Summary of the technology
Cost-Effective, Environmentally-Friendly Removal of Heavy Metals from Water
Project ID : 15-2014-3066
Description of the technology
Easily-manufactured liquid core capsules can be regenerated after use
Cleantech & Environment, Water Technologies
Proof of concept, ongoing research, ready for industrial scale-up
Patent application filed in the United States
- The use of metals and chemicals in process industries results in the generation of large quantities of effluent containing high levels of toxic heavy-metal ions.
- Conventional treatment technologies for the removal of heavy metals from aqueous solutions are expensive and generate large quantities of toxic chemical sludge.
- Naturally occurring cross-linked alginate gel capsules may be used to eliminate metal ions from effluent although these capsules have already utilized part of their ability to adsorb heavy metal ions.
Novel single-step process for producing liquid-core capsules having a new and unique fluid core surrounded by a membrane composed of a different polymer. Capsules efficiently adsorb heavy metal cations and can be regenerated several times after use.
Novel capsule containing liquid core
- Novel capsule contains a unique liquid phase polymeric formulation at its core and a solid or semi-solid hydrocolloid membrane shell.
- This type of capsule has never previously been produced.
- Simple, low-cost production process
- The thin membrane of the liquid-core capsule decreases the diffusion times of the heavy metal cations into the capsule.
- The hydrocolloidal polymeric shell membrane can be further cross linked to increase its mechanical strength.
- The capsules are almost perfectly spherical.
- Capsules with the sorbed heavy metals may be regenerated after use through at least three regeneration cycles.
- In adsorption experiments, the lead adsorption efficiency of capsules was improved from 267 to 316 mg Pb+2/g dry alginate.
- The ability of the capsules to adsorb other heavy-metal cations—copper (Cu2+), cadmium (Cd2+) and nickel (Ni2+)—has been demonstrated.
Adsorption efficiency of different metal cations by capsules. Each result is the average of four different batches ±SD. Different superscripted letters indicate significant differences at P<0.05.
- Alternative methods for employing the capsules are being tested
- Similar liquid-core capsules able to absorb anions such as phosphate, chromate, arsenate, sulphate, etc. are being developed.
Cost-effective and environmentally friendly wastewater treatment