Automated screening of wastewater eliminates OHS hazards

SFC screen extractor technology was installed by CST Wastewater Solutions to improve the treatment system for the conjoined towns of Harden and Murrumburrah in NSW, and it has been shown to have the added benefit of improving OHS hazards for operators.

SFC (screen press for channel installation) allows for a much finer level of screening — 5 mm, compared to the old system at 60 mm — which has led to a significant reduction in solids in the tanks, more efficient treatment and less maintenance issues.

The technology, which is designed to lower the operational and maintenance costs of screening municipal and industrial wastewater with compacting of extracted solids, has also cut the amount of maintenance and waste that has to be handled by plant operators, reducing operational health hazards and improving OHS performance.

“The fine screening at 5 mm aperture made a significant difference within days of commissioning the screen extractor,” said Michael Bambridge, managing director, CST Wastewater Solutions.

The previous system used manually coarse raked bar screens with a 60 mm aperture, which was both operator-unfriendly and inefficient. As a result, a large amount of the fine screenings passed into the downstream sedimentation tanks and trickling filters.

“Not only are the tanks clearer and more efficient now, but the screen extractor also operates on level control and is fully automated, eliminating the previously labour-intensive operator handling of screenings,” said Bambridge.

The highly durable extractor features low-speed operation and a robust shaftless spiral in high-tensile carbon steel and stainless steel AISI 304 or 316. It operates without the need for hanger, intermediate or bottom bearings and can be easily retrofitted into existing pump stations with depths up to 8 m. It allows the removal of material before pumping and can also be installed in a channel or supplied with a self-supporting tank, complete with inlet and outlet flange, and an optional bypass screen.

CST Wastewater Solutions said the SFC screen extractor is suitable for applications such as food and beverages, manufacturing and processing, and mining — where its low-maintenance and high-hygiene qualities are appreciated — as well as agribusiness and remote installations, where low maintenance and high efficiency are priorities for users who do not have specialist staff constantly available.