[in Japanese]

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The Al Akaider Landfill is located in arid zone of northern Jordan, of which is approximately 80ha. The landfill has been operated since 1980, and urban solid waste, urban wastewater, industrial waste water, and industrial waste from olive mill factories are currently being disposed. Due to direct disposal of industrial waste water and olive mill waste, soil and ground water pollutions are concerned.

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[in Japanese]

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It is still hard to predict and control the closing time of the landfills. Stabilization of the organic matters and nitrogen which are hardly degraded in the landfills might take several decades. To facilitate the stabilization of the landfills, "the early stabilization landfill system" which can be constructed inside the landfill was devised and basic tests to see the effects of the forced aeration and of the hyperoxidized water were conducted. By the forced aeration, reduction of the organic matters as shown in BOD, COD, and TOC was facilitated and neutralization of the incinerator ash having strong alkalinity was also accelerated. Hyperoxidized water presented similar effects as with the forced aeration though its effectiveness was less than that of the forced aeration.

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For early stabilization of existing Landfill, I researched and developed a system method of construction to let you decompose the resolution of organic matter by creating aerobic environment forcibly. I planned an extra experiment with a lysimeter and a confirmation experiment of resolution promotion mechanism of organic matter by a lage-sized expriment institution.

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In order to establish the technology that the nitrogen (T-N), which was one of the factor that prevent landfill from termination, was decreased in the landfill wastes, a laboratory examination and a proof examination of using large tanks (W1,750mm*L7,000mm*H2,000mm) was performed. Consequently, it was confirmed that T-N decreased in the wastes by biological nitrification and denitrification for the laboratory examination. Furthermore, it was confirmed that T-N in leachate decreased by making anaerobic state after aerobic state for the proof examination. Namely, it was proved that decreasing T-N flowing out of landfill was possible by making biological nitrification and denitorification in the landfill wastes.

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[in Japanese]

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Microbial population dynamics and performance in lab-scale landfill reactors were investigated. The conventional reactor was operated without leachate recirculation and aeration, but the other reactors used leachate recirculation and without aeration (anaerobic) or with aeration (aerobic). The respective final waste volumes on day 138 of the conventional, anaerobic, and aerobic reactors were 75, 65, and 60% of the initial volumes. Leachate recirculation accelerated biodegradation and methane production. Aeration lowered leachate and methane production and decreased organic matter in the solid waste and leachate. The MPN value of amoA gene was high in the aerobic reactor, where nitrogen was effectively removed.

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[in Japanese]

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Though the amounts of the sewage sludge have been decreased by recycling and its volume reduction, 500,000 m3 of the sludge is still being reclaimed based on the Sewer Statistics (2003). Factors inhibiting the stabilization of the landfills with the sewage sludge are attributed to the decline in ventilation and water penetration and to the deterioration of the leachate quality due to its organic properties. Early stabilization of the sludge has been devised with the neutral solidifier, by modifying the water contents and properties of the sludge like soil, improving ventilation and water penetration, before landfilling and with aeration in the landfill after its reclamation. Lysimeter tests were conducted and leachate qualities were monitored. It was found that BOD (10,000 mg/L, semi-aerobic => 10 mg/L, aerobic) and COD (2,100 mg/L, semi-aerobic => 260 mg/L, aerobic) were effectively decreased after the solidifier treatment.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Municipal solid waste incineration residues (MSWIR) had been landfilled for a long time in Japan. In order to clarify the alteration of the MSWIR in landfill site, drilling investigation had been conducted, the drilling core samples were analyzed to make clear the influence from phisical and chemical weathering, at the same time, the evaluation system for the weathering effects on the MSWIR had also been studied.

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[in Japanese]

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The main component of landfill waste is incineration ash, which is similar in composition to volcanic ash but very different from natural soil, resulting in sterile ground and ecological disturbance. We therefore need to develop a rehabilitation method that causes incineration ash to assimilate natural soil conditions, thereby enhancing the rehabilitation of completed landfills. In this study, we focused on the soil forming processes, especially biological processes, of rocks and volcanic soil. We have been investigated the effectiveness of co-disposal of organic waste and incineration ash in enhancing the microbial activity of incineration ash. From the 5 years study, we obtained that this procedure was effective in enhancing microbial activity, resulting in conversion of incineration ash into a material with a plant production capacity like natural soil. Organic material containing microorganisms and BOD substances such as compost was most effective, with the optimal mixture of ash and compost having an ignition loss of 15%.

