• Resources Recycling
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• v.19 no.1
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• pp.40-48
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• 2010

It was investigated that effects of NaOH concentration on synthesis of mesoporous materials using municipal solid waste incinerator ash slag (MSWI-ash slag). In order to increase the purity and maximize the amount of extracted Si content the raw MSWI-ash slag was mechanically activated. Extraction of Si from the MSWI-ash slag was carried out by alkali treatment using concentrated NaOH solution, which varied from 1M to 4M. Physical properties (i.e., pore size, specific surface area and total pore volume) of the synthesized mesoporous silica were also evaluated as a function of NaOH concentration via BET, SEM, TEM and small-angle X-ray scattering analyses. Over the entire range of NaOH concentration investigated (i.e., 1-4M), the synthesized mesoporous materials were determined to be SBA-15, which exhibited a hexagonal structure with the pore size of approximately 7 nm. On the other hand, specific surface area and total pore volume increased with NaOH concentration up to 3M while the values decreased at 4M, indicating that the optimal NaOH concentration for the synthesized mesoporous silica was approximately 3M. Further comparison analysis between two conditions (3M versus 4M) showed that the decrease in two physical properties at 4M NaOH concentration was likely due to the potential inhibition by excess Na ions on the formation of mesophase and the consequent increase of pore wall thickness by remaining Si ions.

• Resources Recycling
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• v.17 no.4
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• pp.3-9
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• 2008

The total amount of fluidized bed incinerator ash, i.e. incombustion materials generated from the municipal solid waste incineration(MSWI) in Korea was approximately 14,000 tons in 2006. Most of the ash after ferrous metal separation is finally discard to the landfill sites. In the present work, possibility for recycling of the ash is studied to utilize the ash as raw materials for ceramic products. Incombustion materials obtained from the two different incinerators were used to recover the raw materials by applying the magnetic separation and screening process to remove metallic particles. The raw materials show relatively low heavy metals content obtained from the KSLP leaching tests. The ceramic products were prepared by mixing the clay with the various amounts of the raw material. The physical properties, i.e. shrinkage rate, absorbancy and compressive strength of the ceramic products sintered at $1,000^{\circ}C$ and $1,050^{\circ}C$, respectively were improved by increasing the addition amounts of the incinerator ash. Based on the leaching tests the ceramic products also be satisfied with the standard limits on the leachability of heavy metals because most of the metallic materials are effectively removed from the incombustion materials by appling the separation processes.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.573-580
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• 2003

In Taiwan there are 21 Municipal Solid Waste Incinerators (MSWI) built to treat 80% of the MSW nationwide. Approximately 2,000 tons of incineration ashes of municipal waste contain reaction ash and fly ash (3:1 by weight)will be produced daily, and this may cause a serious waste problem. According to EPA regulations, reaction ash and fly ash produced after incineration should be properly treated. Landfill capacity barely meets the general demands. More efficient actions should be planned and taken. The study found 'reclamation' should be the optimal solution to this problem. Only limited research and previous successful experiences are available among other countries. An incinerator in Northern Taiwan is chosen for this study to make environmental bricks from the reaction ash and fly ash. From the previous tests, the results of strength test were measured. From the previous test results, the fly ash products have not reached the desired strength; hence, reaction ash is chosen for further pilot study. In the experiment, incineration ashes, cement and gravel are mixed in the ratio of 1:1:1(by weight), to ground concretization aggregate and pelletization aggregate, the concrete products made from the aggregates were of the strength of 108 $kgf/cm^2$ and 142 $kgf/cm^2$ individually. For the purpose of making nonstructural walls which met the State Building Standards. In the study, 50 tons of concrete products was yielded from aggregate and environmental bricks. Further observation and supervision are recommended to ascertain the resource recycling and reclamation. EPA has planned to build three 'Recycling Plants' in northern, middle and southern Taiwan to develop efficient techniques to produce concrete products, sub-base course, soundproofing wall, gravel, artificial fishing reefs, tiles, drainage, bricks and etc. This experiment of the demonstrative plant solves the problem of the incineration ashes and opens another opportunity to reclaim them.

