Abstract: The present invention relates to a method and apparatus for utilizing solar energy in a water and/or waste management system. At least one rotary chamber having a porous or perforated outer wall structure and an inner disposed filter is oriented within a drying structure having a transparent surface of substantial area for allowing solar radiation to be directed through the drying structure onto said rotary chamber. Water or waste material is directed into said rotary chamber, and free water drained therefrom, leaving a sludge like material within the interior of said rotary chamber. To effectuate drying, the rotary chamber is rotatively driven and solar energy in the form of heat is collected about the exterior of the rotary chamber and utilized to dry the interior sludge. At night and when available solar radiation is minimum, drying is achieved by conventional heating means.