[in Japanese]

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[in Japanese]

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[in Japanese]

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Since just before or after enforcement of the Soil Contamination Countermeasures Law in 2003, the local governments, which regulate a soil pollution problem with local laws and regulations, have increased. Consequently, the cases of the investigations and the countermeasures of soil pollution have increased, and their information disclosures have been followed. To support diagnosis and remediation of the pollution sites based on such public information synthetically, authors have studied and established the three fundamental databases, such as (1)contaminated site database, (2)remediation technology database, and (3)passed events database, and have integrated the advanced database system with those three databases. In this report, the database system is positioned as a Knowledge Database Management System (KDBMS), and its overview, the practical using method and its future prospect are reported and discussed. In the conclusions, the usefulness of the KDBMS and database creation of the public opened cases are proposed.

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Recently, since the amount of livestock manure has increased with rapid magnification of livestock industry, livestock manure is often treated improperly, such as field heaping or disposal to pit without liners. Immediate countermeasures are required, because the improper management might cause river and groundwater pollution. The Law Concerning the Appropriate Treatment and Promotion of Utilization of Livestock Manure was enforced in 2004 and the construction of storage place (called as a composting facility) for livestock manure has been promoted, but relationships between livestock manure and neighboring environmental pollution has not been cleared completely. In this study, a river and groundwater nitrogen pollution model was developed to show quantitatively the relationships between livestock manure and river and groundwater pollution, based on field investigation. The model treats two kinds of total nitrogen sources such as a site on which livestock manure is piled, and a meadow on which livestock manure is put. As a result, loading doses of total nitrogen from the two sources to the total calculated basin area was the same level. In addition, the total nitrogen in groundwater contributed the river pollution more than that in surface water through the site and meadow.

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[in Japanese]

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In recent years, the collected municipal solid waste (MSW) quantity of Beijing has continued to increase, reaching 3.41 million tons in 2004. With predictable increase in future, the pressure on the MSW disposal system will be further intensified in the future. This research is part of a study on improvement strategies for MSW treatment and disposal systems in Chinese metropolises. Based on the prediction of collected MSW quantity and quality of the of collected MSW quantity and quality of the former research, 3 disposal scenarios by the former research, 3 disposal scenarios by 6 recycling cases were assumed with considering of the environmental policy's influence to recycling rate of papers and plastics. Necessary new facilities for 3 scenarios by 6 cases were calculated. Furtherfor, LCE, LCCO2 and cost analysis for 3 LCE, LCCO2 and cost analysis for 3 scenarios in LCCO2 and cost analysis for 3 scenarios in each case were calculated. The result shows that with the increase of recycling rate, the CO2 emission with the increase of recycling rate, the CO2 emission and energy consumption in MSW disposal would decrease gradually.

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This paper presents a survey study on the consumption pattern of five main types of electronic home appliances (Color TV, refrigerator, washing machine, air conditioner and personal computer) and the attitudes of householders to obsolete them after utilization in Beijing, the capital of China. There is still space for consumption growth of air conditioner and personal computer while other three kinds have reached saturation. The average life spans of the appliances are found shorter than the anticipated life time. Half of the householders are willing to sell their used appliances to the private collectors due to the convenience and competitive price. Few of them (7%) would like to store the used appliances because of limit living space. 47% of the surveyed people thought the producer should pay for the possible recycling cost. About 85% of them are reluctant to pay more than 50 RMB for per unit of the appliance if required. This study is helpful for the waste electronic appliances generation amount estimation and flow analysis in Beijing and also can be used for the assessment of management frameworks there.

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In Korea, the 2nd comprehensive national waste management plan of which object is to establish sustainable society has been carried out since 2002. To accomplish this goal, it is need to reduce not only waste generation but also environmental load of waste treatment. The national plan designed changing waste treatment methods as a way to reduce environmental loads, therefore it is need to estimate the environmental improving efficiency of altering waste treatment method. In this study, the environmental load change of waste treatment by comprehensive national waste management plan execution is evaluated with LCA.

