• Journal of Hydrogen and New Energy
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• v.13 no.1
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• pp.52-64
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• 2002

유기성 폐기물을 이용하여 생물학적 수소생산 통합화 시스템 연구를 수행하였다. 통합화 시스템은 유기성폐기물의 전처리, 2단계 혐기발효 및 광합성 배양으로 구성된 생물학적 수소생산 공정, 초임계수 가스화 공정, 생산된 가스의 저장, 분리 및 연료전지를 이용한 전력 생산으로 구성되었다. 실험에 사용된 유기성 폐자원은 식품공장 폐수, 과일폐기물, 하수슬러지이며, 전처리는 폐기물에 따라 열처리 및 물리적 처리를 하였으며, 전처리된 시료는 생물학적 수소생산 공정에 직접 적용되었다. Clostridium butyricum 및 메탄 생성조에서 발생하는 하수슬러지중의 미생물 복합체는 수소생산 혐기 발효공정에 사용되었으며, 광합성 수소생산 미생물인 홍색 비유황 세균은 광합성 배양에 사용되었다. 생물학적 공정에서 발생하는 미생물 슬러지는 초임계수 가스화 공정으로 수소를 발생하였으며, 슬러지 중의 COD를 저하시켰다. 생물학적 공정 및 초임계수 가스화 공정에서 발생하는 수소는 가스탱크에 가입상태로 저장한 후, 95%순도로 분리하였으며, 정제된 수소는 연료전지에 연결하여 전력 생산을 하였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.101-108
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• 2016

Concentrations of Chromium(Cr) and Manganese(Mn) in several kinds of dewatered organic sewage sludges generated from wastewater treatment plants of Pocheon City, Gyeongii Province were examined. In addition, bioaccumulations of Cr and Mn in the body of earthworm Eisenia fetida were also investigated by changing of feed sludge amounts. Cr and Mn concentrations in sludges were in the range of 0.0~0.3 mg/kg and 3.6~17.6 mg/kg, respectively, which would not cause acute toxicities to earthworm population. Cr was bioaccumulated in the earthworm body but bioaccumulation was not proportional to the amount of sludges supplied. The degree of bioaccumulation of Cr decreased in later phase as the supplied amounts of sludges increased. Meanwhile, there were rare bioaccumulation with regard to Mn. In this study, the value ranges of bioaccumulation factor (BAF) for Mn were 0.00~0.12 when 60g of sludges was supplied. In the case of Cr, the value of BAF was 19.33 when 60g of human manure sludge was provided.

• Clean Technology
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• v.15 no.3
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• pp.154-164
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• 2009

In 2007, 94% of organic wastewater sludge from industries located in Ulsan was disposed of by ocean dump. The ocean dump of organic sludge would be totally prohibited by the year of 2012. However, there is no alternative but incinerating the sludge from the industries located in Ulsan. Securing the technology for sludge treatment and on-land disposal is very important issue among the industries in the Ulsan Petrochemical Industry Complex. In this study, the material aspects of dried and carbonized sludge as a fuel were evaluated for petrochemical and sewage sludge from Ulsan. The dried and carbonized sludges from the factories producing terephthalic acid, BTX, propylene, chemical textile, etc. of which the low heat value exceeded 3,000 kcal/kg had high potential as a fuel according to the results of thermal characteristic analysis. However, the dried sludges with heat values lower than 2,100 kcal/kg and carbonized sludges, lower than 1,100 kcal/kg containing more Inorganic material from the industries producing pulp, paper, methylamine, amide, etc. had a little potential to be used as a fuel. In most cases, drying the sludge showed better results than carbonization in the aspect of thermal characteristics of sludge.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.194-195
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• 2011

런던협약 '96의정서' 발효에 의해 2012년부터 하수 슬러지 처분 방법 중 대부분을 차지하고 있는 유기성 슬러지 등 폐기물의 해양투기가 전면 금지되기 때문에 효과적인 하수 슬러지 처분 및 슬러지 감량화에 대한 기술 수요가 꾸준히 제기되고 있다. 본 연구에서는 슬러지 처분법의 대안으로 슬러지 가용화 연구에 고전압 임펄스을 접목시켜 슬러지 가용화 연구를 수행하였다. 본 연구에서 사용된 고전압 임펄스 장치는 power supply, HV generator, capacitor와 switch, impulse generator로 구성되어 있다. 고전압 임펄스에 의한 슬러지의 특성 변화를 관찰하였다. HVI를 90분 인가하였을 경우 하수 슬러지의 MLSS와 MLVSS는 각각 평균 8%와 9% 감소하였다. 또한 SCOD는 341% 증가하였고, TN과 TP는 각각 34%와 90.9% 증가하였다.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.475-484
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• 2000

