• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.29-32
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• 2014

The practical route for disposal of sewage sludge becomes energy recovery by combustion after its ocean dumping is banned in 2012 in Korea. Due to the high moisture content, however, sewage sludge is required to be dried before transport and combustion. In this study, pyrolysis and combustion characteristics of dried sewage sludge was investigated in a small-scale fixed bed reactor in order to provide fundamental data for energy recovery of the fuel. As the first step of combustion, the primary products of pyrolysis were analyzed in a fixed bed reactor for the condensable volatiles (tar), non-condensable gases, and char. For the combustion characteristics, another fixed bed reactor was constructed to monitor the weight and temperature of the fuel particles during ignition and combustion under different air flow rates. The test results were used to derive the ignition and burning rates.

• 상하수도학회지
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• 제28권3호
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• pp.299-304
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• 2014

The need of reusing sewage sludge is highly increasing as the amount of domestic sewage sludge is growing and sewage management strategies were reinforced. Accordingly, in this research, we studied the composting possibility of sludge in sewage treatment plant J, using dryer facility with indirect system by conducting component analysis of dried sludge and experiment on cultivating crops. It was observed from the component analysis, that the dried sludge is appropriate for both decomposed manure standard of Ministry of Environment and fertilizer standard of Rural Development Administration. Besides, in the experiment on cultivating lettuce, the experimental group(soil + dried sludge) was superior to the control group(soil + bed soil) in apparent condition of leaves tensity and damage by disease and pest. In case of cultivating tomato, the experimental group showed stronger durability of fruits dangling on stems compared to the control group after 9 weeks. Consequently, the excess sludge dried by indirect heating system in the sewage treatment plant J is appropriate for the standard of both Ministry of Environment and Rural Development Administration and show good result in experiment on cultivating crops therefore it can be reused for composting.

• 유기물자원화
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• 제22권1호
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• pp.11-19
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• 2014

본 연구에서는 건조 하수슬러지의 화석연료와의 혼소 가능성 평가를 연소특성, 경제적 이익 2가지 관점에서 평가하였다. 공업분석 결과 A하수처리장의 건조 하수슬러지의 휘발분은 36.48%, B하수처리장은 40.10%로 석탄에 비해 매우 높았으며, 연료비는 0.12, 0.14로 매우 낮아 연료로써의 품질은 낮은 것으로 조사되었다. 특히 연소성 지수가 30,000kcal/kg 이상으로 연료의 기준인 3,000~5,000kcal/kg을 크게 초과하여 건조 하수슬러지의 개질이 필요할 것으로 판단된다. 건조 하수슬러지의 경제성 평가 결과 석탄의 절감에 따른 이익은 연간 73.4억원, REC인증 이익은 56.4억원이 발생하는 것으로 산정되었다. 반면에 회분처리비용 증가에 따른 손실은 2.6억원, 건조 하수슬러지의 혼소에 소요되는 설비의 투자 및 운영비가 4.2억원으로 산정되어 건조 하수슬러지의 혼소에 따른 경제적 이익은 연간 123억원으로 추산되었다. 다만, 건조 하수슬러지의 생산에 소요되는 동력 및 건조 하수슬러지의 혼소로 인한 환경오염 등에 대한 비용은 본 연구에서 고려되지 못하였으며 향후 이에 대한 연구가 추가적으로 필요할 것이다.

• 한국환경과학회지
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• 제19권1호
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• pp.9-16
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• 2010

This pilot study evaluated fueling feasibility of sewage sludge, which contains a large amount of water content, by applying melting of thermoplastic polyethylene (PE). This study has identified a simultaneous achievement of drying and heating value improvement of the sewage sludge. The sewage sludge collected from a sewage sludge treatment plant during a winter period had a water content of 83.7 wt%, a combustible volatile content of 12.5 wt%, and an ash content of 3.8 wt%. The higher heating value (HHV) of the dried sewage sludge, before impregnation or coating of PE, was 4,600 kcal/kg. The collected sewage sludge was immersed into the melted PE solution, which had a HHV of 11,070 kcal/kg, and kept immersing with increasing reaction time. As the reaction (immersing or coating or impregnation) time increased, the water content of the sludge decreased. However, the HHV of the sludge increased with increasing the reaction time. The HHVs of the sewage sludge immersed or dipped into the melted PE solution for 15 min ranged from 6,780 to 8,170 kcal/kg with water content less than 7 wt%. This result indicates the melted PE solution can be utilized as an improvement technology for dryness and heating value of the sewage sludge with high water content. The sewage sludge impregnated or coated with melted PE can be utilized as potential fuel or energy resources.

