• 환경생물
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• 제17권2호
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• pp.183-190
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• 1999

The bioleaching of heavy metals from fly ash was performed by Thiobacillus thiooxidans MET isolated from the enrichment culture of an anaerobically digested sludge. The effect of solid concentrations on the efficiency of metal leaching was studied in shaken flasks. In the range of solid concentrations 20 g.L­$^1$to 100 g.L­$^1$T. thiooxidans MET oxidized S$^{0}$ to sulfate without any lag period. The final pH of slurry solution was decreased to below pH 1, and the final oxide-redox potential (ORP) was increased to over 420 mV in the solid concentrations below 100 g.L­$^1$. However, the initial lag period of 4 to 8 days was required to obtain the pH reduction and ORP increase of the slurry solutions in the range of solid concentrations 150 g.L­$^1$to 300 g.L­$^1$. The sulfur oxidation rate of T. thiooxidans MET in 20~100 g.L­$^1$solid concentrations was 0.70~0.75 g-S.L­$^1$ㆍ d­$^1$, but its sulfur oxidation activity was remarkably inhibited with increasing solid concentration over 150 g.L­$^1$. Increasing fly ash solids concentration in the range of solids concentration 20 g.L­$^1$ to 200 g.L­$^1$decreased the removal efficiency of Zn, Cu, Mn, Cr and Pb. The solubilization of heavy metals from fly ash was strongly correlated with the pH value of slurry solution. When the pH of slurry solution was reduced to 3, the solubilization process of Zn, Cu and Mn started, and their solubilization efficiency of Zn, Cu and Mn was progressively increased below pH 2. However, the solubilization process of Cr and Pb started at pH 2.5 and 2.0, respectively.

• 한국축산시설환경학회지
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• 제1권2호
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• pp.165-171
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• 1995

액상 폐기물의 자원화 처리 방법의 하나로서 공해방지와 지력증강을 위하여 액상유우 분뇨의 호기성 처리기술을 실용화하는데 기초자료가 되는 액상유우 분뇨의 화학적 특성 분석 결과는 다음과 같다. 1)고액 분리하지 않은 액상유우 분뇨의 고형물 농도(TS)는 7.54(%wb), 산도(pH)는 6.92, 유기물 농도(TS)는 79.34(%TS), 화학적 산소 요구량(COD)은 81,300~96,500(mg/$\ell$), 암모니아태 질소(NH$_3$-N)는 1,690~2,300(mgfe), 및 질산태 질소(NO,-Pf)는 36.0-40.0(mg/$\ell$) 이었다. 2) 고액분리된 액상유우 분뇨의 화학적 특성은 우사형식, 분뇨배출방식, 고액분리기 종류 등에 따라 상이하며 고형물 농도는 4.43~7.95(%wb), 산도(pH)는 7.31, 유기물 농도(VS)는 74.57~79.93(%TS), 화학적 산소 요구량(COD)은 52,400~73,700(mg/$\ell$), 암모니아태 질소(NH$_3$-N)는 2,035~2,960(mg/$\ell$), 질산태 질소(NO$_3$-N)는 19.0~30.0(mg/$\ell$) 의 범위를 나타내고 있었다.

• 한국환경과학회지
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• 제24권1호
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• pp.25-30
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• 2015

This study aimed to evaluate the effects of probiotics as manure additives on pathogen, mineral, carbon dioxide and methane emissions in pig slurry as a function of time and provide information about the importance of pig slurry management to pig producers. An experiment was a completely randomized design and four treatments: CON: no treatment (5 kg pig slurry), T1: 5 kg pig slurry + 0.2% bacillus subtilis, T2: 5 kg pig slurry + 0.2% yeast, T3: 5 kg pig slurry + 0.2% actinomycetales. All treatments were replicated three times. The results information that is analyzed includes the following: First, in spite of the lack of statistically significant differences, pH values and carbon dioxide were lowered (P < 0.05) in all probiotic treatments compared with the controls as a function of time. Second, all probiotic treatments had no effect on Salmonella enterica, mineral, and methane emission. The results of this study indicated that addition of 0.2% probiotic to pig slurry resulted in lower pH and carbon dioxide emissions, and carbon dioxide and methane emitted from pig slurry is not listed as noxious gases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.605-606
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• 2006

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40 %. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$,$CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.2237-2238
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• 2006

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40 %. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$, $CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1271-1272
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• 2006

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40%. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$, $CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1731-1732
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• 2006

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40 %. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$, $CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

• Journal of Animal Science and Technology
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• 제46권3호
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• pp.469-478
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• 2004

