[in Japanese]

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[in Japanese]

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We dechlorinated DDT, DDE and DDD in 2-propanol/methanol (99:1) mixture by using NaOH and Pd/C catalyst at 313K. First, DDT and DDD released HCl and were transformed to DDE and DDMU, respectively, by reacting with an excess molar amount of NaOH. Then, the produced DDE and DDMU were dechlorinated stepwise by adding Pd/C catalyst to yield a chlorine-free compound (1,1-diphenylethane, >97% yield). In this catalytic reaction, the alcohol solvent behaved as a hydrogen source, and a small amount of methanol added to 2-propanol greatly enhanced the catalytic activity.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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The detoxication processing experiment of the building materials which contain asbestos using overheated steam was conducted.The result has checked that it had been detoxicated also by the method using a phase microscope, or the method using X ray,when the building materials which contain asbestos 5% were processed under 900-degree C overheated steam atmosphere for 30 minutes.If this technology is used, the building materials containing asbestos will become the materials of cement.

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In this experiment, an electric furnace and a fluid furnace were employed to dispose of waste asbestos. Each furnace simulates a cement kiln using a slurry fuel containing the mixture of waste asbestos. The electric furnace was able to eliminate the waste asbestos at a temperature of 1000degrees Celsius in 1.0 seconds. The fluid furnace eliminated the waste asbestos at a temperature of 950degrees Celsius in 0.8 seconds.

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This study is concerned with detoxification technology of asbestos-containing wastes (non-scattering type asbestos wastes).The objective of the study is to get a prospect of the technology in order to start the actual operation soon as the certified detoxification process and facility based on the Minister' s Certification System in the 2006 Revision of Waste Management and Public Cleansing Law. It has been confirmed till now that asbestos wastes can be melted and be detoxified at temperatures below 1,500 degree Centigrade under the mixed-melting condition with incinerated ash of other wastes. However, the mixture ratio of confirmed asbestos waste is low with around 20% at the maximum. The higher mixture ratio of asbestos waste is desirable for practical operation. Then the verification tests with the mixture ratio up to 50% were executed in an existing ash melting facility under the condition that equipments and operation should be basically the same as normal ash melting process. As the result, asbestos was detoxified perfectly and no remaining asbestos could be found in emissions produced through mixed-melting treatment nor in residues inside the melting furnace, flue ducts and the bag-house.

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To develop a testing method for asbestos waste treated materials by transmission electron microscopy (TEM), we evaluated thermally treated chrysotile and crocidolite standard samples. As for thermally treated chrysotile, number concentrations of total and chrysotile fibers decreased with treatment temperature. Forsterite fibers were dominant over 600 C. At 800 C, forsterite fibers thickened and weight concentration increased. At 1000 C, forsterite fibers changed to lumps and number concentration decreased. As for thermally treated crocidolite standards, number concentration of total fibers slightly decreased till 600 C, and largely decreased at 800 C. At 800 C, aegirine fibers were found. At 800 C, number and weight concentrations of crocidolite decreased to 1% of untreated sample.

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[in Japanese]

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Leaching characteristics of hydrophilic compounds in plastic products were investigated by pH dependent test, in addition to content test and serial batch leaching test that were examined in last year. And the effects of ionic strength on the leaching behavior were also investigated. Since 1,4-dioxane is nonelectrolytic, the leaching amount from a PVC sheet with antistatic additives was not affected by pH. On the other hand, the leaching amount of bisphenol A(BPA) was affected by pH and increased in alkaline conditions, because BPA is weak acidic compound. The influence of ionic strength was the same as that of BPA, and the amount of 1,4-dioxane leached increased with the ionic strength for a few substances containing ions, but decreased after that.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Current leaching test methods commonly applied for evaluating environmental safety of recycled materials cannot be regarded as capable enough for assessing their environmental impact at on-site, because these tests don't take various environmental conditions into account. For proper evaluation, actual condition where recycled material is used should be considered. In this study, in order to confirm the influences of environmental factor on heavy metal leaching, recycled materials, such as ASR molten slag, copper slag, MSWI ash, and lead contaminated soil, were tested under different solvent condition in which salt, DOC concentration and redox condition were varied. In consequence, leaching of heavy metals was promoted by increase of salt and DOC concentration. This result indicates that consideration of solvent characteristics that may be altered by various environmental conditions is significantly important for leaching test.

