Some issues encountered in modern wastewater treatment technologies based on activated sludges
are summarized in this paper. It is pointed out that with the increasingly high requests on environmental
quality from the society, the present technologies cannot fulfill the requirements of water area and water
resource protection, and that the function ofwastewater treatment facilities should be extended by confining
and killing resistant pathogens. It is necessary to develop newtechnologies as countermeasures to cope with
the problems of this kind that may arise in China in the near future. The combination of activated sludges
and microfiltration will open a newway in this respect.