BROBY WWTP, a small waste water treatment plant in Sweden, had a pressing need to reduce the momentarily high biological load which occurred when receiving septic sludge (also known as external sludge). The high load caused instability in the biological treatment process which resulted in a waste water treatment plant with substantial problems in meeting the effluent terms of conditions.
To resolve this issue, Broby WWT needed to source a septic unit that combined a short truck off-loading time with a high screening capacity and which could immediately send the sieved effluent further on to the sludge storage.
The innovative Lackeby solution proves ideal for septic handling
With recommendations from the company in charge of septic recovery and transport in the municipality, Broby WWTP found a solution with the Lackeby Roto-Sieve® septic unit.
The septic unit is based on the well-known Lackeby Roto Sieve® drum screen which has been modified for septic receiving. The unit’s updated design efficiently handles high flow rates of demanding septic sludge. Due to the sieve drum design, there is an optimal separation of rocks, gravel and fibrous material without risk of clogging. When the off-loading is completed, an automatic release of accumulated liquid from the trough minimises odour in the surrounding area.
A successful result with no odour risk
All external sludge at Broby WWTP is now received through the Lackeby Roto-Sieve® septic unit, RSS 36. The sieve drum is made of perforated stainless-steel plates with Ø 6mm holes and handles flow rates up to 130 m3/h which means that the off-loading of a truck with trailer is completed in just 15 minutes.
In addition to the septic unit there is a Lackeby Screw conveyor press, SCP 220, equipped with an extended lifting pipe and bag system. The screenings get efficiently dewatered with a small volume and high dryness as a result. Furthermore, it gets encapsulated with no risk of odour at storage and transport to incineration.
The control system and efficient wash function makes the unit almost completely self-cleaning. In combination with the integrated brush and a spray system with optimised run time, it keeps the need of manual cleaning to a minimum.
Swedish manufacturer Lackeby Products AB – represented in South Africa by Monitor Pumps & Systems – has more than 50 years of experience in designing and manufacturing high performance products for resource efficient heat recovery and wastewater recycling.
For more information contact wim@monitorpumps.co.za
www.monitorpumps.co.za
