Recovery of copper and cobalt by biopolymer gels

Abstract

The recovery of copper from synthetic aqueous media circulating in a loop fluidized bed reactor operated batchwise was investigated by using the following biopolymer systems: (1) a viscous solution of sodium alginate (from kelp) dispensed directly into the reactor fluid containing dissolved copper (sulfate salt) at initial concentrations of 60-200 ppm, (2) partially coagulated calcium alginate spheres for absorbing dissolved copper at initial concentrations of 10-40 ppm, and (3) a mixture of green algae Microcystis and sodium alginate dispensed directly into the reactor fluid. The recovery of copper and cobalt, a strategic metal, from cobalt ore leachate was achieved by a two-step approach: direct dispensing of sodium alginate to absorb the bulk of metals followed by the addition of partially coagulated calcium alginate spheres to "polish" the leachate. Metal binding capacity and conditional stability constant of each biopolymer system as well as the effective diffusivity of cupric ion in the matrix of biopolymer gels are reported.

Biosorption of Metal Ions by Seaweed Alginate, Polyguluronate, and Polymannuronate

“…The potential of biopolymers as safe and cost-effective materials to remove heavy metals from dilute aqueous solutions has long been recognized [10,26]. And also, seaweed alginate has been one of the most extensively investigated biopolymers for binding heavy metals [11,23,24]. Recently, biosorption of heavy metals has received a lot of concerns about application of hazardous waste treatment.…”

Kinetic Study of Metal Biosorption to a Brown Alga, Kjellmaniella Crassiforia

“…Biosorption employs inexhaustible, inexpensive, nonhazardous adsorptive materials, and generates low volumes of nonhazardous waste. Microorganisms (1-7), algae (8)(9)(10)(11)(12), and other types of biomass (13)(14)(15)(16)(17)(18)(19)(20) have been investigated for use in this application. An abundant source potentially metal-sorbing biomass are marine algae.…”

Kinetic Study of Lead Adsorption to Composite Biopolymer Adsorbent

“…Many biopolymers, such as cellulosics, carrageenans, lignins, proteins, chitin derivatives, alginates, and humic substances, are known to bind heavy metal ions strongly (1)(2)(3)(4)(5)(6)(7)(8). The use of biopolymers as adsorbents for the recovery of valuable metals or the removal of toxic metal contaminants has been a topic of intense research in recent years (1,(3)(4)(5)(6)(7)(8)(9)(10)(11).…”

“…Both of them are widely and abundantly available biopolymers, and have high complexing ability with various heavy metal ions (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). In our previous studies, the adsorption mechanism of divalent heavy metal ions to the composite biopolymer adsorbent and the effect of immobilization on the metal complexation ability of the biopolymers were elucidated (6,8).…”