Cod end feeding by the euphausiid Meganyctiphanes norvegica

Daytime surface swarms of Meganyctiphanes norvegica in the Bay of Fundy were sampled by hand-held dip nets and by plankton nets. A comparison between the food baskets of the animals from samples obtained by the two collection methods showed that those from plankton nets contained many items whereas those from dip nets rarely contained anything. Samples from towed-nets also had significantly more animals with fuller stomachs than those obtained by dip nets at approximately the same time. It is concluded that the observed differences are due to feeding by the euphausiids in the cod end of plankton nets.     

PM<Subscript>10</Subscript> source apportionment in the surroundings of the San Vicente del Raspeig cement plant complex in southeastern Spain

Introduction  

The concentrations of trace metals, ionic species, and carbonaceous components in PM₁₀ (particulate matter with aerodynamic diameters smaller than 10 μm) were measured from samples collected near an industrial complex, primarily composed of cement plants, in southeastern Spain, from September 2005 to August 2006.     

Obtaining polycyclic aromatic hydrocarbon concentration ratios and molecular markers for residential wood combustion: Temuco, a case study

It is known that residential wood combustion (RWC) is an important source of fine particle emissions. The purpose of this work was to characterize the chemical composition of the particulate matter present in the Temuco urban atmosphere during winter, specifically the polycyclic aromatic hydrocarbon (PAH) profile, because PAHs are considered to be among the key compounds in particulate matter toxicity. During the 2008 winter monitoring campaign, samples of particulate matter with aerodynamic diameters of < or = 10 (PM10) and < or = 2.5 (PM2.5) microm were taken on days with contamination episodes. Sixteen U.S. Environmental Protection Agency (EPA) PAH compounds were extracted with toluene and determined by gas chromatography-mass spectrometry (GC-MS). The results show that phenantrene was the predominant compound associated with particulate matter at a concentration range between 300 and 600 ng m(-3), 18 times higher than the second most abundant PAH compound. High-molecular-mass compounds such as dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3,c,d]pyrene were also found, but they were minorities in the set. It was recognized from the PAH concentration ratios of the Temuco atmospheric aerosol that the main contamination source was in fact residential wood combustion; although not all the concentration ratios evaluated match the reported reference values, probably due to the kind of biomass used, the characteristics of Chilean heating appliances and climate.     

Evaluation of saline tracer performance during electrical conductivity groundwater monitoring

Saline solutions are the most commonly used hydrological tracers, because they can be easily and economically monitored by in situ instrumentation such as electrical conductivity (EC) loggers in wells or by geoelectrical measurements. Unfortunately, these low-cost techniques only provide information on the total concentration of ions in solution, i.e., they cannot resolve the ionic composition of the aqueous solution. This limitation can introduce a bias in the estimation of aquifer parameters where sorption phenomena between saline tracers and sediments become relevant. In general, only selected anions such as Cl(-) and Br(-) are recognised to be transported unretarded and they are referred to as conservative tracers or mobile anions. However, cations within the saline tracer may interact with the soil matrix through a range of processes such as ion exchange, surface complexation and via physical mass-transfer phenomena. Heterogeneous reactions with minerals or mineral surfaces may not be negligible where aquifers are composed of fine alluvial sediments. The focus of the present study was to examine and to quantify the bias between the aquifer parameters estimated during model-based interpretation of experimental data of EC measurements of saline tracer relative to the aquifer parameters found by specific measurements (i.e. via ionic chromatography, IC) of truly conservative species. To accomplish this, column displacement experiments with alluvial aquifer materials collected from the Po lowlands (Italy) were performed under water saturated conditions. The behaviour of six selected, commonly used saline tracers (i.e., LiCl, KCl, and NaCl; LiBr, KBr, and NaBr) was studied and the data analysed by inverse modelling. The results demonstrate that the use of EC as a tracer can lead to an erroneous parameterisation of the investigated porous media, if the reactions between solute and matrix are neglected. In general, errors were significant except for KCl and KBr, which is due to the weak interaction between dissolved K(+) and the sediment material. The study shows that laboratory scale pre-investigations can help with tracer selection and to optimise the concentration range targeted for in situ multilevel monitoring by unspecific geoelectrical instrumentation.     

Policy options to reduce consumer waste to zero: comparing product stewardship and extended producer responsibility for refrigerator waste.

