• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2802-2811
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• 2023

In a first-of-its-kind study, terrestrial radionuclide concentrations were measured in 35 topsoil samples from the outskirts of Dhaka using HPGe gamma-ray spectrometry to assess the radiological consequences of such a vast number of brick kilns on the plant workers, general as well as dwelling environment. The range of activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K is found at 19 ± 3.04 to 38 ± 4.94, 39 ± 5.85 to 57 ± 7.41, and (430 ± 51.60 to 570 ± 68.40) Bq/kg, respectively. ²³²Th and ⁴⁰K concentrations were higher than the global averages. Bottom ash deposition in lowlands, fly ash buildup in soils, and the fallout of micro-particles are all probable causes of the elevated radioactivity levels. ¹³⁷Cs was found in the sample, which indicates the migration of ¹³⁷Cs from nuclear accidents or nuclear fallout, or the contamination of feed coal. Although the effective dose received by the general public was below the recommended dose limit but, most estimates of hazard parameters surpass their respective population weighted global averages, indicating that brick kiln workers and nearby residents are not safe due to prolonged exposures to terrestrial radiation. In addition, the soil around sampling sites is found to be unsuitable for agricultural purposes.

• 분석과학
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• 제19권2호
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• pp.172-180
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• 2006

본 연구는 유해폐기물에 의한 환경오염을 예방하기 위해 폐기물 시험방법과 신규 항목을 설정하기 위해 수행하였다. 국내외 유해폐기물의 규제기준, 시험항목 등을 조사검토하여 유해물질에 대한 우선순위를 선정하였다. 선정한 Ba, Be, Cr(VI), F, Ni, Sb, Se, V 8종의 유해물질을 함유한 오니, 폐유, 소각재 등 폐기물 인증표준물질을 사용하여 전처리방법을 비교분석하였다. 이 결과를 통해 시험방법(안)을 확립하고, 관련 항목 배출 가능성이 있는 표본사업장을 선정하여 시료 37건을 채취분석하였다.

• Journal of the Korean Wood Science and Technology
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• 제52권2호
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• pp.118-133
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• 2024

The sapwood portion of fast-growing teak is mostly ignored due to its inferior quality. One of the possibilities for utilizing sapwood waste is to convert it into activated carbon that has good adsorption capabilities. The raw materials used in this research were sapwood of 14-year-old fast-growing teak sapwood (FTS) waste, which was taken from three trees from community forests in Wonosari, Gunungkidul, Yogyakarta Special Region. FTS waste was taken from the bottom of the tree up to a height of 1.3 m. The activation process is conducted with an activation temperature of 750℃, 850℃, and 950℃. The heating duration consists of three variations: 30 min, 60 min, and 90 min. The quality evaluation parameters of activated carbon include yield, moisture content, volatile matter content, ash content, fixed carbon content, adsorption capacity of benzene, adsorption capacity of methylene blue, and adsorption capacity of iodine. The results showed that the activated carbon produced had the following quality parameters: yield of 75.61%; moisture content of 1.27%; volatile matter content of 9.98%; ash content of 5.43%; fixed carbon content of 84.58%; benzene absorption capacity of 8.58%; methylene blue absorption capacity of 87.73 mg/g; and iodine adsorption capacity of 948.19 mg/g. It can be concluded that activated carbon from FTS waste has good iodine adsorption, which fulfilled the SNI 06-3730-1995 quality standard. Due to the iodine adsorption ability of FTS waste activated carbon, the conversion of FTS waste to activated carbon is categorized as a potential method to increase the value of this material.

• Korean Chemical Engineering Research
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• 제47권5호
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• pp.580-586
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• 2009

본 연구에서는 2 MWe 규모 순환유동층 발전소에서 중국산 유연탄과 북한산 무연탄의 혼합연소특성을 실험적으로 고찰하였다. 중국유연탄과 호주유연탄을 과잉공기량과 층온도 등을 변수로 실험한 결과, 연소효율은 석탄입자의 입도와 석탄중의 휘발분의 영향을 받으며, 이 때 미연탄소분은 Fly ash 5~7%, 바닥회 0.3% 수준으로 중국 유연탄의 연소효율은 99.5% 이상을 보였다. 북한산 무연탄과 유연탄의 혼소시 혼합비 20%에서 무연탄의 평균입도가 작아 연소실에서 비산되는 입자로 인해 연소효율은 5% 이상 저하되었다, 그러나 $SO_2$와 NOx의 배출농도는 크게 변화하지 않았다. 배출되는 대기오염물질의 농도는 $NO_x$ 200~250 ppm($O_2$ 6%), $SO_2$ 100~320 ppm($O_2$ 6%)이었다. SCR 공정에서 2~13 l/min 범위의 $NH_3$ 공급으로 30~65%의 $NO_x$가 저감되었다. Limestone을 이용한 노내탈황에서 약 Ca/S 몰비 6.5를 공급했을 때 $SO_2$가 75% 제거되었고, $Mg(OH)_2$를 흡수제로 하는 FGD를 운전했을 때 pH 5.0 이상에서 100% 탈황효과를 보였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.159.2-159.2
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• 2010

