• 상하수도학회지
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• 제31권3호
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• pp.257-262
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• 2017

Several disposal processes for waste sludge from wastewater treatment plants such as landfill, ocean dump, incineration, reuse as fuels or fertilizers are practiced. However, ocean dumping is prohibited by international treat. New constructions of landfill sites or incineration facilities are limited by NIMBY and reuse processes are still suffering from low energy yield. Therefore, development of alternative processes for sludge disposal are currently needed. In this study, alternative technique for sludge solubilization using HVI (high voltage impulse) was suggested and verified experimentally. Sludge solubilization was carried out for 90 minutes using HVI discharge with peak voltage of 16 kV and pulse duration for 40 microsecond. About 3~9 % of MLSS and MLVSS concentration were reduced, but the soluble COD, TN, TP of the sludge increased to 372 %, 56 % and 102 % respectively. It indicates that the flocs and/or cells of the sludge were damaged by HVI. These resulted in flocs-disintegration and cells-lysis, which means the internal matters were bursted out of the flocs as well as the cells. Thus, electrical conductivity in bulk solution was increased. All of the results verified that the HVI could be used as an alternative technique for sludge solubilization processes.

• 한국습지학회지
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• 제15권4호
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• pp.471-476
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• 2013

위생용지 제조 폐수처리장에서 발생하는 슬러지를 3년간의 일일 운전일지를 토대로 분석하였다. 발생 폐기물은 79% 슬러지, 14% 재, 5%의 합성폐기물 및 기타 2%로 구성되었다. 일일 최대 슬러지 생산량은 233톤, 평균 슬러지 생산량은 113톤으로 분석되었는데, 일차 슬러지가 85% 및 이차슬러지는 15%를 차지하였다. 슬러지 탈수용 응집제의 농도는 과량 주입되고 있어 적정 응집제 주입을 위해 주기적으로 쟈테스트와 같은 부가적인 실험에 의한 주입농도의 설정이 필요한 것으로 나타났다. 현재 발생되는 폐슬러지의 일부는 위탁처리되고 있고, 일부는 자체 처리되고 있지만, 장기적으로는 대부분의 폐슬러지가 제철소 슬러거의 진정재로 재활용될 계획이다.

• 한국해양환경ㆍ에너지학회지
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• 제11권3호
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• pp.132-137
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• 2008

축산분뇨는 화학적산소요구량과 구리함량이 각각 평균 $930,726{\pm}380.801mg/kg$와 $679{\pm}341mg/kg$으로 높아 해양투기 시에는 해양환경에 악영향을 초래할 수 있다. 반면에 육상에서는 유기물 분해를 통해 발생되는 바이오가스 에너지 활용과 양질의 축산분뇨는 풍부한 질소 및 인을 함유하여 퇴비로서의 충분한 경제적 가치를 갖고 있다. 그럼에도 불구하고, 우리나라 축산분뇨 해양투기량은 1997년에 51천 $m^3$에서 시작되어 2005년 2,745천 $m^3$으로 급격히 증가하였고, 2007년 폐기물 해양투기량(7,451천 $m^3$)에서 축산분뇨는 약 27%로서 큰 비중을 차지하였다. 축산분뇨 해양투기 비용은 $20,000{\sim}33,000$원으로서 퇴비(20,000원), 정화처리(10,000원) 보다도 높지만, 축산농가들은 아직도 퇴비와 정화처리 등 육상 활용보다는 해양투기를 선호하고 있다. 이에 따라 본 소고에서는 축산농가들의 해양투기 선호 요인들에 대한 분석을 통해 개선안을 제시하여 축산분뇨 해양투기로부터의 해양환경오염을 방지하고자 한다.

• 한국건축시공학회지
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• 제8권6호
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• pp.83-89
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• 2008

The stone sludge produced during the manufacturing process of stone blocks is considered as one of industrial waste materials. This stone sludge are managed to either burying under the ground or stacking in the yard, but this disposal process is required an extra costs. The stone sludge disposal like burying or stacking also cause environmental pollutions such as ground pollution and subterranean water pollution. Thus, this study was conducted to explore the possibility of recycling of stone dust sludge as a concrete mixing material in order to extend recycling methods and to solve the shortage of aggregate caused by recently increased demand in construction. Based on the experiment results on various ratios of cement to stone sludge content, the compressive strengths of concrete were recorded in the range of $20{\sim}30N/mm2$. The results did not show any decrease in compressive strength due to the stone dust content. It can be concluded that the stone sludge produced by stone block manufacturing can be sufficiently recycled as one of concrete mixing materials in the aspect of compressive strength.

• 환경위생공학
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• 제10권1호
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• pp.86-96
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• 1995

Alum recovery has recently gained more attention because many water utilities need to improve their sludge handling and disposal practices. As part of an overall sludge management program recovery can reduce the amount of solids and allow for reuse of the recovered Alum as a coagulant. This study was examined the effectiveness of Alum recovery from the Sludge at the D water treatment plant in Kwangju city. The results were summarized as follows 1. Alum recovery was obtained sufficiently acidification(An optimum condition was pH2-3) With $H_{2}SO_{4}$ to settled sludge. In this case recovered liquid Alum from sludge of 2.1% solids concentration at pH 2.1 was contains Aluminum $1,602mg/{\ell}$(as $Al_{2}O_{3}$ 0.3% ) and other metal of low level. 2. It was an optimum condition to all reuse of recovered Alum as a coagulant that rate of Commercial Alum:Recovered Alum=$14{\mu}{\ell}/{\ell}{\;}:{\;}200{\mu}{\ell}/{\ell}$ In a result of Jar Tests. 3. It was a result of Alum recovery from sludge, the reduction effect of amount of solids was about 57.4%. 4. If all recovered Alum were reused the reduction effect of solid wastes disposal cost and chemical drug's cost was about 22%.