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In order to clarify the mechanism of alkali elution, sequential leaching test was conducted for bottom ash, stabilized fly ash (SFA), and slag. For bottom ash and SFA total alkalinity mainly consisted of residual alkalinity. The composition of total alkalinity was estimated. Total alkalinity was followed by the power law. Dissolution process might be the rate control process for alkali elution.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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In this study, persistent organic decomposed effect by the electrolytic method and MSWI bottom ash stabilized effect by the circular system of electrolytic water are clarified experimentally. As the results, following conclusions are obtained, 1) There is a sufficient organic decomposed effect by the electrolytic method despite of distance between electric poles. The electric resistance decrease with a reduction of distance between electric poles so the organic can be decomposed by the small energy. 2) When electrolytic water circulated, it is considered that oxidation-reduction potential showed high level and influenced organic decomposed effect. 3) MSWI bottom ash can be stabilized in short-term in comparison with conventional terms by the circular system of electrolytic water to waste leachate.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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A closed old landfill in Japan where leachate collection system and landfill gas recovery system don't work well is surveyed. Passive landfill gas extraction wells were installed for acceleration of reclamation of the landfill. Temperatures in the wells where are located in the center of the landfill rose significantly and methane concentration of landfill gas was low. These data are supposed to result as active aerobic biodegradation. On the other hand, temperatures in the wells where are located at the edge of the landfill were around 10-20 centigrade and methane concentration was high. Anaerobic biodegradation is going very slowly. In 46% of the landfill gas wells methane concentration was more than 10% and it means anaerobic condition is dominant. In 15% of the landfill gas wells maximum temperature was over 40 centigrade and it means aerobic condition is attained locally.

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[in Japanese]

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To cancel traffic congestion of No.42 in national road, Tanabe Nishi bypass is planned. It is scheduled for Tanabe city disposal place in the 346(Miyoro) zone to pass on this bypass. The execution of construction that considers the environment is needed. So we grope for the method of volume reduction with classifying of waste on the site. We report on the result of review about the indoor and outdoor discretion examination as prior construction. It is set up the committee that consists of people from academic background etc. to examine environmental measures.

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[in Japanese]

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[in Japanese]

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In the aftercare management of landfill, to evaluate how long it will take for complete stabilization of waste or to have information on how much degradability the buried waste has at the time of closure is quite important. However, as for the waste in old landfill, slowly biodegradable organic substances are major components that are hardly biodegrade by ordinary biochemical test. In this study, in order to find the suitable method for determining biodegradable potential of old waste obtained from closed landfill, ordinary biochemical test methods were applied for excavated waste and then the results obtained from these tests were discussed. Also, improvement of bioavailability by conducting hydrothermal pre-treatment prior to BMP test was examined.

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[in Japanese]

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In the north part of Yokkaichi city, biggest illegal disposal of waste (2.86 milion m3) in Japan was found. Harmful substance as like arsenic, benzene, boron, fluoride was detected underground water in the disposal site or the border of the site, therefore, possibility of underground water and soil pollution near the waste disposal site is becoming serious problem. We are investigating the influence of the disposal on the underground water pollution; survey was conducted at 20 point around the site 4 times in a year (area within about 8km from the site), till Jul. 06 to Apr. 07. Bad smelling was found in half of the investigated points. High concentration of arsenic, iron, manganese was found in the underground water around of this site. Higher concentration of arsenic was found in the soil near of the disposal site also. The relation between waste disposal and water pollution is discussed.

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[in Japanese]

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[in Japanese]

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Problems on illegal dumping of waste materials are serious. Some illegal dumping sites are polluted by VOCs such as tetrachloroethylene (PCE) with high concentration. A risk reduction process before removal of waste, which can reduce levels of VOCs, is required in order to reduce the risk during removal and transportation of waste. This study investigated the remediation potential by in-situ bioremediation technique as the reduction process, using real samples from illegal dumping site. First, one-dimensional column experiments were conducted to confirm dechlorination of PCE by indigenous bacteria within the waste samples. A model of PCE behavior within the waste was developed considering convective dispersion, adsorption, and biodegradation (dechlorination) processes. A tracer test using NaCl was conducted to obtain the porosity and dispersity neglecting adsorption and biodegradation processes. Next, using static distributions of PCE and the degradation by-products within the column, the degradation rate constants were determined. Our model presented well the PCE behavior within the waste. At last, using the obtained parameters, the time required for bioremediation was predicted, supposing large-scale calculation area, where properties on the waste assumed to be homogenous. Numerical simulation was conducted with six cases, where the degradation rate constants and Darcy's velocity was changed. The changes in PCE concentration were calculated and the effects of the degradation rate constants and Darcy's velocity on the time required for bioremediation were predicted.

