간행물

한국폐기물자원순환학회 학술대회자료집

권호리스트/논문검색
이 간행물 논문 검색

권호

2013년 추계학술발표회 논문집 (2013년 11월) 257

241.
2013.11 서비스 종료(열람 제한)
The estimated that 114 million units of fluorescent lamp are sold every year, and that 70% or more spent fluorescent lamps (SFLs) are generated at business sites. According to Korea Lighting Recycling Corporation, recycled amount of SFLs selected as EPR (Extended Producer Responsibility) items from 2004 has been improved from 35,250,000 units in 2010 to 37,950,000 units in 2011, which recorded the greatest amount. Based on the year 2011, SFLs have been recycled by 31.5%, but their recycled rate is insufficient yet, compared to the recycling rate of metal cans or glass bottles, which are about 80%. The base cap of SFLs as a raw material was used in this experiment. Base cap contains an insulation sieve plate, aluminum cap, copper terminal, tempered glass, filament, and copper/iron mixed wire that goes through this glass. In order to protect a filament that is made up of tungsten for the electricity to flow, circular plate consisted of iron encloses the filament. Separating apparatus of SFL base cap used in this experiment is a device which has used impact crushing technique using hammer, screen separation and magnetic separation for the purpose of recovering aluminum, copper and iron contained in SFL. Impact hammer crusher, a device that separates aluminum from other materials by hammer impaction on the base cap that is separated by end-cutting, causes a significant reduction for other materials to be included in the collectible materials by separating aluminum, copper and iron from the base cap by using hammer crusher at 3 stages. Iron was collected by using a magnetic separation unit and the collectible materials were separated into aluminum with larger particles, and glass and other materials with smaller particles by screen separation. The separation performance was estimated for the 3 stages of hammer crusher unit to recover aluminum from the base-cap of SFLs and the separation performances are 94% at the 1st stage, 97% at the 2nd stage, and 98% at the 3rd stage, respectively.
242.
2013.11 서비스 종료(열람 제한)
Compact fluorescent lamps are strongly encouraged to manage separately in Korea because Compact fluorescent lamps contain mercury. Compact fluorescent lamps have managed as household waste in Korea, however, even though Compact fluorescent lamps contains hazardous material such as mercury. The aim of management of Compact fluorescent lamps separately is to reduce the release of mercury from Compact fluorescent lamp lamps into the environment and to reuse of the glass, metals and other components of Compact fluorescent lamps. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In the crushing process, CFL(compact fluorescent lamp) is separated into glass, plastic, ballast, phosphor powder and vapor. Using the crushing technique, concentration of mercury vapor emission from CFL is evaluated. Through the experiments, the efficiency of the crushing and separation for the unit is estimated by measuring the volume of CFL. In this study, the concentration of mercury is analyzed by MVI(Mercury Vapor Indicator) method for vapor in CFL. From the results of mercury distribution for 3 companies, the concentration of mercury in compact fluorescent lamp is less than that in the other type lamps. And phosphor powder has greater than 99% of total mercury amount in CFL and the mercury concentration in phosphor powder is measured between 1,008ppm and 1,349ppm. The mercury concentration in phosphor powder can be changed by the type of company and period of usage. KET and TCLP are carried out for phosphor powder, glass, plastic, ballast and base cap to estimate the hazardous characteristic. From the results of KET and TCLP test for CFL, phosphor powder from CFL should be controlled separately by stabilization or other methods to reuse as a renewable material because the phosphor powder is determined as a hazardous waste. From the results of characteristics of CFL, the carbonization system of CFL should be carried out in the temperature of less than 350℃. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of Compact fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In Korea, demonstration for recycling of U type lamps had once begun in the area of Seoul Metropolitan, 2000. In 2004, U type lamps was included as an item in EPR(Extended Producer Responsibility) system. According to Korea Lighting Recycling Association, approximately 38 million Compact fluorescent lamps were recycled in Korea, 2011 because 3 recycling facilities for Compact fluorescent lamps are operated in Korea. Recycling rate of Compact fluorescent lamps in Korea is about 31.0% but about 70% of Compact fluorescent lamps may not manage properly. Hence, discarded lamps release approximately 2 to 3 tons of mercury per year into the environment[6]. In USA, Compact fluorescent lamps has controlled by Universal Waste Rule and merchandises containing mercury prohibited to produce. Also, MEBA(Mercury Export Ban Act) is activated in USA from 2013. According to Association of Lighting and Mercury Recycler, member companies accomplish about 85% of the lamp recycling done each year. In Germany, best available technology (BAT) system for recycling of Compact fluorescent lamps is established and about 20 companies are involved in recycling of Compact fluorescent lamps. In 1994, approximately 70-80% of total Compact fluorescent lamps are recycled in 1994 and Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 1996. In Sweden, MRT System, which was developed by Lumalampan, separated mercury from Compact fluorescent lamps by distillation operation, 1979. Reverse route collection system is active to improve the collection of Compact fluorescent lamps. Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 2001. In Austria, about 40 companies are involved in recycling of Compact fluorescent lamps to recycle glass and ferrous metals. And wastes containing mercury are treated in landfill site by using special container [7,8]. In this study, Compact fluorescent lamps is cut by a end-cutting unit with a cam crusher and base-cap is separated from glass part. In the end-cutting unit, a vacuum system is operating to collect mercury vapor to prevent leaking from the end-cutting unit. First of all, characteristics and major composition of Compact fluorescent lamps are estimated. Through the experiments, it is measured mercury concentration in the parts of Compact fluorescent lamps such as glass tube, phosphor powder, and base cap after separation in the end-cutting unit. Also, it is evaluated mercury emission from Compact fluorescent lamps by measuring the concentration of effluent gas in the end-cutting unit with changing flow rate. Finally, Korea Extraction Method (KET) and TCLP(Toxicity Characteristic Leaching Procedure) test are applied to phosphor powder to verify that phosphor powder is a hazardous waste [9].
243.
2013.11 서비스 종료(열람 제한)
In this study, HA removal by electrocoagulation (EC) using Aluminum (Al) electrodes was evaluated based on Al species and HA was characterized to investigate the HA removal mechanisms. Results showed that Al electrodes were better than Fe electrodes, wherein Al flocs were found to be positively charged by which the negatively charged HA can be attracted. HA removal was 88.9% at 10 min and 91.3% at 20 min, at the initial pH of 4.5 and 6.5, respectively. The Ferron analysis showed that the formation of monomeric Al species (Ala), medium polymer Al species (Alb), and colloidal or solid Al species (Alc) was dependent on initial pH and current density (CD). At higher pH, higher concentration of colloidal or solid Al species (Alc)wasobserved. At higher CD, the HA removal was faster than at low CD, and Alcspecie in the floc was dominant. The spectroscopic analysis of the residual soluble HA showed the preferential removal of highly condensed structures of HA, regardless of CD. The results in this study showed that Alb and Alc, especially Alc, contribute much to the HA removal and that the highly conjugated moieties of HA are readily removed by EC. Specific UV absorbance (SUVA) analysis reveals that aromatic compounds were decreased by the oxidation at the anode. Size exclusion chromatography reveals that high molecular weight (MW) fractions were preferentially removed by EC than the low MW component.
244.
2013.11 서비스 종료(열람 제한)
Method 9 is a reference method established by U.S. Environmental Protection Agency (EPA) to quantify plume opacity by the certified observer. Later, digital Optical Method (DOM) was developed to quantify plume opacity from digital photographs for bright and dim conditions. However, there is a limitation for the use of Method 9 and DOM to quantify the plume opacity especially for dim condition. In this paper, DIM-DOM system was used instead of DOM to quantify plume opacity during dim condition. Opacity readings provided by DIM-DOM were compared with the opacity values obtained with the reference in-stack transmissometer of the smoke generator. The individual opacity error results demonstrated that DIM-DOM met Method 9’s requirements. The individual opacity values ranging from 0 to 100% compare well to the corresponding opacity results from the in-stack transmissometer results meeting USEPA’s Method 9 IOE requirement of ≤15%. These results are encouraging and indicate that DIM-DOM has the potential to quantify plume opacity during dim condition.
