1. Institute of Engineering Science and Technology, National Kaohsiung First Univ. of Science and Technology, Kaohsiung City 811, Taiwan.
2. Dept. of Safety, Health and Environmental Engineering, National Kaohsiung First Univ. of Science and Technology, Kaohsiung City 811, Taiwan.
3. Research and Development Center for Water Resource and Conservation, National Kaohsiung First Univ. of Science and Technology, Kaohsiung City 811, Taiwan.
4. Dept. of Safety, Health and Environmental Engineering, National Kaohsiung First Univ. of Science and Technology, Kaohsiung City 811, Taiwan (corresponding author).