• Journal of environmental and Sanitary engineering
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• v.16 no.2
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• pp.63-70
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• 2001

This study was initiated to evaluate and resolve the potential problems caused as the MSWI(Municipal Solid Waste Incinerator) fly ash were stabilized and solidified into the cement. The physical and chemical properties of fly ashes (K and M) used in this study were fixed according to the operating conditions of the incineration plant. The compressible strength of the solidified matrix used in this study were measured at 7, 28, and 56 curing days, respectively, to evaluate the stability of the solidified matrix, which were further analyzed by XRD and SEM. The experimental results obtained in this study showed that the relatively long hours of curing periods were needed to solidify the fly ash. The solidified matrix containing K ash had the high and excellent compressible strength of $200{\;}kg/\textrm{cm}^2$, after 56 curing days, but was not good enough in appearance. The analytical data by SEM confirmed that the alkaline Na and K, which are highly dissolved in water, were included in the fly ash and evenly distributed into the exterior surface of the solidified matrix. Whereas, the solidified matrix containing M ash never showed such a compressible strength as shown in the K ash due to the severe fracture, even as early as 7 curing days. Based on its XRD analysis, it appeared that both $C_2S$ and $C_3S$ highly related to the compressible strength were not crystallyzed into the solidified matrix. However, the compressible strength of the solidified and cemented M ash was remarkably improved by 100 times, after the alkalinity was washed out, which indicated that it is equivalent to 30 to 40g per one kg of fly ash.

• 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.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.78-83
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• 2000

The emission factor of nitrogen oxides(NOx) was evaluate to clarify the characteristics of NOx emitted from seven large combustion facilities in seoul area. The emission factors of NOx at A-1 and A-2 facilities of internal combustion engine were 66.957kgNOx/ton and 20.913kgNOx/ton, respectively. The emission factor of A-1 facility was higher than that of A-2 facility even same internal combustion engine, because A-1 facility adopted SCR(selective catalystic reactor) for reduction of NOx emission factor of A-2, A-4, and A-7 power generation boiler facilities were 4.300kgNOx/ton, 2.460kgNOx/ton and 1.796kgNOx/ton, respectively. The capacity of A-2 facility was about two times than that of A-4 and A-7. These emission factors were lower than those at facilities in other areas of korea, because of using low NOx burner of power generation boiler. The emission factors of NOx at A-3 and A-6 incinerator facilities were 0.147kgNOx/ton and 0.221kgNOx/ton which were lower than other facilities, respectively, because these facilities incinerate municipal solid waste of low heating value and uwe SCR for reducing NOx concentration.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.767-773
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• 2011

The purpose of this study was to investigate the possibility of an alternative fuel resource by incinerating a mix of combustible MSW (municipal solid waste) and offals after separating recyclable material at the MRF (material recovery facilities) location. We analyzed the physical and chemical properties including the 3-contents, the calorific value, and chemical compositions of the separation rejects in MRF, and compared the results with combustible MSW. Moreover, we experimented the trend of combustible properties and the concentration change of air pollutants at mixed incineration in the MSW incinerator. According to the results of the experiment, the separation rejects showed higher heating value (5,865 kcal/kg), and lower moisture and ash content than combustible MSW. Since we have incinerated MSW in the MSW incinerator mixing the offals at 30% and 50% respectively, we know that the change of the concentration of dust, $SO_2$, $NO_2$, and CO did not appear significant, and not exceed the pollutants emission regulation. But, considering the enhancement of the HCl emission concentration (max. 33.7 ppm) at the co-incineration of the 50% offals, we believe that the proper mixing ratio of the separation rejects would become within 30%.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.744-753
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• 2018

