Biomineralisation Of Critical Metals Leading To Functional Materials

Abstract

Currently one of the major sources for high levels of metal contamination in the environment can be attributed to human activity and industry related by-products. When concentrated at high levels metal concentrations can reach dangerous levels of toxicity that is harmful to plants, animals and the wider environment. Land remediation programs aim to restore to more natural levels by removing toxic metals but many are expensive and can cause further waste build-up of their own. Current environmental concerns now highlight a need for further research into greener alternatives with microbe-metal interactions that aid to provide advanced biotechnological applications towards critical metal waste recovery. This study aims to investigate microbial metal sulfide precipitation using sulfate-reducing bacteria. Synthetic phases were used in an attempt to biosynthesise metal nanoparticles via bacterial metabolism, with a focus on metal (cobalt and nickel) sulfide precipitation reactions. A range of analytical techniques (including ICP-MS, IC, SEM, XRD and electrochemical tests) were used to aid this study in the identification of metal precipitation, crystal growth, specific metal concentration, trace element distribution and mineral phases. The results show that SRBs are capable of precipitating metal sulfides over a range of metal concentrations (0.1 mM < 10m M), where a pure strain of D. desulfuricians tolerated doped metal concentrations better compared to a mixed community group. Utilising bacteria in this way for the precipitation of critical metal nanoparticles can provide a three-fold application: (1) to remove contaminants from soils/ aquifers without the need for heavy machinery and at low-cost logistics (2) extract critical metals, specifically in the recovery and recycling of material from waste ores and liquids and (3) to test the potential to synthesise novel metallic bionanoparticles for applications in battery/ supercapacitor technologies

Date of Award	9 Jan 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Samuel Shaw (Supervisor), Jonathan Lloyd (Supervisor) & Victoria Coker (Supervisor)