Simulating the fate of indigenous antibiotic resistant bacteria in a mild slope wastewater polluted stream

The fate of indigenous surface-water and wastewater antibiotic resistant bacteria in a mild slope stream simulated through a hydraulic channel was investigated in outdoor experiments.The effect of(i) natural(dark) decay,(ii) sunlight,(iii) cloudy cover,(iv) adsorption to the sediment,(v) hydraulic conditions,(vi) discharge of urban wastewater treatment plant(UWTP)effluent and(vii) bacterial species(presumptive Escherichia coli and enterococci) was evaluated.Half-life time(T1/2) of E. coli under sunlight was in the range 6.48–27.7 min(initial bacterial concentration of 10~5 CFU/mL) depending on hydraulic and sunlight conditions. E. coli inactivation was quite similar in sunny and cloudy day experiments in the early 2 hr, despite of the light intensity gradient was in the range of 15–59 W/m~2; but subsequently the inactivation rate decreased in the cloudy day experiment(T1/2= 23.0 min) compared to sunny day(T_(1/2)= 17.4 min). The adsorption of bacterial cells to the sediment(biofilm) increased in the first hour and then was quite stable for the remaining experimental time. Finally, when the discharge of an UWTP effluent in the stream was simulated, the proportion of indigenous antibiotic resistant E. coli and enterococci was found to increase as the exposure time increased, thus showing a higher resistance to solar inactivation compared to the respective total populations.     

Identification of heavy metal origins related to chemical and morphological soil properties using several non-destructive X-ray analytical methods

Soils are complex mixtures of organic, inorganic materials, and metal compounds from anthropogenic sources. In order to identify the pollution sources, their magnitude and development, several X-ray analytical methods were applied in this study. The concentrations of 16 elements were determined in all the soil samples using energy dispersive X-ray fluorescence spectrometry. Soils of unknown origin were observed by scanning electron microscopy equipped with a Si(Li) X-ray detector using Monte Carlo simulation approach. The mineralogical analyses were carried out using X-ray diffraction spectrometry. Due to the correlations between heavy metals and oxide compounds, the samples were analyzed also by electron probe microanalyzer (EPMA) in order to have information about their oxide contents. On the other hand, soil pH and salinity levels were identified owing to their influence between heavy metal and soil-surface chemistry. Moreover, the geoaccumulation index (I _geo) enables the assessment of contamination by comparing current and pre-industrial concentrations.     

Detection and quantitative analysis of organochlorine compounds (PCBs and DDTs) in deep sea fish liver from Mediterranean Sea

Background, aim and scope  

Polychlorinated biphenyls (PCB) and dichlorodiphenyltrichloroethane (DDT) concentrations were determined in the liver of two deep sea fish species, Mediterranean slimehead and blackfin sorcerer, from the Adriatic Sea (southeastern Mediterranean Sea).     

Lignin/Poly(ε-Caprolactone) Blends with Tuneable Mechanical Properties Prepared by High Energy Ball-Milling

Polymer blends between lignin, a natural, widely available, no-cost material, and Poly(ε-caprolactone) (PCL), a biodegradable polymer, have been prepared using the ‘clean’, friendly to the environment, technique of the High Energy Ball Milling (HEBM). Two kinds of lignin have been used, Straw lignin, obtained through the Steam Explosion process (SE lignin), and/or Lignosulphonated one (LS lignin). The tensile mechanical tests have shown that, at certain specific compositions, the blends, in particular those with both SE and LS lignin, have good mechanical properties. In particular, by varying the blend composition it is possible to obtain materials with tuneable properties, therefore useful for different applications. Dynamic-Mechanical-Thermal Analysis (DMTA) reveals substantial immiscibility of the blends. Experiments of UV irradiation show that lignin acts as an UV stabilizer for PCL. The effect is higher with SE lignin, likely due to its low molecular weight, which allows the short lignin chains to diffuse more easily within the amorphous regions of PCL.     

