• 에너지공학
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• 제26권1호
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• pp.62-67
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• 2017

Limestone is an important commodity in Philippines. Limestone has numerous uses that range from agricultural applications to building materials to medicines. Many limestone products require rock with specific physical and chemical characteristics. Most limestone is biochemical in origin meaning the calcium carbonate in the stone originated from shelled oceanic creatures. In this paper, we reported the natural sources of limestone, geological formation of limestone and the oyster shell waste in Cebu, Bantayan, Philippines were reported. Due to the mining or quarrying in Cebu, Bantayan, in a limestone area poses the threat of groundwater pollution (since limestone is a porous geologic formation with a high transmissivity). The other environmental issue is oyster shell waste. The oyster shell waste is the major source of limestone. We developed and applied appropriate technologies for the extraction of limestone from oyster shell waste and utilizes as high value added material.

• 에너지공학
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• 제27권1호
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• pp.59-64
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• 2018

In this paper, we investigated the alternative sources of limestone. Oyster shell waste originated from aquaculture that causes a major disposal landfill problem in coastal sectors in southeast Korea. Their inadequate disposal causes a significant environmental problems araised. Bio mineralization leads to the formation of oyster shells and consists $CaCO_3$ as a major phase with a small amount of organic matter. It is a good alternative material source instead of natural lime stone. The utilization of oyster shell waste for industrial applications instead of natural limestone is major advantage for conservation of natural limestone. The present work describes the limestone and oyster shells hydraulic activity and chemical composition and characteristics are most similar for utilization of oyster shell waste instead of natural limestone.

• 한국환경보건학회지
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• 제32권5호
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• pp.469-477
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• 2006

When denitrification was connected with a single stream process by using biofilter and sulfur-limestone, it was found that such connection enabled highly efficient nitrification without special unit operation of microorganisms or injection of external carbon sources which is being shown in general biological treatment processes. It was observed that in the trickling filter bed, decomposition of organic substances and highly efficient nitrification by both the forced pressure feed trickling and the air fan were simultaneously done. In the denitrification tank where sulfur-limestone was mixed at a certain ratio, limestone was used by autotrophic microorganisms as a source of supply for alkalinity, and nitrate $NO_{3}^{-}$-N was denitrified into nitrogen gas. And in the sulfur-limestone autotrophic denitrification, $NO_{3}^{-}-N\;or\;NO_{2}^{-}-N$ was denitrified as a sulfur compound in reduction state was oxidized into a final output of $SO_{4}^{-2}$. The mean concentration of the discharge water was 8.6 mg/l for T-N and 0.8 mg/l for T-P, respectively, and their mean treatment efficiency was 79.2% and 80.8%, respectively. Implementing highly efficient denitrification without injection of an external organic carbon source or internal return, it is concluded that the proposed process is suitable for a sewerage in a small village with the merits of low power consumption and easy maintenance.

• 한국환경과학회지
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• 제15권6호
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• pp.587-592
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• 2006

The advantage of CFBC(Circulating fluidized bed combustor) is that it can apply to various fuel sources including the lower rank fuel and remove SOx by means of direct supply of limestone to the combustor without additional desulfation facility. In this paper, we denote characteristics of fly and bed ash to reuse finer limestone usually abandoned(used spec[Coarse LS] 0.1mm under 25%, new spec[Fine LS] 0.1mm under 50%). According to the results, the chemical composition of fly ash was as follows; $SiO_2\;40.8%,\;Al_2O_3\;31.9%,\;CaO\;10.7%,\;K_2O\;4.46%$ in the case of coarse limestone and $SiO_2\;41.1%,\;Al_2O_3\;31.3%,\;CaO\;10.9%,\;K_2O\;4.66%$ in the case of fine limestone. The chemical composition of bed ash was as follows; $SiO_2\;54.2%,\;Al_2O_3\;33.1%,\;CaO\;1.56%,\;K_2O\;4.34%$ in the case of coarse limestone and $SiO_2\;53.8%,\;Al_2O_3\;32.6%,\;CaO\;2.21%,\;K_2O\;4.45%$ in the case of fine limestone. It showed that there was no significant change in chemical composition. And it is conformed that there was no significant change in particle size and shapes.

