Methods are described for removing contaminates from aqueous industrial
wastewater process streams, specifically industrial laundries to yield a
less contaminated aqueous effluent for discharge to a sewer and reduce
the sludge generated therefrom. A premixed medium/high molecular weight
and medium/high charged cationic coagulant solution polymer and an
inorganic aluminum species is injected into the wastewater, and after at
least a two second delay, a high molecular weight highly charged anionic
flocculent polymer solution is injected into the wastewater which reduces
sludge generation, while maintaining or exceeding effluent quality. Also,
no coagulant, flocculent or sludge aids are needed to attain the results
and the sludge can be dewatered in a plate and frame press.