More and more sewage treatment plant operators rely on HUBER systems when it comes to the treatment of external materials

For almost 20 years already, HUBER SE has provided successful solutions for the treatment of road sweepings, sewer grit and grit from sewage treatment plants. With more than 170 projects executed worldwide HUBER has gained extensive experience in the treatment of STP grit, sewer grit and road sweepings. Our solutions have continuously been further developed in the course of the past years. The major challenge has been and still is the different composition of the raw material which can have a massive impact on downstream grit treatment systems.

The result of our further development efforts are grit treatment plants for a daily raw material throughput up to 60 tons. The raw material can be fed to the plants with a wheel loader or crane installation or directly from tanker vehicles.

In operation since 2015 – grit treatment plants on STPs Schwabach, Koblenz and Frankfurt Niederrad

Grit treatment system RoSF5HW with automatic covering of the acceptance tank on STP Frankfurt Niederrad
Grit treatment system RoSF5HW with automatic covering of the acceptance tank on STP Frankfurt Niederrad
Grit acceptance system RoSF5VW on STP Koblenz
Grit acceptance system RoSF5VW on STP Koblenz

Another three grit treatment plants went into service between 2014 and 2015. The grit treatment plant on STP Schwabach is designed for throughputs of up to 1.5 tons raw material per hour. Due to the low throughput requirements the plant could be designed quite small. On the Schwabach site the liquid phase, which can amount to up to 8 m³ with 10 m³ tanker vehicles, is discharged directly into the sewage treatment plant so that only small-volume acceptance tanks are required.

This is contrary to the situation on the Frankfurt site where the overall plant consists of two lines which can accept and process raw material independently from each other. Two grit washers guarantee a maximum throughput of up to 3 tons per hour. To separate the liquid from the solid phase prior to emptying the material into the acceptance tank, the liquid phase can be discharged via an extra unit that is provided especially for this purpose. Floatable organic matter is separated from the liquid phase which is directly discharged into the grit washer. Upon request of the customer, level measurement systems in the grit containers and automatically closing covers in the grit acceptance tank have been installed.

In contrast to the plants in Frankfurt and Schwabach the grit acceptance plant in Koblenz is a RoSF5 VW system. VW stands for feeding vertically into a wash drum. With the standard RoSF5 HW system feeding takes place horizontally into a wash drum. On this site material dewatering is achieved by means of a pneumatic rake screen system in the tank of the acceptance system. This plant is designed for a throughput of up to 1.5 tons per hour. As the grit washer on this site has not yet reached its capacity by now and organics separation is very effective, the plant operators think about feeding additionally sediments from their grit traps into the grit washer.

Facts and figures





Process type




Acceptance tank type

RoSF7, 6 m3

RoSF8V, 4 m3

2x RoSF7, 9 m3

Wash Drum

RoSF9 size 1

RoSF9 size 1

2x RoSF9 size 1

Grit Washer

RoSF 4 size 2

RoSF4 size 2

2x RoSF4 size 2

Coarse material conveyor ?



2x Yes

Feeding from grit trap ?