Seasonal fluctuations of DDTs and PCBs in zooplankton and fish of Lake Maggiore (Northern Italy)

Concentrations of DDTs and PCBs were determined in the zooplankton and in three different fish species (shad, whitefish and roach) collected seasonally during 2009 and 2010 in three sites in Lake Maggiore, a south-alpine lake that has been contaminated by DDT since 1996. As previously observed in 2008, even during 2009 DDTs concentrations were higher in zooplankton than in fish, probably due to the very unstable situation of the lake still influenced by local inputs. The situation changed in 2010, when all DDT compounds increased in fish to levels much higher than those measured in zooplankton. Biomagnification was statistically demonstrated for pp′DDE in all the three fish species, indicating a probable signal of recovery of the lake.Although with respect to total PCBs we observed that the contamination levels varied across time periods and across fish species, biomagnification was evident from zooplankton to fish both in 2009 and in 2010. As concern individual PCBs, biomagnification from zooplankton to all three fish species was significant for PCB 153 and PCB 138.     

What stops the ‘diploid male vortex’?—A simulation study for species with single locus complementary sex determination

The survival of hymenopteran populations especially that of ecologically and economically important pollinators and parasitoids, has become a major topic for empirical and theoretical studies. Complementary sex determination (CSD) in Hymenoptera may impose a substantial genetic load through the production of inviable or sterile diploid males. Modelling and laboratory studies have indicated that this genetic load may trigger a ‘diploid male vortex’ leading to rapid extinction of populations.Here we take a broader theoretical approach to analyze why populations exhibiting CSD persist in nature, even if they contain large proportions of homozygous diploid individuals. Using an individual-based model of spatially structured hymenopteran populations, we show that (i) inviability or reduced fertility of homozygous individuals, (ii) female-biased sex ratio, and (iii) strong intra-specific competition can mitigate the negative influence of CSD on population persistence and that (iv) already extremely low dispersal rates will result in long term survival. These findings underline the importance of life history traits for population survival and demonstrate that rather specific conditions must be met to initiate the ‘diploid male vortex’.     

Sugarcane vinasse: Environmental implications of its use

The inadequate and indiscriminate disposal of sugarcane vinasse in soils and water bodies has received much attention since decades ago, due to environmental problems associated to this practice. Vinasse is the final by-product of the biomass distillation, mainly for the production of ethanol, from sugar crops (beet and sugarcane), starch crops (corn, wheat, rice, and cassava), or cellulosic material (harvesting crop residues, sugarcane bagasse, and wood). Because of the large quantities of vinasse produced, alternative treatments and uses have been developed, such as recycling of vinasse in fermentation, fertirrigation, concentration by evaporation, and yeast and energy production. This review was aimed at examining the available data on the subject as a contribution to update the information on sugarcane vinasse, from its characteristics and chemical composition to alternatives uses in Brazil: fertirrigation, concentration by evaporation, energy production; the effects on soil physical, chemical and biological properties; its influence on seed germination, its use as biostimulant and environmental contaminant. The low pH, electric conductivity, and chemical elements present in sugarcane vinasse may cause changes in the chemical and physical–chemical properties of soils, rivers, and lakes with frequent discharges over a long period of time, and also have adverse effects on agricultural soils and biota in general. Thus, new studies and green methods need to be developed aiming at sugarcane vinasse recycling and disposal.     

Furniture wood wastes: Experimental property characterisation and burning tests

Referring to the industrial wood waste category (as dominant in the provincial district of Pesaro-Urbino, Marche Region, Italy), this paper deals with the experimental characterisation and the carrying out of non-controlled burning tests (at lab- and pilot-scale) for selected “raw” and primarily “engineered” (“composite”) wood wastes.The property characterisation has primarily revealed the following aspects: potential influence on moisture content of local weather conditions at outdoor wood waste storage sites; generally, higher ash contents in “engineered” wood wastes as compared with “raw” wood wastes; and relatively high energy content values of “engineered” wood wastes (ranging on the whole from 3675 to 5105 kcal kg⁻¹ for HHV, and from 3304 to 4634 kcal kg⁻¹ for LHV).The smoke qualitative analysis of non-controlled lab-scale burning tests has primarily revealed: the presence of specific organic compounds indicative of incomplete wood combustion; the presence exclusively in “engineered” wood burning tests of pyrroles and amines, as well as the additional presence (as compared with “raw” wood burning) of further phenolic and containing nitrogen compounds; and the potential environmental impact of incomplete industrial wood burning on the photochemical smog phenomenon.Finally, non-controlled pilot-scale burning tests have primarily given the following findings: emission presence of carbon monoxide indicative of incomplete wood combustion; higher nitrogen oxide emission values detected in “engineered” wood burning tests as compared with “raw” wood burning test; and considerable generation of the respirable PM₁ fraction during incomplete industrial wood burning.     

