuously for 1 minute and took a rest for 30 seconds, after 30 seconds rest they should have to start kicking again. They repeated it 2 times more(total 3 sets) and the kicking times were measured each sets. Also, body composition, CPK, mean power and peak power were measured before and after experiment. The following results were obtained from this study; 1. The kicking test was significantly increased at 1, 2, 3 sets only in creatine loading group(p<.05, p<.01). 2. Only creatine loading group was significantly increased of plasma creatine phosphokinase(p<.01). 3. Only creatine loading group were significantly increased both of mean power and peak power(p<.05; p<.01). These results suggest that short creatine loading was effective diet protocol in taekwondo player from male high school.

• Journal of Korean Society on Water Environment
• /
• v.22 no.3
• /
• pp.540-545
• /
• 2006

The anaerobic digester supernatant (ADS) with high $NH_4-N$ concentration often results in a $NH_4-N$ overloading to the mainstream process of municipal wastewater treatment plant (MWTP). The nitrogen removal from the ADS is therefore important in order to achieve a stable mainstream process performance as well as to prevent $NH_4-N$ overloading due to ADS. Recently because of several advantages compared to the full nitrification, many works have shown interests in controlling the build-up of $NO_2-N$ in nitritation processes. The application of nitritation could save the aeration power compared to the full nitrification processes. In addition, the denitrification of $NO_2-N$ could reduce organic carbon requirements compared to the $NO_3-N$ denitrification. The purpose of this research was to find out the characteristics of the ADS nitritation and $NO_2-N$ accumulating factors from the laboratory reactor study. As a result based on the long-term laboratory experiment, it can be concluded that the degree of nitritation was closely related with the availability of alkalinity, free ammonia (FA), solid retention time (SRT) and solid concentration in the nitritation reactor.

• Journal of Korean Society on Water Environment
• /
• v.26 no.5
• /
• pp.754-760
• /
• 2010

This study was carried out not only to evaluate optimal operating condition to increase biogas production, but also to estimate feasibility of renewable energy from anaerobic digester of sewage sludge. Semi- continuous Fed and Mixed Reactors (SCFMRs) were operated in various condition to quantify the reactor variables. The result of SCFMR operation showed that the biogas productivity and total volatile solids (TVS) removal of total solids (TS) 4% reactor at hydraulic retention time (HRT) 20 days with Organic Loading Rate (OLR) of $1.45kg/m^3-d$ were $0.39m^3/m^3-d$ and 26.7%, respectively which was two times higher than that of TS 2.5% reactor. Consequently the daily biogas production of $20,000m^3$ would be possible from the total volume of $52,000m^3$ of anaerobic digesters of the municipal wastewater treatment plant in D city. In feasibility study for the Biogas utilization, combined heat and power system (CHP) and CNG gasification were examined. In case of CHP, the withdrawal period of capital cost for gas-engine (GE) and micro gas-turbine (MGT) were 7.7 years and 9.1 years respectively. biogas utilization as Clean Natural Gas (CNG) shows lower capital cost and higher profit than that of CHP system. CNG gasificaion after biogas purification is likely the best alternative for Biogas utilization which have more economic potential than CHP system. The withdrawal period of capital cost appeared to be 2.3 years.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2003.10a
• /
• pp.64-65
• /
• 2003

• Journal of ILASS-Korea
• /
• v.15 no.4
• /
• pp.195-201
• /
• 2010

Due to its carbon-neutral nature, biogas generated from anaerobic digestion or fermentation of biodegradable wastes is one of the important renewable energy sources to reduce global warming. It is mainly composed of methane and various inert gases such as $CO_2$ and $N_2$, and the actual composition of biogas significantly varies depending on the origin of anaerobic digestion process. Therefore, in order to effectively utilize this fuel as an energy source for electricity, it is important to develop power generation engines which can successfully apply biogas with significant composition variations. In this study, efforts have been made to develop a diesel-biogas duel fuel engine as a way to achieve such a stable power generation. The effects of diesel fuel injection quantity and pressure on stable combustion and engine performance were investigated, and an impact of diesel fuel atomization was discussed. The engine test results show that there exists a 2 stage combustion which consists of diesel pilot fuel burning and premixed biogas/air mixture burning in dual fuel engine operation and optimum diesel injection parameters were suggested for biogases with various compositions and heating values.

• Nuclear Engineering and Technology
• /
• v.54 no.1
• /
• pp.130-137
• /
• 2022

In the geological repository of radioactive nuclear waste, anaerobic corrosion can generate hydrogen, and may conservatively lead to the production of hydrogen-air layer. The accumulated hydrogen may cause a hazardous flame propagation resulting from any potential ignition sources. This study numerically investigates the processes of ignition and flame propagation in the layered mixture. Simple geometry was chosen to represent the geological repository, and reactive flow simulations were performed with different ignition power, energy, and locations. The simulation results revealed the effects of power and energy of ignition source, which were also analyzed theoretically. The mechanism of layered flame propagation was suggested, which includes three stages: propagation into the hydrogen area, downward propagation due to the product gas, and horizontal propagation along the top wall. To investigate the effect of the ignition source location, simulations with eight different positions were performed, and the boundary of hazardous ignition area was identified. The simulation results were also explained through scaling analysis. This study evaluates the potential risk of the accumulated hydrogen in geological repository, and illustrates the layered flame propagation in related ignition scenarios.