The importance of achieving a high customer satisfaction with recycling services in communities

Some studies show that there are external, infrastructural, and economic factors that enable individuals and communities to act ecologically. A variable associated with sustainable behavior is the level of satisfaction with infrastructural and economic factors, which in turn relates to recycling behavior. The main aim of this study was to assess the reliability and validity of the customer satisfaction with recycling scale and to analyze its relationship with sociodemographic variables (age and gender), house location (in the center or the suburbs, population size of), and psychological variables (self-reported individual recycling behaviors, general satisfaction with recycling service companies, and the perception of costs and the quality of service). A total of 1498 individuals responded to the in-home questionnaire related to these variables. Exploratory and confirmatory factorial analyses confirm a good fit for a four-dimensional model: assurance, tangibles, empathy, and communication. Results show that those individuals who live in town centers tend to self-report higher levels of satisfaction with tangibles than those living in the suburbs. Population sizes correlate significantly and negatively with the four dimensions of service satisfaction, while age seems to relate significantly and negatively to all the studied variables. Finally, we discuss the implications regarding the importance of customer satisfaction in facilitating the environmentally responsible behavior.     

Ecotoxicity and fungal deterioration of recycled polypropylene/wood composites: Effect of wood content and coupling

Recycled polypropylene (rPP) was recovered from an industrial shredder and composites were prepared with a relatively wide range of wood content and with two coupling agents, a maleated PP (MAPP) and a maleated ethylene-propylene-diene elastomer (MAEPDM). The mechanical properties of the composites showed that the coupling agents change structure only slightly, but interfacial adhesion quite drastically. The durability of the materials was determined by exposing them to a range of fungi and, ecotoxicity was studied on the aquatic organism Vibrio fischeri. The composites generally exhibit low acute toxicity, with values below the levels considered to have direct ecotoxic effect on aquatic ecosystems (<2 toxic units). Their toxicity to V. fischeri depended on the presence of the coupling agents with larger E₅₀ values in 24-h aqueous extracts from composites containing MAPP or MAEPDM in comparison to composites without any coupling agent. Evaluation of resistance against fungal colonization and deterioration proved that wood facilitates fungal colonization. Fungi caused slight mass loss (below 3%) but it was not correlated with substantial deterioration in material properties. MAPP seems to be beneficial in the retention of mechanical properties during fungal attack. rPP/wood composites can be considered non-ecotoxic and quite durable, but the influence of wood content on resistance to fungal attack must be taken into account for materials intended for applications requiring long-term outdoor exposure.     

Quantitative modelling to estimate the transfer of pharmaceuticals through the food production system

Use of pharmaceuticals in animal production may cause an indirect route of contamination of food products of animal origin. This study aimed to assess, through mathematical modelling, the transfer of pharmaceuticals from contaminated soil, through plant uptake, into the dairy food production chain. The scenarios, model parameters, and values refer to contaminants in emission slurry production, storage time, immission into soil, plant uptake, bioaccumulation in the animal's body, and transfer to meat and milk. Modelling results confirm the possibility of contamination of dairy cow's meat and milk due the ingestion of contaminated feed by the cattle. The estimated concentration of pharmaceutical residues obtained for meat ranged from 0 to 6 ng kg^?1 for oxytetracycline, from 0.011 to 0.181 μg kg^?1 for sulfamethoxazole, and from 4.70 to 11.86 μg kg^?1 for ketoconazole. The estimated concentrations for milk were: zero for oxytetracycline, lower than 40 ng L^?1 for sulfamethoxazole, and from 0.98 to 2.48 μg L^?1 for ketoconazole. Results obtained for the three selected pharmaceuticals indicate a minor risk for human health. This study showed that supply chain modelling could be an effective tool in assessing the indirect contamination of feedstuff and animal products by residues of pharmaceuticals. The model can easily be adjusted to other contaminants and supply chain and, in this way, present a valuable tool to underpin decision making.     

Metal toxicity in a sediment-dwelling polychaete: Threshold body concentrations or overwhelming accumulation rates?

We followed the net accumulation of As, Cu and Zn in the deposit-feeding polychaete Arenicola marina exposed in the laboratory to natural metal-contaminated sediments, one exposure leading to mass mortality between day 10 and 20, and the other not causing lethality over a period of 60 days of exposure. The worms showed lower total accumulated metal concentrations just before mortality occurred (<20 days) at the lethal exposure, than after 30 days of exposure to sediments not causing mortality. Moreover rates of accumulation of As, Cu and Zn were significantly higher in the lethal exposure than in the sublethal exposure. Our results show that it is not possible to link mortality to a critical total body concentration, and we add to a growing body of literature indicating that metal toxicity occurs when organisms cannot cope with overwhelming influx and subsequent accumulation rates.     

Supervised neural computing solutions for fluorescence identification of benzimidazole fungicides. Data and decision fusion strategies

Benzimidazole fungicides (BFs) are a type of pesticide of high environmental interest characterized by a heavy fluorescence spectral overlap which complicates its detection in mixtures. In this paper, we present a computational study based on supervised neural networks for a multi-label classification problem. Specifically, backpropagation networks (BPNs) with data fusion and ensemble schemes are used for the simultaneous resolution of difficult multi-fungicide mixtures. We designed, optimized and compared simple BPNs, BPNs with data fusion and BPNs ensembles. The information environment used is made up of synchronous and conventional BF fluorescence spectra. The mixture spectra are not used in the training nor the validation stage. This study allows us to determine the convenience of fusioning the labels of carbendazim and benomyl for the identification of BFs in complex multi-fungicide mixtures.     

