A delegation led by the MEDISS partner ENAS (Sardinian Water Board) and including top representatives of the Cooperativa Produttori Arborea (the associated partner of the MEDISS project in Italy), recently started an important study visit to Switzerland. 

The delegation was composed of the ENAS team represented by the project manager and the scientific manager of the MEDISS experimental pilot plant in Arborea, Maria Antonietta Dessena and Andrea Virdis and the President and vice President of the Cooperativa , Walter Mureddu and Vincenzo Signor, accompanied by their experts Lino Tammaro and Gianni Ragaglia. 

The target of the study visit was the Sewage Treatment Plant in Yverdon-les-Bains (a Swiss municipality of 29,977 inhabitants in the Canton of Vaud, capital of the Jura-Nord vaudois District).  

The site is a pioneer in Europe in the treatment and revalorisation of nitrogen in wastewater, using the stripping technique with a polypropylene membrane that allows nitrogen to be fixed, through a series of different phases developed over the years, and ammonium sulphate to be obtained, which can be used in agriculture. The same type of process has been experimented by MEDISS in Arborea, in the facilities of the Cooperativa Produttori. 

The Yverdon-les-bains plant, which has been in operation since 1957 and treats approximately 11000m3 of effluent per day, is undergoing extensive upgrading to reinforce the overall treatment capacity, improve the ecological balance and increase the treatment of micro-effluents. Today, thanks to the energetic valorisation of sewage sludge, it has 80% electrical and 100% thermal autonomy. 

In view of the excellent results achieved by the MEDISS pilot plant in Arborea in the treatment of livestock waste with the elimination of ammonia and its subsequent valorisation, the impact of agricultural activity on the environment has been greatly reduced, ENAS and Cooperativa Produttori have started measures for the scaling up of the plant to industrial level. 

This is a unique opportunity, for the MEDISS partners, to assess at first hand the potential of exploiting the results achieved so far on an industrial scale and to define a solid investment plan that can provide a long-term solution to the nitrate problem in Arborea.