• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.143-144
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• 2019

Recently, environmental pollution related to global warming is on the rise. Meanwhile, renewable energy is a representative example of many efforts to develop eco-friendly energy to solve the depletion of natural resources and the depletion of petroleum resources in conjunction with global warming. Among them, photovoltaic power generation is increasing the subsidies for the government to increase the production of photovoltaic electricity of the general public, showing a high growth rate. However, polysilicon, which is a raw material of the photovoltaic panel, generates waste called polysilicon sludge in the manufacturing process. In order to produce 1 ton of polysilicon, about 2 tons of waste polysilicon sludge is generated. In 2012, polysilicon sludge was generated at 78,000 tons, with an average of about 220 tons per day. The sludge generated due to insufficient treatment of polysilicon sludge is currently solidified and is processed by landfilling. Therefore, in this study, polysilicone sludge is used as the concept of admixture, and the physical properties of the matrix according to the polysilicon sludge replacement ratio based on light burned magnesia is determined.

• 산업기술연구
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• 제16권
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• pp.169-174
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• 1996

Microstructural analyses of synthetic arsenic-containing heavy metal sludges solidified with Portland cement were performed. Heavy metal sludges containing 0.04M of cadmium, chromium, copper, lead, and arsenic were prepared by sodium hydroxide precipitation and successive vacuum filtration. The sludges mixed with cement were cured for 14 days. The solidified sample was characterized by 1) leaching test, 2) scanning electron microscopy and 3) X-ray diffractometry. Of the metals tested, only Pb concentration in the leachate exceeded the Korean regulatory limit. The level of lead in the leachate was as high as 10 times the regulatory limit. X-ray analysis suggested that the metal hydroxides might be present in complex or impure crystalline phases.

• 한국건축시공학회지
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• 제1권2호
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• pp.146-153
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• 2001

Radical development has been made in the every field of our society for the past scores of year. Radical development of industry and lining environment has mass-produced various toxic wastes . Which comes to the fore as a serious environmental problem. The purpose of this is to suggest the optima mix design by studying the utility of a toxic waste, plated sludge as a building material and deciding the standards of quality and use of cement and evaluating the properties of mortar and concrete in which plated sludge mixed. From an experiment, compressive strength required high early strength cement or special cement. Watertightness proved to be excellent. Heavy metals, such as Cd, Pb, Cu came out below an environmental standard. Cr+6 exceeded an environmental standard under a steam curing, but came out below an environmental under a standard curing. The higher replacement rate was, the lower frost, fusion and resistance were. Thus, got better results above the goal by condition. It was possible that plated sludge was replaced and solidified to aggregate. Therefore, it is necessary to define the standards of quality on strength, replacement rate of wastes, water permeability, endurance in other to solidify plated sludge to concrete products.

• 한국응용과학기술학회지
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• 제22권4호
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• pp.379-384
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• 2005

In general, water treatment sludge (WTS) had high concentration of heavy metal, thus it made the reuse or recycling of WTS difficult. The optimal solidification conditions for maximum suppression of heavy metal elution from WTS were decided in this study. Under the optimal solidification conditions (i.e., temperature, $320^{\circ}C;$ ratio of WTS and MgO, 9:1; solidification time, 1hr), all of heavy metal including aluminum were not detected. Therefore there are no problems for reuse or recycling of WTS which was solidified under the optimal solidification conditions found in the study.

• 한국환경보건학회지
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• 제30권2호
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• pp.167-172
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• 2004

In this study, we carried out the research for the recycling potential of the dyeing wastewater treatment sludges as construction materials. The incineration ash of sludges were solidified as interlocking block in condition of sludge/cement ratio 2.5%, 5.0% and 10%, respectively. Those interlocking blocks were cured for 3days, 7days and 28days in ambient air condition, respectively. The results of this research were summarized as follows: The dyeing wastewater treatment sludges was below the Korea Leaching Limit. After incineration, the ash was manufactured as interlocking block. Bendable strength over 50kg$_{f}$/$\textrm{cm}^2$ suitable for interlocking block was obtained only when the sample was cured for 7days at sludge/cement ratio 2.5% and 5.0%. Hygroscopic ratio of interlocking block was above the Korea Industry Standard. We think that recycling of the incineration ash from dyeing wastewater treatment sludges to interlocking block will have high potential possibility.y.

• 한국환경보건학회지
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• 제19권2호
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• pp.46-54
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• 1993

This study was carried out on the stabilized/solidified treatment for the reducing leachability of hazardous heavy metals copper, lead, chromium and cadmium in the hazardous sludge which treated to be unleached heavy metals by sodium diethyl dithiocarbamate. Cement matrix was analyzed for the leachability of 24 hrs and dynamic leaching test, structure and the optimum condition for the stabilization and solidification of the hazardous sludge. In 28 days of curing time the unconfined compressive strength was 21.5 kg/cm$^2$ at the ratio of portland cement (0.5)+fly ash (0.25) and 23.5 kg/cmz at the ratio of portland cement (0.5)+fly ash (0.25) + cake (0.25). High concentration of Pb, Cr and Cd in the sea water and Cu in the distilled water were leached at the dynamic leaching test. The concentration of leaching heavy metals for specimens which were tested 24 hrs were found low leachability with decreasing pH of leachant. According to dynamic leaching test, the low level of copper, lead, cadmium and chromium were leached in the cement matrix with sodium diethyl dithiocarbamate. But the effective diffusion coefficient of unleached cement matrix which was treated sodium diethyl dithiocarbamate was decreased above 2 times than that of cement matrix. The relation of leachant renewal period (Y) and cumulative fraction ion leached (X) was the following regression equations. Solidification with unleached agent. Y$_{Cu}$ = 1413752X + 247, Y$_{Pb}$ = 223501IX + 214, Y$_{Cr}$ = 8310601X - 472, Y$_{Cd}$ = 168787X + 1061 The structure of' solidified matrix with X-ray diffraction analysis was composed more Ca(OH)$_2$, Si, Mg(OH)$_2$ and Al in the unleached cement matrix than those in cement matrix.