본 연구는 양돈액비의 비료성분 및 유해정도를 분석하고 아울러 전기전도도나 건물 함량을 이용하여 중요 비료성분 함량을 쉽게 추정하는 방벙을 구명하기 위해 2001년 제주도내 109개 양돈 농가를 방문하여 액비를 수집,$4^{\circ}C$냉장고에 보관해 두었다가 꺼내어 pH, BOD, DM, SS, OM, EC, T-N, T-P, K, Ca, $NH_4$-N. Mg 및 Na 등을 분석하였다. 조사대상 농가의 돈분 액비 중 슬러리(70 농가)는 가축분뇨, 사료 및 청소수가 혼합된 것이고 요(19 농가)는 분뇨를 고액분리 시킨 후에 저장해둔 요(20 농가)를 말하며 돈분 발효액은 slurry를 발효, 폭기 및 살수 등의 과정을 거친 액비를 뜻한다. 돈분 액비 중 slurry로 저장한 액비가 요나돈분 발효액 보다 여러 가지 비료 성분함량($NH_4$-N, K, P, Ca, Mg 및 Na)이 높았고 전기 전도도나 건물함량도 마찬가지로 slurry 상태로 저장한 액비가 다른 상태의 액비 보다 높았다. EC, $NH_4$-N, Ca, Mg 및 Na의 함량은 요와 발효액 간에 비슷하였으나 발효 액비의 L 함량이나 건물함량은 요 보다 약 2배 정도 높았다. 한편 P 함량은 반대로 발효 액비보다 요에서 높았다. Slurry의 전기전도도(EC)와 여러 비료 성분간에 상관관계를 통계 분석한 결과, $NH_4$-N와 Na 함량만이 유의적인 상관관계가 인정되었고 slurry의 DM 함량은 $NH_4$-N, P, Ca 및 Mg 함량간에 유의성이 인정되었다 (P<0.05). 고액분리요의 전기전도도와 비료성분간에 상관관계 분석에서 $NH_4$-N만 유의적 상관관계가 있었고 DM 함량에서는 $NH_4$-N와 Ca 간에만 유의적 상관관계가 인정되었다(P<0.05). 발효 액비는 전기전도도와 $NH_4$-N, P 및 Ca 간에만 유의적 상관관계가 있었으며 DM 함량은 K, P, Ca, Mg 및 Na 간 통계적으로 유의적 상관관계가 있었다(P<0.05). 돈분 액비의 종류별로 유해 또는 오염물질 농도를 살펴보면 슬러리의 BOD 농도는 22,520mg/L로 요 및 발효 액비 4,763, 2,701 mg/L보다 크게 높았다. 결론적으로 비료효과는 slurry가 요 및 돈분발효액 보다 좋았지만유해 또는 오염물질농도는 반대로 slurry에서 높았다. 그러나 일반기준치와 비슷한 수준으로 유해위험은 없다고 생각된다.

• 한국전기전자재료학회논문지
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• 제17권9호
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• pp.1001-1005
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• 2004

Rye-sensitized solar cell (DSSC) is a new class of solar cell, which consists of nanoporous TiO$_2$ electrode, dye-sensitizer, electrolyte, and counter electrode. Such cell is operated in sunlight via the principle of photosynthetic electrochemistry. In order to obtain the good dispersion of nano size TiO$_2$ particles In slurry, the pH of solvent, the sort and quantify of solvent additive and the quantity of surfactant were adjusted. As results, the lower the pH of solvent was the lower the viscosity of the slurry became. The addition of ethylene glycol and propylene glycol to dilute HNO$_3$ brought about the lowering of viscosity and the enhancement of stability in slurry. The addition of surfactant lowered the viscosity of slurry. It was possible to obtain the homogeneous and uniformly dispersed mesoporous TiO$_2$ film using the dilute HNO$_3$ solvent of pH 2 with the addition of ethylene glycol and neutral surfactant. DSSC was assembled with TiO$_2$ electrode and Pt electrode, and its photoelectric property was measured using the monochromatic wavelength in the rangee of 350∼700 nm.

• 한국환경과학회지
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• 제18권7호
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• pp.819-824
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• 2009

The objectives of this study were to evaluate the effects of chemical additives on total phosphorus (TP), soluble reactive phosphorus (SRP), and total volatile fatty acids (total VFAs) in hanwoo slurry. The treatments in this study were ferrous sulfate, alum, and aluminum chloride, and applied at the rate of 0, 0.5, and 1.0 g/25 g of hanwoo slurry. All of the chemical treatments significantly lowered TP (11 to 53% of the untreated control), SRP (41 to 99.9% of the untreated control), and total VFAs (22 to 48.5% of the untreated control) by reducing hanwoo slurry pH (3.42 to 6.86). Among these chemical amendments, addition of 0.5 g ferrous sulfate, alum, and aluminum chloride to hanwoo slurry were the best results evaluated on farms with respect to reducing negative environmental impacts. In conclusion, the results of this study indicate that the use of chemical amendments should be considered in the development of best management practices (BMPs) for the hanwoo industries.