The purpose of this study was to develop model for estimating biodegrability of organic sludge (sewage and papermill) in various environmental conditions. to assume degradable degree with operating time of SRB reactor. and evaluate duratior of organic sludge as carbon source. Average TCOD was 28.7~63.2mg/L in effluent. organic sludge did not much supply carbon source for experimental period. But in point of durability. it seemed that organic sludge was efficient because it was not consumed by degradation of much organic matter within short period. With increasing $SO_4{^{2-}}$ reduction rate. Pb and Fe was removed 77~82% and 33~59%. respectively. Because Al was precipitated as a hydroxide. its removal rate wa,. about $54{\pm}2%$ in R-l~R-3 maintaining low pH but about 78% in R-4 maintaining high pH. Because Mn was large in solubility. it showed to be much lower than other heavy metals. Considering supportable capacity or durability of orgainc matter for initial SRB mixing ratio of sewage/papermill 0.5 was regarded as appropriate substituting material and at this time. it estimated that carbon source continued about 3.08 year but safety factor must apply to be thought over. because various factors had an effect on degradation of organic sludge.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.228-231
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• 2012

In this work, the mixture of sewage sludge incubated in an anaerobic bioreactor for 35 days and paperboard sludge was treated in a batch anaerobic digester equipped with a ultrasonicator, and methane production during the treatment was investigated. The Soluble Chemical Oxygen Demand (SCOD) increased with increasing the amplitude of ultrasonicator, which help solubilizing paperboard sludge more effectively. The optimum amplitude of ultrasonicator for the enhancing methane productivity was found to be $142.5\;{\mu}m$ and the methane production amount increased as the anaerobic digestion period became longer. In addition, the anaerobic digestion was performed with various biomass (6000, 9000 and 12000 mg/L) and methane production increased with higher cell mass. These results will be used as valuable data to enhance the methane production from anaerobic digestion of the high concentration of organic wastes containing the paperboard sludge and sewage sludge.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.578-582
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• 2011

Aerobic digestion of organic sludge generates stabilized slurry which could be used as a nitrogen-rich liquid fertilizer. In this study, the effects of air supply rate and eggshell addition on the sludge fertilizer efficiency were examined. Sludge from a wastewater treatment plant in a food industry was fed to a lab-scale aerobic digester, and the fertilizer efficiency was assessed by the growth of cucumber. Increase of air supply rate up to 200 mL/L/min enhanced the fertilizer efficiency as well as the nitrification efficiency. The addition of eggshell, a potassium-rich leftover, in fertilizer application was also beneficial to the cucumber growth. A proper control of air supply rate and the use of an inexpensive additive would guarantee the quality of sludge liquid fertilizer.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.79-89
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• 2017

Changes in pH, EC and water soluble cation and anion of the bed material in the rearing box of earthworms were investigated while sewage sludges or night soil sludge were cumulatively supplied to the 15 grams of initial earthworm population in the rearing box. Initial biochemical properties of sludges such as pH, EC, V.S. and water content were at the edible levels for earthworm. However, as the cumulative amount of sludges supplied to the earthworms were increased, pH of bed material in the rearing box was lowered and EC was increased, which meant that salt contents of bed material in the rearing box had been accumulated. Water soluble cations and anions were also accumulated in the bed material of the rearing box. Accumulation rates of ${NO_3}^-$ were especially prominent. Consequently, feeding rates of earthworm populations were reduced to nearly zero and earthworm populations finally died.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1347-1351
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• 2006

It was tried to utilize organic waste sludge from wastewater treatment plant as a starting material to produce a solid fuel by vacuum flying. The effects of decompression levels, frying time and temperature on the calorific value and moisture of vacuum fried sludge were systematically investigated. Dewatered raw sludge used in this study had a moisture of 81.1% and calorific value of 2,930 kcal/kg. Based on the experimental observation, it was identified that the decompression level and frying time have the greatest influence on the calorific value of vacuum fried sludge. Moistures of the fried sludge at $180^{\circ}C$ for 25 min in 760 mmHg, 684 mmHg and 630 mmHg were 32.4%, 14.2% and 11.6%, respectively. Calorific values of the vacuum fried sludge at $140^{\circ}C$ for 15 min and 25 min were 5,400 kcal/kg and 5,540 kcal/kg in 684 mmHg and 5,520 kcal/kg and 5,660 kcal/kg in 630 mmHg, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.1
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• pp.39-45
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• 1998

As a basic research for developing a sludge application technique in forestry, this study was conducted to investigage a reasonable amount and period of sludge to be applied onto forest nursery of Acer palmatum Thunb. The paper mill sludge was used for the study, and ammonium nitrate was treated to some of them to reduce the C/N ratio lower than 40. The maximum amount of applied sludge was 7ton/ha/year, and they were spread on spring and on late summer. The sludge application did not stimulate early growth of the trees during a year. Since there was no significant changes in soil chemical properties, the amount of applied sludge was thought to be too little to result in a significant role for tree growth. However, the soil water showed significant increase of Cu when the activated sludges were applied during late summer. Thus, the time of application need to be determined cautiously with considering the risk of ground water contamination. In conclusion, if we set a goal from the view point of long-term concept such as forest productivity rather than to get a short-term product, the uncomposted sludge in small amount during growing season might be considered to be applied on forest nursery.