Sand filter for WWTP

Sand filter as the next stage of purification after mechanical-biological water pretreatment. It effectively traps impurities and bacteria, thereby improving water quality. At the same time, it contributes to the protection of water resources and the environment. With the help of a sand filter, you can easily achieve a significant improvement in the purity of wastewater.

The sand filter plays an important role in removing impurities from wastewater before it is released into the environment. It represents the next stage of purification after mechanical and biological water pre-treatment and is made of integrated polypropylene that can withstand aggressive environments. It is characterised by its relatively simple design, operation and low maintenance using minimal chemicals. We offer a sand filter with a gravity drain or we can manufacture a pressure drain.

Benefits and features of a sand filter

  • Simple design and operation
  • low operating costs
  • Environmentally friendly
  • long service life
  • easy maintenance

How the sand filter works

The sand filter is placed in the ground on a concrete foundation slab and is usually concreted in the form of a lost formwork. The top layer of the filter serves to trap escaping suspended solids. The water flows over two layers of gravel and one layer of sand. A polypropylene drainage pipe is placed at the bottom of the sand filter, through which the treated water is drained. Distribution troughs are used to distribute the water evenly over the sand filter area.

The outflow from the filter can be solved by gravity or, in the case of a small gradient , by pressure, by fitting a pump in the last chamber of the filter. The effluent concentrations of suspended solids and biodegradable organic nitrogen are reduced to a value of 15 mg/l for inputs of up to 30 mg/l. For all types of sand filters with displacement, the outlet height V0 is selectable, allowing the flow conditions to be adapted to specific needs and requirements.

Diagram of the discharge outlet of a sand filter

What the sand filter is equipped with

The sand filter is equipped with a safety overflow, lid and inspection covers for safe and easy handling. Extensions can also be ordered to adapt to specific field conditions.

Size Q [m3/d] L [mm] B [mm] H [mm] Vv [mm] Vo [mm]
0,5 0,5 1 000 700 1 500 1 300 100
1,0 1,0 1 500 700 1 500 1 300 100
1,5 1,5 1 500 1 000 1 500 1 300 100
2,5 2,5 2 000 1 500 1 500 1 300 100
4,0 4,0 2 500 1 500 1 500 1 300 100
6,0 6,0 3 000 2 160 1 500 1 300 100
9,0 9,0 4 000 2 160 1 500 1 300 100