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Solid waste is a serious problem in the wake of urbanization. An urgent attention is needed to tackle the problem. There is technology to handle it, yct application of management tools and techniques becomes inevitable. The researchers have conducted an empirical study on solid waste management in Mysore city to test the hypothesis Solid waste causes serious concern on the life of people and environment in urban areas and proved the same.

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This paper focuses on rare metals that are essential materials in high technology field and aims to investigate the possibility of resource recovery in melting fly ash, which are generated from ash melting and gasification/melting of solid waste. Specifically, the content of rare metals in melting fly ash and the behavior of rare metals in melting process are investigated to obtain basic information for rare metals recovery. As a result, Sn, Bi, Ga, Pd, and In showed high content in melting fly ash and mostly transferred to melting fly ash during melting process.

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This study investigated the development and the applicability of the bio-fertilizer made from the waste earthworm casting and the waste Chinese medicine. This new by-product fertilizer might be able to replace the chemical fertilizer which has brought about a lot of environmental pollution problems in farm land and nearby waterways. Elements contents of the bio-fertilizer showed to satisfactorily suffice for the standard guideline commanded by the Administration Law of the by-product fertilizer in Korea. Analyzing the contents of heavy metals, which was the most hazardous component from the treatment process of organic wastes using earthworm, a little amount of heavy metals were detected. The bio-fertilizer developed in this study was thought to be a good fertilizer which had no side effect to plants.

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The leaching behaviors of Zinc and Manganeses of spent alkaline battery in sulfuric acid solution by using H2O2 as a reducing agent were investigated according to concentration of H2SO4, temperature, solid/liquid ratio and rotating speed of stirring bar. And base experiment for Mn-Zn Ferrite using the leaching solution was done. The experimental results of Zinc and Manganeses dissolution rates obtained at 100g/L solid/liquid ratio, 3.0M H2SO4, 60°C and 200rpm were 97.9% and 93.9%. After coprecipitation of leaching solution at pH 12, 80°C, O2 1.3L/min and 500rpm, Mn-Zn Ferrite was synthesized directly at low temperature.

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Spent lithium primary generated from army and household, was dismantled first. Only spent battery without plastic case was put into sulfuric acid solution of 0.5 M. Then spent battery was reacted with acid solution and was corroded by acid slowly. When the inside of spent battery was open, lithium metal in the battery starts to react and turn into the stable material. After this treatment for several days, the spent lithium primary battery was treated by crusher without any firing and explosion.

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This study was conducted to evaluate the digestion efficiency on anaerobic digestion of livestock wastewater and food wastes using hybrid in low temperature. Anaerobic digester was operated from 30 to 60 day's HRT at the temperature of 25°C. The organic removal efficiency was around 60% of TCOD and more than 70% of SCOD. In case HRT 30 and 40, total gas production was over 3000 mL/day and methane gas production was over 2000 mL/day. In case HRT 50 and 60, total gas production was over 1800 mL/day and methane gas production was over 1000 mL/day. So gas production of HRT 30 and 40's rector was about 2 times than HRT 50 and 60.

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In this study, methane generation rate constants(k) were calculated to compare the stabilization of municipal solid wastes(MSW) with different portion of biodegradable component(food wastes and sludge sewage). Four sets of lysimeters(1000mm(Φ) × 5000mm(H), FRP coating steel) were operated to perform MSW decomposition in controllable condition. Compositions of biodegradable component of lysimeters L-1, L-2, L-3, and L-4 were about 35%, 35%, 2.6% and 7.4%,respectively. Constants(k) were calculated by 1st-order decay model( ). Methane generation potential(Lo) was derived from BMP test results. Cumulative methane producton(L) was calculated by using total gas volume and methane concentration, measured by wet gas meter and infrared gas analyzer in each lysimeter. Elapsed time(t) was applied in unit of year. Constants(k) of lysimeters L-1, L-2, L-3, and L-4 were calculated as 0.0339yr^-k) of lysim^eters L-1, L-2, L-3, and L-4 were calculated From these results, it was considered that low portion of biodegradable component of MSW led to low k, and low methane production.

