[1] Kluyverlaboratory for Biotechnol., Julianalaan 67, Delft,2628 BC, Netherlands
[2] Dept. of Envir. Engrg., Tech. Univ. of Denmark, Build. 115, Lyngby,2000, Denmark
[3] Dept. of Civ. Engrg., Hong Kong Univ. of Sci. and Technol., Clear Water Bay, Kowloon, Hong Kong
[4] School of Chem. Engrg., Beijing Technol. and Business Univ., Beijing, China