The Sobye belt filter has gained an excellent reputation over a 25-year period as an automatic, self-cleaning compact solution for primary treatment to replace settlement tanks. More than 200 systems are currently in use, with around 100 of these in the municipal primary treatment market.
The filter takes screened wastewater to an inlet above the screen belt, the wastewater then flows under gravity through the moving filter belt. Filtered wastewater is discharged from the bottom of the tank. The belt speed is controlled, which allows a layer of sludge to build up on the cloth to increase filtration efficiency.
When the screen requires cleaning, the belt rotates so that particles are removed with an integrated brush. A high-pressure spray bar then cleans the belt, and the dislodged sludge can be discharged to a screw conveyor for further washing and pressing to a high dry solids content. The washwater is, together with filtrate from the press, returned upstream. The filter belt is very robust and is readily replaced when required.
There are three sizes of belt filter suited to the municipal wastewater market, the Sobye TD 07, the TD 14 and the TD 20, which are renowned as small-footprint units with a high filtering capacity: Their effective filter areas are 0.74m2, 1.45m2 and 2.0m2 respectively.
The units are fabricated in stainless steel, and the heavy-duty polyester belt mesh aperture size ranges from 60-1000 Microns. Flow volumes are up to 50m3/h for the TD-07, 100m3/h for the TD 14 and 150m3/h for the TD 20.
The effectiveness of BOD and suspended solids removal across the Sobye unit is at least equivalent to conventional primary settlement but performs to this standard with a much reduced footprint. Operational and maintenance costs are also equivalent to conventional primary settlement tanks and scrapers systems.
Jacopa Managing Director, Alex Lloyd said: "We are delighted to be able to provide this well-regarded product from the well regarded Nordic Water company which further consolidates our reputation for providing robust, high quality, innovative and cost-effective wastewater treatment solutions. Early response to the belt filter has been excellent, with several water companies already expressing an interest and options being actively explored. The cost and price data make this system extremely competitive and with capital and maintenance budgets under pressure we anticipate considerable interest within the wastewater treatment market."
The Sobye belt filter can be retrofitted easily into existing facilities, being simple to install. Jacopa envisage that with the speed of implementation it will be embraced as an effective permanent treatment system, with the option for rental where shorter term threats to efficient operation by works overload or maintenance of primary tanks is a concern for operators.