WET News

DECEMBER 2015 WET NEWS 15 A solution: AGM profiling Sampling inlet waters can give an accurate profile of incoming grit. W ith the AMP6 emphasis on effective asset operation and management, grit removal is a particular area for scrutiny. With innovation high on the agenda, it could be that grit removal turns out to be an unlikely game changer and fundamental to achieving progress towards totex objectives in AMP6 and beyond. A radical change of approach called Advanced Grit Man- agement (AGM) is being proposed by Hydro Inter- national in the UK, based on proven technology and experience from North America. "The way grit settles in wastewater is complex, governed by a number of factors including size, specific gravity, shape and tendency for agglomeration," explains Hydro International's Keith Hutchings. "Grit shapes are seldom spherical and shape significantly affects the particle settling rate. Actual particles are frequently rough in texture, which allows even smaller particles and organics to bind to them. "The particles frequently carry organics, such as soaps, fats, oils and grease, which expand the surface area or clump together, and thus significantly affect the settling rate. Experience of working with more than 200 installations in North America has demonstrated that the majority of grit particles can be in the 106 micron to 75 micron range, or even smaller." Accurate profile Hutchings says effective grit removal systems are designed with an accurate understanding of the nature and characteristics of the grit and how it actually behaves in wastewater. "AGM begins with sampling inlet waters to gain an accurate profile of the incoming grit, and then recommending and tailoring a combination of technologies to meet those conditions for an individual plant." The opportunity has come about through the technology transfer of a high-performance grit removal system to the UK from the US called HeadCell, which uses a large surface area and short settling distances to capture fine particles. Combined with the rigorous AGM approach, the system targets to achieve up to 95% removal of all grit 75 microns or larger. High-performance grit removal requires appropriate washing and dewatering systems that achieve the same performance. Without them, the finer grit would be washed back into the waste stream. So, an integrated system is recommended to maximise grit removal performance. The HeadCell, for example, can be combined with Hydro's GritCup washer and classifier and SpiraSnail dewatering system to achieve the best possible results. "The UK industry has accepted and grown to live with the burden of grit because of a "one size fits all" industry standard," adds Hutchings. "We believe the time has come to challenge accepted norms. Grit sampling has never been conducted in the UK before and our sampling studies so far are providing strong evidence to support that view." Hydro International is currently undertaking sam- pling across the UK and is seeking water company partners to conduct pilot trials, as well as to set up a full operating trial site. Already sampling studies underway with several water companies are showing promising results. Wastewater grit sampling underway with Hydro's HeadCell as part of a pilot scheme in the UK s Chemical and corrosion resistance s uPVC, polypropylene, GRP & composite construction s Speciality materials include PVDF, CPVC & ECTFE s Infrared welding capability s One piece or sectional construction Fabrication of bespoke plastic tanks, vessels & ducting info@bhpplastics.co.uk www.bhpplastics.co.uk Steve Vick International Ltd. Treenwood Industrial Estate, Bradford on Avon, Wiltshire, BA15 2AU +44 (0) 1225 864 864 stevevick.com info@stevevick.com NEW Pneumatic, hand held tools for SAFE, FAST and PRECISE cutting of windows or circumferential cuts in abandoned or inserted ductile mains The Rapid Rotary Cutter The Rapid Window Cutter www.utilityweeklive.co.uk A unique opportunity to meet decision-makers from across the water industry. Rachael Lyon Business Development Director, Utility Week Live 2016 T +44 (0)1342 332097 M +44 (0)7968 301370 E rachael.lyon@fav-house.com Connecting Britain's utilities to their suppliers, contractors and partners From the team behind WET News and Water & Wastewater Treatment WET News From the team behind WET News and Water & Wastewater Treatment Download the brochure today from www.utilityweeklive.co.uk or contact:

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