A multistage dissolved air flotation and advanced oxidation systemmethod with multi-functions in oil recovery, solids removal, emulsion breaking, and advanced oxidation. The storage units each include an outer container, a track positioned in a bottom of the outer container, and a hopper movably positioned within the outer container for movement toward and away from the track. The sash section has a latch mechanism supporting part proximate a mid-region of the rearward side of the outer peripheral edge. A transmission signal control section controls the wireless transmission section on the basis of the derived reflected signal. Pure 2-O-ascorbic acid may be produced from such compositions. The CCD solid-state image includes a charge storage section between a vertical transfer register and a horizontal transfer register.