• 상하수도학회지
• /
• 제27권6호
• /
• pp.815-826
• /
• 2013

Using a developed mathematical model and calibrated kinetic constants, numerical experiments for a aerobic digestion of wastewater sludge by SBR aerobic digestion process combined with ultrasonication (USSBR) were performed in this study. It simulated well the phenomena of the decomposition of particulate organics and the release of organic nitrogen and transformation. To achieve 40 % of particulate organics removal, USSBR process requires only 6 days of SRT and 14 W/L of ultrasonic power whereas SBR aerobic digestion process requires 12 days of SRT. Based on the model simulation results, an empirical equation was presented here. This equation will be used to predict digestion efficiency for the given variables of SRT and ultrasonic power dose. USSBR aerobic digestion process can reduce the nitrogen concentration. The optimal operation strategy for the simultaneous removal of solids and soluble nitrogen in this process is estimated to 7 days of SRT with 14 W/L of ultrasonic power dose while anoxic period was 6 hours out of 24 hours of cycle time. In this condition, 40 % of particulate organics as well as 36 % of total nitrogen will be removed and the soluble nitrogen concentration of the centrate will be lower less then 40 mg/L.

• 대한토목학회논문집
• /
• 제26권1B호
• /
• pp.113-118
• /
• 2006

간헐포기방식의 슬러지 소화 기술에 대한 비용을 분석하였다. 포기비율은 간헐포기소화의 가장 중요한 설계인자이며, 포기 비율에 따라 시설비와 동력비가 달라진다. 목표 SS 제거율을 35%로 설정하고, 철근콘크리트형식의 SBR 간헐포기소화조를 설계하였으며, 이로부터 시설비와 동력비를 산출하였다. 비용 평가는 할인율과 경제성장율을 고려하는 현재가치로 환산하는 방법을 사용하였다. 포기비율이 낮은 경우는 시설비가 높지만 동력비는 적게 소요되며, 포기비율이 높으면 반대로 시설비는 낮지만 동력비는 증가한다. 초기시설비는 호기성 소화가 간헐포기소화보다 더 저렴하다. 그러나, 총비용면에서 내용연수 약 10년 이상의 운전에서는 간헐포기소화가 호기성 소화보다 더 유리하다. 특히, 내용연수가 길수록 최적 포기비율은 낮아지며, 내용연수가 45년 정도일 때 최적포기비율은 0.3 정도이고, 이 경우 총비용은 호기성소화의 64% 수준이다.

• 대한한방부인과학회지
• /
• 제23권2호
• /
• pp.95-105
• /
• 2010

Purpose: The purpose of this study was to find out the correlation among Shift Rotation, dysmenorrhea and digestion function. Methods: We conducted a questionnaire survey of 161 nurses about their menstruation and digestion function from several hospitals from Oct to Nov in 2009. Using chi-square test and pearson correlation, statistical analysis was made by SPSS 12.0. We significance level p-value was determined as 0.05. Results: 1. There was no significant correlation between Shift Rotation and the severity of dysmenorrhea. 2. There was statistically mild correlation between Shift Rotation and digestion power. 3. There was statistically mild correlation between dyspepsia and the severity of menstruation. Conclusion: From above results, we could conclude that Shift Rotation, dyspepsia had mild relation to menstruation.

• Bulletin of the Korean Chemical Society
• /
• 제15권9호
• /
• pp.786-791
• /
• 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.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.102.2-102.2
• /
• 2010

We are to evaluate the stabilization technology of actual biogas plant facilities, which is operating currently. It describes the traits of the consistent facilities of mesophilic anaerobic digestion using Unison Biogas plant Recovery system(UBR). Also the economical efficiency is examined with the electric power sales earnings and applying the deserted heating by generating electric power, which is generated by operated combined heat and power using biogas produced by mesophilic anaerobic digestion. We have generated the 481,113kw for electric power and 1,376Gcal for thermal energy simultaneously. If these electric power and thermal energy are converted into diesel, we can achieve savings equal to 114,300L, and 152,109L in the quantity of heat. Finally, if CDM, RPS, liquid fertilizer sales business, etc. is activated, the earnings will be expected to improve dramatically and is considered to contribute a drop of the greenhouse gas.

• Environmental Engineering Research
• /
• 제11권3호
• /
• 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).