On the tolerance of charophytes to high-nitrate concentrations

Currently a debate exists about whether the reduced growth of macrophytes with increased nitrogen loading in shallow ecosystems is determined by ecological or physiological factors. To discover whether nitrate in the water is detrimental per se to charophytes, we subjected Chara hispida and Chara vulgaris specimens, collected from two habitats greatly differing in nitrate concentrations (1.5 and 10?mg NO₃-N/L, annual means), to a wide nitrate range (0.5–50?mg NO₃-N/L) in two experiments (with free-floating specimens using nitrate as the sole N source, and with planted specimens, with other N sources in sediment). Charophytes grew both unplanted and planted in all treatments, and growth reductions occurred at the highest concentration in all cases. Some charophyte responses when faced with nitrate increases were different depending on (i) the species and (ii) population origin. Under the most realistic situation, the growth of both planted C. vulgaris populations was higher than that of C. hispida populations. C. vulgaris specimens from the nitrate-rich waterbody adapted best to the highest nitrate concentrations when they grew floating. Despite charophytes being vital and growing under high-nitrate concentrations in short-term laboratory experiments, such a situation in the environment may eventually not be sustainable, since ecological factors act in the field.     

Removal of organochlorine pesticides from lindane production wastes by electrochemical oxidation

This study is focused on the effective removal of recalcitrant pollutants hexaclorocyclohexanes (HCHs, isomers α, β, γ, and δ) and chlorobenzenes (CBs) present in a real groundwater coming from a landfill of an old lindane factory. Groundwater is characterized by a total organic carbon (TOC) content of 9 mg L^?1, pH₀?=?7, conductivity?=?3.7 mS cm^?1, high salt concentration (SO₄^2?, HCO₃^?, Cl^?), and ferrous iron in solution. The experiments were performed using a BDD anode and a carbon felt (CF) cathode at the natural groundwater pH and without addition of supporting electrolyte. The complete depletion of the four HCH isomers and a mineralization degree of 90% were reached at 4-h electrolysis with a current intensity of 400 mA, the residual TOC (0.8 mg L^?1) corresponding mainly to formic acid. A parallel series reaction pathway was proposed: HCHs and CBs are transformed into chlorinated and hydroxylated intermediates that are rapidly oxidized to non-toxic carboxylic acids and/or mineralized, leading to a rapid decrease in solution pH.     

Bankfull Regional Curves for the Inner and Outer Bluegrass Regions of Kentucky1

Brockman, Ruth R., Carmen T. Agouridis, Stephen R. Workman, Lindell E. Ormsbee, and Alex W. Fogle, 2012. Bankfull Regional Curves for the Inner and Outer Bluegrass Regions of Kentucky. Journal of the American Water Resources Association (JAWRA) 48(2): 391‐406. DOI: 10.1111/j.1752‐1688.2011.00621.x Abstract: Bankfull regional curves that relate channel dimensions and discharge to watershed drainage area are useful tools for assisting in the correct identification of bankfull elevation and in stream restoration and reconstruction. This study assessed 28 stable streams located in two physiographic regions of Kentucky: the Inner Bluegrass and the Outer Bluegrass. Bankfull channel dimensions, discharge, and return period as well as average channel slope, median bed material size, sinuosity, Rosgen stream classification, and percent impervious area were determined. Significant relationships were found between drainage area and the bankfull characteristics of cross‐sectional area, width, mean depth, and discharge for both the Inner Bluegrass and Outer Bluegrass regions (α = 0.05). It was also found that the percent impervious area in a watershed had minimal effect on bankfull dimensions, which is attributed to the well‐vegetated nature of the streambanks, cohesive streambank materials, and bedrock control. No significant differences between any of the Inner Bluegrass and Outer Bluegrass regional curves were found (α = 0.05). Comparisons were made between the Inner Bluegrass and Outer Bluegrass curves and others developed in karst‐influenced areas in the Eastern United States. Although few significant differences were found between the regional curves for bankfull discharge and width, a number of the curves differed with regards to bankfull cross‐sectional area and mean depth.     

Real-world vehicle emissions as measured by in situ analysis of exhaust plumes

Environmental Science and Pollution Research - We conducted a 60-day roadside measurement campaign on a busy street in Münster, Germany, during summer 2016. We used gas and particle...     

Identifying key species in ecosystems with stochastic sensitivity analysis

The development of approaches to estimate the vulnerability of biological communities and ecosystems to extirpations and reductions of species is a central challenge of conservation biology. One key aim of this challenge is to develop quantitative approaches to estimate and rank interaction strengths and keystoneness of species and functional groups, i.e. to quantify the relative importance of species. Network analysis can be a powerful tool for this because certain structural aspects of ecological networks are good indicators of the mechanisms that maintain co-evolved, biotic interactions. A static view of ecological networks would lead us to focus research on highly-central species in food webs (topological key players in ecosystems). There are a variety of centrality indices, developed for several types of ecological networks (e.g. for weighted and un-weighted webs). However, truly understanding extinction and its community-wide effects requires the use of dynamic models. Deterministic dynamic models are feasible when population sizes are sufficiently large to minimize noise in the overall system. In models with small population sizes, stochasticity can be modelled explicitly. We present a stochastic simulation-based ecosystem model for identification of “dynamic key species” in situations where stochastic models are appropriate. To demonstrate this approach, we simulated ecosystem dynamics and performed sensitivity analysis using data from the Prince William Sound, Alaska ecosystem model. We then compare these results to those of purely topological analyses and deterministic dynamic (Ecosim) studies. We present the relationships between various topological and dynamic indices and discuss their biological relevance. The trophic group with the largest effect on others is nearshore demersals, the species mostly sensitive to others is halibut, and the group of both considerable effect on and sensitivity to others is juvenile herring. The most important trophic groups in our dynamical simulations appear to have intermediate trophic levels.