31 research outputs found
Pedagogical Approaches and Design Aspects To Enable Leadership for Sustainable Development
Bacterial diversity in typical abandoned multi-contaminated nonferrous metal(loid) tailings during natural attenuation
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordAbandoned nonferrous metal(loid) tailings sites are anthropogenic, and represent unique
and extreme ecological niches for microbial communities. Tailings contain elevated and toxic
content of metal(loid)s that had negative effects on local human health and regional
ecosystems. Microbial communities in these typical tailings undergoing natural attenuation
are often very poorly examined. The diversity and inferred functions of bacterial
communities were examined at seven nonferrous metal(loid) tailings sites in Guangxi (China),
which were abandoned between 3 and 31 years ago. The acidity of the tailings sites rose over
31 years of site inactivity. Desulfurivibrio, which were always coupled with sulfur/sulfide
oxidation to dissimilate the reduction of nitrate/nitrite, were specific in tailings with 3 years
abandonment. However, genus beneficial to plant growth (Rhizobium), and iron/sulfur-
oxidizing bacteria and metal(loid)-related genera (Acidiferrobacter and Acidithiobacillus)
were specific within tailings abandoned for 23 years or more. The increased abundance of
acid-generating iron/sulfur-oxidizing and metal(loid)-related bacteria and specific bacterial
communities during the natural attenuation could provide new insights for understanding
microbial ecosystem functioning in mine tailings. OTUs related to Sulfuriferula, Bacillus,
Sulfurifustis, Gaiella, and Thiobacillus genera were the main contributors differentiating the
bacterial communities between the different tailing sites. Multiple correlation analyses
between bacterial communities and geochemical parameters indicated that pH, TOC, TN, As,
Pb, and Cu were the main drivers influencing the bacterial community structures. PICRUSt
functional exploration revealed that the main functions were related to DNA repair and
recombination, important functions for bacterial adaptation to cope with the multi-
contamination of tailings. Such information provides new insights to guide future
metagenomic studies for the identification of key functions beyond metal-
transformation/resistance. As well, our results offers novel outlooks for the management of
bacterial communities during natural attenuation of multi-contaminated nonferrous metal(loid)
tailings sites.International Key Project from National Natural Science Foundation of ChinaProjects of Natural Science Foundation of ChinaPublic welfare project of Chinese Ministry of Environmental Protectionnternational key project of Ministry of Science and Technology of ChinaS2016G2135Centre National de la Recherche ScientifiqueRoyal Society Newton Mobility GrantNational Natural Science Foundation International Joint collaboration China-Swede
Conclusions and Activities of Previous Expert Groups: The Scientific Steering Committee of the EU
Soil Burial Degradation of New Bio-Based Additives. Part I. Rigid Poly(vinyl chloride) Films
International audienceCommercial sunflower oil was epoxidized, and the epoxidized sunflower oil (ESO) was used as a thermal stabilizer for poly(vinyl chloride) (PVC). Rigid formulations stabilized with ESO as a new stabilizer and epoxidized soybean oil (ESBO) as a commercial stabilizer for comparison were prepared. The aging of the PVC samples was investigated in landfill soil for 24 months. The structure modifications of the polymer were followed by Fourier transform infrared spectroscopy (FTIR). Furthermore, the variations of density and mechanical properties (tensile and Shore D hardness) were considered. The variations of the mass of the samples, the glass transition temperature (T(g)), the molar mass distribution, and the weight loss were followed as a function of time of soil burial. The soil burial test showed the loss of additives by migration and biodegradation that led to the modification of density, mechanical properties, molar mass distribution, and weight loss of the PVC samples