True Water

Disinfection Solutions

DynaSand Filters

The filters are made as freestanding units in stainless steel or reinforced plastic, with various filter areas and filter bed depths.

Dyna Sand Filters
Dyna Sand Filters

DynaSand filters are also manufactured as units to be built into concrete tanks.

The DynaSand filter is a compact filter without moving parts. No rinsing water supply tanks, sludge water tanks, rinsing pumps or automatic backwashing systems are required.

The standard DynaSand filter system consists of a cylindrical filter container with a conical lower section. The inlet pipe, distributor, air-lift pump and the sand washer are built into the container as standard. A DynaSand filter plant consists of a number of parallel filter units which match with the capacity required. The filter units are connected via an array of pipes to distribute the inflowing water, and to drain the filtrate and the wash water.

Units for installation in concrete tanks DynaSand filter plants with high throughput quantities are generally made of concrete. In this type of construction, several filter units are integrated in a single concrete tank and form a connected filter bed. Cones attached to the floor of the tank ensure that the sand bed is distributed evenly. DynaSand concrete filter plants can be designed for filters of any surface area required.

Processes / applications 
Mechanical filtration 
The most simple form of filtration is mechanical filtration, i.e. filtration without filter aids. Mechanical filters retain suspended filterable matter and are used as:

  • Filter steps after final sedimentation tank for retaining floating sludge flocks (e.g. bulking sludge or scum)
  • Filter steps after industrial waste water treatment (e.g. neutralisation) for retaining floating metal hydroxide flocks 
  • Partial flow filtration in cooling water circuits
  • Filter steps in steel and rolling mills for precipitating coarse and fine scale in water circuits.

Thanks to the continuous operation of DynaSand filters, the filter can cope with fluids with a high ratio of solids.

Contact filtration 
Contact filtration (flocculation filtration) is characterised by the addition of precipitants (e.g. FeCl3 solution) to the supply pipeline of the filter. The goal is to flocculate the matter in the filter bed, which retains primarily colloidal, organic and inorganic compounds and coarse, difficult to filter, particles. Real dissolved water contaminants (e.g. orthophosphate) are also precipitated and retained.

Contact filtration is primarily used when treating surface water to create drinking and industrial water or to eliminate phosphorus in municipal sewage treatment plants; phosphorus concentrations < 0.1 mg/l are reached in the outlet of the DynaSand filter.

Biologically activated filtration 
The filter material in the DynaSand filter is especially suitable as a carrier for a biofilm. The filter bed can be used to degrade BOD/COD and for nitrogen reduction by colonising micro-organisms. This is a significant development which offers new areas of application for the purification of waste water and drinking water.

The DynaSand Oxy and DynaSand Deni systems work according to the same continuous process principle as the tried and trusted DynaSand filter.