“Biologically Dead” Thames Brought Back to Life With Support From Servomex Oxygen Application

 Crowborough, UK, January 2021 – Global expert in gas analysis Servomex has been instrumental in tracking and treating pollution in the tidal Thames with the SERVOTOUGH Oxy 1800 on board specifically designed boats that inject life back into the river.

Since 1999, the O₂ analyzer – which processes 250ml a minute – has assisted the Thames Bubbler and the Vitality boats as they monitor oxygen levels of the river to help preserve a once “biologically dead” ecosystem. Weighing 26kg, the 448mm x 235mm x 229mm application delivers highly accurate and reliable oxygen monitoring capabilities, using the patented Servomex Paramagnetic oxygen transducer, ideal for enriched oxygen samples.

The Thames Water vessels can each inject 30 tonnes of oxygen into the river every day, are approximately 50m long and 10m wide, and cost around £250,000 a year to run. They are vital in ensuring that depleted oxygen levels are restored following heavy rainfall which can result in storm overflows when millions of tonnes of diluted sewage enter the river causing a drop in dissolved oxygen levels. Accurate monitoring means the vessels are used in the most effective way enabling them to follow the area where the oxygen they inject is needed most. Dissolved oxygen in water can fluctuate naturally, however, human activities can have a substantial impact and anything less than 45% of dissolved oxygen can result in depleting fish numbers and affect predator-prey relationships within the Tidal Thames.

Parts of the river had been declared biologically dead in 1957 by scientists at the Natural History Museum as the water quality in the estuary had become so polluted few animals could survive. However the boats and its instruments have formed an important part of the journey to return the river to one now abundant in life, according to a recent report by the ZSL (Zoological Society of London).

In recent years mammals such as the grey seal and harbour seal have been residents at the Tidal Thames, as have a number of birds including the avocet and redshank. Over 120 species of fish have been found in the river which also provides an important spawning area for the smaller cousin of the salmon, the European Smelt, and is a haven for the maturing migratory European eel.

Graeme Watson, Field Service Engineer for Servomex, said he witnessed seals, cormorants and fisherman during his visit on board.

“From witnessing the biodiversity it is clear to see that the river is in great condition and the Environment Agency are doing a spectacular job of allowing that life to thrive,” he said. “We are proud to be able to support this all-important ongoing project with our application.”

Neil Dunlop, Water Quality Technical Specialist for the Environment Agency and “Bubbler Controller”, added: “Dissolved oxygen is not only the best indicator for the health of the river but is also essential for all aquatic life. Being able to measure how much oxygen is in the river water quickly and accurately is essential to be able to position the oxygenation vessels in the correct position.”

Designed to reliably measure up to 100% oxygen in many industrial applications, this is a stable and accurate oxygen analyser for safe area use. Its features have been specifically designed to ease everyday operation and maximise performance. For more information visit: www.servomex.com/gas-analyzers/finder/oxy-1800/