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Food waste output is the largest part of household waste in Republic of Korea. Household waste output was 50,007ton per day, of which 23%, 11464ton is food waste. And it is a huge value of good waste be cause of the life style in Republic of Korea and by using excessed amount of good and results on 80-85% of high moisture content, because of salinity concentration and perishable properties food odor is appearint causing decrease of incineration rate and temperature and increase of air pollutants, which is the subject of concern. It is concerned to make air pollutant from decrease of incineration rate and temperature. Recently, we are interested in resource technology of organic waste since 2005, when landfills in Korea can not be apply as stabilization, for treatment as stabilization, volume reduction, and disposal. At aeration condition, composting is used to convert organic matters of food waste into less hazardous and easily biodegradable organic matters So, in this study, we have compared efficiency of aeration process to detine composting efficiency depending on salinity that is the important factor in food waste treatment.

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Study on the HCl exhaust and reduction behavior of RDF(refuse-derived fuel) pellets was carried out to increase the HCl removal efficiency during combustion. Moreover, the effect of Ca-based absorbent addition on the emission of HCl was investigated. The combustion experiments were performed in an quartz tube reactor which is maintained in the temperature range of 20-1,100°C, using combustion air (1 liter/min).The de-HCl capability of absorbents in RDF was evaluated by measuring the emission fraction of HCl in the flue gas and the capture fraction of Cl in the ash.

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It is important to evaluate microbial immobilization of nitrogen (N) for understanding of N dynamics including NH3 emission during composting process. Several methods such as use of isotopes and plate counting method of microorganisms have been reported as measuring methods of the immobilized N. However, these methods are not simple or not enough to explain the immobilization of N. In this study, quantitative analysis of DNA extraction from the composts was suggested for evaluating the microbial immobilization of N during thermophilic composting. It was found out that the time courses of DNA quantity would better indicate the variations in microbial N than those of the thermophilic microbial density during the composting. Moreover, it was well confirmed from the results of denaturing gradient get electrophoresis (DGGE) profiles of PCR amplified V3 regions of 16S rRNA to assess the microbial diversity of the compost. It was ascertained that the DNA quantification of compost samples would be useful indez to evaluate the microbial N during composting.

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The partial equilibrium method was developed by Fukumoto et al.Dioxins source species such as C6H6 and C6H5OH were calculated by this method.In this research, the simulation of RDF fluidized bed incinerator was performed by the partial equilibrium method and,it was compared between Srivatsa's 4 step model and the experimental data.In this model, the partial equilibrium method considers generation of mixture gas of fuel and air by turbulent mixture rate first. The turbulent mixture rate is estimated by the eddy dissipation model. Next, the mixture of fuel and air is burnt by molecular diffusion and becomes a combustion gas. The burning velocity is calculated by the Arrhenius equation. Finally, the products are determined by the chemical equilibrium method from the combustion gas. This method can calculate chemical species without chemical formula. The result was in good agreement with 4 step model and the experiment data and this model was expected for applying to combustion equipment such as incinerators and gas turbines.

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The breakthrough time of adsorbents for semi-volatile organic compounds in an incineration facility adsorber was estimated by the mass transfer zone method. We calculated breakthrough time under actual conditions of packing length and superficial velocity, and clarified the use time of the adsorbents. Although activated coke adsorbs less than activated carbon, it can still adequately adsorb semi-volatile organic pollutants, and is produced at a lower environmental load and cost.

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In this study, emission sampling and analysis of mercury at inlet and outlet air pollution control devices(APCDs) or bag filter(BF) have been conducted to provide information on the speciation(Hgp,Hg0, Hg2+), removal efficiency and mass distribution in waste combustion processes. Five municipal waste incinerators (MWIs) two industrial waste incinerators (IWIs) each with dry and wet types of APCDs(or BF), and cement kiln were selected to measure mercury concentrations. Speciation whether mercury forms are Hg0, Hg2+, was studied by employing Ontario Hydro method. The results of Hg speciation for MWIs, IWIs and cement kilns were observed the opposite tendency and depended on dry types (BF, SCR) and wet types (wet scrubber, paked tower) of APCDs, flue gas temperature and composition.

