In recent years, numerical analysis method for quantitatively predicting volatilization flux has been required for soil contamination countermeasures and exposure risk management. In particular, there are few models that take into account transport phenomena and phase changes such as advection, diffusion, and volatilization of volatile chemical substances (VCSs) from unsaturated contaminated soil. In this study, a soil column test was conducted on the constructed model to verify the validity of the calculation results. In the history-matching process, the coefficient of relative permeability, the rate constant, and the molecular dispersion coefficient on the ground surface and inside the soil became important parameters, and the consistency of these various values was confirmed. Since these values could be set to appropriate values even if the tortuosity and hydrodynamic dispersion coefficient were also reasoned, numerical model proved to have validity. A volatilization flux prediction method was precisely established through a parameter matching process used in a numerical analysis model that expresses mass transfer phenomena that take into account the environmental dynamics associated with the volatilization of VCSs.

 Since the pandemic of COVID-19, wastewater-based epidemiology (WBE) for monitoring and predicting spread of infectious diseases has been intensively studied and its feasibility has been evaluated all over the world. The WBE has a potential to reduce the number of infections by early warning of its spread to enhance countermeasures at both public (e.g. lock-down and vaccination campaign) and individual (e.g. avoiding closed spaces, crowded places and close contact settings) levels. In this paper, to clarify the factors affecting the individual intentions to strengthen protection against infection based on information about its spread predicted by the WBE, questionnaire surveys were conducted for residents of Sendai and Osaka cities, Japan and the obtained data were analyzed by t-tests and the covariance structure model.

 As a result, the group that was provided with information on the predicted spread of infection, showing the increase of infections in the next week, was generally more willing to strengthen protection measures against COVID-19 than the group that was provided with the number of infections newly reported at the time of the survey. It was also revealed that those with high levels of trust in provided information and recommended countermeasures had high respect for social norms and firm intention to strengthen protection measures both directly and indirectly. In particular, if neither they nor their families are at a high risk of infection, reliable information on COVID-19 spread was suggested to enhance receivers’ respects for social norms and consequently motivate their intentions to strengthen protection measures.

 Particle size separation between sand and silt or finer particle is one of the most expected way to reduce the amount of Cesium-contaminated soil made by the accident of Fukushima Daiichi Nuclear Power Plant. We made hydrodynamic soil wash system which is composed with vortex-breakdown nozzle for soil wash, hydrocyclone and inclined settler for particle size separation. In this study, soil wash and size separation ware examined separately.

 In soil wash experiment, it can reduce radioactive material for 24% when suspend sand with oxalate solution 0.05 mol/L and though nozzle for 40 times. In separation experiment, we set 75 µm as a separation diameter. As the result, fine particle rate in coarse were down from about 25% to below 6% when flow ratio of hydrocyclone were about 30 L/min.