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[in Japanese]

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There have been investigations on the Waste Washing System as a method for the early stabilization of landfills and it met chemical criteria for the early stabilization. However, development on the toxicological criteria with which safety of the landfills can be easily understood to the neighboring residents of the landfills is still demanding. Four lysimeters were filled with A) the ash before washing, B) the ash after washing, C) 35% of A + 65% of B, and D) 65% of A + 35% of B. Acute toxicities of the leachate from the lysimeters were monitored using Microtox™, ToxScreen-II, and DaphTox tests. Leachate toxicities from B and C were reduced faster than those from A and D and it was highly correlated with the changes of Pb, COD, TOC, and BOD. Therefore, landfilling with the high contents of the ash treated with the WWS can reduce hazard to its surrounding environments and it suggests WWS be used as a pre-treatment method for hazard reduction.

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In conventional waste management using bioassay, EC50 (Effective concentration to reduce 50% of bioligical activity) has often been used as a toxicity index. Instead of EC50, risk scoring based on toxicity ranking is analyzed in this study, because the derived score for each waste samples should be user-freindly and easily understandable.

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The objective of this project is to coordinate seventeen local authorities in Jordan River Rift valley and to establish the new solid waste management association in order to provide better solid waste collection service for these local authorities equally.

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In this study, we investigated several waste management scenarios for developing countries in terms of CDM. We considered some indicators, e.g., net energy consumption, landfill volume, global warming potential (GHG emission potential), and CER potential, to evaluate each scenario, which can support decision making of national authorities as well as project developers in CDM. The results show that incineration has advantages in the aspects of landfill volume, however it is not desirable in other aspects such as CER potential, energy consumption. Whereas, LFG recovery activity which is current dominant CDM project activity in waste field has high potential of CER, however it was not good in global warming and landfill volume. We could identify anaerobic digestion of organics was a good alternatives for MSW treatment in developing countries which features high content of organic wastes.

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JICA's 3R project in Hanoi, Viet Nam, gegun since November 2006 and will be ended on December 2009, could provide with a case study of capacity development as an attenpt to involve with wide stakeholders at various levels. This article will examine the strategy, method and prospect of capacity development of the 3R Project.

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As the largest city in China, Shanghai is a representative of the eastern coastal municipalities with high population densities in the field the municipal solid waste (MSW) management. The integrated MSW management framework is developed quite fast in recent years, especially on the construction of new intermediate treatment and final disposal facilities. This paper presents the current status quo and trend of MSW management in Shanghai city.

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In this study, the model by which household waste emission is estimated from consumption expenditure is applied to urban area of Shanghai, China, and the fitness of the model is validated. Through the modeling, the quantitative relationship between the waste emission and the consumption expenditure is identified. As a result, it is cleared that the fractions of recyclable material, that is paper waste and plastics waste, increase if `expenditure for education` as well as `expenditure for transportation` increase. Moreover, through compared with Taiwan, it is found that the kitchen waste is more generated and the recyclable materials are less generated in Shanghai because of the lower consumption propensity on food expenditure and higher propensities on health and education.

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An integrated econometric model for estimating household waste emission considering the relationship among socioeconomic changes, consumption, and household waste emission, is proposed in this paper. This integrated model is composed of a consumer's behavior model based on consumer's preference and a household waste emission model representing conversion from consumed commodities into waste. By the model, household waste emission can be estimated from consumption expenditure and socioeconomic variables. Applying this model to a case study of Taiwan, household waste emission by waste category is fitted well in the sequential modeling. This integrated model will contribute to the planning of waste management system.

