Marine macrophytes as effective lead biosorbents

Several species of seagrass and marine macrophytes were investigated for their biosorption performance in the removal of lead from aqueous solution. The effect of pH on the equilibrium of the seagrass Cymodocea nodosa as a biosorbent also was studied. It was found that increasing pH increased lead biosorption, with a maximum uptake of approximately 140 mg/g in the range pH 3.3 to 5. Equilibrium data at different pH levels were successfully fitted to competitive equilibrium models. In addition, the seaweeds belonging to different phyla (i.e., Chlorophyta, Heterokontophyta, and Rhodophyta) were studied for the effect of their structure on equilibrium at a constant pH 5. The brown algae (Heterokontophyta) showed the highest potential for lead sorption, with a maximum uptake of 220 mg/g for C. compressa and 140 mg/g for S. lomentaria. The green algae (Chlorophyta) showed lead uptake in the range 40 to 90 mg/g, and the red algae (Rhodophyta) was least effective, with uptake in the range 10 to 40 mg/g.     

Microbially assisted phytoremediation approaches for two multi-element contaminated sites

Phytoremediation is an environmental friendly, cost-effective technology for a soft restoration of abandoned mine sites. The grasses Agrostis capillaris, Deschampsia flexuosa and Festuca rubra, and the annual herb Helianthus annuus were combined with microbial consortia in pot experiments on multi-metal polluted substrates collected at a former uranium mine near Ronneburg, Germany, and a historic copper mine in Kopparberg, Sweden, to test for phytoextraction versus phytostabilization abilities. Metal uptake into plant biomass was evaluated to identify optimal plant–microbe combinations for each substrate. Metal bioavailability was found to be plant species and element specific, and influenced by the applied bacterial consortia of 10 strains, each isolated from the same soil to which it was applied. H. annuus showed high extraction capacity for several metals on the German soil independent of inoculation. Our study could also show a significant enhancement of extraction for F. rubra and A. capillaris when combined with the bacterial consortium, although usually grasses are considered metal excluder species. On the Swedish mixed substrate, due to its toxicity, with 30 % bark compost, A. capillaris inoculated with the respective consortium was able to extract multi-metal contaminants.     

Aerosol and ozone observations during six cruise campaigns across the Mediterranean basin: temporal,spatial, and seasonal variability

The Mediterranean basin, because of its semi-enclosed configuration, is one of the areas heavily affected by air pollutants. Despite implications on both human health and radiative budget involving an increasing interest, monitoring databases measuring air pollution directly over this area are yet relatively limited. Owing to this context, concentrations of fine (PM_2.5) and coarse (PM_2.5–10) particles along with other ancillary data, such as ozone levels and meteorological parameters, were measured during six cruise campaigns covering almost the whole Mediterranean basin. Elemental composition of both PM_2.5 and PM_2.5–10 was also determined to identify specific tracers for different classes of particles that can be found in the Mediterranean atmosphere. Outcomes resulting from the integration of a preliminary qualitative examination with a more quantitative analysis, based on receptor modelling, suggested that European continental influence, Saharan dust outbreaks, wildfire events, sea spray and fossil fuel combustion were the leading causes of the aerosol-ozone variations within the Mediterranean basin. Shipping emissions, consisting in both local harbours and maritime traffic across the basin, were also tested using the marker ratio of V/Ni. Peak values observed for coarse fraction have shown to be driven by the occurrence of African dust events. Considering the major influence of Continental pollution and wildfire events, the spatial variability resulted in larger fine particle concentrations and higher ozone levels over the Eastern Mediterranean side in comparison to the Western one.     

Biochemical modifications in Pinus pinaster Ait. as a result of environmental pollution

Exposure to chemical pollution can cause significant damage to plants by imposing conditions of oxidative stress. Plants combat oxidative stress by inducing antioxidant metabolites, enzymatic scavengers of activated oxygen and heat shock proteins. The accumulation of these proteins, in particular heat shock protein 70 and heme oxygenase, is correlated with the acquisition of thermal and chemical adaptations and protection against oxidative stress. In this study, we used Pinus pinaster Ait. collected in the areas of Priolo and Aci Castello representing sites with elevated pollution and reference conditions, respectively. The presence of heavy metals and the levels of markers of oxidative stress (lipid hydroperoxide levels, thiol groups, superoxide dismutase activity and expression of heat shock protein 70, heme oxygenase and superoxide dismutase) were evaluated, and we measured in field-collected needles the response to environmental pollution. P. pinaster Ait. collected from a site characterized by industrial pollution including heavy metals had elevated stress response as indicated by significantly elevated lipid hydroperoxide levels and decreased thiol groups. In particular, we observed that following a chronic chemical exposure, P. pinaster Ait. showed significantly increased expression of heat shock protein 70, heme oxygenase and superoxide dismutase. This increased expression may have protective effects against oxidative stress and represents an adaptative cellular defence mechanism. These results suggest that evaluation of heme oxygenase, heat shock protein 70 and superoxide dismutase expression in P. pinaster Ait. could represent a useful tool for monitoring environmental contamination of a region and to better understand mechanisms involved in plant defence and stress tolerance.     

