Project description
The Problem
As a result of emissions from automobile catalytic converters there are high concentrations of platinum deposited in the soil next to highways and big roads, often higher than in mines.
Platinum is an essential natural resource with no real method of extraction than destructive mining methods.
Platinum resources are draining and if recycling methods are not developed, the world could run out of platinum in the upcoming 50 years.
There is also a smaller issue of wastewater treatment plants where there is so much minerals and metals accumulated that companies just prefer to abandon a plant and rebuild a new one. Platinum concentrations are elevated in the plants too because of the treatment of rainwater that passes through roads.
Platinum is a rare metal because there are only a few mines in the world where it can be obtained. And even then it is only a by-product of nickel and copper mining. During the process of extraction huge amounts of hydrochloric and sulfuric acid are used to eliminate impurities.
There are also various socio medical complications associated with platinum mining. Miners and workers are usually exposed to unsafe chemical substances and toxic fumes. Safety measures are often disregarded. An alternative solution to mining could help in the resolvement of this issue.
Most importantly, platinum resources are draining. Experts have estimated that in the year 2064 all known economically workable platinum deposits will be exhausted. It will be necessary to exploit other sources of platinum and develop viable recycling methods.
Finally, there are no current methods of recycling platinum from the soil next to highways that have been shown to work.
The Solution
- Concentrate the platinum accumulated in plants by phytoremediation or present in sludge in rainwater treatment centers.
- Purify the Platinum from other metals or inorganic compounds.
- Transform it into a highly desirable form - nanoparticles.
Overview
The main goal of our project is to
The first step relies on the affinity of small organic molecules, siderophores, to bind solubilized Platinum atoms and thus favor the further solubilisation of more platinum compounds. We accomplish this by inserting a plasmid containing an operon with the four enzymes (Des A, Des B, Des C, Des D) necessary to synthesise our siderophore - Desferrioxamine B, into E. coli.
As a second level of concentrating the platinum even more, we plan to use the principle of biosorption. A modified fliC protein complex will be cloned into E. coli and enable the flagella of the bacterium so that it can bind platinum atoms. This specificity will be possible thanks to a recently discovered peptide that will be inserted into the sequence of the fliC. The benefit of using the biosorption is to obtain nanoparticles of platinum, a highly valuable form of the metal.
