RESUMO
In 2019, Stromboli volcano experienced one of the most violent eruptive crises in the last hundred years. Two paroxysmal explosions interrupted the 'normal' mild explosive activity during the tourist season. Here we integrate visual and field observations, textural and chemical data of eruptive products, and numerical simulations to analyze the eruptive patterns leading to the paroxysmal explosions. Heralded by 24 days of intensified normal activity and 45 min of lava outpouring, on 3 July a paroxysm ejected ~6 × 107 kg of bombs, lapilli and ash up to 6 km high, damaging the monitoring network and falling towards SW on the inhabited areas. Intensified activity continued until the less energetic, 28 August paroxysm, which dispersed tephra mainly towards NE. We argue that all paroxysms at Stromboli share a common pre-eruptive weeks-to months-long unrest phase, marking the perturbation of the magmatic system. Our analysis points to an urgent implementation of volcanic monitoring at Stromboli to detect such long-term precursors.
RESUMO
The development and spread of mechanical biological treatment (MBT) and composting plants is often hindered by the problems and concerns arising from emission bad odors. Several technologies are now available to process exhausted air originated from these or similar plants. Exhausted air emissions contain a large amount of organic compounds, most of them in very low concentrations. This determines the advantage in using biological abatement systems (biofilters) instead of physical-chemical treatments. This article describes the operative results obtained in two Italian waste treatment plants, one in Albano, near Rome, and the other in the "ex-Maserati area" of Milan, including (i) the analysis of operational parameters as temperature, pH. humidity, loss of pressure of the biofilter affecting the biofiltration efficiency, for both chemical parameters and odorous compound concentration, measured by means of odor panel evaluation technique and (ii) the efficiency of the biofiltration system for several compounds present in air emissions, analyzing organic substances by means of gas chromatography/mass spectrometry. The two plants used similar biofiltration systems except for the material used as biofilter bed. A bioscrubber pretreatment of the air flow coming from the aerobic reactor was tested in the Albano plant for the purpose of reducing the odor concentration of the most impacting flow going to the biofilter.
