US 5,635,073 A · Method for the purification of metal-containing aqueous media and method of preparing an adsorbent

Abstract

A method for the removal of metal from a metal-containing aqueous medium wherein the aqueous medium is passed through a particulate carrier material in the presence or ferrous iron and an oxidant and at such velocity and in such direction that the carrier material particles are fluidised in the aqueous medium and wherein metal-containing coatings are formed on the surfaces of the carrier material particles and wherein the particles thus coated are separated from the aqueous medium. A method for the production of iron oxyhydroxide-containing adsorbent wherein the carrier material particles are fluidised in an aqueous medium in the presence ferrous iron and an oxidant so as to form iron oxyhydroxide coatings on the particles and wherein the particles thus formed are separated from the aqueous medium.

Claims16

Dependent claims

A method for the removal of dissolved heavy metal ions from a metal-containing aqueous medium wherein the aqueous medium is contacted with a particulate carrier material so as to form a metal-containing iron hydroxide coating on the carrier material particles and wherein the coated carrier material particles are separated from the aqueous medium, the method comprising the steps of:

(a) introducing a volume of carrier material particles into a reactor;
(b) directing the metal-containing aqueous medium into the reactor in the presence of dissolved ferrous ions;
(c) introducing an oxidant into the aqueous medium;
(d) fluidising the carrier material particles in the reactor by passing the aqueous medium through the reactor at such a velocity and in such a direction as to fluidise the carrier material particles;
(e) forming an iron oxyhydroxide coating on the carrier material particles by oxidizing the ferrous ions and hydrolyzing the resulting ferric ions;
(f) adsorbing heavy metal ions onto outer surfaces of the carrier material particles;
and
(g) separating and removing the carrier material particles having the heavy metal ions adsorbed thereon from the aqueous medium.

5 more elements

A method for the continuous removal of dissolved heavy metal ions from wastewater, comprising the steps of:

(A) introducing a volume of carrier material particles into a reactor vessel;
(b) introducing wastewater containing dissolved heavy metal ions into the reactor vessel in the presence of dissolved ferrous ions;
(c) passing the wastewater through the reactor vessel at such a velocity and in such a direction as to fluidize the carrier material particles;
(d) introducing an oxidant into the wastewater, said oxidant oxidizing the ferrous ions to ferric ion, hydrolyzing the ferric ion into iron oxyhydroxide thereby forming in-situ an iron oxyhydroxide coating on the outer surfaces of the carrier material particles;
(e) adsorbing metal ions onto outer surfaces of the carrier material particles coated with said iron oxyhydroxide coating;
(f) oxidizing the metal ions adsorbed on the carrier material particles;
(g) hydrolyzing the oxidized metal ions to form a metal-containing hydroxide coating on the carrier material particles;
(h) adsorbing additional metal ions on the metal-containing hydroxide coating, thereby increasing the thickness of the metal-containing hydroxide coating;
and
(i) continuously separating the coated carrier material particles from the wastewater, thereby removing the metal ions from the wastewater.

7 more elements

Dependencies are inferred from the claim text.

Method for the purification of metal-containing aqueous media and method of preparing an adsorbent

Life of this patent

Method for the purification of metal-containing aqueous media and method of preparing an adsorbent

Life of this patent

Abstract

Claims16