245.
2013.11 서비스 종료(열람 제한)
Due to rapid industrialization and population growth uncontrolled release of heavy metals are entered into the waters. Among these heavy metals Pb(II) is one of the major toxic metal and in recent years the production and consumption of lead is increasing worldwide. Pb(II) can be entered to aqueous streams from several industries and can enter into the humans food chain through drinking water and crop irrigation. Lead can causes severe damage to the kidney, nervous system, reproductive system, liver and brain. The permissible level for lead in drinking water is 0.05 mg/l. Thus in recent years a number of methods and materials were developed to removal Pb(II) from aqueous solutions. Among these material bio-chars obtained from plant materials have gained special attention due to their low-cost and abundant nature. In present investigation we have developed magnetic bio-char composite from pine bark. Pine trees are wide spread throughout the South Korea and the bark from pine tree has no commercial use and is available as waste. Thus we have utilized this waste inexpensive material from preparing bio-char composite. The pin bark obtained was initially made into fine powder and washed several times with water and was filtered. To this powder an appropriate amounts of nitrate salts of cobalt and iron dissolved in ethanol solution was added and stirred for 15 minutes. This solution was oven dried at 70℃ and this was further calcined at 900℃ in nitrogen atmosphere. As obtained material was washed several times with water and dried in oven over night. This was used as adsorbent for treating lead contaminated aqueous solutions. As obtained bio-char composite was used to remove Pb(II) from aqueous solutions. Various parameters influencing Pb(II) removal like initial pH, contact time and initial concentration were studied. Effect of pH on Pb(II) removal was studied in the pH range from 2-8 at Pb(II) concentration 10 mg/L using an adsorbent dose of 300 mg. At below pH 3 a lower percent removal was observed whereas above pH 4>90% removal was observed. Further effect of contact time on Pb(II) removal was studied from time range between 10-180 min. Two kinetic models pseudo-first, pseudo-second-order models were used to evaluated the kinetic data and found that the data was better fitted to the pseudo-second-order model. From the overall results it was found that as prepared magnetic bio-char composite prepared from pin bark waste was effective and economic for treating Pb(II) contaminated aqueous solutions.
247.
2013.11 서비스 종료(열람 제한)
Magnetite (Fe3O4) has been prepared directly to avoid the reduction process prior to the H2 production from the high temperature water gas shift reaction of the simulated waste derived synthesis gas. Citric acid has been employed as a complexing agent for the direct synthesis of magnetite. Notably, without the reduction process, the catalyst prepared at the citric acid molar ratio of 1.0 showed 80% CO conversion at 350℃ at a gas hourly space velocity of 40,057 h-1.
248.
2013.11 서비스 종료(열람 제한)
This is aim to use and recycle the wasted heat from the dispose process of the incineration plant facility in Daegu. Furthermore, the saturated vapor is to be supplied for the Industrial Complex as energy resource. It is to receive the superheated steam that shows 250℃ temperature and 18kg/cm² steam pressure from the Boiler system of the incineration plant facility. This condition is not suitable for end-users’ specification of the manufacturing process. The Desuperheater is to be researched and developed for controlling high temperature and steam pressure. It is necessary to calculate condition of product vapor for establishing the steam network with water cooling and condensate system. The Heat Reclaiming Steam Arising System is to reduce the temperature to 220℃ and increase the pressure to 22kg/cm² at the final point of product supply line. It is expected Environmental and Economical effects with establishing optimum network for the use of waste heated vapor. Environmentally, it could reduce the Global Warming Potential, use fossil fuel and Green-house gases. Economically, it will bring down the production cost of end-users by using the wasted heated vapor.
249.