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Large amounts of spent electroless nickel plating baths are being treated by the conventional precipitation method. The stringency of the landfill space and big loss of nickel have given the researchers an urgent task to develop a less sludge generation and effective nickel recycling technique. High recovery efficiencies of nickel from the model spent baths by solvent extraction using a mixer-settler extractor were reported by us. It was found that the extraction efficiency was affected by the operation parameters such as the flow rates of aqueous and organic phases and the number of extraction stages. In this study, these effects were quantitatively studied on the basis of the extraction rate equation considering the hydrodynamics in the mixer. Then an engineering model was established for simulating the extraction efficiency of nickel during a multistage operation.

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There is well known that tetrabromobisphenol A (TBBPA) and many systems based on synergistic effect of brominated organic compounds with Sb2O3 are extensively used as effective brominated flame retardants (BFRs) in many plastics, textiles, etc. Thermal degradation of BFRs-containing plastics leads to formation of hydrocarbons and gaseous compounds such as HBr and SbBr3. Thermodynamic considerations indicate that these gases can act as bromination agent of metallic oxides – including heavy metals (e.g. contained in the plating sludge, incinerator ashes), moreover, these metallic oxides have a thermodynamic tendency to be brominated easier than Sb2O3. The aim of this study was to investigate experimentally the reactivity of selected metallic oxides such as ZnO, PbO, CuO, Fe2O3, and Sb2O3 with: 1) HBr, originating from thermal decomposition of TBBPA, and 2) SbBr3 which is formed during thermal degradation of brominated flame retardant plastics. In this paper the results obtained for ZnO are discussed.

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In this study, recycling of polypropylene(PP)/polyethyleneterephtalate(PET) blends from waste automobile interior parts were studied. PP/PET were mixed with inorganic fibers to improve the mechanical properties after recycling. Several compatibilizers were added to increase the compatibility between blend components. PP/PET/compatibilizer blends were melt compounded using twin screw extruder and the test specimen were prepared by compression molding. Mechanical properties of composites were examined using UTM and Izod impact tester. SEM pictures were taken to investigate the morphology of the recycled composites. Effect of compatibilizers along with optimum level of organic and inorganic additives will be presented.

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A process for the preparation of cobalt compound from the spent lithium ion batteries using sulfuric acid and oxalic acid was proposed, and metal leaching performance was investigated. The proposed procedure consisted of mechanical separation of metal containing particles and a chemical leaching process. The effect of leaching agent, reaction temperature, solid/liquid ratio and equivalent ratio for the cobalt compound preparation, were examined here.

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Red mud is a waste generated by the aluminium industry, and its disposal is a major problem for this industry. Red mud has a reddish-brown color and superfine particle characteristics. So, it can be a promising pigment admixture for concrete industry. An experimental study is conducted to investigate the potential use of red mud in colored concrete. The micro structures of red mud and iron oxide pigment such as porosity, pore size distribution, diameter of particle are analyzed with the aid of SEM, X-ray diffraction(XRD), and the infrared absorbance. Tests on physical properties of colored concrete, such as strength, slump, early shrinkage crack patterns, and color characteristics are carried out and the results are reported in this paper.

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Millions of used & end-of-life mobile phones are being generated in Korea each year. In order to more effectively recover and process electronic waste produced from consumers and to reduce its impact on the environment, Korea Ministry of Environment (Korea MOE) promulgated an extended producer responsibility (EPR) regulation for a number of electronic equipment (televisions, personal computers, refrigerators, washing machines, air conditioners). Mobile phones were included in the EPR program in 2005. Since collection and recycling of mobile phones has only recently started, the methods and infrastructure for collection and recycling processing for used and end-of-life mobile phones are not yet well-established and need to improve. This paper discusses current practices and management of used and end-of-life mobile phones in Korea, based on a survey of more than 1,000 consumers, review of the existing literature, site visits at mobile phone recycling facilities, and conversations with telecommunication companies and environmental regulatory authorities. successful collection schemes. The results show that approx. more than 15 millions of mobile phones are being annually replaced with new ones. The results of consumer survey showed an average of 28.8 months replacement period, which is typically higher than normal replacement period (18 months) in many developed countries. Economic incentives should be provided to remove used mobile phones from storage to increase recycling among consumers who have access to inexpensive storage. The recycling rates of cellular phones are found to be lower, when compared to other electronic waste stream. This results partly from lacks of an established collection system and unclear responsibility of between producers and telecommunication companies in the EPR. More collection points where consumers will find it convenient to dispose their mobile phones should be installed. The principal interest for metal recovery from used mobile phones is in the recovery of the metals of great value such as copper and cobalt. Government, consumers, telecommunications, recycling companies, and other stakeholders related to cellular phones should consider more collective actions that can be taken to promote successful collection schemes.

