Water purification methods
AssigneeInternational Telephone and Telegraph Corporation
InventorEdgar W. Sawyer, Jr.
Life of this patent
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Abstract
Treating water with various grades of attapulgite clay and sepiolite using contacting or percolation techniques removes substances not removable by standard water purification methods under many conditions. Substances such as pesticides, toxins, hormones, heavy metal cations and viruses are removed from water by adsorption upon the clay surface. When contacting is employed, the clay containing the adsorbed substances is subsequently removed by sedimentation or filtration. The clays can be regenerated by appropriate chemical or thermal techniques.
Claims11
A method for purifying water containing heavy metal cations comprising the steps of:
- adding a plurality of colloidal clay particles selected from the group of natural clays consisting of attapulgite and sepiolite to the water to provide absorption surfaces for contact with metal cations;
- dispersing the clay particles in the water to form a plurality of accicular-type needles for electrical attraction of the metal cations;
- and
- separating the accicular-type needles containing the metal cations from the water.
A method for purifying contaminated water containing heavy metal cations comprising the steps of:
- treating said water by adding a flocculating chemical to coagulate and settle at least part of said contaminants from said water;
- filtering said treated water to remove a further part of said contaminants;
- treating said filtered water with a germicide to kill bacteria;
- and
- adding a plurality of colloidal clay particles selected from the group of natural clays consisting of attapulgite and sepiolite to said germicide-treated water dispersing the clay particles in the water to form a plurality of of accicular-type needles to remove remaining contaminants and heavy metal cations from the water.
A method of treating water containing heavy metal cations to purify the water for human consumption comprising the steps of:
- contacting the water with a flocculating chemical and a plurality of dispersed colloidal clay particles selected from the group of natural clays consisting of attapulgite and sepiolite, said clay particles being in the form of accicular-type needles to absorb the heavy metal cations from said water;
- settling said impurity-containing flocculating chemical and colloidal clay particles to remove at least part of said impurities and heavy metal cations from said water.
- filtering said water to remove a further part of said impurities;
- and
- chemically treating said filtered water to render said water safe for human consumption.
Dependencies are inferred from the claim text.