• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.76-88
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• 2012

In this study, the treatment flow of the recyclables(paper, plastic, metal, etc.) collected and separated from MSW was investigated throughout entire phase from separation and collection to final disposal. Based on the site survey, most recyclables came into six material recovery facilities were comparatively managed well. However, some of recyclables showed irrelatively transportation flow. Because the main income source of the recyclables transportation companies is profit margin between treatment and transportation cost based on economics only therefore, it occurs an unnecessary route and long distance transportation while going to final destination. This unreasonable system should be a serious problem relating establishment of the resource recycling system. As a result of this study, in order to establish the reasonably resource recycling system, recycling center including material recovery facility has to manage the recyclables generated in close range preferentially. Also integrated its treatment system over a wide area will need to be considered as a basic step for the reasonable reasonably resource recycling system.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.757-762
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• 2002

The interest of incineration, which is one of the effective methods for municipal waste disposal, has gradually increased because the incineration could reduce the volume and weight of the waste, and produce useful energy from the waste. This study has developed the 3-dimensional numerical model, and applied for the investigation of combustion characteristics and optimized operating conditions in MSW incinerator in Gwangju. The model developed in this study has been verified through the comparison between the predicted and the measured temperature in combustion chamber which is operating. By predictive results, the Sangmoo incinerator has a good characteristics of combustion efficiency and a low emission by the second burning in the main flame zone, even though after burning zone produces incomplete products by which primary air is introduced not enough.

• Environmental Engineering Research
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• v.11 no.1
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• pp.14-27
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• 2006

The proper management of discarded electronic devices (often called electronic-waste) is an emerging issue for solid waste professionals throughout the world because of the large growth of the waste stream, and the content of toxic metals in them, most notably heavy metals such as lead. Notebook computers are becoming one of the major components of discarded computer devices and will continue to increase in the waste stream in the future. While the computers hold great promise for recycling, a substantial amount of this waste is often disposed in municipal solid waste (MSW) landfills. The toxicity characteristic leaching procedure (TCLP) is commonly used to simulate worse case leaching conditions where a potentially hazardous waste is assumed to be disposed along with municipal solid waste in a landfill with actively decomposing materials overlying an aquifer. The objective of this study was to examine leaching potential of lead from discarded notebook computers using the scale-up TCLP, other standard leaching tests such as California waste extraction test (Cal WET), and the synthetic precipitation leaching procedure (SPLP) and actual landfill leachates as leaching solution. The scale-up TCLP is a modified TCLP (where the device was disassembled and leached in or near entirety) to meet the intent of the TCLP. The results showed that the scale-up TCLP resulted in relatively high lead found in the leachate with an average of 23.3 mg/L. The average level was less than those by the standard TCLP and WET (37.0 mg/L and 86.0 mg/L, respectively), but much greater than those by the SPLP and the extractions with the landfill leachates (0.55 mg/L and 1.47 mg/L, respectively). The pH of the leaching solution and the ability of the organic acids in the TCLP and WET to complex with the lead were identified as major factors that controlled the amount of lead leached from notebook computers. Based on the results obtained by a number of leaching tests in this study, notebook computers may present a potential leaching risk to the environment and human health upon land disposal. However, further investigation is still needed to assess the true risk posed by the land disposal of discarded notebook computers.

• Environmental Engineering Research
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• v.24 no.2
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• pp.220-237
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• 2019

Solid waste management (SWM) is one of the poorly rendered services in developing countries - limited resources, increasing population, rapid urbanization and application of outdated systems leads to inefficiency. Lack of proper planning and inadequate data regarding solid waste generation and collection compound the SWM problem. Decision makers need to formulate solutions that consider multiple goals and strategies. Given the large number of available options for SWM and the inter-relationships among these options, identifying SWM strategies that satisfy economic or environmental objectives is a complex task. The paper develops a mathematical model for a municipal Integrated SWM system, taking into account waste generation rates, composition, transportation modes, processing techniques, revenues from waste processing, simulating waste management as closely as possible. The constraints include those linking waste flows and mass balance, processing plants capacity, landfill capacity, transport vehicle capacity and number of trips. The linear programming model integrating different functional elements was solved by LINGO optimization software and various possible waste management options were considered during analysis. The model thus serves as decision support tool to evaluate various waste management alternatives and obtain the least-cost combination of technologies for handling, treatment and disposal of solid waste.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.6
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• pp.657-665
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• 2010

