Modular Hybrid Submerged Aerate Filter (SAF) Launch

  • Flexible, modular system designed to bespoke specifications
  • Hybrid packaged plant designed to fit current water industry needs
  • Exceeds UK water industry standard of 25-year lifespan

An innovative package treatment plant that can be adapted to the needs of each client, but is based on tried and tested technology, has been brought onto the market by wastewater specialist WPL.

The Hybrid Submerged Aerated Filter (SAF) is manufactured out of a combination of both steel ‘exoskeleton’ and glass-reinforced plastic (GRP) and can treat wastewater to the highest environmental standards.

Hampshire-based WPL has more than 20 years’ experience manufacturing packaged plants in both steel and GRP has created the new product in response to demand from the water industry.

Divisional director Simon Kimber says: “We have created the Hybrid SAF packaged plant in response to our clients’ requirements for AMP 6. One of the requirements is for new equipment to be manufactured and engineered off-site as much as possible.

“This cuts down the installation time, reduces the carbon footprint and also reduces the health and safety risks.”

New regulatory guidance for AMP 6 (2015-2020) asks utilities to calculate new investment on the basis of capital cost plus 20 years’ operational cost, which means utilities are able to invest in new equipment according to whole life installation and operational costs (totex).

The robust glass-reinforced plastic (GRP) tank has a galvanised or stainless steel structural ‘exoskeleton’, which exceeds the UK water industry standard requirement of 25-years life. The modular design and optimised treatment process of the WPL Hybrid SAF offer a competitive whole-life cost to utilities, industrial and commercial wastewater treatment operations.

Units can usually be installed even where sites face height and width constraints, while the low weight of each unit means it can be delivered and off-loaded with a Hiab crane or fork-lift truck. This flexibility removes the need for large lifting equipment onsite during installation and reduces delivery costs.

The modular system also permits a larger tank configuration, exceeding 5,000 population equivalent. This gives the system adaptability to accommodate future site expansion or higher in-flow volumes at a later stage.

Units for international export are built to a standard size to fit five units in to a 40-foot (12m) shipment container and two units in to a 20-foot (6m) shipment container.

Environmental benefits

The key sustainability benefit of WPL bespoke package wastewater treatment systems, which can be purchased or hired, is to reduce the risk of environmental pollution. This can include meeting ammonia consents below 1mg/l and >95th percentile spill frequency.

Energy efficiency can be enhanced by opting for blowers driven by variable speed drives, controlled by monitors for dissolved oxygen and/or ammonia. This delivers further reductions in energy consumption, reducing overall carbon footprint.

 WPL packaged treatment tanks can usually be re-sited if an existing installation becomes redundant before end-of-life for the equipment. This reduces the risk of premature scrappage and waste.

Robust process design

WPL SAF technology can be adapted for the removal of carbonaceous organic matter, total Kjeldahl nitrogen, nitrification and de-nitrification (Total N), when strict standards are required.

The high surface area and open structure of the filtration media enables higher wastewater loading rates than competitor systems. This means WPL designers can optimise tank volumes, reducing overall equipment footprint.

Tank volumes have been further enhanced by a reconfiguration of the internal flow-control baffles in Hybrid SAF tanks, improving the characteristics of flow performance.

Client benefits

One of the key benefits of the SAF Hybrid package treatment plant is that it is factory-built in a quality-controlled environment and made ready for onsite installation.

 The systems are fully compliant with the Water Industry Mechanical & Electrical Specifications (WIMES), which define requirements for a wide range of mechanical and electrical equipment used in the UK. They also meet British and European standards.

Andrew Baird, Technical Director of WPL and Convenor of British Water’s Package Treatment Plant Focus Group said: “WPL has fully reviewed all aspects of its product offering and undertaken considerable research and development to meet customer and site demands. We have done this whilst retaining the essence and performance of a popular product and putting environmental and public health considerations to the forefront.”