2013.11 서비스 종료(열람 제한)
In Korea, two decommissioning projects have been carried out due to retire of nuclear research facilities such as Korean research reactors (KRR-1 & KRR-2) and a uranium conversion plant (UCP). The decommissioning of the KRR-2 and a uranium conversion plant (UCP) at KAERI were finished completely by 2011, whereas the decommissioning of KRR-1 is currently underway. The large quantity of radioactive waste was generated during the decommissioning the KRR and UCF such as concrete waste, soil, combustible and non combustible waste. The volume reduction of the combustible wastes through the incineration technologies has merits from the view point of decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost. Incineration is generally accepted as a method of reducing the volume of radioactive waste. The incineration technology is effective treatment method that contains hazardous chemical as well as radioactive contamination. Incinerator burns waste at high temperatures. Incineration of a mixture of chemically hazardous and radioactive materials, known as“mixed waste,”has two principal goals: to reduce the volume and total chemical toxicity of the waste. Incineration itself does not destroy the metals or reduce the radioactivity of the waste. A proven melting technology is currently used for low-level waste (LLW) at several facilities worldwide. These facilities use melting as a means of processing LLW for unrestricted release of the metal or for recycling within the nuclear sector. Fig. 1 shows the schematic diagram of the oxygen-enriched incineration (OEI) and melting facility. The oxygen-enriched incinerator located at the KAERI. The system consists of a waste preparation system, incineration system, off-gas cooling system, and off-gas treatment system. Demonstration incineration facility took over the responsibilities of KHNP for decommissioned combustible waste. After taking over the demonstration incineration facility from KHNP, the facility was modified, and work toward the licensing procedure, and an extension of the object waste including alpha-bearing waste and increase incineration capacity, began in June 2011. The melt decontamination technology is the most effective treatment method for decommissioned metal waste. Melting for size reduction would require no prior surface decontamination and very little sorting of the waste material. Also, the recycling or volume reduction of the metallic wastes through the melt decontamination technologies has merits from the view point of an increase in resource recycling as well as a decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost and an enhancement of the disposal safety. Melt facility consist of four system such as preparation system, melting system, ingot treatment, and off-gas treatment system. The decommissioned combustible waste has been incineration by incinerator from last year. In case of metal waste, metal waste will be melt for self-disposal and volume reduction by induction furnace. Combustible wastes were treated by incinerator and ash dispose permanently site. In case of metal wastes is treated by induction furnace and slag dispose permanently site and ingot will be reuse.
250.
2013.11 서비스 종료(열람 제한)
This study characterized PM and VOC emissions from cow dung combustion in a controlled experiment. Dung from grass-fed cows was dried and combusted using a dual cone calorimeter. Heat fluxes of 10, 25, and 50 kW/m² were applied. The concentrations of PM and VOCs were determined using a dust spectrometer and gas chromatography/mass spectrometry, respectively. PM and VOC emission factors were much higher for the lower heat flux, implying a fire ignition stage. When the heat flux was 50 kW/m², the CO₂ emission factor was highest and the PM and VOC emission factors were lowest. Particle concentrations were highest in the 0.23-0.3-μm size range at heat fluxes of 25 kW/m² and 50 kW/m². Various toxic VOCs including acetone, methyl ethyl ketone, benzene, and toluene were detected at high concentrations. Although PM and VOC emission factors at 50 kW/m² were lower, they were high enough to cause extremely high indoor air pollution. The characteristics of PM and VOC emissions from cow dung combustion indicated potential health effects of indoor air pollution in developing countries.
251.