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This study was conducted to evaluate the digestion efficiency of hybrid reactor according to mixture ratio of influent. Anaerobic digester was operated from 30 to 60 day's HRT in low temperature. Influent mixed livestock wastewater and food wastes was used and the mixture ratio was 5:1, 5:2 and 5:3 (livestock wastewater:food wastes). In proportion to increase of the ratio of foodwaste, TCOD concentration was on the decrease and SCOD concentration was on the increase. The removal rate of TCOD was a range of 53∼65% in 5:3 and 63∼72% in 5:2. And the removal rate of SCOD was a range of 58∼73% in case of 5:3 and 51 ∼72% in 5:2.

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The pretreatment of waste activated sludge (WAS) by electron beam irradiation was examined to improve the anaerobic sludge digestion. The irradiation dose of the electron beam varied between 0.5 and 10 kGy (kilo Joule/kg). A graphical method was developed to separate two distinctive decay coefficients (k1 and k2) for their respective substrate fraction (S1 and S2). Anaerobic mesophilic batch tests of sewage sludge were carried out to evaluate their ultimate biodegradability and first-order decay rates. The results showed that the ultimate biodegradability was 48∼51% for WAS and 38∼40% for thickened sludge. At the substrate to innoculum ratio (S/I) of 0.5, 70% of total biodegradable volatile solid (TBVS) were degraded with an average k1 of 0.149∼0.153day-1 for WAS, whereas only 39% of TBVS were degraded with an average k1 of 0.123 day-1 for thickened sludge. The ultimate biodegradability of the sludge irradiated with electron beam was 15% higher than that of the sludge without irradiation. The k1 of irradiated WAS at 10kGy was found to be 0.342day-1 , which was two times higher than that of WAS without irradiation. These results indicate that the disintegration of sludge cells using electron beam would be able to improve the biodegradability and accelerate the organic degradation rates of sewage sludge. As a result, anaerobic digesters may be operated with a much shorter solid retention time (SRT).

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To reuse sludge discharged from waste oil purification process and sawdust as an alternative fuel used for cement kiln, some feasibility tests such as manufacturing parameters, thermal characteristics, and storage and transport characteristics of BOF, were carried out in this study. In BOF manufacturing process press type was more effective than extending type. As the mixing ratio of oil sludge was increased, the heating value of BOF was increased and it was over 5,500kcal/kg for oil sludge's mixing ratio of 60%. The pyrolysis of sawdust was occurred in 2 steps, but the pattern was changed to one step as the mixing ratio of oil sludge was increased and the main reaction was between 300 and 400°C. Theoretical terminal velocity of single BOF pellet was calculated to 5.0∼7.2m/s, but the actual value of the pellets was measured to 9.0∼13.0m/s and a pneumatic transport system could be economically applied for feeding BOF into cement kiln.

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Korea has constructed many apartments and buildings since 1960's∼1970's. Recently reconstruction of buildings increases to reform housing condition. It is increased rapidly that a quantity of construction wastes is 129,572 ton/day in 2005, from 78,777ton/day in 2000. The construction wastes as concretes, asphalt concretes, woods, and metals have been increased due to demolishing the antiquated apartments and expanding social facilities. Therefore, we need reducing and recycling construction waste. Construction waste has little harmfulness, and it could be used by circulation aggregate by proper treatment. But recycling rate is very low because of a term of works and expense problem. The purpose of this study is to offer basic data for kind of construction waste when demolishing building and to find the way to reduce the construction wastes.

