With increased industrial uses of precious metals, their price has increased considerably over the past decade. It has been suggested that biosorption may be exploited in the remediation of waste-water by removing contaminating entities but more recently the emphasis on exploitation of this phenomenon has been re-directed to the more lucrative sequestration and recovery of precious and semi-precious species, e.g. gold, silver and platinum. Locally sourced biomass materials including distillery yeast (Saccharomyces cerevisiae) obtained from the Old Bushmills Distillery, peat and seaweed (Fucus serratus), were shown to be suitable biosorbent materials and were able to sequester several metals from solution. The distillery yeast was found to work well with equilibrium dialysis, which allowed convenient separation of biomass from the sorbate. A biosorption process using electric fields to assist contact between membrane-enclosed biomass and the relevant sorbate solution was described and termed "Electric FieldMediated Biosorption". In this system, the biomass was enclosed in a dialysismembrane with an electrode, a counter electrode was placed in the sorbate solution and an established potential across the electrodes facilitated electrokinetic movement of the sorbate to the biosorbant material. This system was adapted to increase the contact between the distillery yeast biomass and the sorbate solution by immobilising the biomass in a PV A matrix. This modified-EFMB system better presented the biomass to the sorbate solution forcing ions into contact with the biomass. The PV A allowed better physical handling and this durability increased the life-time of the PV A matrix system, reducing the cost of replacing damaged and fouled dialysis membranes. During the study, the generation of gold nanoparticles was observed and the EFMB system may provide an alternative to the Turkavitch et al. method. The range of metals that the system is capable of actively sequestering demonstrates the functionality, efficiency and application range of the system
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:674966 |
| Date | January 2012 |
| Creators | Hughes, Paul |
| Publisher | Ulster University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0024 seconds