Intrinsic vulnerability assessment of Sette Comuni Plateau aquifer (Veneto Region, Italy)

Maps illustrating the different degrees of vulnerability within a given area are integral to environmental protection and management policies. The assessment of the intrinsic vulnerability of karst areas is difficult since the type and stage of karst development and the related underground discharge behavior are difficult to determine and quantify. Geographic Information Systems techniques are applied to the evaluation of the vulnerability of an aquifer in the alpine karst area of the Sette Comuni Plateau, in the Veneto Region of northern Italy. The water resources of the studied aquifer are of particular importance to the local communities. This aquifer must therefore be protected from both inappropriate use as well as possible pollution. The SINTACS and SINTACS P(RO) K(ARST) vulnerability assessment methods have been utilized here to create the vulnerability map. SINTACS P(RO) K(ARST) is an adaptation of the parametric managerial model (SINTACS) to karst hydrostructures. The vulnerability map reveals vast zones (81% of the analyzed areas) with a high degree of vulnerability. The presence of well-developed karst structures in these highly vulnerable areas facilitate water percolation, thereby enhancing the groundwater vulnerability risk. Only 1.5 of the studied aquifer have extremely high-vulnerability levels, however these areas include all of the major springs utilized for human consumption. This vulnerability map of the Sette Comuni Plateau aquifer is an indispensable tool for both the effective management of water resources and as support to environmental planning in the Sette Comuni Plateau area.     

Assessment of Ball Milling as a Compounding Technique to Develop Nanocomposites of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) and Bacterial Cellulose Nanowhiskers

The aim of this study was the assessment of high energy ball milling technique to develop poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanocomposites containing bacterial cellulose nanowhiskers (BCNW). Crystallization behaviour of PHBV/BCNW nanocomposites was studied under non-isothermal and isothermal conditions using differential scanning calorimetry. The changes in PHBV crystalline structure were also studied using X-ray diffraction. The results confirmed that BCNW acted as nucleating agents and, hence, favored the crystallization of the PHBV. The oxygen permeability of the nanocomposites was reduced by ~22 % when compared to that of the neat PHBV. This work provides a new insight into the development of polyhydroxyalkanoate composites by means of the high energy ball milling technique.     

Trade-Offs Between Forest Protection and Wood Supply in Europe

Forest protection is one of the main measures to prevent loss of biological and landscape diversity. This study aimed to assess to what extent forests are currently protected and how felling restrictions affect the potential annual wood supply within 27 European Union member states, Norway, and Switzerland and to discuss trade-offs between intensified use of forest biomass and forest protection efforts. Protected forests covered 33 million ha (20 % of total forest area) in 2005, of which 16 million ha was protected for biodiversity and the remaining area for landscape diversity. Within the protected areas, on average 48 % of the volume cannot be harvested in forests protected for biodiversity and 40 % in forests protected for landscapes. Consequently, 73 million m³ (10 % of the annual theoretical potential supply from the total forest area) of wood cannot be felled from the protected forests in Europe. Protected forests do not necessarily affect wood supply given the current demand for wood in Europe. However, if demand for wood from European forests for material and energy use significantly increases, the impact of existing protected forest networks may become significant after all. On the other hand, wood harvesting is allowed to a fair extent in many protected areas. Hence, the question could be raised whether biodiversity and landscape diversity within designated areas are sufficiently protected. Careful planning is required to accommodate both the protection of biological and landscape diversity and demand for wood, while not forgetting all other services that forests provide.     

Polyalkylphenyl-sulphonic acids with acid groups of variable strength from animal-vegetable wastes

The insoluble organic fraction isolated from rice-hulls residues and animal fecal matter mixture is sulphonated in liquid SO3 at 200 degrees C to a water soluble sulphonate (III). III is compared to the sulphonate (IV) obtained from the same mix after composting. Both products have been found to contain mixtures of molecules with close molecular weight. These molecules consist of a central cicloaliphatic cluster with peripheral pending aromatic chains. III and IV appear to have the same sulphonation degree. However, the latter contains higher concentrations of cicloaliphatic fragments and of amide, phenol and ether bonds, but less carboxylic and amine functional groups. These differences may be reasonably traced back to the starting materials. By comparison with commercial lignosulphonates derived from the paper and pulp industry, the above arylsulphonates are likely candidates for a variety of applications in the chemical industry and in agriculture. We conclude that sulphonation, even under the drastic experimental conditions of this work, does not seem to erase the memory of the parent matter structure. This reaction is capable of upgrading recalcitrant organic matter in vegetable waste residues to an interesting variety of lignosulphonates.