• Title, Summary, Keyword: 비산재

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Field Evaluation of Particulate Control Efficiency of Electrostatic Precipitator in Thermoelectric Power Plant Associated with Addition of Triethyl Amino(TEA) (트리에틸아민 첨가에 따른 열병합발전소 전기집진장치의 집진효율 특성의 현장 평가)

  • Jo, Wan-Kuen;Jeon, Ok-Sang
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.4
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    • pp.445-449
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    • 2005
  • Present study was designed to evaluate the practical application of triethyl amine(TEA) injection for improving the collection efficiency of electrostatic precipitator(ESP) connected to a real operating plant. The major fuels used at the domestic power stations were bituminous coals imported from Australia, China, South Africa, and USA. Although the values of the electric resistance would be more or less different according to the type of the coals used, the unique electric resistance values of fly ash from the coals were mostly higher than $1{\times}10^{12}\;{\Omega}-cm$ and therefore, back corona problems were always expected to occur in the electrostatic precipitator. The particulates concentrations, smoke concentrations and their electric resistivity measured at the outlet of ESP, and the inspection of collection indicated that the injection of TEA improved the collection efficiency of particulate at collection plates of ESP. The electric resistance for, fly ash with the injection concentration of TEA 15 ppm(Purity 99.7%) was lowered to $2.1{\times}10^{11}\;{\Omega}-cm$ after injection from $1.9{\times}10^{12}\;{\Omega}-cm$ before injection. Under this condition, the dust emission content at the stack was reduced to approximately 80%, lowering the average outlet concentrations of particulates from $70\;mg/Sm^3$ to $14\;mg/Sm^3$.

Physical and Mechanical Properties of Cements for Borehole and Stability Analysis of Cement Sheath (관정 시멘팅 재료의 물리역학물성 및 시멘트층의 안정성 분석)

  • Kim, Kideok;Lee, Hikweon;Kim, Taehee;Kim, Gyo-Won
    • The Journal of Engineering Geology
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    • v.26 no.1
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    • pp.101-115
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    • 2016
  • We carried out laboratory material tests on two cements (KS-1 ordinary Portland and Class G) with changing W/S (Water/Solid) and the content of fly ash in order to evaluate their physical and mechanical properties. The specimens of KS-1 ordinary Portland cement were prepared with varying W/S (Solid=cement) in weight, while those of Class G cement were prepared with changing the content of fly ash in volume but maintaining W/S (Solid=cement+fly ash). The results of the material tests show that as the W/S in KS-1 ordinary Portland cement and the content of fly ash in Class G cement increase, the properties (density, sonic wave velocity, elastic constants, compressive and tensile strengths, thermal conductivity) decrease, but porosity and specific heat increase. In addition, an increase in confining pressure and in the content of fly ash leads to plastic failure behavior of the cements. The laboratory data were then used in a stability analysis of cement sheath for which an analytical solution for computing the stress distribution induced around a cased, cemented well was employed. The analysis was carried out with varying the injection well parameters such as thickness of casing and cement, injection pressure, dip and dip direction of injection well, and depth of injection well. The analysis results show that cement sheath is stable in the cases of relatively lower injection pressures and inclined and horizontal wells. However, in the other cases, it is damaged by mainly tensile failure.

Synthesis of Zeolite P1 and Analcime from Sewage Sludge Incinerator Fly Ash (하수슬러지 소각 비산재를 이용한 제올라이트 P1 및 Analcime의 합성)

  • Lee, Je-Seung;Chung, Sook-Nye;Park, Chul-Hwi
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.6
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    • pp.659-665
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    • 2008
  • This study is about zeolite synthesis from the sewage sludge incinerator fly ash of "S" sewage treatment center located in Seoul. For this purpose, the properties of raw fly ash as starting material, the hydrothermal conditions for zeolite synthesis and the environmental applicabilities of synthesized zeolites were examined. Fly ash from sewage sludge incinerator has large quantities of SiO$_2$ and Al$_2$O$_3$ and their contents are 42.8 wt.% and 21.2 wt.% respectively. So fly ash is considered to be possible starting material for zeolite synthesis. The results from leaching test of fly ash showed that the concentration of hazardous metals were very low as compared with the Korea leaching standard of the Waste Management Law. But the concentration from total recoverable test of fly ash were higher than the fertilizer standard of Fertilizer Management Law. Major zeolite products synthesized by hydrothermal reaction are analcime in teflon vessel and zeolite P1 in borosilicate flask. Optimum conditions for the synthesis of analcime were 1 N of NaOH concentration, 16 hour of reaction time and 135$^{\circ}C$ of reaction temperature. For the zeolite P1 formation, the proper conditions were demonstrated to be 5 N of NaOH concentration, 16 hour reaction time and 130$^{\circ}C$ of reaction temperature in this study. Hazardous metal contents in the analcime product are similar with those in raw fly ash. In case of the zeolite P1, the contents are reduced to nearly a half. Raw fly ash and the analcime product showed NH$_4{^+}$ ion exchange capacity of 0$\sim$1.0 mg of NH$_4{^+}$g$^{-1}$ and 3.0$\sim$7.4 mg of NH$_4{^+}$g$^{-1}$, respectively. However, the zeolite P1 product reached exchange capacity to 14.6$\sim$17.8 mg of NH$_4{^+}$g$^{-1}$. This values are in the range of those of natural clinoptilolite and phillipsite. From this point of view, zeolite synthesis from sewage treatment sludge incinerator fly ash is a good alternative for solid waste recycling.

