[1] Dept. of Civil Engineering, National Chi Nan Univ., 1 University Rd., PuLi, Nantou 545, Taiwan
[2] Dept. of Bioenvironmental Engineering, Chung Yuan Christian Univ., 22 Pu-Jen, Pu-chung Li, Chung Li 32023, Taiwan
[3] Dept. of Environmental Engineering and Management, Chaoyang Univ. of Technology, Wufeng, Taichung 413, Taiwan