An innovative way of dealing with the lorry loads of sludge waste produced at sewage treatment plants is this month being demonstrated to the Environment and Heritage Service (EHS), local politicians and those involved in the waste industry. A Fermanagh based firm, Preseco, is hoping that new technology they have developed with their parent company in Finland will help to turn the problem of dealing with sludge waste into a practical solution of producing compost for gardens.
A trial demonstration is currently on-going at the Northern Ireland Water sewage treatment works at Silverhill on the outskirts of Enniskillen. It involves a scaled down version of the full-size machine and is being operated as it would on a commercial basis. A manufacturing facility outside Newtownbutler is currently working on orders from Monaghan County Council for three full-size machines, and the firm is hopeful that more orders will come in as a result of tightening environmental restrictions on waste.
The process involves sludge from sewage treatment works at 20% solids being fed into a screw auger and mixed 1:1 with peat. This is then fed into a composting drum which is rotated over 7-14 days for accelerated composting under aerobic conditions. The heat generated rises to between 55-70ºC, and when the exhaust air is filtered the heat produced can be easily recovered for alternative uses such as heating water. The resultant compost is then stored for settlement and used as a typical garden compost, which is odour-free and easy to use.
At present, the sludge is taken to treatment works all over Fermanagh where it is pressed down then transported again for incineration or willow growing. If the trial is successful the new system would avoid such long road journeys. Preseco is hopeful of grant-aid from Invest Northern Ireland and has plans to double their workforce by the end of 2008.
