Production and energy transformation of herbaceous biomasses irrigated with treated wastewater – first results

The first results on experiments with the goal of an agronomical, environmental, energetic and economical evaluation about the biomass production from herbaceous species irrigated with treated wastewater are reported in this paper. The experiments were conducted in collaboration with four Italian universities (within a National Research Project, PRIN 2007): Padova, Bologna, Reggio Calabria and Catania. Six main herbaceous species were tested by each university in their own experimental fields. In particular, each university planted four species common to all units, one in the biggest plot and the others in three smaller plots. Physical, chemical and microbiological analyses were carried out on wastewater samples. In particular, the following parameters were evaluated: pH, electric conductivity, TSS, BOD5, COD, total phosphorus, ammonia, nitrite, nitrate and total nitrogen. From an agronomic point of view, the growth dynamics, the translocations of assimilates between aerial and subterranean organs, and the different species productivity were analysed. On the top part of the plants, the average height, the biomass production, the moisture content at the harvesting and the heating values were measured.