Application of membrane bioreactor technology for wastewater treatment and reuse in the Mediterranean region: Focusing on removal efficiency of non-conventional pollutants

The Mediterranean Region is a semi-arid area whose land is facing serious erosion, causing adverse impacts on agriculture. To improve the water availability, researchers have proposed the reclamation and reuse of treated wastewater. In this paper, we report the main findings of 10 years of research on the efficiencies of a conventional activated sludge process and a submerged membrane bioreactor, with particular emphasis on the removal of non-conventional pollutants. The studies showed that the membrane bioreactor produced a virtually solids-free, high-quality permeate: most nutrients, heavy metals, and persistent organic pollutants were removed, and in particular, dioxins, furans, and polychlorinated biphenyls were typically present at concentrations below the detection limit. Moreover, the total coliforms count decreased by 4–5 log and Escherichia coli was absent from the membrane bioreactor permeate. These results, combined with the continuing reduction of the capital and operating costs for this approach, suggest that membrane bioreactors are an increasingly cost-effective technology to produce treated effluents that are suitable for reuse.     

Bioaccumulation and effects of perfluorinated compounds (PFCs) in zebra mussels (Dreissena polymorpha)

Perfluorinated chemicals (PFCs) have been used for many years in numerous industrial products and are known to accumulate in organisms. A recent survey showed that tissue levels of PFCs in aquatic organisms varied among compounds and species being undetected in freshwater zebra mussels Dreissena polymorpha. Here we studied the bioaccumulation kinetics and effects of two major PFCs, perfluorooctane sulfonic acid compound (PFOS) and perfluorooctanoic acid (PFOA), in multixenobiotic transporter activity (MXR) and filtration and oxygen consumption rates in zebra mussel exposed to a range of concentrations of a PCF mixture (1–1,000 μg/L) during 10 days. Results indicate a low potential of the studied PFCs to bioaccumulate in zebra mussel tissues. PFCs altered mussel MXR transporter activity being inhibited at day 1 but not at day 10. Bioaccumulation kinetics of PFCs were inversely related with MXR transporter activity above 9 ng/g wet weight and unrelated at tissue concentration lower than 2 ng/g wet weight suggesting that at high tissue concentrations, these type of compounds may be effluxed out by MXR transporters and as a result have a low potential to be bioaccumulated in zebra mussels. Oxygen consumption rates but not filtering rates were increased in all exposure levels and periods indicating that at environmental relevant concentrations of 1 μg/L, the studied PFCs enhanced oxidative metabolism of mussels. Overall, the results obtained in this study confirm previous findings in the field indicating that an important fraction of PFC accumulated in mussel tissues is eliminated actively by MXR transporters or other processes that are metabolically costly.     

Comparative study based on sediment characteristics and macrobenthic communities in two Italian lagoons

The aims of this study were to analyse sediment characteristics and macrobenthic assemblages in two very close Italian coastal lagoons (Lesina and Varano) and to assess the different behaviour between the two basins and the relationship between sediment matrix and benthic organisms within and between the two lagoons. The comparative study was performed in July 2007 at 13 sampling sites in Lesina lagoon and 15 sites in Varano basin for sediment grain size, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP) and macrobenthic structure analyses. Both lagoons were generally dominated by fine-grained sediments (clay and silt components). The average contents of TOC and TN measured in Lesina was higher than in Varano (3.31% vs 2.52% for TOC and 5,200 μg·g^???1 vs 3,713 μg·g^???1 for TN); in contrast, the TP was lower (540 μg·g^???1 vs 620 μg·g^???1). Based on macrobenthic community patterns, the central zone in Varano lagoon and the eastern area in Lesina lagoon were characterised by the lowest abundance (168.7 ind·m^???2 and 503.2 ind·m^???2, respectively) and by the lowest number of species, as highlighted by the diversity indices (Shannon–Wiener, H ^′ range was 0.47–1.45 for Lesina and 0.00–1.68 for Varano; Margalef species richness, d range was 0.00–1.67 for Lesina lagoon and 0.00–2.38 for Varano basin). Ordination diagrams suggested an influence of marine and freshwater inputs on the sediment distribution in Varano lagoon and on macrobenthic assemblages in Lesina lagoon.