2013.11 서비스 종료(열람 제한)
Waste gasification can generate hydrocarbon gases that may be utilized for the synthesis of chemicals or liquid fuels, or for fuel cell power generation, if extensive, deep syngas cleaning is initially conducted. Conventional gas cleaning technology for such applications is expensive and may limit the feasibility of wet technology. Conventional cold gas cleanup (scrubbing by solvents) technique needs the temperature of raw waste gasification gas ranging from 900 to 1600℃ reduced to room temperature. Then, the cleaned - up syngas needs to be reheated. Obviously, the process is energetically inefficient. It is the objective of this study to economically meet the most stringent cleanup requirements without reheating syngas for these applications. We investigated the temperature and pressure effect in breakthrough performance of various sorbents for desulfurization and de-chlorination. Based on the results obtained during the desulfurization (Fe₂O₃, Fe₃O₄, ZnO) and the dechlorination (Na₂CO₃, NaHCO₃, Na₂O) screening tests, ZnO and Na₂O were selected as preferred optimum sorbents. H₂S breakthrough time corresponds to an effective capacity of approximately 11 g Cl/100 g of material. Also, HCl, breakthrough time corresponds to an effective capacity of approximately 5 g Cl/100 g of material. ZnO and Na₂O at high temperature of around 550℃ display high sorption performance and removal efficiency for waste syngas along with H₂S and HCl. Although there is an issue of CO₂ recovery in warm gas clean-up technology for desulfurization, we have obtained an interesting new alternative warm gas clean-up system with heat budget merit.
252.
2013.11 서비스 종료(열람 제한)
In recent years, the demand of renewable energy fuels has been increased in worldwide because the capacity of fossil fuel would be not affordable in the near decade. As one of renewable energy fuels, the production of sewage sludge would be gradually increased by year, and it would be over than 10million tons in 2015 in Korea. Since ocean dumping was inhibited due to London Convention with being in effective at the end of 2012 in Korea, the combustion of sewage sludge has been emerged as one of alternative technologies of waste to energy. Meanwhile, it would be necessary to apply the carbon capture & storage (CCS) technology to reduce carbon dioxide originated from waste sludge incineration. During oxy-fuel combustion, a combination of oxygen typically of greater than 95% purity and recycled flue gas is used for combustion of the fuel. By recycling the flue gas, a gas consisting mainly of CO₂ and water is generated, ready for sequestration without stripping of the CO₂ from the flue gas. In this study, the pilot test was conducted by a circulating fluidized bed (CFB) combustor consisting of a riser, a cyclone, a down-comer, and a loop-seal. The CFB combustor has a riser with an inner diameter of 0.15m and a height of 6.4m. The experimental test was carried out with waste sludge in 30kwth CFB combustor operating with oxy-fuel and typical air conditions. The optimum temperature for waste sludge incineration was determined as 800℃. Oxygen with carbon dioxide as a combustion air was fed into a riser and a loop-seal in pilot test bed. The oxygen rate as a combustion air was ranged from 21% to 30% to observe the condition of waste sludge oxy-fuel combustion. The temperature and pressure profile in CFB reactor were depicted in the condition of typical air and oxy-fuel combustion. The flue-gas from typical air and oxy-fuel combustion was analyzed to observe the trend of carbon dioxide and air pollutants emission such as CO, NOx, and SOx, respectively. The production of carbon dioxide was approximately 90% in flue-gas from waste sludge incineration with oxy-fuel condition.
253.
2013.11 서비스 종료(열람 제한)
Eddy current separation technique to separate non-ferrous metal particles (Al, Mg, Cu, Sn, Pb, Zn, etc.) and non-metallic particles (plastic, ceramic etc.) of crushed materials of laptop computers was established. As preliminary treatment, laptop computers was shredded and optical sorting machine segregated PCB from Non-PCB. Non-PCB sample was pulverized by cut crusher under the size of 12mm for liberation. Upward flow air separator and magnetic separator were used for eliminated shredding dust, vinyl, paper, and ferrous metal particles from Non-PCB sample. The sample was injected into drum type eddy current separator. Recovery of metals was not enough to separate the sample, the non-conducting part (non-metals part) was repeatedly injected into separator. Recovery of metals increased as the step of repetition, but the cumulative recovery until 4th repetition did not exceeded 65%. However, metal content of non-ferrous metals part (the bounced material) was high and it did not change the grade as the repetition. Therefore, drum type eddy current separator has low recovery in case of small particles but also has the advantage of getting high grade non-ferrous metal.
254.
