In a rapidly urbanising world, sustainable water infrastructure is becoming a central challenge. New and growing cities either require new water infrastructure or to radically improve the productivity of their existing assets. Pressure on water supplies is a growing issue and traditional approaches to its management have often been inefficient – for example, the UK can reduce its freshwater use by up to 40% by using rainwater and greywater for non-potable uses at home.
One way of meeting the sector’s priorities would be to rethink how our water cycle operates, applying ‘circular economy’ principles across the productive process. The circular economy aims to recast the way we produce and consume the world around us, keeping materials at their highest value for longer, finding ways to conserve energy and re-use resources. It’s circular because ideally this results in a productive system where almost nothing is wasted. It’s economic because it’s aligned to smart commercial objectives.
At many stages in the water cycle, from abstraction to treatment, distribution to discharge, a circular approach reveals opportunities for all stakeholders, including water utility companies in particular, to conserve water, capture and re-use energy, extract and reuse valuable materials and by-products, and, crucially, improve commercial operations.
Switching from our existing, largely unsustainable, linear mindset of ‘take, make, use, dispose’ to a circular paradigm requires rethinking many aspects of production. The systemic nature of the circular economy requires both the ecosystem of water management and its individual components to change.
However, the good news is that many of the ideas and technologies required already exist, they’re just not currently being deployed on a widespread and in a joined-up way to achieve that goal.
Let’s examine three key areas of water utility operations where innovative use of technology and circular thinking could be applied:
From pipes to power
Drinking wáter moves through pipe networks using pressure reducing valves (PRVs), a process that creates energy. New in-pipe hydrokinetic systems use micro-turbines to convert this energy into electricity that can be fed back into the grid. This means lower costs and greener operation for utility firms.
Minerals and resources
A number of innovative technologies have been developed that can extract heavy metals and minerals from the effluent discharges from animal farms and wastewater treatment plants. Some of these can be reused in the industry, while others such as phosphorus, can be used as fertilizer for agricultura.
Turning algae into energy
Algae processing bio-reactors don´t just treat and clean wastewater- they also produce usable materials such as biomass (for energy production) or otherwise hard to synthesise chemicals for the pharmaceutical industry.