• Nuclear Engineering and Technology
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• 제4권3호
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• pp.194-202
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• 1972

방사성 폐액처리에서 나오는 방사성 Sludge의 Solar energy에 의한 고화 처리방법은 가장 효과적이고 경제적인 처리방법의 하나이다. 본연구를 통해서 Sludge의 고화처리는 3月부터 8月사이가 가장 적정기이고, 또 Mass-transfer방법에 의해 증발량 추정에 대한 실험식을 유도하였다.

• 유기물자원화
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• 제13권2호
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• pp.74-84
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• 2005

본 연구의 목적은 열풍건조를 이용하여 슬러지를 감량화하는 과정에서 발생되는 열적거동을 조사하는데 있다. 실험에서 중요한 운전매개변수는 공급되는 건조온도가 $130{\sim}170^{\circ}C$와 증발속도 WD를 변화시켜 실행하였다. 슬러지내 수분을 증발하는 과정에서 열적거동의 변화에 미치는 영향인 주요매개 변수는 공급되는 온도변화에 따른 건조시간, 슬러지내 수분함량, 슬러지의 고형물량에 따른 결과를 조사하였다. WD=0.95m/s의 조건에서 $170^{\circ}C$의 건조온도에서 수분이 증발되는 포화점은 95분과 $130^{\circ}C$에서 120분에서 조사되었다. 열풍의 의한 증발속도가 1.0 m/s로 일정할 때 건조온도가 130와 $150^{\circ}C$일 때 보다 $170^{\circ}C$인 경우가 증발율이 더 높게 나타났고, 건조기 온도가 $130^{\circ}C$인 경우는 WD=1.0 m/s일 때 WD=0.5 m/s 보다 증발율이 높게 나타남을 볼 수 있었다.

• Geomechanics and Engineering
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• 제13권1호
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• pp.25-41
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• 2017

In recent years, the amount of sludge ash (SA) has considerably increased due to rapid urbanization and population growth. In addition, its storage in landfills induces environmental pollution and health problems. Therefore, its disposal in an environmentally friendly way has become more important. The main goal of this study is to investigate the reusability of sludge ash as an additive with polypropylene fiber (PF) to stabilize marginal sand based on the compressive strength performances from UCS tests. For this purpose, a series of UCS tests was conducted. Throughout the experimental study, the used inclusion rates were 10, 15, 20 and 30% for sludge ash and 0, 0.5 and 1% for polypropylene fiber by total dry weight of the sand+sludge ash mixture and the prepared samples were cured for 7 and 14 days prior to the testing. Freezing and thawing resistance of the mixture including 10% sludge ash and 0, 0.5 and 1% polypropylene fiber was also examined. On the basis of UCS testing results, it is said that sludge ash inclusion remarkably enhances UCS performance of sand. Moreover, the addition of polypropylene fiber to the admixtures including sand and sludge ash significantly improves their stress-strain characteristics and post-peak strength loss as well as UCS. As a result of this paper, it is suggested that sludge ash be successfully reused with polypropylene fiber for stabilizing sand in soil stabilization applications. It is also believed that the findings of this study will contribute to some environmental concerns such as the disposal problem of sludge ash, recycling, sustainability, environmental pollution, etc. as well as the cost of an engineering project.

• 한국농공학회지
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• 제39권5호
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• pp.64-70
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• 1997

Sludge is generated in the process of water and wastewater treatment, and it has been causing various problems environmentally and economically. The firing technology in pottery industry was applied to the sludge treatment, and the final product was called artificial soil. For the production of artificial soil, lime and chabazite was used as additive, and the mixed material was thermally treated in the firing kiln at $300^{\circ}$ temperature for about 15 minutes. The physico-chemical characteristics of the artificial soil was analyzed and it showed that the artificial soil could be used as a soil conditioner for farmland. The concentrations of the toxic heavy metals in the artificial soil were lower than those in the soil quality standard for farmland. It was high in permeability, total nitrogen and total phosphorous concentrations and surface area of the artificial soil compared to the common field soil. Preliminary cost analysis showed that the sludge treatment cost for artificial soil was less than the disposal cost in the current landfill disposal method. This study illustrated that the artificial soil production process can be a feasible alternative for sludge treatment, and produced artificial soil may he applied to farmland without causing significant adverse effect. Further study is recommended for practical application of the system and verification of the longterm effect of the artificial soil on farmland.

• 한국안전학회지
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• 제17권1호
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• pp.72-78
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• 2002

Among the disposal techniques of inorganic wastewater sludges from industries most of sludges were dealed with buring underground inefficiently. But we have tried to recycle the resources that exhausted inorganic sludges were properly blended to certain ratioes to make lightweight aggregate, that means manufacturing of it can be possible through blending of various components, drying, sintering, cooling and crushing to certain sizes that are needed by consumers. As disposal method of inorganic wastewater sludge is changed to environmentally fraternative method, this method could be very useful to make lightweight aggregates for decoration of building and the other so many purposes of those usages. That could be economically useful due to expected income for buring costs of ordinary disposal method form industries and sales income after manufacturing it. The second important profit is saving foreign currency from purchasing self-developed lightweight aggregate insteas of importing expensive foreign product. This product will be also very impressive to user because of the fraternative lightweight to be composed of apatite structure that is important part of human body.