2013.11 서비스 종료(열람 제한)
Prediction method for the long-term chemical leaching amount from by-product/recycled materials such as waste concrete and steel slag and so on is necessary to widely promote their effective utilization and evaluate their environmental safety. Although there are the batch leaching tests and the column leaching test as the testing methods for evaluating the long-term leaching behavior, the leaching mechanism and the testing result compatibility in both tests has insufficiently been clarified yet. Thus, the prediction of the leaching behavior from the by-product/recycled materials used in actual civil works and their environmental safety evaluation are by no means certain. This paper shows the difference between the batch leaching tests and the column leaching tests in the chemical leaching behavior of Cu-slag. The batch leaching tests were conducted under liquid/solid ratio = 10, liquid = distilled water, stirring strength = 0, 30, or 120 rpm. After a certain elapsed time, the leaching solution was exchanged with the pure distilled water and then the stirring was restarted. The elapsed time was set at 1, 2, 4, 8, 16, 32 days. The column leaching tests were also conducted under the same conditions as those of the batch leaching tests in order to evaluate the effects of the pore distribution and the pore flow velocity in the Cu-slag column on the leaching behavior. In the column leaching tests, the effluent passing through the column was circulated as the influent (Fig. 1). The leaching duration in the column tests can be equivalent as that in the batch tests, so that the difference in the leaching behavior between the batch leaching tests and the column leaching tests may be dependent on the pore-scale heterogeneous flow and path generated in porous materials. Figure 2 shows the leaching rate evaluated from the batch leaching tests and the column leaching tests. In the same fluid velocity levels, the leaching rate in the column tests was larger than that in the batch tests. The leaching rate has been considered large with the fluid velocity. Although the fluid velocity generated by the stirring was the same as the flushing velocity on the surface of the Cu-slag in the batch tests, the fluid velocity in the column tests was enhanced because the permeant liquid was concentrated into the limited pore space in the Cu-slag column. Thus, the pore-scale heterogeneous flow and path generated in porous materials should be evaluated in order to clarify the compatibility between the batch leaching tests and the column leaching tests.
255.
2013.11 서비스 종료(열람 제한)
Stabilization of landfill gas (LFG) generation is recognized as the critical indicator to evaluate the future possibility of environmental impact from the waste landfill. In comparison with leachate quality, the amount of LFG generation is considered more difficult to integrate the sequential monitoring results. Spatially and temporal high variation of the LFG generation and the emission would be influenced by the micrometeorological condition. One of the helpful information to predict the behavior of LFG generation is to estimate the remaining of LFG source in the waste. Biological degradation should decrease the amount of component that should be transformed LFG in the waste. Hence, the LFG generation potential of waste in landfill must be gradually decreased as time goes on. In order to support the assessment of the landfill stability from the viewpoint of LFG, the estimation of the potential of LFG generation of the landfilled waste has been investigated at the landfills that was received the waste incineration ash, slag, C&D inert residue, dredged soil, and so on. The LFG emission behavior has been predicted by using the remaining LFG potential, and it was validated by the investigation of surface LFG emission. Degraded organics by anaerobic incubation had been calculated by Buswell's theoretical equation (Bockreis, et al. 2007). Objected samples that were excavated from 10-15 years old waste layer have shown the little potential of LFG generation (Table 1). A highest content of gasified organics was observed for 2.0m depth of C10 though it was less than 1% of the total weight of sample (dry weight). It would be strongly attributed to intensive pretreatment of waste before the landfilling. Since the landfill operator required the strict quality control for the waste to be disposed of, the content of organics in the waste should be enough low at the initial phase of landfill management. In addition, the effort of the landfill management to promote the biodegradation, such as the lowering of the water level in landfill layer, or ventilation of LFG, had contributed to reduce the biodegradable organics. Fig.1 shows the prediction of methane emission from the landfill. It also exhibited results of investigation of surface LFG emission. The prediction of landfill methane emission was developed by using the parameter that was obtained from excavated waste.
256.
