Experimental laboratory activities preparatory to the remediation of contaminated marine sediments

Marine ecosystems around the world are threatened by human activities. Human activities can directly or indirectly change their biodiversity and environmental quality, endanger valuable goods and services, and ultimately endanger human health. height. Especially in coastal areas, pollution is the cause of habitat changes. The impact of such activities on all biological components and the physical and chemical conditions of the environment may vary depending on the intensity, spatial and temporal scope, and complex interactions between different pressure sources, for example. The Mediterranean Sea has changed a lot. It is one of the most severely affected marine areas in the world in history. The current impact is exacerbated by climate change. The present thesis work aims to evaluate the effect of bioremediation treatment of contaminated marine sediments from Bagnoli area on the geotechnical properties (deformability and hydraulic conductivity). In marine biology laboratory, the sediments were treated using different microorganisms (i.e., bacteria, fungi and mixed of bacteria and fungi) and monitored until 87 days. In the geotechnical laboratory, both compressibility and hydraulic conductivity were evaluated by means of one-dimensional incremental load compression tests and permeability tests respectively. Tests were carried out on the untreated sample and on treated samples after 28 days of treatment. Additionally, the capability of the samples of leaching inorganic compounds was assessed. According to the results, there is a remarkable degradation of PAHs after 87 days of bioremediation using the specified organisms; the mix of bacteria and fungi is the most efficient type of treatment, showing good degradation ability also after 28 days of treatment. The samples subjected to geotechnical tests showed no significant differences between contaminated and biotreated samples, highlighting low compressibility and a high permeability, typical of sandy soils. Zinc, Nickel and Manganese were detected in the leachate of the tested samples but the treatment by bacteria and fungi seems not to affect the mobility/bioavalilability of the metals.