Asbestos is the collective name for a group of naturally occurring minerals in their fibrous form and hydrous silicates of magnesium and a mineral fiber that has been used commonly in a variety of building construction materials for insulation and as a fire-retardant. Asbestos has been used for a wide range of manufactured goods, because of its fiber strength and heat resistant properties. Nevertheless harmful of asbestos is quite serious. Exposure to airborne friable asbestos may result in a potential health risk because persons breathing the air may breathe in asbestos fibers. Continued exposure can increase the amount of fibers that remain in the lung. Fibers embedded in lung tissue over time may cause serious lung diseases including asbestosis, lung cancer. In this paper, we carried out as fundamental study for dispose of asbestos cement slate safely and perfectly. Melting Temperature of asbestos need to more than $1,520^{\circ}C$ and specially asbestos cement slate need more energy than that of pure asbestos. We need to decrease melting temperature of asbestos cement slate for economical efficiency. To the purpose, glass and bottom ash were chosen as additives for basicity control. we analyzed about properties of asbestos cements slate, melting characteristics on the additives ratio and temperature. We confirmed about harmlessness of melting slag through analysis of scanning electron microscope(SEM) and x-ray diffractometer(XRD).

• 한국해양공학회지
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• 제22권5호
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• pp.112-118
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• 2008

The purpose of this study was to determine the engineering and environmental properties of the waste tire powder-added lightweight soil (TLS) used as flowable backfill. The TLS used in this experiment consisted of dredged soil, bottom ash, waste tire powder and cement. Test specimens were prepared with various contents of waste tire powder ranging from 0% to 100% at 25% intervals and water contents ranging from 140% to 200% by the weight of the dry dredged soil. Several series of unconfined compression tests, flow tests, and leaching tests were carried out. Experimental results for the TLS indicated that the unconfined compressive strength, secant modulus (), and unit weight of the TLS decreased with an increase in waste tire powder content. However, as the waste tire powder content increased, the stress-strain relationship of the TLS showed more ductile behavior rather than brittle behavior. The flow value increased with an increase in water content, but decreased with an increase in waste tire powder content. The result of the leaching test showed that the leaching amounts of heavy metals were lower than the permitted limits suggested by the Ministry of Environment.

• KIEAE Journal
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• 제16권1호
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• pp.73-79
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• 2016

This study aimed to investigate the flood prevention effect expected from the afforestation of a large area metal roof of an industrial complex located in an area prone to floods in the rainwater outflow reduction aspect through computer simulation based on soil, which is a key element of the system. In order to conduct a more realistic simulation, the properties of the surveyed soil were generated through substantive analysis, soil texture analysis, and saxton method. A comparative performance evaluation was conducted by using soil depth and ponding depth, which are key elements of the system, as variables. The study result showed that during the heavy rainfall period, the bottom ash artificial soil had 61% rainwater outflow reduction effect, which was 11% higher than the SWMM standard sand.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.247-248
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• 2010

본 연구는 산업폐기물을 이용한 인공경량골재의 제조에 관한 실험적 연구이다. 실험결과, 산화슬래그를 부원료로 사용한 경우, 소성온도 $1,150^{\circ}C$에서 낮은 절건밀도와 낮은 흡수율을 나타내었고 유리연마슬러지의 경우는 본 연구에서 사용한 범위 이상을 사용하여야 경량화가 가능할 것으로 판단된다. 그러나 고로슬래그 미분말은 경량골재 원료로 사용하기에는 부적합한 것으로 판단된다.

• 청정기술
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• 제22권1호
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• pp.1-8
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• 2016

최근 나노기술의 급격한 발전은 산업 분야에 새로운 활용 가능성을 제시하고 있다. 그러나 나노물질의 연간 생산량 증가와 함께, 비의도적인 환경 노출이 야기되고 있다. 따라서 지속적인 나노기술의 발전을 위해서도 나노폐기물에 관한 효과적인 관리가 필요하다. 나노폐기물 처리의 최종 단계는 바로 소각시설을 이용하는 것으로 보고 있다. 나노물질의 소각처리에 관한 문헌자료가 부족하지만, 일부 선도적인 연구자들에 의하면 소각시 나노물질의 대기노출은 억제되지만 바닥재는 결국 매립되어 나노물질은 잔존하게 된다는 것이다. 아직까지는 소각장내 나노물질의 거동과 다양한 질문거리가 남아 있지만, 무엇보다도 소각을 통한 나노폐기물 처리가 인간 및 환경 영향을 최소할 할 수 있는 안전하고 효과적인 나노물질 처리법인지가 검토되어야 할 것이다.

• KIEAE Journal
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• 제13권1호
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• pp.65-74
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• 2013

Recently, greenery system is frequently applied on buildings and artificial grounds to improve urban ecological functionality. Specifically, architectural greenery is also known as an architectural language that can meet the sustainable design concept of architects. Although the architectural greenery system can be optimized through an interdisciplinary approach between architecture, horticulture and landscape- architecture, there is a problem of communication on the ideal gap between them. Therefore, this study is expected to establish the comtemporary architecture as hi-tech and the organic architecture in internationalism. Moreover, it can analyze the case study on architectural greenery system designed by a Pritzker Prize winner who represents the comtemporary architectural trend. In this analysis, we calculate and compare the U-value of the free-form surface system based on the international standards: ISO and CIBSE etc. Moreover, we calculate a change of artificial soil transmittance respect on compounding ratio of the bottom ash and pearlite. In the case of California Academy of Science by Renzo Piano, total transmittance of the greenery system results in 48% of domestic thermal insulation standard in dry condition. This result will be used as a basic study to promote developing the advanced system based on the concept of consilience.