• 상하수도학회지
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• 제19권6호
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• pp.720-727
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• 2005

This study was performed to advance nitrogen removal efficiency by employing an single biofilter packed with granular sulfur, which consists of nitrification occurring at upper part and denitrification at lower part of the reactor. Continuos nitrification/denitrification was carried out with different alkalinity sources, which were $NaHCO_3$ and $CaCO_3$(limestone). In the downflow nitrification/denitrification biofilter packed with granular sulfur, first, terms for nitrogen removal was decided. As results, nitrification and denitrification rate with NaHCO3 at 0.85 kg $NH_4^+-N/m^3{\cdot}d$ were accomplished $0.80kg\;N/m_3{\cdot}d$, $0.43kg\;N/m^3{\cdot}d$, respectively. In the sulfur/limestone packed downflow nitrification/denitrification biofilter, sulfur and limestone were mixed packed, preliminary test showed sulfur/limestone mixing ratio was 3:1 and that was ideal. In the result, nitrification and denitrification rate at $0.7kg\;NH_4^+-N/m^3{\cdot}d$ were accomplished$0.65kg\;N/m^3{\cdot}d$, $0.34kg\;N/m^3{\cdot}d$, respectively. In general, employing granular sulfur can be implemented for only denitrification, but this system can accomplish nitrification as well as denitrification in a single reactor even though low carbon concentration was present in influent limiting to nutrient removal process. This biofilter system of limestone and granular sulfur packed together can successfully apply for nutrient removal effectively.

• 한국농공학회논문집
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• 제49권2호
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• pp.75-86
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• 2007

This process which has a connection of biofilter and sulfur-limestone has been developed to treat organic substances including BOD, COD and SS etc. and to treat sulfur-limestone is for denitrification.. The whole process consists of chemical reaction tank, sedimentation tank, trickling filter, denitrification tank The trickling filter is equipped with a reactor filled with absorptive filter, and the sulfur denitrification tank is filled with sulfur-limestone mixed media. After setting up practical facilities whose capacity is 60 tons a day, we have observed the removal efficiencies of pollutants through 60 experiments during Summer and Winter seasons. The average concentration of polluted water was BOD for 3.6 mg/L, $COD_{Mn}$ for 11.3 mg/L, SS for 2.8 mg/L, T-N for 8.6 mg/L, and T-P for 0.8 mg/L, and the rate of treatment efficiencies 96.5%, 84.7%, 96.5%, 79.2%, and 80.8%, respectively was found through the experiments. The average treatment efficiency for BOD and $COD_{Mn}$ was 85.0% and 55.7%, respectively and the average removal efficiency for NH4+-N was 84.9% in the trickling filter. The removal efficiency in the denitrification tank is as follows; The removal rate of $NO_3^--N$ was as high as 93.2% within the compass of pH 6.3 to 7.3 through $16.8{\sim}37.0mg/L$ flown into $NO_3^--N$ and $0.1{\sim}8.3mg/L$ outflown. It had observed that this process has implemented highly efficient and advanced treatment without external carbon sources and internal recycle during its process. In conclusion, this process is suitable for a sewerage in a small village due to the merits of low power consumption and easy maintenance.

• 한국토양환경학회지
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• 제4권2호
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• pp.63-75
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• 1999

본 연구에서는 폐탄광폐수를 처리하기 위한 SRB의 탄소원으로 하수슬러지와 제지슬러지를 활용가능성과 아울러 석회석에 의한 영향을 검토하였다. 유입 폐탄광폐수의 pH가 평균 3.3정도로 낮음에도 불구하고 전 실험기간동안에 유출수중 평균 pH는 약알칼리성으로 SRB의 생육에 적합한 pH를 유지하였다. 실험초기에 Washout현상으로 높은 TCODcr농도를 나타내었지만 시간이 경과함에 따라 낮아져 유기물의 상승으로 인한 이차적인 오염문제는 없을 것으로 여겨진다. Mn을 제외한 대부분의 중금속은 ${SO_4}^2$ 환원량이 많아짐에 따라 고정경향이 강하여 유출수 중 낮은 농도를 나타내었으나, Mn의 경우에는 유출수중 높은 농도를 나타내었다. 하수슬러지의 혼합비율이 제지슬러지와 같거나 많은 경우에 비교적 중금속 제거효율과 ${SO_4}^2$ 환원율이 높으나 제지슬러지 보다 단기간 분해가능한 하수슬러지가 2배 정도 많은 경우에 유기물의 지속성 측면에서 적절하지 못하며 오히려 혼합비율이 같은 경우가 더 적절하다고 여겨진다. 석회석과 생물학적 처리에 의한 효율을 비교.검토해본 결과, 생물학적 처리에서 pH 중화와 중금속 제거효율이 높았다.