• 청정기술
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• 제24권4호
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• pp.323-331
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• 2018

실험실 규모 기포 유동층 반응기를 이용한 하수 슬러지와 석탄 및 우드 펠렛의 혼소 실험 및 회분 분석을 통한 슬래깅 성향을 살펴보았다. 연료는 일반 건조 및 수열탄화를 통해 제작된 하수 슬러지와 아역청탄, 우드 펠렛이 적용되었다. 연소 실험은 당량비 및 산화제 유량, 초기 온도를 고정하고 2종의 하수 슬러지 연료와 석탄 또는 우드 펠렛을 발열량 기준 50 : 50 비율로 혼합한 총 4개의 조건에 대해 반응기 온도 및 배가스 조성을 측정하였다. 배가스 중 $NO_x$는 모든 조건에서 대부분 NO의 형태로 400 ~ 600 ppm 범위에서 측정되었다. $SO_2$는 원료 내 황 함량을 고려하면 하수 슬러지의 투입량이 큰 영향을 미쳤을 것으로 예상되는 가운데 수열탄화 연료가 일반 건조 연료에 비해 다소 낮은 경향을 보였다. 비산 회분 조성 분석 결과 하수 슬러지 연료가 슬래깅/파울링 가능성을 높일 것으로 생각되며, 수열탄화 연료가 일반 건조 연료에 비해 상대적으로 양호한 결과를 보일 것으로 예상되었다.

• 자원리싸이클링
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• 제26권2호
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• pp.33-38
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• 2017

폐기물은 이차연료나 대체연료로 사용될 수 있다. 본 연구에서는 고형연료(SRF)와 건조 하수슬러지를 연소하여 배출되는 중금속 물질을 분석하였다. 석탄, SRF, 건조 하수슬러지의 구리(Cu), 크롬(Cr), 카드뮴(Cd), 니켈(Ni), 아연(Zn), 납(Pb), 비소(As), 수은(Hg) 함량을 조사하였고, 각 물질이 연소가스에서 가스상으로 존재하는 농도를 분석하였다. 실험결과, 가스상으로 배출되는 Cu, Cr, Cd, Ni, Zn, Pb의 양은 매우 적은 것으로 나타났다. 그러나 가스상 수은은 연소 배기가스에서 많은 양이 배출되었다. SRF는 연소 배기가스에서 높은 수은 산화도를 보였고, 건조 하수슬러지는 높은 수준의 수은 배출농도를 보였다.

• 수도
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• 제24권5호통권86호
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• pp.29-44
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• 1997

