Sustainable laboratories: Reducing water

Water is the forgotten consumable of chemistry and we often take for granted how easily available it is for washing, cooling and performing reactions. But while the financial cost is usually absorbed by university departments, excessive and unchecked water use also has a substantial social and environmental cost that lab users have a responsibility to mitigate.

Chill and recirculate

This is particularly the case in water-stressed regions, such as Portugal, that suffer from annual water shortages. Many in-lab technical solutions already exist – air condensers and recirculating chillers both eliminate water wasted through cooling – but specialist equipment comes with a hefty price tag that most researchers cannot afford without support.

Conscious of this serious resource issue, nanochemist Carlos Lodeiro Y Espiño at the Universidade NOVA de Lisboa had a clear plan for how his six-lab group could slash its water consumption. As a recipient of the Royal Society of Chemistry’s (RSC’s) Sustainable Laboratories grant in 2022, he was able to buy three chillers and has since completely eliminated water wastage in two of his laboratories. ‘We’ve reduced almost 70% of the water misuse across the group. In fact, now we are only using water to clean our labware,’ he says. ‘We put connections between the different instrumentation to recirculate the water through these systems. In the past, one of our spectrophotometer instruments was controlled by a flow of water. Now, it is also controlled by a recirculating bath.’

Improvised solutions – including creating little cars to wheel the chillers between labs – are helping to maximise the impact of this initial investment and Lodeiro Y Espiño hopes future funding opportunities will enable him to deploy the same solution across the remainder of his lab space. To his delight, the group has also become something of an inspiration within his department. ‘Many colleagues come to our lab to see how we implement this and they try to use the same idea without the expensive technology,’ he explains. ‘One group, they put boxes of water by the ceiling then recycle the water with a small pump to reduce the cost.’

But beyond the dramatic reduction in water, Lodeiro Y Espiño believes there is also an important social and educational benefit to investing in this technology. ‘It is very important when you are teaching students that they learn about the misuse of these precious materials,’ he says. ‘Every time we receive students from local schools, we teach them this instrumentation is important to have in the lab to prevent water misuse: the litres we aren’t using here can then be used in another place.’

A water audit

However, the relative impact of water-saving interventions is also location-dependent as the value of saved water must be balanced against the energy required to recycle it. In the wetter environs of the University of York, UK, technical staff Hannah Briers, Richard Gammons and Lee Duff organised a department-wide audit of water-fed equipment, creating a comprehensive report of current water usage and assessing the potential impact of chillers on the department’s ecological footprint.

‘We wanted to identify where we can make water savings, taking into account the energy use of the chillers, how much it costs to clean the water going down the drain, and looking at lifecycle assessments and the carbon footprint,’ explains deputy technical operations manager Briers. ‘With this chunk of calculations, we could then come to a proper conclusion about what is the most sustainable solution across different areas of the department and where to best spend available funding to make the biggest impact.’

The initial audit, which involved almost all the members of the technical staff, identified rotary evaporators as responsible for the bulk of the department’s water use. ‘They’re one of these secondary pieces of equipment: fundamentally important but complicated to look at and not “exciting” pieces of kit,’ says Gammons, who is green chemistry technical manager. ‘Just off-the-cuff, no one’s got the time to look into them in detail.’

However, using the RSC’s Sustainable Laboratories grant, Briers and Gammons were able to fund two student technicians, Megan Goss and Will Heamen, to carry out an in-depth analysis of how this equipment is used and how this could be improved by future investment. Baseline use established, Goss calculated the carbon footprint of cooling via running water versus recirculating chiller across the teaching and research labs while Heamen optimised the capacity and running conditions of different chiller setups.

To have this information collated together in such detail is really useful 

Hannah Briers

Their analysis revealed that the introduction of chillers into the organic research labs would have by far the most significant impact, and the team were able to use some of the remaining grant money to purchase several equipment units for this research block. ‘I think a lot of people were surprised that the teaching labs wouldn’t be the first target, but it’s purely based on activity duration – it’s the fact that the organic labs run 50 weeks a year and the teaching labs don’t,’ says Briers.

With this body of evidence in place, Briers and Gammons hope to be able to implement further changes as new funding becomes available and are aiming to eliminate water cooling from the entire department by 2027. ‘I would hope that the format of the report could also be applied to other bits of kit, for example, vacuum pumps,’ says Briers. ‘To have this information collated together in such detail is really useful and means we can fill these gaps to operate more sustainably as a department.’