There
is considerable information on the advantages of using
photosynthetic organisms for the amelioration of
wastewater, since photosynthesis-produced oxygen is
effective in BOD removal, even of refractory organics
(Oswald, 1988), and because the high pH values typical
of dense algal cultures cause phosphate and heavy
metal precipitation (Ramani, 1974) and abatement of
coliform and other enteric bacteria (Marais, 1974).