FLOCKING AGENT USED FOR GRAVEL CLEANING – Waste water treatment in the gravel plant


Polymer solutions are used wherever the sedimentation or flotation of suspended solids in water is to be accelerated and the dewatering behaviour of thickened sludge is to be improved. This is mostly the case in wastewater treatment, paper production, drinking water treatment and sewage sludge dewatering.

The PolyLine polymer preparation stations from sera are simple, flexible as well as economical and efficient systems for the preparation of polymers. They are available in three different series, in which either liquid or dry polymer is used. Depending on the application, the versions offer individual advantages. The systems are equipped with precise flow measurement for solution preparation and level measurement, thus ensuring efficient and economical operation.

PolyLine polymer preparation system in the gravel cleaning process

For the process of cleaning industrial water, in this case for cleaning gravel, sera was able to offer a customer, operator of a gravel plant, the right solution for his application:

The process
Water is needed to clean the gravel. This water is collected and used again and again. Due to the constant washing of the ballast, the pollution of the water is very high. However, a high degree of purification of the water is important in order to clean the ballast on the one hand and to protect the facilities of the entire cycle on the other.

The solution – polymer preparation system PolyLine
In autumn 2022, sera delivered a PolyLine Flow with a preparation volume of 1000 l polymer to the customer in Austria. This PolyLine version is a system with 3 chambers that is designed for powder polymer. The powder enters the system via a dry material feeder, which is equipped with a ring heater to prevent the powder from clumping. In the first chamber, the powder is dissolved with water. In the second chamber, the product has sufficient time to ripen. After a predefined ripening time, the finished solution enters the third chamber via an overflow, from which it is removed.

The contaminated water is pre-cleaned with the help of a lamella separator. In order to increase the efficiency of the lamella separator, flocculation aid with sera PolyLine is added to the feed line.

The before-and-after comparison clearly shows the positive effect of the use of flocculant already after a very short time. In projects like this, it is also always important to fine-tune the polymer preparation station and the flocculant. Only then can an optimal result be achieved.

Commissioning on site

Two sera employees accompanied the commissioning and trained the employees on site for the future handling of the system. Various setting options of the PLC control as well as the functionality of the PolyLine were explained. The on-site consultation is an important part of the sera philosophy „Everything from a single source“, as it ensures that the system is fully understood and minor challenges can be solved by the customer directly on site. In addition, sera Service is of course available to its customers and partners with advice and support if they have any questions.

As a specialist in the field of wastewater treatment as well as in the preparation of flocculants, sera was once again able to simplify and improve a customer’s process here and thus create added value for people and the environment.

The sera delivery programme for waste water technology comprises essential areas:

  • Complete dosing plants and systems
  • Plant accessories
  • Dosing units for operational tests
  • Preparation and dosing systems for polymer solutions