Method for treating process waste streams by use of natural flocculants

A method of treating a process waste stream selected from the group consisting of cattle processing waste streams, fish processing waste streams, and poultry processing waste streams by the sequential addition of at least two natural flocculants, wherein at least one of the natural flocculants is a cationic liquid chitosan and another of the natural flocculants is an anionic natural flocculant, the method comprising the sequential steps of:

• adding a first natural flocculant to said waste stream while agitating the mixture sufficiently so that a substantially homogenous mixture is formed;
• and,
• adding at least a second natural flocculant to said mixture while agitating sufficiently to form a flocculent mass of a density allowing subsequent recovery thereof, provided:
• A) when said waste stream is a cattle processing waste stream, said anionic natural flocculant is xanthan gum, and said method comprises adding said xanthan gum to said waste stream followed by addition of liquid chitosan to said waste stream;
• B) when said waste stream is a fish processing waste stream, said anionic natural flocculant is an alginate, and said method comprises the consecutive steps of adding to said waste stream a cationic bentonite natural flocculant, adding said liquid chitosan, and adding said alginate, with agitation during or following addition of each said natural flocculant;
• and
• C) when said waste stream is a poultry processing waste stream, said anionic flocculant is an alginate and is added to said waste stream before or after said liquid chitosan provided that:
• 1) when said poultry processing waste stream has a positive ionic charge said alginate is added first followed by said liquid chitosan,
• 2) when said poultry processing waste stream has a negative ionic charge said liquid chitosan is added first followed by said alginate, and
• 3) when said poultry processing waste stream has an amphoteric ionic charge, the method comprises the consecutive steps of adding to said waste stream a cationic bentonite natural flocculant, adding said liquid chitosan, and adding said alginate, with agitation during or following addition of each said natural flocculant.