Phytopurifycation is a system based on physical, chemical, and biological processes performed enacted by wetland vegetation. Since January 2004, SELC has been working on the restoration of a wetland treatment plan on the Lazzaretto Nuovo Island, in the northern lagoon of Venice .

Wetland treatment systems for the treatment of reflux water are generally adopted when, as on the Island of Lazzaretto Nuovo , the area is small and isolated, and the water volume to treat is subjected to variations. In this case, another aspect to take into account is the need to adopt solutions with low environmental impact, as the island lies in a natural lagoon.

Phragmites australis is the species used in the water treatment system because it is widespread in the lagoon, and because it removes organic pollutants efficiently.

The island is currently entrusted to Archeoclub and Ekos Club, which are associations of volunteers who work on the island permanently and organise archaeology courses of about 40 people in the summer.

The system has therefore been designed to treat the seasonal production of drainage waste by a small community of maximum 40 people. Due to the characteristics of the area, used for recreational purposes, the wetland treatment system system adopted flows sub-superficially, to prevent the development of insects and foul smell.

The main elements composing the phytopurifycation system are:

• separate waste and meteoric water drains;
  
  
• two pools, working in parallel or in series, with gravelly beds containing Phragmites australis;
  
  
• septic tank divided into three chambers;
  
  
• discharge pit in the curing basin;
  
  
• curing basin;
  
  
• discharge pit in the lagoon.

The combined use of these elements purifies drains:

• downspouts collect meteoric water, which flows into the two pools. When the system does not require any water, it drains into the curing basin, or directly into the lagoon.
  
  
• waste water is distributed in a more complex way: it flows into the drainage pit and is collected in the three-chamber septic tank, or manually connected to the pools. Waste water then flows from the septic tank into the curing basin and, if necessary, into the lagoon.
  
  

The efficiency of the wetland treatment system  in removing pollutants is monitored by the system itself, which checks the type of flowing effluence. This work is carried out in collaboration with the University of Padua – Dipartimento of Processi Chimici dell’Ingegneria – which analyses the chemical content of water samples collected at the entrance and exit of the system, to check the capacity for pollutant removal.