Water clarification
AssigneeCommonwealth Scientific and Industrial Research Organization
InventorsDonald E. Weiss, Luis O. Kolarik, Anthony J. Priestley, Nevil J. Anderson
Life of this patent
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Abstract
A particulate coagulant/adsorbent for removing suspended impurities and colored substances from water by coagulation comprises a finely divided particulate mineral or clay material, the individual particles of which have been treated to produce a thin hydroxylated surface layer haivng a positive zeta potential at the adsorption pH. A process and an apparatus for water treatment utilizing the coagulant/adsorbent and providing for regeneration and recycling thereof are also described.
Claims29
A process for the clarification of water which comprises the steps of:
- (a) contacting water at pH 3-5 with a coagulant/adsorbent consisting of a finely divided particulate mineral or clay material, the individual particles of which have a particle size of 10 microns or less and have a thin hydroxylated surface layer which has a positive zeta potential at the adsorption pH;
- (b) separating the water from the coagulant/adsorbent to obtain the clarified water;
- (c) treating a suspension of the spent coagulant/adsorbent to raise the pH to about 10.5;
- (d) separating the coagulant/adsorbent from the resulting effluent solution;
- (e) where necessary regenerating the coagulant/adsorbent by treatment with an alkaline solution;
- (f) separating the coagulant/adsorbent from the alkaline solution;
- (g) washing the regenerated coagulant/adsorbent with water;
- (h) separating the coagulant/adsorbent from the water;
- and
- (i) recycling the regenerated and washed coagulant/adsorbent to step (a).
A method for removing suspended impurities and colored substances from water by coagulation which comprises contacting the water at pH 3-5 with a coagulant/adsorbent consisting of a finely divided particulate mineral or clay material, the individual particles of which have a particle size of 10 microns or less and have been treated to produce a thin hydroxylated surface layer having a positive zeta potential at the adsorption pH and then separating the thus treated water from the coagulant/adsorbent.
Dependencies are inferred from the claim text.