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Polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) and dioxin-like PCBs in slag and char from automobile shredder residue (ASR) were analyzed to observe any changes in characteristics and distribution of their congeners by the pyrolysis and melting process. In char, solid product from ASR pyrolysis, lack of air caused a higher concentration of PCDFs than that of PCDDs, and a large quantity of dioxin-like PCBs existed in low chlorinated isomers. The concentration of PCDDs/PCDFs in char was 0.542 ng/g, and the toxicity equivalent concentration was 0.072 ng-TEQ/g, and those of dioxin-like PCBs were 0.869 ng/g and 1.579 pg-TEQ/g, respectively. The melted slag of char was fabricated by different cooling methods: water quenching, air cooling and slow cooling. Concentration distributions of PCDDs/PCDFs were 1.513, 1.376, 2.432 pg-TEQ/g, respectively, and those of dioxin-like PCBs were 0.004, 0.005 0.010 pg-TEQ/g, respectively.

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A small-size fluidied bed was used to study the pyrolysis characteristics of MSW (Municipal Soild Waste) at different operation conditions. A lot of energy have to be supplied for pyrolysis . The current method of pyrolysis should be supplied with a lot of energy to reach the elevated temperature. To solve the problem of high energy input, we used two reaction furnaces. The high temperature gas coming up from the bottom increases the temperature of the waste products entered at normal temperature and them the first pyrolysis occurs, the second products(char etc.) fall to the bottom furnace and second pyrolysis and combustion occurs. The reaction furnace used the fluidized bed and we used the waste products from processing facilities such as woods and scrapyard. Through elemental analysis, we analyzed the composition and also found the three components (moisture, ash, combustible components) and their heating values. The characteristics of the waste products were known through thermogravimetric analysis experiment by TGA/DTG.We analyzed compositions of the waste gases at different temperatures (300°C~500°C) and measured concentrations of carbon monoxide, sulfer dioxide, nitrogen oxide, hydrogen chloride and dioxins from inlet and outlet of APC (air pollutants control) devices. Also, we analyzed concentrations of the pollutants and the removal efficiency of APC devices.

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Organic wastes such as sewage sludge is abundant materials in volatile matter and thus can be converted into usable energy or valuable chemicals by thermal treatment. Pyrolysis is one of recovery process which has the potential to generate various products like oil, char and gas. Also, it was known that fluidized bed process was suitable for pyrolysis because of high heat transfer and mixing effect. This study had been performed to collect pyrolytic products on the operating parameter such as temperature and u₀/u_mf. To determine chemical composition and yield of pyrolytic products, qualitative and quantitative analysis was carried out.

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Municipal solid waste incinerator (MSWI) fly and bottom ashes were vitrified at about 1450°C, for the first time, using electolysis gas. Vitrification of pelletized fly ash (fly ash + water glass) results in decrease in leaching of toxic heavy metals to much below the Korean regulatory limit value, though melted fly ash was a poor vitrified product having dark grey appearance As the vitrified ash product of bottom ash and its mixture with fly ashes were found to be non-hazardous in nature and glassy in appearance, they could be considered as construction and road building material in future.

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A carbonization can be suggested as one of the recycle methods for organic wastes such as food wastes or sewage sludge. The authors have developed the efficient carbonizing facilities composed of direct drying and indirect pyrolysis processes. Carbonized residue can be utilized as adsorbents or fuel because of its physical and thermal properties. In this study, mass and heat balances for the carbonization of garbage or sewage sludge were established and thermal properties of carbonized residues were estimated. To upgrade their fuel characteristics, several methods such as making pellets and/or adding cokes or other materials were also applied.

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Polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) byproducts can be formed in combustion systems by a variety of mechanisms. PCDD isomer patterns from municipal waste combustion are most similar to those produced by CuCl2-catalyzed phenol condensation from 10 chlorinated phenols. PCDF isomer patterns, on the other hand, are most similar to those produced by chlorination and dechlorination.

