Search results for "remediation."
showing 10 items of 267 documents
A battery of toxicity tests as indicators of decontamination in composting oily waste.
2000
Heterogeneous oily waste from an old dumping site was composted in three windrows constructed from different proportions of waste, sewage sludge, and bark. The objectives of this pilot study were to examine the usefulness of composting as a treatment method for this particular waste and to study decontamination in the composting process by using a battery of toxicity tests. Five samples from the windrow having intermediate oil concentrations were tested with toxicity tests based on microbes (Pseudomonas putida growth inhibition test, ToxiChromotest, MetPLATE, and three different modifications of a luminescent bacterial test), enzyme inhibition (reverse electron transport), plants (duckweed …
GEOBACTER METALLIREDUCENS MUTANTS FOR CHROMIUM BIOREMEDIATION
2011
Geobacter metallireducens is known to use oxidized metals such as Fe(III) and Mn(IV) as terminal extracellular electron acceptors. G. metallireducens can reduce the highly soluble and toxic Cr(VI) to its insoluble form Cr(III), thus enabling chromium removal from contaminated water and soil. This process is limited by the low toxicity resistance of G. metallireducens to Cr(VI). Genome shuffling can generate mutants with improved phenotype. In our work we are carrying out G. metallireducens genome shuffling, in order to increase its resistance to Cr(VI). In Geobacter species, metal toxicity resistance is correlated to the respiration rate, hence to the reduction rate of the metallic electron…
Genetic technology to improve biofilms electroactivity for bioremediation applications
2010
Hexavalent chromium bioremediation occurs through its reduction to Cr(III) and its following precipitation. Geobacter metallireducens is a dissimilatory metal reducing bacteria known to reduce Cr(VI) to Cr(III) through extracellular electron transfer. However, the effectiveness of this bioreduction process is limited by the low toxicity resistance of G. metallireducens to Cr(VI). G. metallireducens mutants with improved Cr(VI) toxicity resistance can be obtained by genome shuffling method. Here we present the experimental setup for genome shuffling of G. metallireducens, including the optimization of mutagenesis procedure and the respiration rate measure for G. metallireducens in potentiost…
NEMATODE COLONIZATION OF PYRITE CINDER-POLLUTED SOIL
2020
The nematofauna was studied in the early stages of a remediation trial at an industrial site where pyrite cinders had accumulated for 40 years in a large area and were then covered with mineral soil. The cinders were contaminated with several metals and metalloids. The soil of the experimental plots was derived from the mixture of cinders with the covering soil in a 1:1 ratio. Plots were amended with manure and sown with 3 metal resistant plants: Sorghum bicolor L., Helianthus annuus L., and Arundo donax L. Samples were taken : a) at the beginning of the trial on the pyrite cinders and covering soil, separately; b) from the mixture before the application of manure; c) from cultivated plots.…
The effect of peatland drainage and restoration on Odonata species richness and abundance
2015
Background Restoration aims at reversing the trend of habitat degradation, the major threat to biodiversity. In Finland, more than half of the original peatland area has been drained, and during recent years, restoration of some of the drained peatlands has been accomplished. Short-term effects of the restoration on peatland hydrology, chemistry and vegetation are promising but little is known about how other species groups apart from vascular plants and bryophytes respond to restoration efforts. Results Here, we studied how abundance and species richness of Odonata (dragonflies and damselflies) respond to restoration. We sampled larvae in three sites (restored, drained, pristine) on each o…
Fighting carbon loss of degraded peatlands by jump-starting ecosystem functioning with ecological restoration
2015
Degradation of ecosystems is a great concern on the maintenance of biodiversity and ecosystem services. Ecological restoration fights degradation aiming at the recovery of ecosystem functions such as carbon (C) sequestration and ecosystem structures like plant communities responsible for the C sequestration function. We selected 38 pristine, drained and restored boreal peatland sites in Finland and asked i) what is the long-term effect of drainage on the peatland surface layer C storage, ii) can restoration recover ecosystem functioning (surface layer growth) and structure (plant community composition) and iii) is the recovery of the original structure needed for the recovery of ecosystem f…
Effect of river restoration on life-history strategies in fish communities
2019
Assessments of river restoration outcomes are mostly based on taxonomic identities of species, which may not be optimal because a direct relationship to river functions remains obscure and results are hardly comparable across biogeographic borders. The use of ecological species trait information instead of taxonomic units may help to overcome these challenges. Abundance data for fish communities were gathered from 134 river restoration projects conducted in Switzerland, Germany and Finland, monitored for up to 15 years. These data were related to a dataset of 22 categories of ecological traits describing fish life-history strategies to assess the outcome of the restoration projects. Restora…
Soil remediation: humic acids as natural surfactants in the washings of highly contaminated soils
2005
The remediation of the highly contaminated site around the former chemical plant of ACNA (near Savona) in Northern Italy is a top priority in Italy. The aim of the present work was to contribute in finding innovative and environmental-friendly technology to remediate soils from the ACNA contaminated site. Two soils sampled from the ACNA site (A and B), differing in texture and amount and type of organic contaminants, were subjected to soil washings by comparing the removal efficiency of water, two synthetic surfactants, sodium dodecylsulphate (SDS) and Triton X-100 (TX100), and a solution of a natural surfactant, a humic acid (HA) at its critical micelle concentration (CMC). The extraction …
Selecting Microbial Strains from Pine Tree Resin: Biotechnological Applications from a Terpene World
2014
Resin is a chemical and physical defensive barrier secreted by many plants, especially coniferous trees, with insecticidal and antimicrobial properties. The degradation of terpenes, the main components accounting for the toxicity of resin, is highly relevant for a vast range of biotechnological processes, including bioremediation. In the present work, we used a resin-based selective medium in order to study the resin-tolerant microbial communities associated with the galls formed by the moth Retinia resinella; as well as resin from Pinus sylvestris forests, one of the largest ecosystems on Earth and a yet-unexplored source of terpene-degrading microorganisms. The taxonomic and functional di…
Partitioning study of polycyclic aromatic hydrocarbons between water and some selected water-insoluble phases
2007
An investigation on the partitioning of naphthalene and phenanthrene between water and some water-insoluble phases has been carried out by Uv-vis-NIR spectrophotometry. The analysis of the experimental results emphasized the role of intermolecular interactions and structural features of the hosting phases as driving forces of the partitioning of these polycyclic aromatic hydrocarbons. The critical comparison of the resulting distribution constants allowed to evaluate the potentials of some extracting phases to set up sensitive analytical methods and/or effective environment remediation technologies.