Today, over-consumption, pollution and resource depletion threaten sustainability. Waste management policies frequently fail to reduce consumption, prevent pollution, conserve resources and foster sustainable products. However, waste policies are changing to focus on lifecycle impacts of products from the cradle to the grave by extending the responsibilities of stakeholders to post-consumer management. Product stewardship and extended producer responsibility are two policies in use, with radically different results when compared for one consumer product, refrigerators. North America has enacted product stewardship policies that fail to require producers to take physical or financial responsibility for recycling or for environmentally sound disposal, so that releases of ozone depleting substances routinely occur, which contribute to the expanding the ozone hole. Conversely, Europe's Waste Electrical and Electronic Equipment (WEEE) Directive requires extended producer responsibility, whereby producers collect and manage their own post-consumer waste products. WEEE has resulted in high recycling rates of greater than 85%, reduced emissions of ozone-depleting substances and other toxins, greener production methods, such as replacing greenhouse gas refrigerants with environmentally friendly hydrocarbons and more reuse of refrigerators in the EU in comparison with North America.     

Effect of stage-specific vital rates on population growth rates and effective population sizes in an endangered iteroparous plant

Effective population size (N(e)) determines the strength of genetic drift and can influence the level of genetic diversity a population can maintain. Assessing how changes in demographic rates associated with environmental variables and management actions affect N(e) thus can be crucial to the conservation of endangered species. Calculation of N(e) through demographic models makes it possible to use elasticity analyses to study this issue. The elasticity of N(e) to a given vital rate is the proportional change in N(e) associated with a proportional increase in that vital rate. In addition, demographic models can be used to study N(e) and population growth rate (λ) simultaneously. Simultaneous examination is important because some vital rates differ diametrically in their associations with λ and N(e). For example, in some cases increasing these vital rates increases λ and decreases N(e). We used elasticity analysis to study the effect of stage-specific survival and flowering rates on N(e), annual effective population size (N(a)), and λ in seven populations of the endangered plant Austrian dragonhead (Dracocephalum austriacum). In populations with λ ≥ 1, the elasticities of N(e) and N(a) were similar to those of λ. Survival rates of adults were associated with greater elasticities than survival rates of juveniles, flowering rates, or fecundity. In populations with λ < 1, N(e) and N(a) exhibited greater elasticities to juvenile than to adult vital rates. These patterns are similar to those observed in other species with similar life histories. We did not observe contrasting effects of any vital rate on λ and N(e); thus, management actions that increase the λ of populations of Austrian dragonhead will not increase genetic drift. Our results show that elasticity analyses of N(e) and N(a) can complement elasticity analysis of λ. Moreover, such analyses do not require more data than standard matrix models of population dynamics.     

Distribution of contaminant trace metals inadvertently provided by phosphorus fertilisers: movement,chemical fractions and mass balances in contrasting acidic soils

The frequent use of phosphorus (P) fertilisers accompanied by nitrogen and potassium sources may lead to a serious long-term environmental issue because of the presence of potentially hazardous trace metals (TM) in P fertilisers and unknown effects on the TM chemical fractions in agricultural soils. A 16-month-long column experiment was conducted to investigate the mobility and chemical forms of Cd, Cu, Cr, Ni, and Zn introduced into a Mollisol and an Andisol through surface incorporation (0–2 cm) of triple superphosphate (TSP) fertiliser. The effects of urea and potassium chloride (KCl) applications were investigated as well. After 15 cycles of 300-mm irrigation, TSP addition increased the 4 M HNO₃ extractable TM concentration in the upper (0–5 cm) section of soils. Beyond this depth, metals showed no significant mobility, with minimal leaching losses (<?1.9%, 25-cm depth). The TM chemical forms in the 0–5 cm section were significantly (p?<?0.01) affected by the soil type and fertilisers addition. Cadmium, Ni, and Zn were the elements which appeared in a larger proportion (up to 30%) in the most labile fraction (KNO₃ extractable) in fertilised soils. The impact of urea depended on the nitrification-related changes in soil pH, while fertilisation with KCl tended to increase the KNO₃ fraction of most metals probably due to K⁺ exchange reactions. Chromium remained minimally affected by the urea and KCl applications since this contaminant is strongly bound to the less labile solid phases. The low mobility of TM was governed mainly by their interaction with the solid phases rather than by their speciation at soil pH. The mass balance showed that the geochemical processes underwent in time by the P fertiliser increased the amount of TM extracted by the chemical fractionation scheme, therefore the reaction period of TSP with soil particles should be taken into account for evaluating TM availability. Long-term soil fertilisation could inadvertently contribute to an increased concentration and availability of these P fertilisers-born contaminants in the cultivated layer of acidic soils.     

Enhanced removal of mercury and lead by a novel and efficient surface-functionalized imogolite with nanoscale zero-valent iron material

Environmental Science and Pollution Research - A novel hybrid nanomaterial, nanoscale zero-valent iron (nZVI)-grafted imogolite nanotubes (Imo), was synthesized via a fast and straightforward...