Patent ID: 6896815

Claim:
A water treatment method comprising the following steps: (a) Precipitating heavy metals by adding lime, limestone, caustic, magnesium hydroxide, soda ash or any other material that will precipitate the heavy metals as hydroxides or carbonates; (b) Removing the precipitated heavy metal formed in step (a) by gravity clarification methods or by field separation methods selected from the group consisting of magnetic separation, dissolved air flotation, vortex separation, expanded plastic flotation or any other method that uses field forces rather than filtration to remove particles from the water; (c) Precipitating the residual heavy metals remaining in solution after steps 1 ( a ) and 1 ( b ) by using organic sulfides, inorganic sulfides, sodium borohydride, ferrous, or any other chemical that can precipitate more metals from the water than hydroxide and carbonate chemicals; and (d) Removing the heavy metals precipitated in step 1 ( c ) by field separation methods selected from the group consisting of gravity clarification, magnetic separation, dissolved air flotation, vortex separation, expanded plastic flotation or any other method that uses field forces rather than filtration to remove particles from the water wherein at least one of said removal steps (b) or (d) is performed by magnetic separation using a bonding agent comprising an organic flocculating polymer to attach magnetic seed material to non-magnetic particles and/or metal precipitated particles, so as to allow the bonded particles to be removed from the water by magnetic forces, and wherein the steps of using a bonding agent to attach the magnetic seed material to the particles to be removed and the step of removal of the magnetic seed material with the particles to be removed attached thereto are performed in the same vessel.