An in situ remediation technique, applicable to saturated soil and capillary fringe, which consists of injecting pressurised air at saturated soil level to cause the volatilisation and desorption (stripping) of volatile and semi-volatile organic compounds. The process is often associated with the Soil Vapour Extraction (SVE) system for the recovery of contaminated vapours.
The conversion of pyruvate molecules to carbon dioxide and ethyl alcohol (ethanol).
From the Greek ἄλλος (àllos) 'other', and χθών (chthòn) 'soil/land', it indicates something or someone originating at a distance from their present location.
In geology, rocks or minerals that were not formed at the location but were transported there by external agents or tectonic causes.
In biology, an allochthonous or alien species is defined as any living species that, due to human action, finds itself inhabiting and colonising a territory outside its native range.
A solid solution consisting of more than one element and possessing metallic properties.
Area of an aquatic environment below the photic zone, where insufficient light penetrates for photosynthesis to take place.
ATOMIC MASS UNIT
Atomic mass unit: Unit of measurement of relative atomic mass, relative molecular mass and formula weight, 1 u = 1/12 of the mass of the carbon atom 12.
From Late Latin autochton -ŏnis, Gr. aytókhthōn -onos, comp. of aytós 'same' and khthṓn 'earth'. Indigenous, originating from the same place where it is currently located.
In geology, rock formed in its current location without having undergone tectonic shifts.
In biology and biogeography, a species indigenous to a given region is one that has originated and evolved in the territory in which it is found.
Naming system developed by Linnaeus to classify organisms. Each species is defined by two Latin terms: the first indicates the genus, the second the specific name.
Fraction of a nutrient that the body is able to absorb and utilise for its physiological functions. Availability to an organism of certain substances in very low concentrations.
A process that uses microorganisms or their enzymes to decontaminate polluted sites and restore them to their original condition. It refers to the set of biological processes performed by micro-organisms, plants, fungi or their enzymes, naturally present in environmental matrices (soil and water) and used as an alternative to traditional remediation processes to remove contaminants in situ, transforming them into non-toxic products or by-products. It is mainly applicable to the remediation of organic compounds.
An in-situ remediation technique, applicable to the saturated zone and the capillary fringe, which consists of injecting oxygen or air at low pressure into the water table to stimulate biodegradation by indigenous micro-organisms (naturally present in the soil) of organic compounds adsorbed to the saturated soil.
Using living organisms to produce useful substances through molecular biology and genetic engineering techniques.
An in situ remediation technique, applicable to unsaturated soil. By introducing oxygen or air at low pressure into the soil layers affected by the presence of organic contaminants, it stimulates biodegradation of organic compounds adsorbed to the unsaturated soil by indigenous micro-organisms (naturally present in the soil). It can be applied in conjunction (alternating phases) with a Soil Vapour Extraction (SVE) process to ensure the removal of both volatile/semi-volatile and non-volatile hydrocarbon fractions.
Solution consisting of a weak acid and its salt with a strong base or a weak base and its salt with a strong acid, which tends to minimise pH changes resulting from the addition of small amounts of acids or bases. There are numerous buffer systems in the body that ensure the maintenance of internal physiological conditions: the main buffer system is the blood.
An organism that obtains both energy and carbon from inorganic substances; it produces its organic compounds from CO2 without using solar energy.
An organism that obtains energy and carbon from organic molecules.
A receptor that detects chemical changes within the body or the presence of specific molecules in the external environment.
Change in concentration of a chemical. Cells often maintain an ion concentration gradient across their membranes. When a concentration gradient is present, the ions or other substances involved tend to diffuse from the zone of higher concentration to the zone of lower concentration.