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Trap grease, so called brown grease, is the grease collected in sewage interceptor at eating places. In contrast to yellow grease usually recycled for animal feed, soaps, cosmetics, and boiler fuels, most trap grease has been treated at waste incinerators or dumped in landfill. However, BDF production from trap grease can give considerable merits not only in terms of the supply of inexpensive BDF feedstock, but also waste reduction itself. However, its low quality for BDF production is still a matter of concern, e.g., higher content of fatty acid and moisture. Moreover, it is probable that serious contamination can be occurred by various unknown compounds in wastewater, and it raises another obstacle for the usage of trap grease. To design the optimal BDF manufacturing process from trap grease and evaluate its feasibility, it is important to understand its characteristics with respect to the content of mono-, di- and tri-acylglycerols as the target compounds for transesterification reaction, as well as to guarantee its good quality and environmental safety. In this work, it was determined major lipids components of trap greases from the restaurants in Japan and identified their potential contaminants.

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Carbonization process is a good practical utilization of biomass, which can transform various lignocellulosic wastes into charcoal. To improve the current charcoal production, which is time-consuming and inefficient, high pressure carbonization has been introduced as quick and efficient technologies. This study focused on the mechanism and applicability of this technique on agricultural wastes including wood residues. It was confirmed that the carbonization reaction was enhanced at elevated pressures, 0.4-0.8 MPa in our study: the reaction time was significantly shorter than in the conventional processes at ambient pressure. Not only pressure but also air delivery considerably affected the reaction performance. High airflow promoted reaction propagation but unfavorably decreased charcoal yields. The manipulation of air delivery and pressure could improve carbonization process and offer higher charcoal yields.

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The exhaust gases from incinerators of municipal solid waste (MSW), large amounts of which are generated in many countries, can have an enormous environmental influence. Flue gases contain inorganic pollutants such as nitrogen oxides and organic micropollutants such as dioxins. In Japan, the emission of particulate matter and inorganic gases is controlled by air pollution control laws. The current regulation concerning dioxins in waste gases came into effect in December 2002. In this study, information on the operation and maintenance of incineration facilities was collected from 2001 to 2003. The emission status of dioxins over the period since enforcement of the new regulation is summarized. The discharge status of particulate matter and inorganic gases is also reported.

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Water washing with CO2 bubbling as pretreatment of Melting furnace fly ash (MFA) for recovery of rare metals was investigated. CO2 bubbling which was applied to control pH during water washing decreased the leachg of Pb, Zn, and Cd remarkably. In addition, bubbling process was found to be an effective way to increase the removal rate of chlorine from MFA. Target rare metal elements including Cu, Pb, and Zn were about four times concentrated by water washing.

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Conventional dewatering technology can not be applied effectively to domestic sewage sludge with 80% or more water content which is burned in incinerator itself. In this research, the simple immersion drying technology, which is called fry-drying of sewage sludge is developed to reduce the water content of 80% to less than 15% using heated waste oil in 10 minutes. When sewage sludge is heated with hot waste oil, the temperature of sewage sludge and waste oil is constant at 123°C due to evaporation of water contents in sludge. In this fry-frying process of sewage sludge, water contents of sewage sludge is decreased as temperature of waste oil is increased at 120∼160°C for 10 minutes. Water contents of sludge from 85∼87% to 6∼9% at 160°C for 10 minutes and low calorific value of sludge is increase from 545∼539 to 5,710∼5,730 kcal/kg because the water contents of sludge is substitute with waste oil. The dried sewage sludge has sufficient heat value can be utilized as solid fuel in coal combustor. Also the dried sewage sludge is able to burn easily because of impregnation of oil and porosity inside

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Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In order to evaluate the quality of char as fuel, proximate analysis and caloric value were examined. The composition of raw sludge had a significant influence on the quality of produced char. The higher the ratio of carbonate and volatile matter in sludge, the higher caloric value of char produced. Moreover, an equation to estimate caloric value of char was developed by using the weight fraction of fixed carbon and volatile matter in char. Temperature's control was performed to improve the quality of char. But the char's caloric value was lower than common fuel such as coal, petrol, briquet etc. Therefore, the char was mixed with high caloric value's matter such as coal, briquet etc. for using available fuel. In this study, chars derived from various sludge were characterized from the standpoint of fuel recovery and reducing quantity of sludge. Industrial wastewater sludge such as dehydrated sludges, dried sludge were carbonized at 350°C, 450°C and 550°C for 20 - 30 min. under anoxic. From results, carbonization could be considered as a reducing quantity of sludge, as well as for fuel recovery.