• 동서간호학연구지
• /
• 제17권1호
• /
• pp.71-79
• /
• 2011

Purpose: The purpose of this study was to compare the neonatal birth weight, birth height, Apgar scores, sucking power, and digestion difficulties between smoking and non-smoking women following cesarean birth. This study analyzed the effects of smoking on the neonatal health status in pregnant women to provide fundamental data for smoking prevention education for women of childbearing ages and non-smoking practice protocols for pregnant women with smoking. Methods: A comparative survey design was used. Fifty-four newborn infants of pregnant women with smoking and seventy-four newborn infants of pregnant women with non-smoking participated in this study. The scores of neonatal birth weight, birth height, Apgar scores, sucking power, and digestion difficulties were assessed. Data were analyzed using SPSS Windows 15.0 program. Results: Smoking in pregnant women leads to the decrease of birth weight (F=4.75, p=.030) and birth height (F=14.19, p<.001), negative effects on the Apgar scores (F=36.02, p<.001) and sucking power (t=-4.26~-5.60, p<.001), and digestion difficulties ($x^2$=6.72, p=.010) of neonates. Conclusions: This study demonstrated that smoking in pregnant women leads to the decrease of fetus development. These findings would be utilized for the development of not only smoking prevention programs for women of childbearing ages but also prenatal education programs for pregnant women.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2004년도 학술논문집
• /
• pp.158-166
• /
• 2004

원자력 발전소에서 발생하는 방사성 폐기물인 이온교환수지, 제올라이트, 활성탄 및 슬러지에 포함된 핵종 분석을 위한 최적의 산분해 조건을 확립하였다. 방사성 폐기물의 분해에는 혼합산을 이용한 밀폐형 극초단파 산분해법을 사용하였으며, 제안한 방법에 따른 산분해 후의 용액은 맑고 색이 없는 투명한 상태임을 확인할 수 있었다. 또한, 산분해 과정을 거친 각각의 용액 시료는 ICP-AES와 AAS를 사용하여 분석하였고, 모의 방사성 폐기물에 첨가한 5종의 금속 원소들은 94% 이상의 높은 회수율을 보여주었다. 화학적 특성을 고려하여 제안된 산분해 조건은 핵종 분석을 위한 효과적인 전처리 방법으로써, 향후 원전의 유형별 방사성 폐기물에 대해 보편적으로 적용될 수 있을 것으로 판단된다.

• 대한수의학회지
• /
• 제43권3호
• /
• pp.393-398
• /
• 2003

Simple and rapid sample preparation method for trace elements in foods of animal origin using ultra high pressure microwave digestion system (UHP/MDS) and inductively coupled plasma atomic emission spectrometer (ICP/AES) were developed. 1. For the digestion of sample using UHP-MDS, 20% nitric acid (v/v) was the most suitable solvent for the determination of trace elements in foods of animal origin. 2. The optimal digestion conditions for UHP-MDS were as follows: final temperature $180^{\circ}C$, final pressure 400 PSI, and magnetic power 900 W in the solid sample. For the liquid sample final temperature $170^{\circ}C$, final pressure 300 PSI and magnetic power 700 W were optimal conditions. 3. As result of interlaboratory test, the average recovery rate of the for solid sample were 88.3~99.1% for As, 82.4~93.3% for Cd, 89.2~101.2% for Hg and 86.5~93.8% for Pb, respectively. In liquid sample, it were 87.0~96.8% for As, 80.9~96.6% for Cd, 87.5~91.2% for Hg and 91.4~95.5% for Pb, respectively. 4. The average coefficient variation rate were 3.3~15.9% for solid sample and 2.9~10.8% for liquid sample.

• 대한한방부인과학회지
• /
• 제22권4호
• /
• pp.109-121
• /
• 2009

Purpose: The purpose of this study was to find out the correlation among body mass index (BMI), dysmenorrhea and digestion function. Methods: We conducted a questionnaire survey of 307 high school girls about their menstruation and digestion function from one high school located in Seoul from Mar. 23 to Mar. 28 in 2009. And the we measured their height and weight to calculate their BMI. Using one way ANOVA, chi-square test and pearson correlation, statistical analysis was made by SPSS 12.0. We significance level p-value was determined as 0.05. Results: 1. There was no significant correlation between BMI and the severity of dysmenorrhea. 2. There was no significant correlation between BMI and digestion power. 3. There was statistically mild correlation between dyspepsia and the severity of menstrual pains. Conclusion: From above results, we could conclude that dyspepsia had mild relation to menstrual pains.