VOC (Volatile Organic Compound) gas extraction from the sub-soil is an effective skill to recover the soil contamination, but the detailed relationship between soil structure and mechanism of VOC sorption in the unsaturated zone is not solved. In this paper, the retardation factor R in the diffusion equation is formulated in consideration of the sorption balance of VOC between gas, liquid, and solid phases of soil model. Hereby, on the basis of the experiment of TCE (Trichloroethylene) adsorption for several model soils including one with aggregate structure, the movement of VOC in the soil could be represented by the application of basic soil parameters such as specific surface area, water content, and adsorption coefficients with gas-liquid, gas-soil, soil-liquid interfaces.

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The road works discharge several by-products such as aggregates and gravelly soil. While a large quantities of recycling resources and virgin materials are used in each road work. This is caused by the present enacted policy on the recycling plan and road works. This paper has presented an advanced recycling plan and alternative way of works to reuse and reduce generated and/or virgin aggregates based on the analytical results of the mass flow on road works. They have applied to analyze annual data of aggregates used and discharged in P prefecture as a case study. Estimated quantities of aggregates based on the alternative way of road works, coincide with observed ones. The results obtained in this paper suggests that aggregates generated in road works may be reused in situ to reduce its supplies of ones from other sources.

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An approach to evaluate the composition of background organic matter (BOM) in accordance with the adsorbability and the molecular weight (MW), and that to mathematically describe the adsorption equilibrium of BOM onto activated carbon were developed. The approaches were based on BOM's batch adsorption isotherm data and MW distributions, as well as the IAST-Freundlich model, and were confirmed to be effective in quantitatively evaluating the composition and the adsorption isotherms of the total BOM and its MW fractions. Compared to previously proposed methods, the approaches required less computer search and the effects of coagulation and ozonation on the adsorption of BOM could be easily and reasonably interpreted.

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Municipal solid waste management is a complex system with a variety of choices concerning source separation and alternative treatment/disposal options. A computer model which assesses life-cycle energy consumption, life-cycle emission of carbon dioxide, and cost was developed as a decision making tool for waste management systems. Waste streams in the system are modeled with twenty-eight waste components, the sub-system facilities are designed according to resulted waste streams, and only a minimal number of user-inputs are required for the simulation. The model has flexibility for the future changes in waste management options.

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Both of methanogenic reaction and denitrification were observed at an anaerobic digester fed with synthetic substrate which contained glucose and nitrate. The anaerobic digester to which nitrate was not fed converted 64.2% of influent COD to methane. On the other hand, the COD conversion efficiency decreased to 21.8% when the COD/NO3-N ratio of the substrate decreased to 6. The highest conversion ratio of nitrate to nitrogen gas was observed at the COD/NO3-N of 9. ORP of the digester contents were maintained between -376 and -330mV if the COD/NO3-N were higher than 6, While on the other hand, the ORP level reached extremely high value of +68mV and the number of methanogenic bacteria decreased dramaticaly when the COD/NO3-N ratio of the substrate decreased to 3.

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In order to utilize empty cans in construction as a lightweight fill material from point of scatter prevention and recycle of empty drink cans views, a feasibility study used these empty cans was carried out. These cans used in this study were ones of old and new types with regard to their shape and material. This paper presents compressive tests of one empty can, a unit composed of several empty cans, real load test running an automobile and a forklift upon the road model combined these empty cans, and unconfined compressive tests were carried out in order to discuss a fall of strength induced by corrosion. Results indicate these empty cans can be considered as one of most recommended alternatives in construction due mainly to their lightweight, high strength and low price.

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Compact wetland was developed using subsurface flow (SF) and more porous artificial filling. This paper mentions comparison of three experimental wetlands, which are a free-water-surface wetland (FWS), SF wetland with gravel filling and SF wetland with artificial filling. Each wetland has an area of 50m². Two kinds of SF wetlands purify water better than FWS wetland, however there is not obvious difference between two kinds of SF wetlands with gravel and artificial fillings. Two SF wetlands are able to remove nitrate nitrogen efficiently with a removal ratio of 66 to 77 percentage under the condition of water temperature is less 15 degree Celsius and dissolved oxygen is less than 3mg/l.

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In order to obtain knowledge of the effects of air temperature, precipitation, and solar radiation to river water temperature of different timescales, statistical analyses were conducted using the meteorological and river water temperature data of 10 years. Two types of data set were used; one was 82 sampling points of 27 rivers where data were obtained monthly, and the other was the 5 sampling points of different rivers where data were obtained daily. The variations of the river water temperature on the variations of air temperature of daily scale were estimated to 0.1-0.5 (°C/°C) and were also influenced by the hydrological scale of river basin. The variations in yearly scale were estimated to 0.5-1.5 (°C/°C). The variations in summer were bigger than those of other seasons, suggesting the effects of solar radiation. Assuming that solar radiation was constant, the variation of yearly scale was estimated to about 0.5-0.85(°C/°C). Under similar assumption, the long term variation was estimated to about 0.84-0.89(°C/°C).

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The objective of this study is to clarify the penetration behavior of spilled oil stranded on sandy beach and to evaluate the effects of the penetrated oil on the infiltration of dissolved and particulate matters by wave action into sandy beach sediments. The penetration depth of stranded crude oil was deeper than that of fuel oil C, which caused by the difference in viscosity between those two oils. Most of the applied oils penetrated into the sediments. Seventy-two percent of crude oil and 98% of fuel oil C in penetrated oil remained in 2cm depth from the surface. The penetrated oil significantly reduced the infiltration of dissolved and particulate matters into the sediments. These results indicate that the penetrated oil prevents the infiltration of both dissolved and particulate matters into the sediments and, therefore, results in the reduction in the supply of oxygen, nutrient, and organic matters for the benthic organisms in the sandy beach.

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This study investigated soil colloid mobilization and leaching through a Hiroshima loam soil during three irrigation periods. The experiments were carried out using both intact soil columns and repacked columns with and without continuous macropores. Large effects of irrigation intensity and of irrigation water chemical composition (sodium content and ionic strength) were seen. Colloid leaching was higher in repacked soil than in undisturbed soil. During the first irrigation, an enhanced colloid leaching in soil containing macropores was seen, but during the next two irrigation the leaching became smaller and could be described by a parabolic diffusion type model. This suggests that the mobilization of colloids is controlled by colloid diffusion from the soil into the macropores. This mechanism needs to be included in models for transport of colloid-bound contaminants in macropore soils.

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The role of polyvinyl chloride (PVC) and sodium chloride (NaCl) salts as organic and inorganic sources of chlorine in the formation of PCDD/Fs was investigated in a simple lab-scale incinerator simulating a batch-type combustor operating at around 500°C. Non-chlorinated polymers were incinerated separately with PVC and NaCl. As compared to NaCl, PVC yielded 45, 43, and 16 times more total PCDD/Fs with PS, PE, and PP, respectively. Maximum TEQ of 27ng per gram of plastic was detected in the combination of PE and PVC, while with NaCl the same non-chlorinated polymer produced only 1ng-TEQ/g. A TEQ value of 13ng/g was detected in PVC sample incinerated individually.

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