Energy and Process Efficiency – savings at Thames Water
Lambert, S..1 and Fountain, P.2, 1SEEPEX UK Ltd, UK, 2Thames Water, UK
(free)
Thames Water’s energy strategy focuses on increasing energy production and recycling 100% of
energy from wastewater. SEEPEX has worked with Thames Water to improve process efficiency and
reduce energy consumption of dewatered biosolids sludge handling.
Reading STW generates biogas and energy using anaerobic digestion. The final biosolids by-product
is dewatered to 22-25% dry solids content.
In 2014, SEEPEX installed multistage progressive cavity pumps to replace piston pumps which had
process limitations and high operating costs. In 2018, SEEPEX launched Smart Air Injection (SAI) to
improve dewatered sludge handling, enabling long distance transfer with reduced operational costs.
Thames Water’s interest in SAI was linked to a new project at Riverside STW to handle dewatered
sludge.
Installation of a trial system at Reading proved energy savings using SAI technology compared to the
use of a multistage PC pump without air injection to be of 15% – 61% compared to the original piston
pumps. If single stage pumps were used instead of multistage, the energy saving would be
approximately 40% – 75% compared to the original piston pumps.
SAI is being installed as part of the new Thames Water Riverside project as an energy-efficient, highperformance alternative to conventional sludge handling systems
