A post by Rob Rawlings
Production Manager
Three of our water treatment centres (WTCs) use ion exchange plants to remove nitrate from high-nitrate water sources. This produces high-salinity waste (brine). At one of these sites, near Blandford, the brine can only be disposed of in limited quantities at the nearby water recycling centre (WRC), with surplus waste being tankered to a larger site.
Over time we have seen an increase in the nitrate levels in the ground water source. As a result, additional treatment is required, which has led to an increase in brine waste from the site. The financial cost and carbon impact of additional tankering led us to run a Marketplace challenge attempting to find a more sustainable approach to the brine waste.
One of the solutions identified through the challenge was a software monitoring tool proposed by datumpin, which provides data and insights to help optimise the operation of the ion exchange plant. We decided to trial the tool to assess the benefits it could bring.
A range of benefits
The technology has now been in use at the site for over 18 months and has demonstrated fantastic value, with a net saving of over £40,000 per year.
We’ve used insights from the datumpin technology to inform adjustments to the plant’s control software. Optimising the process in this way has reduced the amount of brine waste generated. With less brine waste to tanker away, we are now saving at least £20,000 per year on average tankering costs.
Thanks to the tool, we’ve implemented operational changes to reduce scaling issues, saving a further £25,000 per year. By separating the brine waste from a second waste stream (softener), we have significantly reduced scale accumulation in the brine discharge system, bringing substantial savings on man hours spent cleaning as well as the cost of the descaler chemical.
Finally, more efficient performance brings various additional benefits – such as lower salt usage (and therefore cost) and a reduction in the amount of maintenance required at the plant.
The optimisation will also mean that we can plan for proactive maintenance on key components of the ion exchange plant before they become a major issue and begin to impact our ability to treat water and put it into supply. Work can then be programmed to take place outside of critical periods, thereby avoiding unplanned outages that could lead to tens of thousands of pounds worth of costs.
What’s next?
As well as continuing to use the datumpin tool at the original site, we plan to install the technology at our two other water treatment centres that utilise ion exchange later this year.
By optimising their operation now, we can avoid a significant increase in future operation and maintenance costs. The datumpin software will also likely form part of ongoing optimisation at a new nitrate treatment plant to be built in the 2025-30 investment period at a WTC near Poole.
We are continuing to consider potential applications for this technology in other types of water treatment centres.