PROJECT DESCRIPTION
BACKGROUND
The Mar Piccolo is a coastal basin extending over more than 20 km2 to the north of the city of Taranto (Puglia). It is characterised by the presence of many plant and animal species, a reason for which it has been recognised as an environmental priority area within the Habitats Directive. Its importance for the national fishing industry has also been acknowledged.
However, the basin has been affected by the intense industrialisation of the city of Taranto. As a result, in 1998, the government classified this area as of "high environmental risk", and in 2001, Taranto was included in the "National Programme for environmental remediation and restoration". The intensive industrialisation has caused severe pollution to the basin: both the marine waters and the seabed are contaminated by heavy metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). These pollutants, located mainly in the superficial layers of the sediment and as such easily spreadable, have affected not only the biodiversity of the basin but also the aquaculture activities, with significant damage to this economic sector. Due to this critical situation, the Italian government set up a steering committee in 2012 involving all relevant stakeholders to define urgent restoration measures.
OBJECTIVES
The main objective of the Life4MarPiccolo project was the ecological restoration of Mar Piccolo in Taranto, through the recovery of a contaminated portion of the seabed and seawater.
Specific project objectives were to:
- Restore approx. 3 000 square metres of the basin using a purification pilot plant, based on membrane microfiltration, to reduce contamination of PCBs, PAHs and heavy metals on the seabed and, consequently, in the water column above - reaching concentrations within the limits set by existing national and Community legislation;
- Provide the authorities in charge of the basin with tools for the sustainable management of marine areas, with the help of an intervention protocol for the environmental recovery of Italian and European coastal marine sites with pollution problems similar to those of the Mar Piccolo; and to
- Define a diagnostic kit for assessing the quality of marine waters.
RESULTS
The Life4MarPiccolo project set up a membrane-based purification pilot plant to restore a 2 100 m2 section of the Mar Piccolo coastal basin. It also installed a photovoltaic system to produce most of the energy needs of the plant. Other main outcomes of the project included the validation of a molecular diagnostic assay kit for the rapid assessment of the quality of marine waters and the drawing up of an experimental protocol for myco-remediation.
The on-shore microfiltration membrane reactor eliminated 100% of the contaminants in the re-suspended pelitic fraction in the permeate, constituted by the water and by part of the substances which were dissolved in it. However, the mobile unit of the plant at sea was able to remove only 32% of the contaminants within the seabed sediments because contaminated particles were also stratified in deeper layers of the seabed and therefore not re-suspended by the plant, which was limited to 5-10 cm. Another limiting factor was the slow pace of the recovery action that allowed surrounding contaminant particles to be displaced to areas that were just recovered, or to be displaced by sea currents during treatment. As a result, in order to increase the decontaminating efficiency, it would be necessary to increase in the future the plant's re-suspension power and its flow-rate capacity and pace of work, in line with the seabed composition specific to the treated site.
A cost-benefit analysis conducted showed that the project’s approach is less expensive than dredging, the most common technique. However, it should be noted that not all of the project’s objectives were reached. Actions to enhance socioeconomic impact, marketability and replicability were carried out at the end of the project on a reduced scale, while the protocol on recovery of European coastal marine sites dd not reach many public authorities.
Further information on the project can be found in the project's layman report (see "Read more" section).
