Snow filtration

Snow filtration is a system to deal with left-over snow in an environmentally friendly way. Snow is removed from roads is done to ensure road safety. Roads are salted to cause the snow to melt on the road so that it doesn't freeze after melting. The conventional method is by dumping the snow into rivers, which increases the salt concentration in the water.

Method

In spring, as snow melts the salt that was put on it is left behind, which can be environmentally damaging as it creates a hypertonic environment for plants that are affected.

The snow runoff is collected and brought to a collection center. It is directed through an oil and grit separator which also monitors the consistency of pollutants in the runoff. The oil and grit separator causes electrochemical and biological processes, which bind heavy metals and nutrients to the sediment by means of reduction-oxidation reactions. At the same time, this reduces the amount of chlorine present in the runoff.

The runoff then flows into a catch basin, where plants use the salt ions (e.g. K⁺, P³⁻, N³⁻) for their growth.The runoff is further filtered by the plants, leaving only clean water to go back into streams and rivers.