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The physical and chemical characteristics of PCDDs/DFs and Co-PCBs are persistent, bioaccumulative, potential for long-range environmental transport and toxic. Korea joined the 'Stockholm Convention on Persistent Organic Pollutants' in 2007. PCDDs/DFs and Co-PCBs in some kinds of industrial wastes in Korea were analysed, which were 6 kinds and 13samples, such as waste acid, waste alkali, waste organic solvent, landfill leachate, sludge, and dust. All analytical data of PCDDs/DFs and Co-PCBs were in the wide range of concentration depending on the different kinds and processes, which were 0.001〜14.446 ng I-TEQ/L,g and 0.000〜11.391 ng I-TEQ/L,g respectively.

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Due to the rapid industrialization and the population growth, the amount of MSW (municipal solid waste) has been dramatically increasing. The advantage of incineration is the reduction of the volume of waste; however, significant amounts of bottom ash and fly ash were generated in the incineration process. Many researchers have made advances in their studies to find ways use MSW ash as resources. In this study, we studied how to prepare adsorbent and its characteristics by pre-treating it with citric acid, HCl and NaOH. High porosity and large surface area were acquired by acid-base treatment. The phase of adsorbent after treatment was identified by X-ray diffraction (XRD), the morphology was examined by scanning electron microscopy (SEM), and the CEC was analyzed by the ammonium acetate method. CEC and BET values were analyzed to evaluate the potential as an adsorbent.

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Benzene, toluene, ethylbenzene, xylene (BTEX) and odorous compounds are the typical volatile organic compounds (VOCs) found in urban area and industrial sites. The photodegradation of BTEX in photocatalytic fluidized bed reactor with TiO₂/SiO₂ is investigated. The TiO₂ film is prepared by the sol-gel method and coated on the silica-gel powder. The UV lamp is installed in the center of the reactor and the BTEX is analyzed by GC/FID/MSD. The odorous compounds are analyzed by Multi-matrix Cryo-Concentration System integrated with GC.

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Porous concrete enables water and air to pass through a firmly hardened material and allow required nutrients to reasch root of plant. The purpose of this study is to analyze void ratio, strength property and made vibrating press, kind of curing when using bottom ash, river and crushed aggregate. As a result of the experiment, the compressive strength is higher when the crush aggregate, but porous property is higher when the bottom ash.

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The recycling program on waste concrete is being progressed to national research. But research on waste concrete powder which is occurred in control process of concrete powder is not enough. Waste concrete powder includes in SiO₂, Al₂O₃, and CaO so that the manufacture of tobermorite is possibile through Hydrothermal Reaction. Tobermorite have an advantage of high strength, chemical acid resistance and the lower drying shrinkage. Accordingly, this study investigate on properties of the light-weight foamed using waste concrete powder. As a results, the light-weight foamed concrete using waste concrete powder is the same than silica powder of the density and porosity, but the lower compressive strength. Therefore, it is thought that light-weight foamed concrete using waste concrete powder is possible.

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This research analyzes pyrolysis characteristics of sewage sludge though pyrolysis experiments of sewage sludge from 4 domestic sewage treatment plant. First, before carrying out pyrolysis experiment moisture content, apparent density, thermogravimetric analysis, ultimate analysis, heating and elemental analyses of sludge were done based on sludge characteristics. Second, pyrolysis experiment were done in 500, 600, 700, 800°C, the waste reduction rate of sewage sludge and characteristic of char, tar, gas formed during pyrolysis process were analyzed. Specially, quantity of pyrolysis gas was compared with that predicted by CEA Code. Third, recycling possibility of pyrolysis by-products were estimated for most suitable pyrolysis condition. Pyrolysis experiment resulted decreasing tendency of char and tar as temperature rises. And in case of gas as temperature rises, hydrogen increased; carbon dioxide showed decreasing tendency, but methane, carbon monoxide, hydrogen sulfide did not showed regular trend.

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