1. Sr. Res., Dept. of Envir. Technol., Agriculture Univ., 6700 EV Wageningen, The Netherlands.
2. Sr. Res., Dept. of Chem. Enzymology, Moscow State Univ., 119899 Moscow, Russia.
3. Mgr., Emission Control, Afvalzorg Deponie BV, Haarlem, The Netherlands.
4. Asst. Prof., Dept. Envir. Technol., Agriculture Univ., 6700 EV Wageningen, The Netherlands.