Vast quantities of water falls on roads and paving - and is immediately flushed down the drain. This practise is no longer tenable in a world facing serious water shortages. In a step-change in water treatment, this proposal will embed biotechnology into roads and paving, enabling them to filter and clean the water for domestic and commercial use.
The challenge: The IPCC predicts that climate change will bring water scarcity to up to 3.2 billion people (approximately half the world's population). While water shortages can have considerable humanitarian impact, their economic impact is also staggering, with droughts over the past 30 years costing 100 billion euro in Europe alone. Urban environments are very effective at capturing water due to the abundance of impermeable surfaces, such as roads and pavements. The great paradox, however, is that much of this captured water is simply washed away down the drain. Pervious paving (PP) exists which can capture and filter water, but not to a sufficiently high and reliable standard for it to provide a real solution to our water needs.
The solution: The bacteria present in PPs are known to be key in degrading and removing pollutants from street-water. However, PP design is fundamentally floored as it is not designed to enhance and optimize the microbial communities present. In a step change in PP design, we will utilize a probiotic approach to re-imagine and re-engineer PPs so that they nurture the optimal consortia of microorganisms to ensure far greater pollutant removal.
This will be achieved with the following aims/objectives:
1) Harnessing the power of the Sun: Photosynthetic (solar powered) bacteria have been shown to dramatically improve pollutant removal and degradation in a wide range of contaminated settings, but have yet to be applied to PPs. Here the studentship will redesign the PP to allow more sunlight into its structure, enabling these vital organisms to flourish inside the PP. Pollutant removal will be assessed using CEE's state-of-the-art analytical equipment, including ICP-AES, GC-MS and HPLC.
2) Nurturing the right relationships: Degradation of pollutants by bacteria relies on complex inter-species interactions, where different bacteria undertake specific tasks for the benefit of the whole community. Using next-generation genomics and advanced bioinformatics, this studentship will unlock the complex species interactions which are vital to the success of the PP. Inspired by how minerals in soils and rocks control bacterial species, we will then focus on using aggregates of different composition to promote the right bacterial species for better pollutant removal.
3) Hydraulics: The ability of the bacteria to capture and degrade pollutants is intimately linked with hydraulics. The rate of flow of polluted water through the PP and its residence time within the PP define the length of time bacteria have to clean the water. This component of the project will explore hydraulic behaviour of the new designs and then optimise them to ensure appropriate hydraulic behaviour of the system.