For a wastewater treatment plant, EMHA developed and implemented a new grease removal system for four primary settling tanks. By converting the existing wet grease pits into a dry system, recurring blockages and cleaning requirements have been significantly reduced. The solution improves process reliability and delivers estimated savings of €160,000 per year.
Situation
The four primary settling tanks were equipped with grease pits that regularly became blocked. Floating layers of grease and debris, sometimes up to one metre thick, obstructed the discharge process and required frequent cleaning. Several modifications had been made to the existing system over the years, but none provided a structural solution.
The objective was to improve the reliability of the grease removal process while significantly reducing cleaning and maintenance costs.
- Recurring blockages caused by thick floating layers
- Frequent cleaning required to keep the process operational
- Previous modifications had not solved the problem
- Need for greater reliability and lower operating costs
Approach
Together with Hidrostal, EMHA developed a dry grease removal system. In the new configuration, floating debris is transferred through a buffer tank and pumped directly into the existing return sludge line. The solution was first developed, installed and tested as a pilot. Following successful testing, the remaining three primary settling tanks were converted to the new system.
To minimise installation time and risks on site, EMHA designed a prefabricated cassette construction. The existing pits were accurately 3D scanned, after which point cloud data was used to create detailed 3D models. This allowed the steel construction and plastic pipework to be manufactured with millimetre accuracy.
As many components as possible were pre-assembled in the workshop, reducing installation time and simplifying the work on site.
EMHA was responsible for:
- Design and engineering of the grease removal system
- 3D scanning and digital preparation
- Prefabrication of the cassette constructions
- Coordination of specialised partners
- Installation and commissioning on site
Result
The new dry grease removal system provides a structural solution to the recurring blockage problems. Floating debris is now discharged in a controlled manner, improving the reliability of the primary settling tanks and reducing the need for cleaning.
The prefabricated approach also shortened the installation time and reduced execution and safety risks on site. Estimated savings amount to approximately €40,000 per primary settling tank per year, or around €160,000 annually in total. This results in an expected payback period of approximately 2.5 years.
- Improved reliability of the grease removal process
- Significant reduction in blockages and cleaning requirements
- Estimated annual savings of €160,000
- Expected payback period of approximately 2.5 years
- Shorter and more controlled installation through 3D engineering and prefabrication
