UTILIZATION OF ULVA-RIGIDA BIOMASS IN THE VENICE LAGOON (ITALY) - BIOTRANSFORMATION IN COMPOST

In the Venice Lagoon (Italy), about 10(6) t (wet weight) of Ulva rigid a biomass are produced annually as one of the major results of eutroph ication. Harvests have been initiated to reduce negative impacts of th is biomass, however, due to the high costs of such effort, only 40 000 t yr(-1) are currently being collected. At the moment, biotransformat ion into compost seems to be the only feasible technology for utilisin g large quantities of Ulva biomass. We describe and discuss here a suc cessful composting strategy together with the chemico-physical and mic robiological characteristics of the resultant composts. Our composting experiments were conducted at a scale of 20 t. The composting technol ogy utilises large proportions (70-90%) of Ulva biomass and results in a valuable, high-quality end product (compost and compost-based produ cts). This process and the resulting products represents a relatively simple way of utilising the Ulva biomass produced annually in the Veni ce Lagoon.