An advanced precision analyser has dramatically reduced the time and complexity of measuring trihalomethane (THM) levels in drinking water at Anglian Water, says manufacturer Parker Hannifin.
The instrument can analyse samples in less than 30 minutes, with no reagents or sample preparation.
Anglian Water is the first water company in the UK to install the technology. During the last five years, the company has invested more than £100 million in drinking water improvements, surpassing some of the most stringent quality targets in the world. In July 2015, Anglian Water decided to install an in-house trihalomethane (THM) sample monitoring and analysis system.
In England and Wales, water supply regulations enforced by the Drinking Water Inspectorate (DWI) set a maximum limit of 100 micrograms/litre for total THM concentration. Water supply companies therefore closely monitor THM levels to ensure compliance with this regulatory limit and maintain water quality and safety.
Comparison with conventional methods
Until now, like many water supply companies, Anglian Water has relied on a laboratory for THM analysis. This involved sending samples to the laboratory and waiting for the results. Anglian Water therefore decided to look for an alternative on-site method which would take pressure off its laboratory and deliver a same-day result.
The THM Analyzer that Parker has supplied is an integrated purge-and-trap system connected to a compact gas chromatograph column and a very sensitive surface acoustic wave (SAW) detector. It provides a completely self-contained solution for real-time measurement and analysis of THM concentration levels, down to as low as 1 part per billion (ppb) for each individual species of THMs. The analyser can measure chloroform, dichlorobromomethane, dibromochloromethane and bromoform – the four species that make up total THMs – to within 10% accuracy.
Mark Berry, Innovation Project Manager for Anglian Water, said: “Using the Parker THM analyser we are now able to measure THM concentrations in-house, and in less than 30 minutes. We are currently analysing over 20 samples a week and have found the system to be very easy to use. Aside from the potential cost-saving benefits, the much faster analysis capabilities provide scope for further improvements in operational efficiency.”
Graham Johnson, Downstream Applications Product Manager for Parker’s Instrumentation Product Division, highlighted the significance of the Anglian Water order: “This is the first THM analyser that we have supplied in Europe, following its recent CE marking. The feedback from Anglian Water is very positive and we believe that there is a ready market for this versatile type of water quality monitoring and analysis equipment throughout Europe. Along with its speed and simplicity of use, the analyser’s annual running costs are very low – the only consumables are high purity helium and concentrated standard solutions for verification runs.”
Parker supplies the THM analyser as a complete turnkey package. The high purity pressure regulators and precision control valves for its helium carrier gas system are manufactured by the company’s Veriflo Division.