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Abstract (No more than 800 bytes)Waste-to-energy (WTE) is seen as one of the solutions to the worsening problem of major dumpsites in Metro Manila, Philippines. Thus, the Payatas Landfill Gas Recovery Project is being implemented, mainly, to curb greenhouse gas emission, control leachate contamination and improve the overall condition of the dumpsite. The mechanism for this project is the Clean Development Mechanism (CDM) which is an offshoot of the Kyoto Protocol. In this poster, environmental, economic and social impacts are analyzed. Role of the community living within the dumpsite is considered since scavenging is a major source of living for the people. Recommendations are also determined as the project is considered for replicability in other dumpsites in Metro Manila. Valuable lessons may arise as developing countries, like the Philippines, venture into renewable energy development.

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The concentrations of PCDDs/DFs and co-PCBs in leachate from disposal sites contained municipal solid waste and incineration residues were average 48.006 pg/l(16.220-959.509 pg/l) and 85.553pg/l (22.720-2,179.683 pg/l), respectively. The major congeners of PCDDs/DEs and co-PCBs in leachate were OCDD (approximately 70%) and 2,3',4,4',5-PeCBs (approximately 50%), respectively. The concentration of PCDDs/DFs in leachate decreased with increasing the ratio of non-combustible matter including incineration residue to total wastes in landfill.

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Dissolved organic matter (DOM) which is ubiquitous in environment shows various properties with its origin. Many studies have been carried out widely to characterize physicochemical properties of DOM derived from different origins. the reason why DOM is important in environment is that DOM is known as significant factor which affects behavior of trace pollutants (by redox reaction and hydrophobic adsorption) rather than it could be a contaminant by itself. The objective of this study were to characterize DOM derived from leachate of incineration residues contained landfill sites which have different ages by fractionation method and to examine the interaction between DOM fractions and trace pollutants (Cu2+, PAHs) by fluorescence analysis.

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Just as there are changes in methane production pattern over time. Quantities and rates of methane production are a function of numerous factors, including waste composition and internal landfill environmental condition such as pH, temperature, and nutrient or inhibitor concentration. Since 2005 years, burials of food wastes in landfill were ban in the South Korea. This phenomenon caused dramatic changing waste composition and internal landfill environmental condition affecting methane production. In order to investigate the changing of methane production pattern with changing of environmental condition in landfill connected with changing waste composition, we have being operated two simulated landfill test cells with 147 tons of mixed municipal solid waste. It is expected that this is the most effective method for gaining the most realistic information. The test cell of 480 m3 is isolated from the rest of the landfill site by a HDPE membrane. In order to monitor gas composition, PVC pipes punctured were installed vertically inside the waste layer. The final soil cover (52 to 70 cm) is the surface to be placed over a landfill after all waste are received. The leachate was collected in the leachate collector for measuring leachate composition. Through the monitoring results during passed 1 year, we could confirm that methane production pattern is fluctuating according to internal landfill environmental condition.

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In order to reuse the residual soil in the M landfill, the characteristic of buried wastes was examined by analyzing the physical property, and proximate analysis. Also, the BMP(Biochemical Methane Potential) test was conducted to measure CH4 yield and estimate the biological stabilization of residual soil in the open dumped waste landfill. The residual soil was simulated approximately 70ml/day with leachate in four lysimeters. Not only leachate to measure pH, BOD, COD_cr, and TOC, tedlar bags were installed to gauge gas rates such as CH4, CO2, on the top of four lysimeters. Although the volatile solid of residual soil in the M landfill is a little higher than general soil, authors were incapable of measuring CH4 yiele by Gas Chromatograph for BMP test even lysimeters. Moreover, pH value of leachate in lysimeters was approached around neutral pH range after 25 days and BOD, COD, TOC values were also decreased gradually. The results make it possible to reuse residual soil in the M landfill as the landfill cover soil or banking material.

