Improvement of Impact Toughness of Biodegradable Poly(butylene succinate) by Melt Blending with Sustainable Biobased Glycerol Elastomers

Poly(butylene succinate) (PBS) was melt blended with glycerol based polyesters (PGS) synthesized from pure and technical glycerol aiming to improve the impact strength of PBS. It was found that after addition of 30 wt% PGS to PBS its impact strength was significantly increased by 344% (from 31.9 to 110 J/m) and its elongation at break was maintained at 220%. Infrared spectra of the blends showed the presence of hydroxyl groups from the PGS phase suggesting that hydrogen bonding between the phases could be responsible for a good stress transfer and an efficient toughening in the PBS/PGS blends. Scanning electron microscopy imaging showed a good dispersion of PGS phase into PBS with a PGS particle size of 10 μm and less and no agglomeration. Addition of PGS to PBS was shown to be an effective strategy for improvement of PBS impact resistance without serious detrimental effects on its thermal and rheological properties.     

Carbon and nitrogen mineralization in Vertisol as mediated by type and placement method of residue

Selection of appropriate residue application method is essential for better use of biomass for soil and environmental health improvement. A laboratory incubation experiment was conducted for 75 days to investigate C and N mineralization of residues of soybean (Glycine max L.), chickpea (Cicer arietinum L.), maize (Zea mays L.), and wheat (Triticum aestivum L.) placed on the soil surface and incorporated into the soil. The residue of soybean and chickpea had a greater decomposition rate than that of maize and wheat, despite of their placements. Higher rate of decomposition of the residue of soybean and chickpea was recorded when it was kept on the soil surface while soil incorporation of residue of wheat and maize resulted in faster decomposition. Therefore, these findings could be used as guidelines for management of crop residue application in farmland to improve soil and environmental quality.     

Contamination of soil and the medicinal plant <Emphasis Type="Italic">Phyllanthus niruri</Emphasis> Linn. with cadmium in ceramic industrial areas

Phyllanthus niruri is a plant that is used to prevent calcium oxalate crystallisation and to block the stone formation in urolithiasis. Contaminants in the environment can be readily taken up by medicinal plants due to their ability to absorb chemicals into their tissues. If contaminated plants are ingested, they have the potential to negatively affect human and environmental health. The aim of this study was to assess contamination in the soil and the medicinal plant P. niruri by cadmium (Cd) in ceramic industrial areas of Monte Carmelo, Brazil. Soil samples and plant samples (divided in root, shoot and leaves) were collected from a contaminated monitoring site and from a rural area (which was used as a reference site for comparative purposes). The Cd concentrations of the samples were analysed with an atomic absorption spectrometer. P. niruri was found to be sensitive to soil contamination by Cd that was attributed to ceramic industrial emissions. The results revealed that Cd bioaccumulation in the roots and shoots of P. niruri was associated with a significant increase (p?<?0.05) in the concentration of active lignan compounds (phyllanthin and hypophyllanthin) in the leaves. The identification of high concentrations of Cd and active lignan compounds suggests a risk of contamination of the site and the risk of a high dose of Cd to people exposed at the site.     

Greenlandic water and sanitation systems—identifying system constellation and challenges

A good water supply and wastewater management is essential for a local sustainable community development. This is emphasized in the new global goals of the UN Sustainable Development, where the sixth objective is to: “Ensure availability and sustainable management of water and sanitation for all” (United Nations 2015). This obviously raises the question of how this can be achieved considering the very different conditions and cultures around the globe. This article presents the Greenlandic context and elucidates the current Greenland water supply system and wastewater management system from a socio-technical approach, focusing on the geographic, climatic and cultural challenges. The article identifies a diverse set of system constellations in different parts of Greenland and concludes with a discussion of health and quality of life implications.     

