Pre-screening of wastewater upstream of membrane systems in the USA
Pre-screening the wastewater before it goes through a membrane system plays a crucial role in water treatment and is becoming increasingly important in the USA. Its main aim is to protect downstream membrane systems and improve the efficiency of water treatment. At the same time, it relieves the downstream treatment stages and reduces maintenance costs.
Various HUBER technologies are used for pre-screening, including the ROTAMAT® STAR and RPPS screens. Similar to the ROTAMAT® Ro2 screen, these machines combine the functions of screening, washing, discharging, compacting and dewatering in one compact and robust unit. In contrast to the ROTAMAT® Ro2, however, the ROTAMAT® STAR and RPPS are equipped with a perforated plate screen. This enables two-dimensional screening, which ensures a higher separation efficiency. The screen basket of the ROTAMAT® RPPS has an aperture width of at least 1.5 mm, which already makes it suitable for membrane pre-screening. If even finer screening is required, the folded screen basket of the ROTAMAT® STAR can be used. This can be designed with a hole diameter of 1 mm and thus enables even finer separation. In addition, the screening surface is increased, which leads to a higher flow rate due to the star-shaped folding of the screen basket.
In the USA, these two machine types have proven their worth in membrane pre-screening over the last two years. As in Salzburg-Siggerwiesen, the large machines are now also being used there. Both the ROTAMAT® RPPS with a hole diameter of 2 mm and four machines are being used in one project, as well as the ROTAMAT® STAR with two machines and a hole diameter of 1 mm. Two further orders were landed in the USA last year. ROTAMAT® STAR with a basket diameter of 2.0 m and ROTAMAT® RPPS with a diameter of 2.2 m are being used to protect the membranes. Another special feature of the two orders is that these machines are manufactured entirely at the HUBER Technology, Inc. production site in Denver, North Carolina and therefore directly in the USA.