Successful Trial for New Remote Phosphate Monitor

Researchers at the UK’s Centre for Ecology & Hydrology (CEH) have conducted trials on the river Thames to evaluate a new remote phosphate monitoring technology (Cycle-P) as part of a high-frequency (hourly resolution) monitoring programme that is studying river nutrient concentrations and how they affect algal abundance. The monitoring system ran continuously over the summer of 2014, measuring total reactive phosphate levels in the river, day and night, seven days a week. These results have now been compared with manually collected samples that were analysed in a laboratory with the traditional Murphy and Riley spectrophotometric method on unfiltered samples, and Dr Mike Bowes, senior nutrient hydrochemist at CEH, says: “The Cycle-P is working really well; the system operated independently for long periods and produced results that tracked our lab samples closely.”

The Cycle-P from OTT Hydrometry (UK) is gathering considerable interest because it is battery powered and able to operate unattended in the field, running over 1,000 tests before a field service is necessary to change the reagents.

Dr Bowes has tried a number of phosphate monitoring technologies in the past but has found them to be either too unreliable or power-hungry. “Our research is designed to identify the causes of algal blooms and to understand the factors that trigger both blooms and algal dieback,” he says. “The ability to monitor phosphate in remote locations is therefore critical to the success of our work, because manual or even automatic sampling for laboratory analysis, incurs significant delays and increases costs.”

OTT Hydrometry’s Nigel Grimsley says: “The Cycle-P has already worked extremely well in a variety of international projects, but it was vital for its capabilities to be demonstrated in UK waters, and the CEH Thames Initiative provided an ideal platform to do so. I am grateful to CEH for the opportunity that they have provided and I look forward to reporting feedback from a number of recent further installations.”