A Study on Changes in Heavy Metal Contents in Concrete Prepared Using Coal Ashes (석탄재의 콘크리트 활용에 따른 중금속 함량변화 연구)

  • Lee, Jinwon;Choi, Seung-Hyun;Kim, Kangjoo;Kim, Seok-Hwi;Moon, Bo-Kyung
    • Economic and Environmental Geology
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    • v.51 no.4
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    • pp.371-379
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    • 2018
  • In many countries, recycling coal ashes as backfill materials for subsided lands, abandoned mine tunnels, and road pipeline constructions by making low-strength concretes with minimal amounts of cement is frequently considered for massive treatment of coal ashes. This study investigates the variation of heavy metals in the concrete test pieces prepared for the cases of using only Portland cement as binding material, fly ash as a replacement of the cement, sand as aggregates, and disposed ashes in the ash ponds as a replacement of aggregates. Heavy metal contents were measured based on the aqua regia extraction technique following the Korean Standard for Fair Testing of Soil Contamination and the influences of each materials on the total heavy metal contents were also assessed. Results show that the cement has the highest Cu, Pb, and Zn concentrations than any other materials. Therefore, the test pieces show significant concentration decreases for those metals when the cement was replaced by fly ash. Ponded ash shows low concentrations relative to fly ash in most of the parameters but shows higher Cu and Ni, and lower Pb levels than the sand aggregate. In overall, heavy metal levels of the test pieces are regulated by mixing among the used materials. Test pieces prepared during this study always show concentrations much lower than the Worrisome Level of Soil Contamination (Area 1), which was designated by the Soil Environment Conservation Act of Korea.

An Experimental Study of the Effect of Vehicle Speed on Resuspension of Road Dust (차량속도 영향에 의한 도로 표면 먼지의 재 비산에 관한 실험적 연구)

  • 원경호;정용원;홍지형
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • pp.378-379
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    • 2003
  • 도로에서의 비산먼지는 건설현장 트럭에 의한 토사의 유입, 운반 중에 날리는 토사, 토양의 침식, 겨울철 모래살포, 타이어의 마모등에 의하여 도로표면에 쌓인 먼지가 차량의 운행이나 바람으로 인하여 발생한다 국내 주요도시 및 산업단지는 대부분이 포장도로로서 주변환경에서 유입되는 먼지와 함께 차량의 운행으로 인한 비산먼지(Fugitive dust)의 영향이 지대하며, 건설현장에서 발생되는 비산먼지와 함께 도시ㆍ산단지역의 미세먼지 배출량에 큰 기여를 하는 것으로 조사되었다. (중략)

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Preparation of a CRM for QA/QC in dioxin analysis and inter-laboratory study (다이옥신 정도 관리용 CRM 제조와 실험실간 비교평가)

  • Yu, Byeong-Woon;Moon, Young-Hoon;Kim, Min-Kwan;Kyoung, Jong-Dai;Chang, Yoon-Seok
    • Analytical Science and Technology
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    • v.17 no.2
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    • pp.153-162
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    • 2004
  • Dioxin CRM for QA/QC was prepared with fly ash collected from municipal waste incinerator. With that CRM inter-laboratory test was carried out. The collected fly ash was conducted several homogeneity steps including sievings and mixing. Homogeneity test and estimation of uncertainty was performed by one-way ANOVA based on ISO guide 35. Compared concentrations of fly ash of participants to CRM values, PCDDs value was lower than that of CRM in almost participants, and showed higher PCDFs concentration than that of CRM. Although there is a small difference in PCDD/Fs concentrations with congeners of extract, the result was close to mean value.

A Comparative Study on Adsorption Characteristics of Total Nitrogen and Phosphorous in Water Using Various Adsorbents (여러 흡착제를 이용한 총질소와 총인 흡착특성에 관한 비교연구)

  • Ryoo, Keon Sang;Choi, Jong-Ha
    • Journal of the Korean Chemical Society
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    • v.56 no.6
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    • pp.700-705
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    • 2012
  • The present study is to explore the possibility of utilizing loess and fly ash as well as activated carbon for the adsorptive removal of T-N and T-P in water. Here, we investigated adsorption efficiency and Freundlich constants k and 1/n of each adsorbent. It was found that fly ash has not adsorptive capability for both T-N and T-P in water. Adsorption of T-N from water by loess has not occurred, but showed that adsorption efficiency for T-P reached approximately 57.5% at equilibrium time of 24 hr and room temperature. Activated carbon was shown to be an effective adsorbent for adsorption of T-N from water. Freundlich constant 1/n value of activated carbon represented that adsorptive capability of activated carbon is almost equivalent to loess.