1. Department of Technology Education Support Center, National Institute of Technology, Akita College, Akita, Japan
2. Department of Chemical Engineering, Tokyo University of Agriculture and Technology, Koganei, Japan
3. Department of Civil and Environmental Engineering, Tohoku University, Sendai, Japan
4. Kennan Environmental Conservation Center Inc., Daisen, Japan
5. Department of Biological Environment, Faculty of Bioresource Sciences, Akita Prefectural University, Akita, Japan
6. Department of Civil Engineering and Architecture, National Institute of Technology, Akita College, Akita, Japan