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The Permeable Reactive Barriers (PRB) are a relatively simple remediation technology in which a zone of Permeable reactive media is placed in the folw of a contamination plume. Multi-PRBs can be expressed enhanced PRB. This study is focused that M-PRBs are composed of zero valent iron barrier and biological barrier with tire rubbers to treat contaminated groundwater in the Landfill. This study is performed by large scale of column (Φ60mm X H 515mm) in laboratory. Upflow-throug column experiments for this study were performed to evaluate the reaction efficiency of two reactive barriers. First column is set by the wasted iron scrap (size: 2-10mm) with converter slag and the latter part column is set by the rubber scrap (size: 2-7mm) with anaerobic sludge. The synthetic contaminated groundwater is mixed heavy metals (Cr, Cd, As, Zn, Cu), salt irons (NO₃^-, NH₄⁺), TCE(trichloroethylene) and Organic material (COD). The condition of columns has maintained anaerobic condition. Most of contaminants were degraded in the zone containing Fe⁰ with converter slag (95:5%,w/w), and Organic material (COD) was just removed (87%) in bio-barrier zone with rubber scrap and anaerobic microorganisms.

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In this study, we sampled leachates from 13 landfill sites containing incineration residue as well as municipal solid waste, and investigated the reverse mutation and cytotoxicity of the leachates by TA98, a salmonella typhimurium variation cell and sulforhodamine B assay (SRB assay), respectively.As a result, the reverse mutation test demonstrated a dose-response increase in all of samples, and represented 2.0 or higher comparing to standard solution ratio. Such a result corresponds to the positive effect decision value established by the US EPA, which indicates that the samples contain reverse mutation-inducing substances. The cytotoxicity also showed a dose- response increase in all the investigated samples. One site (MC), in particular, showed 97 % increase (max), which is a clear indication that this site includes cytotoxicity-inducing substances.

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Waste steel scrap was obtained from an industrial complex and washed with solvent in order to remove oil on the surface (ID). Waste steel scraps, acid-washed with a hydrochloric acid solution for 2, 5, 10, and 20 hours, were prepared through pretreatment (AD). Batch studies were subsequently run to test the reactivity of the waste steel scrap towards NO3^-(at 10 mg/L) and heavy metals (As and Cd, at 10 mg/L each), which are commonly present in leachate from landfill. Reactors were shaken on a reciprocating shaker (150 rpm, 25°C) and periodically analyzed for NO3- and heavy metals using IC and ICP, respectively.Waste steel scrap through pretreatment showed a high reactivity to remove nitrate. According to the results, AD should be pretreated for shorter to be a better reducing agent. Batch experiments suggest that waste steel scrap can effectively remove nitrate. The removal assays of heavy metals were also conducted in additional batch reactors to investigate the ability of AD to remove heavy metals. Based on adsorption results, significant heavy metals removal (As and Cd) was observed by AD. Laboratory experiments suggest that waste steel scrap can be recycled as reactive materials in a permeable reactive barrier (PRB) system to remove contaminants in leachate from landfill. This approach may also be practical and effective to treat other redox-sensitive groundwater pollutants, such as nitroaromatic compounds, chlorinated solvents, hexavalent uranium, and some pesticides.

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This work examined the extraction properties of metallic elements from municipal incinerator fly ash under hydrothermal conditions. The ash was firstly pre-washed by distilled water, then subjected to hydrothermal treatments. The pre-washing process was effective for Na, K, Ca extraction with extraction percentages of 67%, 76% and 48%, respectively. The optimum contact time was 30 minutes for the pre-washing process. Five types of acids were tested for the extraction experiments and hydrochloric acid was found to be most effective for metal extraction from the ash. Compared to room condition, hydrothermal treatment accelerated the dissolution of the ash, thus promoted the reaction of acid with hazardous metals such as Cr, Cd, Pb, and furthermore, the consumption speed of acid was slowed down under hydrothermal condition. The acid simultaneously reacted with all the metal in the ash under hydrothermal condition but preferentially reacted with Ca at room condition. The optimum hydrothermal treatment temperature, time and liquid/solid ratio were 150 oC, 5 h and 10:1 (ml:g), respectively.

