A thick brown to black viscous organic liquid, too thick to migrate easily through most porous sediment.

Synonym for petroleum residuum, either straight run (see) or cracked (see).

Tender ship
A boat for carrying passengers and supplies to and from a ship close to shore.

Tension-Leg Platform (TLP)
A floating offshore structure held in position by a number of tension-maintaining cables anchored to the seabed. The cables dampen wave action to keep the platform stationary.

Abbreviation of tetra-hydro-furan (see Furan), a common solvent in organic reactions.

Tidal energy
Mechanical power, which may be converted to electrical power, generated by the rise and fall of ocean tides. The possibilities of utilizing tidal power have been studied for many generations, but the only feasible schemes devised so far are based on the use of one or more tidal basins, separated from the sea by dams (known as barrages), and of hydraulic turbines through which water passes on its way between the basins and the sea. (source: European Environment Agency).

To germinate
To sprout from a seed.

Total Organic Carbon (TOC)
A measure of the organic carbon content of sediment expressed as a percent. Total organic carbon (TOC) represents an elemental analyser for the determination of the organically-linked carbon in biological, environmental, solvents, and other organic samples.

Total Oxygen Demand (TOD)
Total oxygen demand means the amount of oxygen required to oxidize both the organic and inorganic matter in a sample under specific conditions.

Total Suspended Particulate (TSP)
A measure of the total liquid and solid particulate matter (see) suspended in a gaseous emission. Among the many constituents of particulates the principal one is carbonaceous material produced by incomplete combustion. The most important characteristic of such particulates is the distribution of their diameter because there is a range of particulates which can be inhaled by men and as such may be hazardeous to their health.

Total Suspended Solid (TSS)
Total Suspended Solids (TSS) are the materials, of whatever nature, in suspension (especially in water bodies). The TSS index is a parameter measuring the degree of transparency of water. The higher the transparency (i.e. few TSS), the lower is the reading of this parameter.

Toxic & noxious waste
A waste that can be harmful or injurious to health or physical well-being. It can produce injury if inhaled, swallowed, or absorbed through the skin.

Tradeable discharge permit
A permit that allows a certain source to emit a specified volume of some pollutant. (Also called marketable or transferable discharge permits).

Tradeable environmental permits
A type of market based incentive in which firms are issued with permits permitting them to pollute up to a certain level. If they do not need the permits because they are (or become) cleaner they can sell them to those who have not yet succeeded in doing so. This creates an incentive to install cleaner processes.

Transformation losses
Transformation of energy from one form to another always results in conversion losses. Transformation losses are shown as the (negative) totals at the right of the energy balance tables. Transformation losses in electricity generation are derived from the electricity generated, assuming efficiencies of 100% for hydro, 10 % for geothermal, 33% for gas plants, 34% for coal plants, and 30% for cogeneration from either gas, coal, biogas, wastes and wood.

Trickling filter
An aerobic, fixed film wastewater treatment process where organic matter present in a wastewater is degraded as it is distributed over a biological filter bed.

Relating to nutrition; a trophic level is the position of an organism in a food chain or food (trophic) pyramid.

Trophic level
Levels of the food chain. The first trophic level includes photosynthesizers that get energy from the sun. Organisms that eat photosynthesizers make up the second trophic level. Third trophic level organisms eat those in the second level, and so on. It is a simplified way of thinking of the food web; some organisms eat members of several trophic levels.

The portion of the Earth’s atmosphere ranging from the Earth’s surface to approximately 10 – 15 km (0 to 8 miles).

Trunk lines
Large-diameter pipelines that transport crude oil, natural gas liquids and refined petroleum products to refineries and petrochemical plants; some trunk lines also transport refined products to consuming areas.

Relatively small-diameter pipe that is run into a well to serve as a conduit for the passage of oil and gas to the surface.

A machine for generating rotary mechanical power from the energy of a stream of fluid (such as water, steam, or hot gas). Turbines convert the kinetic energy of fluids to mechanical energy through the principles of impulse and reaction, or a mixture of the two.


Eni S.p.A. - P.IVA 00905811006