Sewage sludge produced in Korea was 1,275,800 tons (dewatered sludge cake) per year in 1996, which is 3,495 tons per day, 0.303% of 11,526,100 tons per day of sewage treated in 79 sewage treatment plants. Sludge production has been and will be increasing in accordance with construction of new facilities for sewage treatment. Most of the sludge is currently disposed by landfill and ocean dumping, but it is becoming difficult to find suitable sites for landfill, particularly in big cities such as Seoul. In addition, rapid increase of landfill cost is anticipated in a near future. Current trend for sludge disposal in advanced countries is land application. Over the past 10 to 20 years in the United States, sludge management practices have changed significantly, moving from disposal to beneficial use. They use biosolid for utilization instead of sludge for disposal. Under the Clean Water Act of 1972, amended in 1987 by Congress, the U.S. EPA was required to develop regulations for the use and disposal of sewage sludge. The EPA assessed the potential for pollutants in sewage sludge to affect public health and the environment through a number of different routes of exposure. The Agency also assessed the potential risk to human health through contamination of drinking water sources or surface water when sludge is disposed on land. The Final Rules were signed by the EPA Administrator and were published (Federal Register, 1993). These rules state that sewage sludge shall not be applied to land if the concentration of any pollutant in the sludge exceeds the ceiling concentration. In addition, the cumulative loading rate for each pollutant shall not exceed the cumulative pollutant loading rate nor should the concentration of each pollutant in the sludge exceed the monthly average concentration for the pollutant. The annual pollutant loading rate generally applies to applications of sewage sludge on agricultural lands. The most popular beneficial use of sewage sludge is land application. The sludge has to be stabilized for appling to land. One of the stabilization process for sewage sludge is lime stabilization process. The stabilization process is consisted of the stabilizing process and the drying process. Stabilization reactor can be a drum type reactor in which a crossed mixer is equipped. The additive agents are a very reactive mixture of calcium oxide and others. The stabilized sludge is dried in sun drier or rotary kiln.

• 한국환경과학회지
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• 제15권3호
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• pp.229-236
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• 2006

Organophosphorus pesticides (OPPs) contents in the sewage sludge derived from the residential and industrial areas were determined in order to characterize contemporary organic contamination levels as a part of the ongoing development of the environmentally sound sewage sludge management strategy in Korea. OPPs were extracted from freeze-dried sludges in a ultrasonic extractor. The extracts were cleaned-up by florisil column and subsequently fed into gas chromatograph/nitrogen phosphorus detector (GC/NPD) for determining OPP contents. Diazinon, dimethoate, disulfoton, EPN, malathion, methyl parathion, parathion, phorate and sulfotep were present in the appreciable amount in the domestic sewage sludges. The sum of the 9 OPPs in the sewage sludge varied from 534.8 to 15552.1 ${\mu}g/kg$, dry wt..

• 유기물자원화
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• 제22권3호
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• pp.53-59
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• 2014

본 연구에서는 A 지역의 하수슬러지 건조장치가 설치되기 전과 후 탈수슬러지의 조성 및 성상, 중금속함유량 등을 측정 및 조사 분석을 하였다. 분석결과 건조로 설치전보다 약 95.7%의 제거효율을 보였으며, 설계값으로 1차건조로 35%, 2차건조로 10% 함수율을 제거하지만, 측정해본결과 1차건조로 20.8%, 리본 3.3%로 실제 운전효과가 더 좋은 것으로 나타났다. 중금속 함유량은 건조장치 설치 전 Cu : 352~614ppm, Hg : 1.3~1.44ppm, Cd : 1.1~1.86ppm, Pb : 17.25~ 28.93 ppm, As : 1ppm 이고 설치 후 Cu : 340~350 ppm, Hg : 0 ppm, Cd : 0~0.021 ppm, Pb : 0 ppm, As : 0~0.043 ppm으로 건조장치설치 전과 후 모두 법정 기준치에 초과하지 않음을 확인하였다. 또한 건조장치를 통과한 하수슬러지는 평균적으로 ${\frac{1}{4}}$의 건조슬러지가 발생하였다.

• 동력기계공학회지
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• 제21권5호
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• pp.55-62
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• 2017

In this study, the water content and the low calorific value of the dried sludge are analyzed by using a vertical cylinder type indirect heating type dryer for evaluatation of energy source value. The vertical cylindrical thin film dryer was an Okadora Pilot Plant, and the dryer was indirect heating vertical thin film type. The internal standard consisted of 500 mm in diameter and 700 mm in height. In the drying experiment, 10 kg of dehydrated sewage sludge was added to the dryer and the total amount of the sludge was adjusted to 27 times by variable of the time, the number of revolutions and the steam temperature. The results of analysis of the 27th experiment component of the dried product showed that the average low calorific value of about 11.2 MJ/kg and the water content of 6%. This is satisfy the fuel use standard of the thermal power plant of the sludge.