Physical Properties, Photo- and Bio-degradation of Baked Foams Based on Cassava Starch, Sugarcane Bagasse Fibers and Montmorillonite

The objectives of this work were to develop biodegradable trays from cassava starch, sugarcane fibers and Na-montmorillonite (Na-MMT) using a baking process and to study the effects of these components on the physical properties, photo- and bio-degradation of the trays. The sample F20 (produced with 20 g fiber/100 g formulation) showed the maximum yield production (100 %). All formulations resulted in well-shaped trays with densities between 0.1941 and 0.2966 g/cm³. The addition of fibers and Na-MMT resulted in less dense and less rigid trays compared to control samples (only starch). The studied processing conditions resulted in good nanoclay dispersion, leading to the formation of an exfoliated structure. The evaluation of the photo-degradation stability of the trays under UV exposure for 336 h showed that a sample produced with a specific combination of fiber and nanoclay (20 g fiber and 5 g nanoclay/100 g formulation) had the highest loss in stress at break (91 %). Biodegradation assays showed that Control trays (starch) and F20 (20 g fiber/100 g formulation) lost a greater percentage of their weight after 90 days of incubation in soil, with losses of up to 85.50 and 82.70 %, respectively.     

A Critique of Estimating Future Costs Using Most Likely Value

ASTM E2137 (Standard Guide for Estimating Monetary Costs and Liability for Environmental Matters, or E2137) is the guidance for developing estimates of future environmental costs. E2137 provides a hierarchy of cost estimation approaches, and expresses an explicit preference for the use of probabilistic cost analysis to develop expected values for environmental costs. Dr. Ram and his colleagues have published an article (Remediation Journal, Autumn 2013) which rejects the use of EV analysis, arguing that while “good in principle” it has little practical value because it is nearly impossible to develop supportable probabilities. The E2137 principles and processes have been used for more than a decade in the context of addressing future environmental costs, yet their view of E2137 renders the standard meaningless. We conclude that the deficiency is not in the ASTM standard, and that when properly constructed, probabilistic analyses can be used to develop expected values with supportable probabilities. ©2015 Wiley Periodicals, Inc.     

Suitability analysis for siting MSW landfills and its multicriteria spatial decision support system: Method,implementation and case study

Multicriteria spatial decision support systems (MC-SDSS) have emerged as an integration of geographical information systems (GIS) and multiple criteria decision analysis (MCDA) methods for incorporating conflicting objectives and decision makers’ (DMs’) preferences into spatial decision models. This article presents a raster-based MC-SDSS that combines the analytic hierarchy process (AHP) and compromise programming methods, such as TOPSIS (technique for order preference by similarity to the ideal solution) and Ideal Point Methods. To the best of our knowledge it is the first time that a synergy of AHP and compromise programming methods is implemented in raster-driven GIS-based landfill suitability analysis. This procedure is supported by a spatial decision support system (SDSS) that was developed within a widely used commercial GIS software package. A real case study in the Thrace region in northeast Greece serves as a guide on how to conduct a suitability analysis for a MSW landfill site with the proposed MC-SDSS. Moreover, the procedure for identifying MSW disposal sites is accomplished by performing four computational models for synthesizing the DMs per criterion preferential system. Based on the case study results, a comparison analysis is performed according to suitability index estimations. According to them Euclidean distance metric and TOPSIS present strong similarities. When compared with Euclidean distance metric, TOPSIS seems to generate results closer to that derived by Manhattan distance metric. The comparison of Chebychev distance metric with all the other approaches revealed the greatest deviations.     

The possible origin of Zostera noltii in the Canary Islands and guidelines for restoration

Seagrasses and their habitat are declining worldwide. Zostera noltii in the Canary Islands has been drastically reduced, mainly by anthropogenic disturbance, to three small surviving patches in a single harbor in Lanzarote. A previous genetic study, using neutral microsatellite markers, revealed that these patches consist of a single clonal individual. Here, an assignment test, using microsatellite data, was used to locate the most likely population of origin from a set of possible donor populations. Our results show that the Moulay Bousselham population in northern Morocco is assigned as the most likely population of origin (88%), although the probability of being at one generation time distance is low (2.7%). This result, however, allows locating the most closely related stands that may be the most successful donor populations for future restoration based on shoot or seed transplantation.     

Background metal levels determination in bivalves – quality assessment of the European Water Framework Directive

Background levels of metals (Ag, Cd, Cu, Cr, Hg, Ni, Pb and Zn) in biomonitors (Mytilus galloprovincialis mussels and Crassostrea gigas oysters), in estuarine waters within the Basque Country (south-east Bay of Biscay) are estimated using non-parametric statistical tools and data are presented graphically, with the aim of being used in assessing the ecological status, within the European Water Framework Directive (WFD). The basis for this study was the statistical analysis of data compiled from monitoring programmes undertaken along the Basque coast, between 1990 and 2008. For this analysis, a heuristic method was adapted and used. Results showed different metal background ranges throughout the year for both mussels and oysters. Values corresponding to the upper limit of the background range (i.e. value of the upper whisker of the box-plot) are proposed as the ‘high/good’ status boundary, according to the WFD.     

Extrinsic and intrinsic controls of zooplankton diversity in lakes

Pelagic crustacean zooplankton were collected from 336 Norwegian lakes covering a wide range of latitude, altitude, lake area, mean depth, production (as chlorophyll a), and fish community structure. Mean zooplankton species richness during the ice-free season was generally low at high latitudes and altitudes. Further, lower species richness was recorded in western lakes, possibly reflecting constraints on migration and dispersal. However, despite obvious spatial limitations, geographic boundaries were only weak predictors of mean zooplankton richness. Similarly, lake surface area did not contribute positively to mean richness such as seen in other ecosystem surveys. Rather, intrinsic factors such as primary production and fish community (planktivore) structure were identified by regression analysis as the major predictors of zooplankton diversity, while a positive correlation was observed between species richness and total zooplankton biomass. However, in spite of a large number of variables included in this study, the predictive power of multiple regression models was modest (<50% variance explained), pointing to a major role for within-lake properties, as yet unidentified intrinsic forces, stochasticity, or dispersal as constraints on zooplankton diversity in these lakes.     

Feedbacks between bivalve density, flow, and suspended sediment concentration on patch stable states

We explore the role of biophysical feedbacks occurring at the patch scale (spatial scale of tens of meters) that influence bivalve physiological condition and affect patch stability by developing a numerical model for the pinnid bivalve, Atrina zelandica, in cohesive sediments. Simulated feedbacks involve bivalve density, flow conditions (assumed to be primarily influenced by local water depth and peak current speed), suspended sediment concentration (evaluated through a balance between background concentration, deposition, and erosion), and changes in the physiology of Atrina derived from empirical study. The model demonstrates that high bivalve density can lead to skimming flow and to a concomitant decrease in resuspension that will affect suspended sediment concentration over the patch directly feeding back on bivalve physiology. Consequently, for a given flow and background suspended sediment load, the stability of a patch directly depends on the size and density of bivalves in the patch. Although under a range of conditions patch stability is ensured independently of bivalve density, simulations clearly indicate that sudden changes in bivalve density or suspended sediment concentration can substantially affect patch structure and lead to different stable states. The model highlights the role of interactions between organisms, flow, and broader scale environmental conditions in providing a mechanistic explanation for the patchy occurrence of benthic suspension feeders.