Phytodepuration is a natural process to purify sewages that uses plants as biological filters that are able to reduce the polluting substances/contaminants present in them*.
The phytodepuration treatments are secondary biological treatments (that need a primary sedimentation treatment such as a septic tank) and/or tertiary (refinement) treatment that exploit the [natural] self-purification ability of the aquatic environments. In these biotopes the pollutants are naturally removed through physical, chemical and biological processes among which filtering, adsorption, assimilation by the vegetable organisms, bacterial degradation and antibiosis are the most effective (Brix, 1993).

Since the water purification costs are increasing the phytodepuration plants are an alternative that respects the environment and that is favourable from an economic point of view. In fact, above all in rural districts where it is not possible the hookup to the public sewerage, the proposed solutions are often onerous, however without a guarantee of a suitable treatment of the waste waters, with the risk of pollution of the aquifers (see absorbing wells, sub-irrigations, active sludges for small towns).

The phytodepuration plants show numerous features that make them good solutions at low expense and with an high purifying power:

A) a reduced and easy maintenance that can be performed by not specialized personnel

B) the creation of a green area perpetually irrigated and with a pleasant aspect

C) the possibility to re-use the purified water, still rich of nutrients, in the fertirrigation, to water the garden or in a pond or as not drinking water in the house (in the water closet, to wash the car, etc.).

Moreover, a phytodepuration plant, compared to a traditional water-softener (active sludges and total oxidation systems), allows to consume 80% less of electrical energy, since they are not needed blowers for the oxygenation; besides this treatment consists of only one process and therefore doesn't require chlorinations and chemical-physical finishing treatments, if it is used as secondary purification .

The phytodepuration plants can be used as secondary treatments (after a sedimentation) for civil or civil and domestic waste waters, or as a tertiary treatments (finishing) for industrial waste waters, dump percolates or for roads and highways leaching waters.

As regards the civil wastes the fields of use are many:

1) in rural housing sites where it is not possible, or it is too much expensive, the hookup to the public sewerage

2) as draining of civil wastes in campings, agritourisms or scattered houses groups

3) as town purification plants up to 2,000 equivalent inhabitants, as provided by the Legislative Decree 152/99 and following amendments

4) in reclamation and renovation projects of rural buildings built according to sustainability principles, and using bioarchitectural principles

5) in projects in which one want to use a [eco]sustainable management of the water cycle that foresees a backward water saving, the rainwaters and purified waters re-use with a zero environmental impact natural treatment and with low use of technologies and electrical energy

* There are other water purification natural systems in which the plants don't play an active role in the depurative process such as surface impoundment, the absorbent tray and the subirrigation