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In pursuing their aims of reducing health problems and eliminating potential risks to people's health, health-care services inevitably create waste that may itself be hazardous to health. Indonesia's current health care waste (HCW) management policy covers only the waste from hospitals and clinical laboratories. Thus, there is a need to establish similar standards and procedures of waste management for small health care establishments (HCE) like community health centers (CHC). Though they may generate less waste quantity compared with those from hospitals, the waste management from CHC becomes important due to their broad range health care activities. In the present an attempt is made to analyze the current management of HCW from CHC in Bandung and to propose a framework for the system improvement.

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A significant mercury pollution has been detected in water and sediments of the Oued El Harrach river, Alger, where industrial zone has been developed. The mercury pollution is probably caused by the discharge of untreated industrial waste and waste water into the river that was generated from a mercury electrode plant of chlorine factory.

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Polychlorinated biphenyls(PCBs), the most important compound of POPs, are managed in an environmentally sound manner and by the year 2025, every country should take actions to remove PCBs found above certain thresholds. The goal in Korea is totally remove PCBs by 2015. There exist various chemical treatments of PCBs. Among these, We selected SDMA(sodium bis(2-methoxyethoxy)aluminum hydride) and cobalt catalyst, which had been reported to have rapid reaction time and high efficiency. This objectives of this study were to determinate the optimal operation condition and major variables of PCBs dechlorination by applying different SDMA and catalyst loads, hydrogen donors, temperatures. In this work, target compounds were Aroclor products(Aroclor 1242, 1254). Through the series of experiments, following conclusions were drawn. The described method of using SDMA and cobalt catalysts is suitable for fast, safe and complete dechlorination of PCBs. The optimal operation condition was at 110°C with the use of SDMA in a certain mole ratio(n_Na : n_Cl = 50 : 1) and with Co(acac)2 in less than the stoichiometric amount of Cl(n_Co(acac)2 : n_Cl = 0.1 : 1) . The decomposition of PCBs with the SDMA in the presence of cobalt catalysts occurred rapidly in early stage. The SDMA was considered more effective than catalysts in terms of decomposition efficiencies of PCBs. Dechlorination efficiency of TEQ concentration was higher than those of total concentration, because there was a shift in the isomer profile from higher to lower chlorinated biphenyls. The dechlorination method reported in the present study may be considered a useful alternative of chemical treatment technology of PCBs in Korea.

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This study aims to the modification of the bio-slurping that used in LNAPL free product remediation. Whenever the variation of water-table in groundwater on seasonal, the pumping of groundwater decrease extract efficiency. The authors developed M-float type slurper to solve this situation. The modified slurper acts the end of extraction pipe by itself, because the M-float has a specific gravity between LNAPL layer and water-table. The M-float applied system has more efficient removal rate than conventional Pump & Treat method. Both the extraction ratio and quantity are increased as much as 8% in the M-float type system in comparison with conventional Pump & Treat system. As a result, the M-float type system can extract more rapidly than the conventional Pump & treat system. For that reason, the concentration of LANPL in contaminated soil declined more rapidly. The removal efficiency can be improved by increment of the distribution of subsurface vacuum. The vacuum of M-float applied test increased approximately 3kPa in compared with conventional Pump & Treat system. Consequently, the M-float can be used as the method of LNAPL removal in field scale.

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Environmental problems caused by certain geologic conditions include contaminated soil by acid mine drainage (AMD) are recently serious problem. This investigation has performed three times at site during 8 months. It was collected that 15 surface water samples, 2 groundwater samples, and 20 soil samples in sampling of each time. The AMD of pyrophyllite ores caused by the oxidation of weathering. The AMD contains Mn, Fe, Ni, Cd, Pb, As that enriched in the mine water with low pH. The pH value various in water sample was 3.1~7.9, and concentration of Mn, Fe, Ni, Cd, Pb, As and sulfate (SO₄^2- in the samples measured 0.016~2 383 mg/l.

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