Water & Wastewater Treatment

The Ovivo® screw compactor incorporates the original Jones+A wood™ features that have a proven record of reliability and robustness. Our new design now receives flows from water powered launders and incorporates a 9mm thick drainage trough for ruggedness and 6mm TAPERED holes for improved drainage– built with lowering TOTEX in mind. Available in 5 standard sizes the Ovivo screw compactor loading capacity ranges between 0.5 and 9.5 (M³/Hr) and launder flows up to 8.0l/s. OVIVO ® Screw Compactor Call: 0121 511 2400 or visit: www.ovivowater.com © 2014 GLV Inc. All rights reserved. incorporates the original Jones+A wood™ features that have a proven record of reliability and robustness. Our new design now receives Screw Compactor Screw Compacting since 1986! Old Dog. New Tricks. Great Plug. C M Y CM MY CY CMY K Screw Compactor Ad 0314_PRINT READY.pdf 1 19/03/2014 5:02:20 PM www.wwtonline.co.uk | WWT | MAY 2014 | 29 Digging deeper Cleaning flooded lakes and reservoirs A gricultural run-off, sewage discharge and, more recently, floodwater all compromise water quality in lakes, rivers, reservoirs and coastal waters. But what's the best way to clean up flooded lakes and reservoirs? High concentrations of manganese, iron, aluminium and phosphates, which contribute to algal bloom and noxious gases, are affecting our aquatic animals and flora. Unhealthy, polluted water limits leisure activities and expensive chemical treatments are required to treat reservoir water – neither scenario is desirable, or even necessary. Floodwater has been running off the land into rivers and lakes, carrying with it all sorts of waste, including raw sewage. Tests from Reading University recently showed floodwater contained 60-70 times the amount of bacteria recommended by the World Health Organisation. But this is only compounding a growing problem. A lack of management and investment, together with an increase in agricultural chemicals, has seen a steady decline in the health and ecology of many lakes and reservoirs. Thermal stratification One of the causes is thermal stratification, a common condition affecting bodies of water with little or no flow in the summer months – the result of heating by the sun. It causes layers of unmixed water at different temperatures with extremely poor levels of dissolved oxygen in the deeper water and a consequent disruption to the normal water ecology. This anoxic layer is bad for fish and the other organisms, which normally breakdown organ- ics deposited in the lake. Studies also show that low levels of dissolved oxygen in deeper waters is linked to the development of toxic blue green algal blooms and increased concentrations of manganese and iron. The Environment Agency is trying to improve lake water with the 2015 Water Framework Directive, which will make county councils Reservoir aeration naturally improves water quality Tony Wynes of Aquarius Marine Group talks us through aeration "Studies also show that low levels of dissolved oxygen in deeper waters is linked to the development of toxic blue green algal blooms and increased concentrations of manganese and iron". Tony Wynes

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