Carbon dioxide ($CO_2$) is known to be a major greenhouse gas partially emitted from waste combustion facilities. According to the greenhouse gas emission inventory in Korea, the quantity of the gas emitted from waste sector in 2005 represents approximately 2.5 percent of all domestic greenhouse gas emission. Currently, the emission rate of greenhouse gas from the waste sector is relatively constant partly because of both the reduced waste disposal in landfills and the increased amounts of waste materials for recycling. However, the greenhouse gas emission rate in waste sectors is anticipated to continually increase, mainly due to increased incineration of solid waste. The objective of this study was to analyze the property of Municipal Solid Waste (MSW) and estimate $CO_2$ emissions from domestic MSW incineration facilities. The $CO_2$ emission rates obtained from the facilities were surveyed, along with other two methods, including Tier 2a based on 2006 IPCC Guideline default emission factor and Tier 3 based on facility specific value. The $CO_2$ emission rates were calculated by using $CO_2$ concentrations and gas flows measured from the stacks. Other parameters such as waste composition, dry matter content, carbon content, oxidation coefficient of waste were included for the calculation. The $CO_2$ average emission rate by the Tier 2a was 34,545 ton/y, while Tier 3 was 31,066 ton/y. Based on this study, we conclude that Tier 2a was overestimated by 11.2 percent for the $CO_2$ emission observed by Tier 3. Further study is still needed to determine accurate $CO_2$ emission rates from municipal solid waste incineration facilities and other various combustion facilities by obtaining country-specific emission factor, rather than relying on IPCC default emission factor.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.105-110
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• 1997

Sanitary landfill is a general method as a final disposal of municipal solid waste(MSW), therefore leachate characteristics are very various as lime goes by because of highly concentrated organic acids are contained non biodegradable COD. So it is hard to abide by the mandatory standards of discharge eventhough applying the physicochemical and biological processes to treat the leachate. The process of treating leachate are determined by the degree of removal and components, but they are highly contained organic materials. It is a removal method to use jointly with the physicochemical process if the hard and fast rule is needed. The critical components of material are COD, ammonia, salts and heavy metals in the case of treating biologically. Biological process is to use metabolism of microorganism, therefore it is a desirable condition which heavy metals are not contained, because they acting as an inhibitor of enzyme. Of these are contained, organic decomposition and synthetic function of microorganisms decrease significantly. Consequently, this research paper lays emphasis on the concentration of heavy metals in leachate and for the purpose of forecasting the factors which are affecting the leaching of metalic waste in some degree, experimented the various reacting conditions. 1. When the concentration of heavy metals in leachate is in comparison with the level eluted after reaction, at pH 7.9 the result of reaction for PCB to CCL scrap showed that Zn, Mn, Cu was more eluted 11.6 times, 340.3 times, and 2,705.5 times respectively than the leachate undiluted solution. 2. At the condition of strong acid pH 4.7, the concentration of heavy metals in EM undiluted solution showed that Zn, Mn, Cu was more eluted 26.5 times, 147.3 times, and 3,656.3 times respectively than leachate undiluted solution. 3. When the ratio leachate to EM was 50 vs 50(V/V%), Mn was more eluted 198.7 times than leachate undiluted solution, but Zn and Cu do not show the meaningful results. 4. The color of landfill leachate was black-brown. And fulvic acid that is main ingredient of NBD COD contained, oxygen of 44~50%. For that reason, I estimated that the level of Zn, Mn, Cu was higher than the case of leachate. 5. COD of leachate from general landfill is difficult to remove. Because the solution of heavy metals is improved by the character of leachate(pH & ingredient of oxygen etc.) hence the Mn, Cu, Zn act as disturbing factor, the biochemical treatment is hard. Therefore the type of PCB & CCL scrap, iron, aluminum contained metals need to previously separate from general wastes as much as possible.