Six Trends in Wastewater Screening Equipment and Wastewater Treatment

As the diversity, types, and amounts of materials that enter wastewater treatment facilities increase, municipalities must have the knowledge and resources to respond with the proper screening system. New technologies are improving the equipment and processes that can improve operations by meeting these escalating wastewater treatment demands. By being aware of these trends and developments, you’ll be better able to optimize your operations.

Because operating expense comprises almost 50% of a municipalities total cost, optimization is needed. These six trends help to further optimize plant performance and reduce long-term costs, improving outcomes for the municipality and its’ wastewater treatment facility.

Developments in wastewater screening

At Hydro-Dyne Engineering , it’s our business to help advance wastewater screening technology to improve wastewater treatment. Here’s a quick look at recent developments in wastewater screens and treatment.

1. Reduction in process equipment maintenance. Reducing screen maintenance requires moving service points from within the channel to above grade, where they are easier to access. Additionally, replacing screen materials that wear out with better materials and better designs, reduces maintenance frequency and replacement of wear parts. To reduce overall maintenance in downstream equipment (pumping out tanks, removing rags from clarifiers, RAS Pumps), finer screens with higher capture are being installed at the headworks. This leads to better results for the rest of the plant.
2. Coarse screening for pump stations. Pumps are clogging up more frequently with the introduction of wipes, along with fats and greases that congeal. Coarse screens with half-inch or up to one-inch openings are replacing grinders and static screens to help take out the larger solids, thus improving the pumps’ effectiveness.
3. Fine screening and better capture for protection of downstream equipment. By removing more and smaller debris at the headworks, you’ll help prevent downstream problems like clogged-up aerators and RAS pumps. More sophisticated plant processes – including membranes and rotating cloth filters – are driving the application of ultra-fine screens, which take out even smaller materials, requiring manufacturers to design screens with smaller openings and higher screening capture. The net result is reducing stress and extending the life of downstream processes and equipment.
4. Multiple stages and combination designs. Large plants are using a combination of screens to improve their overall process. Fine screens can complement the work of the coarse screens. Coarse screens first remove the large debris and leave the smaller inorganic material for removal by the fine screens. The key is to balance the amount of debris removed by both screens in order to optimize sizing, performance and operational flexibility. Some manufactures are also combining coarse and fine screens in a single unit but are struggling for acceptance in a market that demands reliability and performance.
5. Emphasis on separating organic and inorganic materials at the plant. More sophisticated and finer screens are capturing more organic materials, as well as the inorganic. The focus now is on screenings handling so as to wash and remove the organic material, then return it back to the plant.
6. On-site sampling of unique waste streams. Every municipality has unique influent flow characteristics. Sampling the site-specific influent stream can provide valuable insight into existing screen performance, proper screen selection, grid opening, and overall design for most effectively removing materials and optimizing plant-wide operations.

The Educated Approach to Wastewater Screening

Traditional approaches to screen design use “estimated” or “standard” input for influent flow characteristics. The problem with this method is that it isn’t specific to a location. Factors such as population density, collections systems, and flow variations influence the site-specific flow influent characteristics. Better processes will sample and analyze the influent flow to understand its characteristics, making it possible to custom design the wastewater screening equipment around flow specifics. The result includes better performance and lower costs.

The industry has also come a long way in improving materials — from the days of galvanized screens and frames to today’s industry-standard stainless steel. And we’ve witnessed the introduction of polymers and plastics that lead to longer-lasting equipment. As these materials improve, maintenance needs and frequency decrease.

Manufacturers are creating more product lines to address different applications. We’re seeing a variety of designs that are working well in different environments. Selecting the right screen for your application is essential to improve short- and long-term outcomes. Connect with us to learn more about wastewater screening equipment for your specific needs or to discuss the trends we’ve looked at above. on