Microplastics in water surface and in the gastrointestinal tract of target marine organisms in Salento coastal seas (Italy, Southern Puglia).

Microplastic pollution is a major global environmental threat that has attracted increasing interest from the scientific community over the past decade. The semi-closed and highly urbanized Mediterranean Sea has been investigated since 2012, in several specific studies that have identified it as a target hotspot for microplastic contamination. The marine coastal zone of the Salento peninsula (Apulia, Italy) has peculiar geographical and hydrodynamic features, although there are few published data detailing the level of microplastics present in this area. The present manuscript contains both data on the concentration of microplastics in surface waters and the level of microplastics ingested by selected marine organisms in the Salento coastal zone. Microplastics floating on the water surface were monitored during Autumn 2020 and Spring 2021 using neuston Manta net at three different distances from the coasts (Lizzano, Gallipoli and Otranto). The level of microplastic ingestion was monitored in fish species (Sardina pilchardus, Boops boops, Mullus barbatus) and in mussels (Mytilus galloprovincialis). Episodic peaks of microplastic concentrations were found on the sea surface during transects performed in the 3 nautic miles from the seashore. High values of ingested microplastics were found in S. pilchardus. and B. boops (5.4 and 4.6 items/individual respectively). A higher concentration of microplastics was detected in the Adriatic Sea than in the Ionian Sea by comparing the gastrointestinal tract of S. pilchardus and B. boops, in the monitored areas. These results are correlated with the concentration of floating microplastics, although this last result is not validated by statistical analysis. These results support the effectiveness of S. pilchardus and B. boops used as targets in monitoring activity for these pollutants. Results show a worrying increase in the concentration of microplastics on the sea surface and in the gastrointestinal tract of the target species compared to data reported in the literature.

Biochar effect on crop performance and Pb and Zn uptake of tomato (Solanum lycopersicum, L.) plants grown on heavy metals contaminated Kosovo soils.

A greenhouse pot experiment was conducted to evaluate the effect of biochar on the growth and uptake of Pb and Zn by tomato plants (Solanum lycopersicum, L.) cultivated in two highly contaminated Kosovo soils, A and B. Plants were cultivated in the biochar amended and unamended soils. As expected, the biochar addition to the two polluted soils has contributed to significantly improve the crop yields, in terms of both fresh and dry weight. Further, results indicated that the effect of biochar on metal mobility is closely related, besides its properties, to soil's native characteristics. In fact, the addition of biochar to soil B had also beneficial effects on the uptake of both metals, halving in some cases the values of the biological accumulation and transfer coefficients, while it did not show the same efficacy on soil A.

Assessment of addition of biochar to filtering mixtures for potential water pollutant removal.

Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ultimately end up in sewage sludge that is spread on agricultural soils. The most common substrates used in green roofs have limited capacity for filtration and sorption. Also, more sustainable alternatives are sought, due to the high carbon footprint of these materials. Biochar is a carbon-rich material produced by pyrolysis of biomass, and several types of biochar have been described as good sorbents and filter materials. Biochar is also a light and carbon negative material, which may fulfill other desired criteria for new green roof substrates. We here report on an experiment where two types of biochar, produced from olive husks at 450 °C or from forest waste at 850 ° C were mixed with volcanic rock or peat, and tested for retention capacity of phenanthrene and six heavy metals in a column experiment with unsaturated gravimetric water flow lasting for 3 weeks. The results suggest that biochar as a component in green roof substrates perform better than traditional materials, concerning retention of the tested pollutants, and that different types of biochar have different properties in this respect.