• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.351-354
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• 2006

본 연구에서는 산발효산물과 하수슬러지의 혼합소화를 위한 적정 혼합비를 도출을 위하여 음식물찌꺼기 고온 산발효산물과 하수슬러지의 생분해 특성과 적정혼합비를 도출하고자 수행한 결과 음식물찌꺼기 고온 산발효액과 하수슬러지를 혼합비별로 회분식 혼합소화 실험을 실시 한 결과 혼합비 1:1에서 385ml CH$_4$/g VS$_{added}$로 가장 높은 메탄발생량을 나타내었다. 이러한 결과는 음식물찌꺼기와 하수슬러지를 1:1로 동일하게 혼합하여 비교 소화실험을 실시했을 때 의 293m1 CH$_4$/g VS$_{added}$와 비교하여 상대적으로 높은 메 탄발생량을 나타내었다.

• The magazine of the Korean Society for Advanced Composite Structures
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• v.5 no.4
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• pp.21-28
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• 2014

최근 증가하는 현무암 석분슬러지를 건설재료로 재활용하기 위한 방안으로, 시멘트 몰탈에서 잔골재의 일부를 현무암석분슬러지로 대체한 후, 기능성 마감재로서의 성능을 검증한 결과 다음과 같은 결과를 얻었다. 1. 현무암 석분슬러지를 포함한 몰탈의 휨인장강도와 압축강도는, 대체율 21%에 도달할 때까지 압축 및 휨인장강도는 일반 시벤트몰탈 대비 각각 47%와 35% 증가하였다. 2. 원적외선 방사율에 있어서도 기존몰탈보다 높은 0.933까지 이르렀으며, 이 수치는 기타 기능성 마감재보다 우수한 원적외선 방사율을 나타내는 것이다. 3. 음이온 방사량은 현무암석분의 대체율에 따른 일관된 경향을 보이지는 않았으나, 일반 시멘트몰탈 보다는 5% ~ 12% 증가효과가 나타났다. 4. 기존 시멘트몰탈의 잔골재의 21%를 현무암석분슬러지로 대체할 경우, 시멘트 몰탈보다 물리적 성질이 증가 함과 동시에, 기능성몰탈로서의 원적외선 방사율, 음이온 방사량의 증진효과가 있었다. 또한 새로운 건축자재의 생산을 통한 경제적 이득은 물론, 산업폐기물의 양을 줄일 수 있다.

• 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.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.7
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• pp.665-675
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• 2010

The effects of chemical binders (ladle slag, ordinary portland cement (OPC), hydroxyapatite and calcium hydroxide) on the solidification/stabilization of heavy metals (Cd, Cu, Ni, Pb, Zn) in sewage sludge were evaluated by chemical leaching tests such as EDTA extraction, TCLP and sequential extraction. The results of EDTA extraction showed that heavy metal concentrations in sewage sludge were highly reduced after solidification/stabilization with slag, cement or calcium hydroxide. However, EDTA interrupted solidification/stabilization of heavy metals by hydroxyapatite. The TCLP-extracted heavy metal concentrations in sewage sludge after solidification/stabilization with chemical amendments were highly reduced. However, Cu concentration in the sewage sludge solidified/stabilized with slag, cement or calcium hydroxide increased because the pH of TCLP solution was higher than 7. Mixtures of sludge 1 : slag 0.2 : calcium hydroxide 0.1 (wt ratio) showed the least leachability in batch TCLP and EDTA extraction. The results of sequential extraction (SM&T, formaly BCR) indicated that the distribution of heavy metals changed from exchangable and carbonate fractions to strongly bound organic fraction. It was found that maximum leachate concentrations of Ba, Cd, Cr and Pb from sewage sludge amended with slag and calcium hydroxide were far below US EPA TCLP regulations.

• KSBB Journal
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• v.19 no.2
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• pp.93-97
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• 2004

We investigate the effect of enzyme pretreatment using protease, carbohydrase, and lipase on improvement of sludge treatment efficiency by measuring SCOD and TCOD. The enzyme-pretreatment increases SCOD of excess sludge. In addition, the amount of sludge reduction during digestion, in terms of SCOD and TCOD, are enhanced by enzyme-pretreatment. Among pretense, carbohydrase, and lipase, pretense showed the best enhancement of the sludge treatment efficiency. Sludge digestion followed by ozone and enzyme treatments showed more effective sludge treatment when compared with ozone treatment alone. Therefore, we expect that enzyme pretreatment can be used as a useful tool for enhancing the sludge treatment efficiency.

