Abstract
In a gasification system, char is a solid by-product mainly composed of carbon and ash. This by-product was usually disposed as a waste but a recent Decree completely changed the Italian scenario authorising the utilization of char as soil amendment. There are several controversial opinions regarding the utilisation of char in agriculture and moreover, on the characteristics of char to be considered char. On the one hand, char application to soil could improve several physical and chemical soil characteristics, on the other hand, char may contain hazardous inorganic and organic contaminants. This study focuses on char produced by four commercial gasification systems, representative of the most common technologies in South Tyrol (Italy). These by-products have been characterized by means of heavy metals analysis, PAH analysis and phytotoxicity tests. Preliminary results showed very low germination indexes (i.e. smaller 20 %) and seedlings had necrotic brownish root tips indicating high char toxicity. Further discussion on the characteristics of these char by-products are reported in the paper.