2013.11 서비스 종료(열람 제한)
Korea Ministry of Environment (Korea MOE) enacted the “Greenhouse Gas and Energy Target Management System (GETMS), which requires annual GHG reporting to establish GHG reduction targets for large-scale business places (458) emitting large amount of greenhouse gases (60% of total amount in Korea). The waste sector has higher potential for reduction of greenhouse gases compared to other sectors. Thus, this paper reviewed the methodologies modified based on national guidelines and estimated the greenhouse gas emissions for three categories of the waste sector in Daejeon Metropolitan City (DMC), South Korea. Further analysis for basic unit, i.e., greenhouse gas emissions per ton of solid waste, wastewater, and purified water in the waste sector was conducted to figure out main contributors for GHG emissions. Direct emissions (Scope 1) and indirect emissions (Scope 2) of 11 environmental infrastructures managed by DMC were selected for quantifying and managing of regional GHG emissions. The annual estimation for greenhouse gas emissions in the waste sector in DMC with a population of 1.52 million people was 254,235 tons CO₂ equiv. per year, which includes the main contributor of wastewater treatment 78,063 tons CO2 equiv., waste incineration 76,186 tons CO₂ equiv., and managed waste disposal sites 70,455 tons CO₂ equiv. Basic unit showed that most contributors were waste incineration, followed by the waste disposal site, biological treatment of solid waste, wastewater treatment, and public water supplies. Solid waste treatment/ disposal has best potential role in reducing GHG emissions. In general, therefore, it seems that reduction strategies for the main contributor should be prior to other categories and lead to best practice for managing GHG emissions, especially considering annual budgets.
257.
2013.11 서비스 종료(열람 제한)
In the sustainable society, the recycling of resources should achieve the preservation of regional and global environment and should be coordinated with regional agricultural and industrial activities. Especially for waste biomass resources, it will be supplied or discharged by multiple industries as agriculture, forestry, fisheries, manufacturing, commerce and living, and will be demanded by multiple purposes as foods, supplements, feeds, fertilizers, industrial materials and fuels. Therefore, waste biomass flows connecting these supplies to demands will be extremely complex. In order to judge the effectiveness of introducing technologies for recycling, a comprehensive framework, which can estimate impacts of technologies on regional material cycles and regional and global environment, is need. For this purpose, we are developing a physical input-output table (PIOT) for describes complex material flows of waste biomass, water and their constituents (e.g. carbon, nitrogen and phosphorus) in a region by integration of quantity data. This PIOT sets not only industries but also activities on recycling, waste disposal and wastewater handling in detail as sectors. Import and export between regions, and emissions to environment are also set in the table. Applying content rates of carbon, nitrogen and phosphorus to mass flows of each item, elemental flows of those are accounted for estimating emission to water (as organic pollutant and nutrients) and atmosphere (as greenhouse gas) from the whole system. The energy consumed by activity in each sector is also accounted for estimating greenhouse gas emission. Another originality of this PIOT is that physical data obtained from relevant statistics will be directly integrated to values in the table. As a case study, we are surveying the waste biomass flow at the Kochi prefecture, Japan. Administrative information on industrial waste was acquired from the Kochi Prefecture and the Kochi City with their cooperation. For municipal waste, annual survey on municipal solid waste business by the ministry of the environment was used. For by-product, generation amount, sort, composition and usage of biomass waste were surveyed by hearing, sampling and questionnaire at recyclers of biomass waste. Amounts of generation, recycling and disposal of each biomass waste item, disposal method and municipality were built up from these reports and survey. Using above information, flows of each lot (the annual generation an item of waste from a source) of biomass waste from generation via treatment to disposal or reuse were compiled in the database and set into the PIOT. The current biomass PIOT for Kochi Prefecture is shown in Figure. This table shows weight of materials as wet basis. The 1.43 × 108 tons/year of total demand and the 1.34 × 108 tons/year of total supply were accounted at this time. The difference between demand and supply would mainly be resulted from unrecorded flows in our database, especially on supply of water from the waterworks and the natural water, and the biomass production. We will survey constituents of carbon and nutrients in materials and expand our PIOT to depict the substance flows of elements, in order to estimate quality and quantities of emissions.
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