The Stockholm Convention, which was adopted in Sweden in 2001 to protect human health and the environment, includes regulations for Persistent Organic Pollutant Rotors such as toxic and bioaccumulatives. Currently, there are 28 types of materials. This prohibits and limits the production, use, and manufacture of products. Korea is a member of the Convention, and it is necessary to prepare management and treatment plans to address the POP trends. Thus, we experimentally investigate whether the environmentally stable incineration is achieved when the sample is thermally treated using the Lab-scale (1 kg/hr). The target samples is pesticides in liquid phase and solid phase. In this study, organic chlorinated pesticides and their thermal characteristics were analyzed. We calculated the theoretical air volume based on the element analysis results. Because the interior of the reactor is small, more than 10 times of the air ratio was injected. The retention time was set to at least 4 seconds using a margin. The incineration temperature was $850^{\circ}C$ and $1100^{\circ}C$. Thus, we experimentally investigated whether the environmentally stable incineration was achieved when the sample was thermally treated using the Lab-scale (1 kg/hr). We analyzed five types of exhaust gas; the 02 concentration was high, but the CO amount decreased. Complete combustion is difficult because of the small size of the furnace due to the nature of Lab-scale. The organic chlorine-containing pesticide had an average decomposition rate of 99.9935%. Considering the decomposition rates of organic chlorine-containing pesticide in this study, the incineration treatment at over 2 ton/hour, which is typical for a conventional incinerator, is possible. Considering the occurrence of dioxins and unintentional persistent organic pollutants, it can operate at more than $1,100^{\circ}C$.

• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.337-347
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• 2006

이 연구의 목적은 자원회수시설 근로자 및 인근 지역 거주 주민의 혈중다이옥신류 농도를 평가하고, 혈중 다이옥신류 농도에 영향을 미치는 요인을 평가하는 것이다. $2002{\sim}2004$년까지 대상 자원회수시설에 3년 이상 근무한 근로자 31명과 시설로부터 300 m이내 지역에서 3년 이상 거주한 주민 68명을 선정하여 혈액을 채취하였다. 참고 자료로 대상 자원회수시설에 영향을 받지 않는 도시 지역에 거주하는 일반 주민 11명을 함께 평가하였다. 혈액 채취 시 개인 특성에 대한 설문조사도 함께 실시하였다. 시설 근로자의 혈중 다이옥신류 농도는 평균 $2.09{\sim}66.67pg/g$ lipid, 인근 거주 주민은 $1.00{\sim}29.33pg/g$ lipid, 일반 도시 주민은 $5.29{\sim}35.93pg/g$ lipid로 측정되었다. 시설 인근 지역 거주 주민 및 일반 도시 주민 중 비 흡연자의 인체 부하량은 각각 3.0 ng TEQ/g lipid와 4.5 ng TEQ/g lipid로 평가되었다. 대상군의 특성에 따른 혈중 다이옥신류 농도 차이는 관찰되지 않았으며, 연령과 유의한 양의 상관성이 있었다.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.6
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• pp.539-546
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• 2002

The physicochemical properties of solid wastes generated from seven highway service areas, four branch offices, and one construction site were analyzed in concert with air pollutants including heavy metals emitted from near-by small-scale incinerators. The amount of solid wastes generated from highway areas has been increasing with recent increases in the number of highways and passengers. Twelve incinerators examined in this study generally had capacity smaller than 100 kg/hr, most of which were equipped with cyclone for dust removal. It was seen that the concentrations of the gas-phase air pollutants (e.g., SO$_2$, NO$_{x}$, HCl and H$_2$S) were above the acceptable emission standards except one or two sites. CO concentrations at all incinerators were also higher due to incomplete combustion. In addition, particulate matters showed concentration six times higher at their maximum. The results of heavy metal analysis showed that the concentrations of Cu, Cd, and Ni satisfied the emission standards. whereas Pb at one site and Zn at five sites exceeded the standards. Cr measurement results indicated that 9 of 12 incinerators had higher values than the standard; especially one branch office showed nine times higher than normal concentration. In order to satisfy more stringent emission standards in the near future, it is necessary to install air pollution control system and to develop an intensified management plan.n.