Method of clarifying proteinaceous waste water containing solid impurities
AssigneeSilverton Tannery Limited
InventorSarel D. Roets
Life of this patent
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Abstract
A method of clarifying proteinaceous waste water is provided involving feeding the water through a treatment zone where it is subjected to various treatment steps and from which it issues as a clarified product. Solid impurities are coagulated in said zone and 20-50% by mass of the waste water feed is recirculated as clarified product which is aerated to provide a foam containing less than 10% by volume of liquid, and which is mixed with the feed in or upstream of the treatment zone. Foam rises and floats to the surface of the liquid in the treatment zone from which it, with solids entrapped therein, is removed.
Claims18
In clarifying proteinaceous aqueous waste water containing solid impurities by:
- feeding a proteinaceous waste water feed into and through a water treatment zone where it is subjected to various water-purification steps and from which it issues as a clarified product;
- coagualating solid impurities in the waste water as it passes through said water treatment zone;
- recirculating a proportion of the clarified product through the water treatment zone;
- aerating the recirculated clarified product to form a foam, the recirculated foam being mixed with the waste water feed in or upstream of the water treatment zone;
- permitting the foam to rise to and float on the surface of the water in the water treatment zone;
- and
- removing said foam and coagulated solids entrapped therein from the surface of the water in the water treatment zone,
- the improvement which comprises at least reducing the use of surfactants in foam production by
- recirculating a proportion of the clarified product amounting to 20-50% by volume of said waste water feed;
- and
- aerating said recirculated clarified product to form a foam which is continuous and which comprises no less than 90% by volume of air, so that the air recirculated amounts to no less than 18% by volume of said waste water feed.
A method of clarifying proteinaceous tannery waste water containing solid impurities, to provide a clarified water product containing a reduced proportion of said solid impurities and a fast-draining foam product containing solid impurities removed from the tannery waste water, the method comprising treating a proteinaceous tannery waste water feed in a single water treatment zone into which it is fed and from which issue a clarified water product and a fast-draining foam product, by:
- coagulating solid impurities in the waste water as it passes through said water treatment zone;
- recirculating a proportion of the clarified product through the water treatment zone, the proportion recirculated amounting to 20-50% by volume of the waste water feed;
- aerating the recirculated clarified product to form a continuous foam comprising no less than 90% by volume of air, the recirculated foam being mixed with the waste water feed in or upstream of the water treatment zone so that the air recirculated amounts to no less than 18% by volume of said waste water feed;
- permitting the foam to rise to and float on the surface of the water in the water treatment zone;
- and
- removing, as a fast-draining foam product, said foam and coagulated solids entrapped therein from the surface of the water in the water treatment zone, while removing fully clarified final water product directly from the water treatment zone.
In clarifying proteinaceous aqueous waste water containing solid impurities by:
- feeding a proteinaceous waste water feed into and through a water treatment zone where it is subjected to various water-purification steps and from which it issues as a clarified product;
- coagulating solid impurities in the waste water as it passes through said water treatment zone;
- recirculating a proportion of the clarified product through the water treatment zone;
- aerating the recirculated clarified product to form a foam, the recirculated foam being mixed with the waste water feed in or upstream of the water treatment zone;
- permitting the foam to rise to and float on the surface of the water in the water treatment zone;
- and
- removing said foam and coagulated solids entrapped therein from the surface of the water in the water treatment zone,
- the improvement which comprises recirculating a proportion of the clarified product and aerating said recirculating clarified product to form a foam, the air content of which amounts to no less than 18% by volume of said waste water feed.
A method of clarifying proteinaceous tannery waste water containing solid impurities, to provide a clarified water product containing a reduced proportion of said solid impurities and a fast-draining foam product containing solid impurities removed from the tannery waste water, the method comprising treating a proteinaceous tannery waste water feed in a single water treatment zone into which it is fed and from which issue a clarified water product and a fast-draining foam product, by:
- coagulating solid impurities in the waste water as it passes through said water treatment zone;
- recirculating a proportion of the clarified product through the water treatment zone and aerating the recirculated clarified product to form a foam, the air content of which amounts to no less than 18% by volume of the waste water feed;
- permitting the foam to rise to and float on the surface of the water in the water treatment zone;
- and
- removing, as a fast-draining foam product, said foam and coagulated solids entrapped therein from the surface of the water in the water treatment zone, while removing fully clarified final water product directly from the water treatment zone.
Dependencies are inferred from the claim text.