• Journal of Animal Science and Technology
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• 제50권6호
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• pp.799-806
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• 2008

본 연구는 산란계에 있어 오전오후 사료 분리급여를 위한 실용적 방법을 모색하고자 고칼슘수준(칼슘 3.7%) 사료와 저칼슘사료(칼슘 0.3%) 2가지 기초사료에 석회석을 정확히 칭량한 후 배합사료 위에 고루 뿌려 주면서 0, 10g 및 20g씩을 각각 급여하여 산란생산성 및 계란품질에 미치는 효과를 구명하였다. 시험 전기간 동안 산란율, 난중 및 1일 산란량에서는 처리구간 유의적 차이는 나타나지 않았으나 시험 기간이 지나면서 칼슘 3.7% 수준에서 석회석을 10g 추가 급여한 처리구와 무칼슘 사료에 칼슘 10g 별도 급여 처리구에서 산란율이 개선되는 것으로 나타났다. 칼슘 및 석회석 섭취량은 공급수준이 증가할수록 증가하는 것으로 나타났는데 고칼슘 급여구가 저칼슘에 비하여 다소 낮은 경향을 보였다. 난각강도 및 난각두께는 석회석을 추가 급여한 처리구에서 개선되는 것으로 나타났다. 혈액 생화학분석에서 glucose는 관행수준 칼슘급여량이 칼슘 추가 급여구에 비하여 높은 수준을 보였다(P<0.05). Total protein은 고칼슘 급여구가 상대적으로 높은 수준을 보였으며 Inorganic P은 고칼슘 급여구에서 전반적으로 높았으나(p<0.05), 처리구간 비교 시 일정한 경향을 나타내지는 않았다. 따라서, 결과적으로 본시험에서는 고칼슘 사료 내 석회석의 추가 급여 하였을 때 10g 정도가 적절하였으며 일정기간이 지나면서 생산성 및 계란품질에 있어 개선효과가 나타나는 것으로 알 수 있었다.

• 대한환경공학회지
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• 제22권3호
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• pp.463-473
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• 2000

폐금속광산폐수를 혐기성 생물학적 처리를 함에 있어서 석회석에 의한 화학적 전치리의 특성을 파악하고 SRB를 위한 탄소원으로서 제지 및 축산슬러지의 적용 가능성을 검토하였다. 혐기성 석회석층의 효능은 시간이 경과함에 따라 급격하게 감소하였지만 폐금속광산폐수의 혐기성 생물학적 처리에 있어서 전처리공정으로 활용할 경우에 초기에 중화능이 우수하여 후속처리 공정에 높은 pH를 제공함으로서 시스템의 안정화에 기여할 수 있을 것으로 여겨진다. R-1~R-3에 비하여 R-4에서 실험초기 HRT 5일에 유출 SCOD가 낮을 뿐만 아니라 시간이 경과한 후 HRT 1일에 오히려 높은 농도를 나타내어 유기물의 지속성과 공급 측면에서는 단기간 내에 다량의 분해에 의한 유기물 소실보다는 유용할 것으로 판단되어진다. 모든 반응조에서 전 HRT에 걸쳐 SRB의 성장에 적합한 안정적인 pH를 유지하였으나, ORP를 보면 HRT 2일 이후에 SRB의 생육을 위한 최적조건을 유지하고 있어 SRB의 활성이 가장 활발하였던 것으로 평가되었다. $SO_4{^{2-}}$ 환원효율에 따라 중담속 제거효율 또한 비슷한 경향을 보여주고 있으며, HRT 2일에 $SO_4{^{2-}}$ 환원효율과 중금속 제거효율이 비교적 높은 것으로 평가되었다.

• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2001년도 International Symposium on Food,Nutrition and Health for 21st Century
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• pp.126-133
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• 2001

As dietary intakes levels of Calcium decrease below those recommended by health authorities the incidence of Osteoporosis is set to continue to rise. To address this issue it is becoming necessary to fortify regularly consumed foods such as cereals, biscuits etc. with ingredients such as AquaCal. AquaCal is a natural, organic source of calcium that is produced from calcified seaweed, Phymatolithon and Lithothamnion and can be utilised for Calcium and magnesium supplementation in a broad range of foods and beverages. AquaCal presents a great potential over other calcium sources because of its porous structure and it composition associating key minerals as calcium, magnesium and boron in addition to being neutral in taste in applications. Once consumed the efficacy of AquaCal must then be verified therefore a bioavailability a comparative feeding study to assess effects of AquaCal on bone density was carried out. There was no significant difference in bioavailability based on calcium absorption between AquaCal and Limestone however the weights of the femurs of the animals fed AquaCal did significantly increase over the group fed Limestone. As a natural and organic mineral AquaCal has many different fields of application.