Violence in environmental conflicts: the need for a multidimensional approach

Although studies on environmental conflicts have engaged with the subject of violence, a multidimensional approach has been lacking. Using data from 95 environmental conflicts in Central America, we show how different forms of violence appear and overlap. We focus on direct, structural, cultural, slow, and ecological forms of violence. Results suggest that the common understanding of violence in environmental conflicts as a direct event in time and space is only the tip of the iceberg and that violence can reach not only environmental defenders, but also communities, nature, and the sustainability of their relations.     

Novel Tough Crystalline Blends of Polylactide with Ethylene Glycol Derivative of POSS

Blending of polylactide (PLA) with low stereoregularity and polyhedral oligomeric silsesquioxane grafted with arms of poly(ethylene glycol) methyl ether, acting as a plasticizer, allowed us previously to obtain a novel stable elastomeric-like material. The present contribution focuses on the properties of semi-crystalline PLA plasticized with this compound. Melt blends of PLA with 5–15 wt% of the plasticizer, were compression molded, quenched and annealed, which enabled cold-crystallization. The glass transition temperature of the blends and their drawability depended on their crystallinity and plasticizer content. The best ductility was reached at the plasticizer content of 15 wt%; the achieved strain at break was 6.5 (650%) and 1.3 (130%), for the quenched and annealed material, respectively. The latter value exceeded 20 times the strain at break of neat crystalline PLA. The tensile toughness of the annealed 15 wt% blend was 12 times larger than that of crystalline PLA. Moreover, annealing of 15 wt% blend improved its yield strength by 40%. Despite the two peaks of the loss modulus, indicating the two glass transitions in this blend, no heterogeneities were found by scanning electron microscopy, indicating that the plasticizer enriched phase formed instead of distinct inclusions of the plasticizer.     

Production of Curdlan Grown on Cassava Starch Waste Hydrolysates

Cassava starch waste hydrolysates (CSWHs) with different degrees of polymerisation, i.e., CSWHs-1, CSWHs-2 and CSWHs-3, were prepared through the hydrolysis of cassava starch waste with thermostable a-amylase from Thermococcus sp. HJ21. The prepared CSWHs were then used as a carbon source for curdlan production with Alcaligenes faecalis ATCC 31749. The amount of curdlan produced and the glucosyltransferase activity during curdlan synthesis increased more obviously when CSWHs-2 was used as the carbon source than when glucose was used. Using both carbon sources, the maximum curdlan production was observed at day 5, and the maximum glucosyltransferase activity was observed at day 4. Glucosyltransferase activity decreased thereafter, and biomass continued to increase until the end of the experiment (day 6). Results indicated that the enhanced curdlan production with CSWHs as the carbon source was highly correlated with glucosyltransferase activity.     

Difference in the net value of ecological services between natural and artificial forests in China

Land degradation is a global problem that seriously threatens human society. However, in China and elsewhere, ecological restoration still largely relies on a traditional approach that focuses only on ecological factors and ignores socioeconomic factors. To improve the effectiveness of ecological restoration and maximize its economic and ecological benefits, a more efficient approach is needed that provides support for policy development and land management and thereby promotes environmental conservation. We devised a framework for assessing the value of ecosystem services that remain after subtracting costs, such as the opportunity costs, costs of forest protection, and costs for the people who are affected by the program; that is, the net value of ecosystem services (NVES). To understand the difference between the value of a resource and the net value of the ecosystem service it provides, we used data on VES, timber sales, and afforestation costs from China's massive national afforestation programs to calculate the net value of forest ecosystem services in China. Accounting for the abovementioned costs revealed an NVES of ¥6.1 × 10¹² for forests in 2014, which was 35.9% less than the value calculated without accounting for costs. As a result, the NVES associated with afforestation was 55.9% less than the NVES of natural forests. In some regions, NVES was negative because of the huge costs of human-made plantations, high evapotranspiration rates (thus, high water opportunity costs), and low forest survival rates. To maximize the ecological benefits of conservation, it is necessary to account for as many costs as possible so that management decisions can be based on NVES, thereby helping managers choose projects that maximize both economic and ecological benefits.