• Resources Recycling
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• v.7 no.3
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• pp.52-57
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• 1998

The objective of this study was to investigate the effect of cow manure as additive material on the ripening of sewage s sludge for vermistabiJization. The changes of the waste properties by ripening for 50days were observed as a function of the v various mixture ratios of sewage sludge ‘and cow manure. The pH values of the mixture wastes decreased from 7.5-7.67 to 6_ 9~7.2 by the ripening for 50days, and the mixture ratio made dIfferent pH values. The initial value of oxidation-reduction p potential (Eh) of the mixture waste was a negative (-) value indicating an unfavorable condition for earthworm after, but the v values of Eh increased with the opening time. The Increase rate at Eh value was prop$\alpha$rtional to the mixture ratio of cow m manure. The value of alkalinity was also changed into the favorable range for earthworm after 50days except for non-use of 1 the cow manure When the mixture ratio of the cow manure increased from 10% to 30%, the growth of earthworms increased h from 63.7% to 88.3 % tor the survival rate, 265% to 321% for the liveweight increasing rate and 66.7_7% to 91% for hatching f rate of the cocoons. It can be concluded that the proper content of tbe cow manure in the sewage sludge to ensure effective v vermistabilization was over 20%, when the mixture was ripened during 50 days. The quantity of ingestion and 며ectian at 20%-30% was found to be O.15--i.L18g sludge and 0 1l--O.14g solid per capacity earthworm per day, respectively.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.579-585
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• 2005

Cheap and environmental sound biosorbent was made for the adsorption of arsenate using an waste activated sludge. The biosorbents were methylated in 9hours and 24 hours respectively for the better adsorption of arsenate. The amount adsorbed of arsenate(V) increased with increasing methylation time. The specific arsenate adsorption was 0.06mmol As(V)/g biomass when the biosorbent was methylated in 24 hours. The methylated biosorbents were also studied with pH 5, 7 and 9. The pH of the solution affect the amount of adsorption of arsenate of the biosorbent even though it was methylated. The specific arsenate adsorption of the biosorbent at pH 5 was best and it was three times greater than the amount of arsenate adsorbed at pH 9.

• Resources Recycling
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• v.23 no.6
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• pp.47-53
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• 2014

Effective treatment and energy conversion technologies are necessary due to the ban of the dumping of organic waste including the sewage sludge. In this study, the kinetics of pyrolysis and combustion were derived in a TGA and thermobalance reactor, which is essential for thermal conversion of sewage sludge to energy. Three steps are shown for the pyrolysis in TGA and the different pre-exponential factors and activation energies are derived depending on the temperature range. Three models of gassolid reaction were applied to the reaction kinetics analysis for the combustion of sewage sludge char and shrinking core model was an appropriated model. Apparent activation energy and pre-exponential factor were evaluated and the effect of oxygen partial pressure was examined.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.206.2-206.2
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• 2010

현재 RPF 생산공정에서 생산된 RPF는 약 7,500~8,500kcal/kg 의 높은 열량을 지니고 있다. 이러한 특성으로 연소시 소각로 내부의 온도가 부분적으로 급격히 상승하여 적정온도조절이 어렵고, 로내 장치들의 내구성이 저하되는 등 문제가 발생하고 있다. 또한, RPF에 포함된 비교적 높은 농도의 염소 함량(0.8~1.8% wt)으로 인해 다량의 대기오염물질이 발생되는 단점이 나타나고 있다. 따라서, 이러한 문제점들을 개선하기 위해 RPF의 개질이 필요하며 본 연구에서는 슬러지와 RPF를 혼합하여 열량, 성형성, 염소함량등을 고려하여 최적의 혼합비율을 선정하였다. J하수처리장에서 발생하는 하수슬러지를 이용하여 5, 15, 25, 30, 35%를 RPF 성형공정에 혼합하여 실험하였다. 5% 혼합시 발열량은 약 6,300~6,800kcal/kg, 염소농도는 0.8~1.6%(wt), 15% 혼합시 발열량은 5,500~6,000kcal/kg, 염소농도는 0.7~1.4%(wt), 25% 혼합시 발열량은 5,200~5,900kcal/kg, 염소농도는 0.6~1.1%(wt), 30% 혼합시 발열량은 5,000~5,700kcal/kg, 염소농도는 0.6~1.0%(wt), 35% 혼합시 발열량은 4,800~5,200kcal/kg, 염소농도는 0.4~0.6%(wt)으로 나타났다. 각 혼합비율에서 관찰된 성형성은 5~25% 혼합까지는 성형된 RPF와 유사하게 일정한 크기 및 강도를 유지 할 수 있었으나, 25% 이상 혼합시 분말형태의 가루가 많이 발생되며 강도가 약해져 쉽게 부스러지는 문제점등이 나타났다. 연료의 개질 형태나 성형성등을 고려하였을 때 슬러지 혼합비율이 약 15~25% 정도가 최적 혼합비율인 것으로 나타났다.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.104-111
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• 2000

The study war carried out to evaluate the characteristics of inorganic phosphate factions in soil mixed with paper mill sludge compost(PMSC). The experiments were conducted by an incubation test. For the incubation test, application rates of PMSC to soil were 0, 2, 8, and 16%. Water content of the samples mixed with PMSC were adjusted to 10% and 15% and incubating temperatures of the samples were kept at $4^{\circ}C$ and $30^{\circ}C$, respectively. The results can be concluded as follows; pH increased depending on the higher rates of PMSC application to the soil during the incubation tests, because calcium content was $4.9cmol_c/kg$ and contents of nutrients were high. When the application rates of PMSC were increased Saloid-P and Fe-P decreased, while Al-P and Ca-P in soil increased during the incubation tests.