• 상하수도학회지
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• 제14권4호
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• pp.303-310
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• 2000

This study is conducted in order to find more improved solidifying effects than the former converter slag solidification technology. The converter slag is used as a solidifying agent, and the quick lime and the gypsum are used as solidifying aids. Several tests are performed for the purpose of investigating the solidifying effects and the applicability of the solidified sludge as a daily or intermediate landfill cover. The unconfined uniaxial compressive strength, pH and leaching of heavy metal are investigated. In the case of using both quick lime and gypsum as solidifying aids, the compressive strength of specimen has significantly increased that of specimen which used quick lime only. The compressive strength of each specimen cured for 7 days which is mixed with quick lime and gypsum as mixing ratios 7:1, 5:1 and 3:1 are $0.59kg/cm^2$, $1.18kg/cm^2$, and $1.25kg/cm^2$, respectively. The results of all the leaching tests of specimen cured for 7 days show that the concentrations of leachate heavy metals(Cu, Pb, Cd and $Cr^{6+}$) are lower than the Korea toxic waste criteria. The microstructure analysis by SEM shows that needlelike crystals appear as the solidification proceed. The analysis of these crystals by EDS confirms that these main components are Ca. Si etc. Also, XRD analysis shows that the main solidification products are CSH and Ettringite; in addition, $Ca(OH)_2$ CAH are observed. When the added gypsum is used as a solidifying aid, more improved solidifying effects are obtained and the solidified sludge may be appropriately used as a daily or intermediate landfill cover.

• 한국환경보건학회지
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• 제41권5호
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• pp.327-334
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• 2015

Objectives: In order to review both the effects of sewage sludge dewaterability and deodorizing ability in the existing advanced sewage treatment process, BIO-CLOD (a solidified mixture of 10% Bacillus concentrate and inorganics) was used as an inorganic conditioner effective for deodorization treatment in addition to the removal of organic matter and nutritive salts. Methods: Sludge dewaterability was evaluated using specific resistance to filtration (SRF) experiments with six agitators and two types of commercially available BIO-CLOD; one that is made by grinding solid matter (powdered BIO-CLOD) and one that has been obtained by sieving a separation with a particle diameter of 100 mesh (100 mesh BIO-CLOD). For deodorization odor treatment experiments, 20 g of commercially available solid BIO-CLOD was submerged in four liters of sewage sludge and mixed and agitated for 45 days. Results: When BIO-CLOD was injected into sewage sludge to experimentally compare specific resistance to filtration (SRF), the optimum amount of BIO-CLOD to be injected was shown to be 2% w/v and the SRF value in this case was $1.35{\times}10^{12}m/kg$. pH changes following BIO-CLOD injection were within 6.5-7.0. By 14 days after submerging BIO-CLOD into the sewage sludge to evaluate its deodorizing ability, $H_2S$ decreased by 68% and methyl mercaptan decreased by 74%. By 45 days after the submergal, both items decreased by 100%, indicating deodorizing ability. Conclusion: To compare the levels of dewaterablity of sewage sludge at different particle sizes of inorganic conditioner, powdered BIO-CLOD, particle size 100 mesh BIO-CLOD, and bentonite were tested. It could be seen that as the powdered BIO-CLOD increased, the precipitability increased up to 62% in 30 minutes. As an inorganic conditioner, BIO-CLOD was identified as a stable sludge conditioner that does not affect pH.

• 대한환경공학회지
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• 제37권7호
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• pp.412-417
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• 2015

본 연구는 하수처리장에서 발생하는 하수슬러지 소각재와 Geobond를 이용한 응용 블록의 개발을 위하여 수행하였다. 실험은 무소성 공정으로 진행하였으며, Sewage Sludge Ash (SSA)를 Geobond(무기바인더)와 특수시멘트인 초조강 시멘트 마이크로 시멘트, 모래 등의 바인더를 혼합한 각각의 페이스트 시편을 성형 후 건조 및 양생과정을 거친 시편을 단기 압축강도를 측정한 후 28일 장기 양생한 결과 압축 강도가 64.6 MPa로 발현하였다. 이는 KS기준치 22.54 MPa ($229.7kg/cm^2$)을 훨씬 상회하는 고강도의 압축강도를 나타내었다. 하수슬러지 소각재(SSA) 첨가율은 각 바인더 별 약 10~40%까지 혼합 가능한 것으로 나타났다. 따라서 SSA를 무기바인더인 Geobond와 특수시멘트(HESPC, MC)의 대체 물질로의 사용이 가능함을 입증하였다.

• 대한환경공학회지
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• 제36권12호
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• pp.843-850
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• 2014

본 연구는 국내 하수처리장에서 발생하는 감량화/안정화된 소각재를 무기바인더로 재이용하기 위하여 수행하였다. 실험은 무소성 공정으로 진행하였으며, Sewage Sludge Ash를 시멘트, Geobond 등의 바인더와 모래를 혼합하여 페이스트 시편과 몰탈 시편으로 성형하였다. 성형 후 양생과정을 거친 시편을 압축강도를 측정한 결과 KS 기준치 22.54 Mpa ($229.7kg/cm^2$)을 상회하고, 하수슬러지 소각재(SSA) 첨가율은 약 10~40%까지 가능한 것으로 나타나 개발하고자 한 하수슬러지 소각재를 무기바인더인 시멘트, Geobond의 대체 물질로 재활용이 가능함을 입증하였다.