1. Ctr. for Water Res., Univ. of Western Australia, Perth 6009, Western Australia. E-mail: dallimor@cwr.uwa.edu.au
2. Ctr. for Water Res., Univ. of Western Australia, Perth 6009, Western Australia.
3. Dept. of Envir. Sci. and Technol., Tokyo Inst. of Technol., Tokyo, Japan.