Every year large quantities of floating logs are transported by rivers downstream and finish to be deposited by oncoming waves on the seashores. Driftwood is the remains of trees that have washed into the river or sea by flooding or other natural forces. In Italy the accumulation of driftwood along the shore is a significant issue, especially for the coastal municipalities of the Central and Northern regions. The purpose of this study was to evaluate the distribution and availability of the coastal driftwood in Italy and its impacts, as well as analyzing its chemical-physical properties for evaluating possible employment in combustion applications. On the basis of a data gathering campaign for the period 2010-2014, every year about 200000 tons of driftwood are reported to accumulate along the Italian shores. The two regions hardest-hit were Liguria and Veneto, with about 15000 tons and 12000 tons, respectively. Three sites (Jesolo, Sarzana and San Benedetto del Tronto) were selected for driftwood sampling. The main issue deriving from chemical characterization was the high chlorine content (up to 2% on dry basis) and metal oxides in the ashes. Driftwood samples were then subjected to a natural washing cycle for 1 month; results revealed a significant drop in chlorine and metal oxides contents (up to 80%) and a low decrease of the lower heating value (about 20%). Furthermore the percolated water was analyzed in terms of COD content, showing values (up to 1100 mg O2/L) above the Italian limits for discharges into surface waters.
Driftwood biomass in Italy: estimation and characterization
COTANA, Franco;BURATTI, Cinzia;BARBANERA, MARCO;CAVALAGLIO, GIANLUCA;FOSCHINI, DANIELE;NICOLINI, ANDREA;PISELLO, ANNA LAURA
2016
Abstract
Every year large quantities of floating logs are transported by rivers downstream and finish to be deposited by oncoming waves on the seashores. Driftwood is the remains of trees that have washed into the river or sea by flooding or other natural forces. In Italy the accumulation of driftwood along the shore is a significant issue, especially for the coastal municipalities of the Central and Northern regions. The purpose of this study was to evaluate the distribution and availability of the coastal driftwood in Italy and its impacts, as well as analyzing its chemical-physical properties for evaluating possible employment in combustion applications. On the basis of a data gathering campaign for the period 2010-2014, every year about 200000 tons of driftwood are reported to accumulate along the Italian shores. The two regions hardest-hit were Liguria and Veneto, with about 15000 tons and 12000 tons, respectively. Three sites (Jesolo, Sarzana and San Benedetto del Tronto) were selected for driftwood sampling. The main issue deriving from chemical characterization was the high chlorine content (up to 2% on dry basis) and metal oxides in the ashes. Driftwood samples were then subjected to a natural washing cycle for 1 month; results revealed a significant drop in chlorine and metal oxides contents (up to 80%) and a low decrease of the lower heating value (about 20%). Furthermore the percolated water was analyzed in terms of COD content, showing values (up to 1100 mg O2/L) above the Italian limits for discharges into surface waters.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