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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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This study tried to distinguish the presence of pollution with the domestic animal excreta by comparing the E. coli bacteria group genes in the livestock manure and in the river, by using the fact that the genotype of E. coli bacteria was different depending on living animal's kind. This study used the AFLP method with the high accuracy that was able to be identified to the strain in this study. First, I found the index gene to distinguish coliform bacteria between livestock manure and sewage sludge. Then, I analyzed gene of coliform bacteria in river and groundwater sampled from Y river, where has only four farmers as nitrogen sources. As a result, livestock manure had influenced on the quality of river and groundwater because the index gene was found in the river. In addition, I tried to clarify which farmer has relatively high contribution to nitrogen pollution, but did not get enough information from the AFLP pattern.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Incineration is a major process for treatment of the MSWs in Japan. During the incineration, incinerator residues (fly ash and bottom ash) are produced and heavy metals are concentrated in the residues. Especially, fly ash has high contents of heavy metals and dioxins and it should be removed to safe levels. Thus, stabilization and recycling of the incinerator residues are imperative. Previous tests using the washing and fractionation technology with the bottom ash demonstrated that Cl was reduced below 1000 mg/kg at the liquid to solid ratio of 1, showing that the technology was effective for the stabilization of the ash. For this time, effectiveness of the washing and fractionation technology with the fly ash having high concentrations of Cl, heavy metals, and dioxins was tested. As a result, Cl was reduced lower than 10000 mg/kg at the liquid to solid ratio of 7.6 and the treated ash can be recycled as cement materials.

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[in Japanese]

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Sulfate pitch discharged into 232 drums and a stainless-steel tank in one factory at Saitama prefecture was removed by the administrative subrogation. We carried out the countermeasure of emitted sulfure dioxide gas and assured the safety of ambient environment and worker through the removal of sulfate pitch based on the multiple safety action. The concentration of sulfur dioxide gas in tank headspace was 40,000 ppm, and it was found that the surface oil in tank contained 6.7 % sulfur and caused an anomalous high sulfur dixide concentration. On the other hand, we experimented and found that the addition of calcium hydroxide on oil and sulfate pitch was able to prevent not only an emission of sulfur dioxide, but also an increasing inside temperature.

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Recently, soil and groundwater pollution caused by waste materials such as illegally dumped waste has been becoming serious. Since it costs enormously remediation of such pollution, cost effective treatment of waste and securing safety are necessary. Bioremediation technology is considered as one of the methods. Therefore, in this study, biodegradation process of PCE was observed quantitatively and the influencing factors were investigated, using illegally dumped waste. First, gas-liquid or liquid-solid partition coefficients were measured and PCE biodegradation tests were carried out. The influencing factors such as kind of waste, nutrient addition and temperature were examined. As a result, about 90% of injected PCE was dechlorinated to VC and ethylene. In addition, degradation rate of PCE within the sludge was smaller than that within the bark. Nutrients promoted biodegradation of PCE within the sludge sample. Furthermore, it was confirmed that raising the temperature also promoted biodegradation.

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Drying treatment of hazardous liquid wastes is one of the way to reduce the amount of wastes.However,it is necessary to supply more than 0.3 MPa steam to a drier to dehydrate liquid wastes, and the energy input by far exceeds the theoretical energy. Secondary, when the stream pressure is higher, although dehydration becomes easier, the residue crystallizes and fixes to the surface of the dryer. This lessens the thermal conductance and causes imperfect drying or decreases treatment capacity. In this context, in order to resolve these problems, the drying method was studied to control the residue crystallization by polysaccharide as an organic catalyst. It is succeeded to control the residue crystallization by making carboxymethylcellulose as an organic catalyst gelled in the liquid waste by the salting out effect and various ions included in the gel. Consequently, the fixed residue on the surface of the dryer is eliminated and the drying efficiency increases and it becomes possible to decrease the steam pressure less than 0.2 MPa.

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[in Japanese]

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