The systematic position of some boring sponges (Demospongiae,Hadromerida) studied by molecular analysis

A phylogenetic analysis of some bioeroding sponges of the family Clionaidae (Order Hadromerida) was performed to resolve some taxonomic problems both at the specific and the supraspecific level using the D2 and D3 regions of 28S rDNA. Species belonging to the genera Cliona, Cliothosa, Spheciospongia (fam. Clionaidae) and Diplastrella (fam. Spirastrellidae) from the Mediterranean Sea and Celebes Sea (Indonesia) were analysed. In the phylogenetic tree, the species clustered on two main branches, one comprising Cliona celata, C. rhodensis, C. utricularis, and Cliothosa hancocki, and the other made up of C. viridis, C. nigricans, C. schmidti, C. jullieni, Spheciospongia solida and S. vagabunda. Above the species level, data do not support the separation of the genus Cliothosa from Cliona, while they do support the inclusion of some massive boring species, previously assigned to the genus Spirastrella, in the family Clionaidae. At the species level, data demonstrated the genetic identity of taxa C. viridis and C. nigricans, in spite of their considerable morphological differences. In contrast, the yellow species commonly attributed to C. celata are probably to be considered as a complex of sibling species with a number of distinct taxa present in the Mediterranean. Data also showed the identity of the Mediterranean and Pacific populations of C. schmidti, suggesting the status of a Tethyan relict for this species.     

Effects of temperature on the acute toxicity of cadmium to Corophium Insidiosum

This study aimed to optimise the methodology for the use of Corophium insidiosum in a bioassay. Taking into account that it would be suitable to execute the bioassay with organisms having a good sensitivity during the year and low mortality in control sediment, the influence of different temperatures (10–15–20 and 25°C) has been examined. C. insidiosum was collected during August, November 2005 and January 2006, in Mar Piccolo basin (Ionian sea). The results obtained show that this species mortality in the negative control sediment, ranged from 2.6 ± 0.6% at 10°C in August to 17 ± 2.2% at 20°C in November, at different temperatures tested. At 20°C there were significant differences in mortality among different months examined. Indeed no relationship among months was found at 15°C. Significant differences between August and November at 25°C, between November and January were not found at 10°C. The 96-h LC50 values found for cadmium at all temperature experimental conditions ranged from 2.11 mg/l (1.57–2.82) to 0.70 mg/l (0.54–0.93). The highest values were found at 10°C in November and January. The results showed that the optimal temperature for the bioassay seems to be between 15°C and 20°C. Even if, at 20°C the mortality differs significantly among organisms sampled.     

Past ownership makes crayfish more aggressive

There is plenty of evidence that resource value is one of the most important non-strategic variables in animal fighting behavior. Here, we tested whether the past ownership of a shelter might modify the agonistic behavior of the crayfish Austropotamobius pallipes, eventually increasing its probability to win when it reencounters a previously met conspecific away from that resource. The agonistic behavior of familiar pairs composed of size-matched males was observed for an hour; after that, the two contestants had been kept in isolation for 2 days, either in the presence or in the absence of a shelter. Specifically, in the isolation phase, a shelter was offered to (1) both crayfish, (2) no crayfish, (3) the dominant crayfish only, and (4) the subordinate crayfish only. The following combat was conducted in the absence of any refuge. The crayfish that previously owned a shelter showed a higher aggressive motivation to fight than the individuals kept without a shelter. Particularly, in the pairs (4), subordinate crayfish were even more aggressive than dominants but were never able to invert hierarchies. Taken together, our results confirm the role played by shelters as determinants of agonism and also show, for the first time, how the behavior of crayfish and their internal state may be affected by their past ownership of a resource.     

Effect of MBT on landfill behavior: an Italian case study

Bad choices in municipal waste (MW) management cause negative effects on sustainability. Evolving regulation has identified prevention and recycling as the best strategies; nevertheless, disposal in landfilling sites plays an essential role since a complete zero-waste scenario is not realistic, currently. Nowadays, policies require a preliminary waste stabilization to decrease the putrescible content. Therefore, mechanical biological treatment (MBT) has replaced the previous crushing, aimed at simple volume reduction. Literature has proved the effectiveness of MBT when MW collection system is ineffective. The present paper considered a facility in an area with a high-performance MW collection system. A long-term (1999–2019) on-site sampling allowed the comparison between two sites of the facility: the old site (before the MBT activation) and the new area, where the stabilized waste is disposed of. Monitoring of biogas, leachate (analyzed parameters: pH, BOD₅, COD, ammonia-nitrogen) and odorous emissions was performed to verify the effect of the stabilization process. The considered long period and the on-site sampling support the relevance of the results, compared to the available literature, often referred to as laboratory scale. The results proved the relatively low benefit of stabilization at the considered facility, which cannot justify the energy consumption of MBT.

     

The changing state of contamination in the Lagoon of Venice. Part 2: heavy metals

In order to verify whether pollution is increasing or decreasing, in 25 locations uniformly distributed in the central part of the Lagoon of Venice, a transitional environment suffering from man's urban and industrial activities, the same sampling scheme was repeated three times (in 1987, 1993 and 1998) over a 12-year period during which the lagoonal environment underwent substantial changes. Superficial sediments were sampled and analysed for heavy metals and total organic carbon contents, grain size and density. In general heavy metal contents were found to be correlated, with concentrations above the background level, e.g., for Hg, a concentration factor of 24 was observed in 1987. A temporal decrease in concentrations was observed for most of the metals. Detailed analysis on a smaller spatial scale showed that contamination significantly decreases from the inner border of the lagoon seawards, as highlighted in contour maps. The role of the Porto Marghera industrial zone as a source of pollutants at the border of the Lagoon was confirmed. The decrease in contamination could not be attributed only to a decrease in the intensity of sources, but also to erosion processes, worsened by intensive harvesting of clams with hydraulic dredges.     

Arsenic and subclinical vascular damage in a sample of Italian young adults: a cross-sectional analysis

Environmental Science and Pollution Research - Exposure to arsenic (As) increases cardiovascular risk. The purpose of this study was to evaluate the relationship between As and intima-media...