An overview of bioreactor applications in treatment of gaseous, liquid
and solid wastes is presented with emphasis on newer technologies. Wa
ste treatment is considered in a broad context including concentration
by bioaccumulation, degradation to substances with reduced environmen
tal impact and upgrading to such useful products as feeds, foods and f
uels. Biofilters and bioscrubbers for gaseous pollutants, high-rate mu
nicipal and industrial wastewater treatment in airlift bioreactors, re
actor-based soil bioremediation, artificial wetland filters for liquid
effluents, and protein enrichment of agricultural solid residues are
some of the technologies reviewed. The various treatment strategies ar
e illustrated with examples. The developments discussed point to an in
creasing role for bioreactor based processes in waste treatment and re
use.