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Created by Denise Catsman
over 2 years ago
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Question | Answer |
Pollution | making something impure and harmful by adding another substance. |
Contamination | making something impure by adding another substance. |
Brownfield | abandoned land that’s available for building development and which is (potentially) contaminated by industrial and commercial activities. |
Primary pollutants | pollutants that cause harmful effects in the form in which they are released into the environment. |
Secondary pollutants | pollutants that are formed as a result of a chemical process in the environment, often from less harmful precursors. |
Background concentration | a substance’s natural concentration in soil or water (so without human interference). |
Point source | direct releases of pollutants from a single location. Mostly confined to a plume in the downstream direction from the source. In general, easily monitored and controlled because they can often be identified as being caused by a particular individual or organisation. |
Diffuse source | a pollutant release that occurs over a wide area, non-point source. Pollutant gradients are usually gradual. Possibly a cumulative effect of multiple undistinguishable point sources. |
Toxicity | the capacity to cause harm to a living organism. Measurable in LD50/LC50, ED50/EC50, NOEL/NOED/NOEC. |
LD50 / LC50 | Median lethal dose/concentration. It describes the level of exposure that kills 50% of the population. |
ED50 / EC50 | Median effect dose/concentration. It describes the level of exposure that causes a defined effect to 50% of the population. |
NOEL / NOED / NOEC | no observed effect level/dose/concentration. Level at which a test chemical does not cause an effect that is statistically significantly different from the control. |
Bioavailability | the rate and extent to which a substance can be taken up or absorbed into the tissues of organisms and so influence their physiology. It is the most important factor determining the extent to which a contaminant in soil and water wil enter the food chain. |
Bioaccumulation | the extent to which pollutants accumulate over time in the tissues of organisms through any route, including respiration, ingestion, or direct contact. |
Biological half-life | the time it takes to remove 50% of the quantity of a substance in a specific tissue organ, or any other specified biota as a result of biological processes. |
Biomagnification | the increase in concentrations as the pollutant passes through the food chain. |
Speciation | the occurrence of different forms, whether chemical or physical, of an element. It determines its bioavailability and toxicity and controls its transport and fate in soil and water. |
TDS | total dissolved solids |
Electrical conductivity | a measure of the water’s ability to conduct electricity and therefore measure of the water’s ionic concentration. |
Activity | a concentration corrected for the non-ideal effects in aqueous salutation arising from the electrostatic forces between all dissolved ions in the water. |
Phase | distinct and homogeneous state of a material with no visible boundary separating it into parts. |
Partition coefficient Distribution coefficient | ratio between the concentration in the adsorbed phase and the concentration in the dissolved phase. |
Henry's law KH | the ratio for portioning among the aqueous and gas phase in equilibrium. |
Octanol-water partitioning coefficient Kow | the ratio between the concentration of a chemical in octanol and in water at equilibrium and at a specified temperature and is a measure of the tendency of chemical to partition itself between the aqueous phase and organic phase. |
Octanol | an organic solvent used as a surrogate for natural organic matter. |
Isotherm | GRAPH OF TEMPERATURE Freundlich isotherm Cs = K Cwn Langmuir isotherm Cs = (Q0K Cw)/(1+K Cw) |
Adsorbent | the substrate onto which a substance is sorbed. |
Adsorbate | substance that becomes adsorbed. |
Fugacity | the tendency of a substance to flee from the phase it is in. |
Solubility | the concentration of the saturated solution at a given temperature and pressure. |
Solubility product | the equilibrium constant for dissolution-precipitation reactions. |
Buffered solution | solution that is barely sensitive to changes in their pH as a result of the addition of moderate quantities of strong acids or strong bases. |
Reductant | electron donor. |
Oxidant | electron acceptor. A substance that causes oxidation by accepting electrons from a reductant, while being reduced itself. |
Redox potential | the tendency of the system to donate of accept electrons. |
pH-Eh diagram | a two-dimensional graph. The fields of stability or dominance of both dissolved species and minerals as function of the pH and Eh are indicated, whereby the dominant stable species can be recognized directly and easily. |
Vadose zone | the unsaturated zone |
Preferential flow | heterogeneous soil properties that govern soil water flow. |
Aquifer | a water-yielding rock formation that contains and is able to transmit sufficient groundwater to be a source of water supply. |
Aquitard | a layer of low permeability. |
Aquiclude | an impermeable body of rock. |
Phreatic aquifer | bounded from above by a phreatic surface (the surface at every point of which the pressure in the water equals the atmospheric pressure) |
Perched aquifer | phreatic aquifer formed on a semi-permeable, or impermeable layer below which unsaturated material is present. |
Confined aquifer | bounded by aquitard or aquiclude at both the top and bottom. |
Artesian aquifer | confined aquifer that is characterized by an hydraulic head that is higher than the local ground surface level so that water can flow out of wells without any need for pumps. |
Groundwater | the water present in the saturated zone beneath the water table. |
Recharge | the replenishment of groundwater. |
Hydraulic conductivity | the ability of the porous material to transmit water and is largely determined by the texture of the porous material. |
Surface water | all water on the surface of the Earth found in rivers, streams, canals, ditches, ponds, lakes, marshes, wetlands, coastal and marine water, and as ice and snow. |
Hyporheic zone | the zone of bed sediments. |
Epilimnion | he upper, well-mixed, warm layer of a water body. |
Hypolimnoin | the lower, cold layer of a deep water body caused by thermal stratification. |
Thermocline | the zone of rapid temperature change between the epilimnion and the hypolimnion. |
Colloids | a special intermediate case between dissolved and particulate matter. They consist of particles dispersed in water. |
Sesquioxides | mineral structure of Al and Fe oxides/hydroxides. |
PZC | point of zero charge, the pH at which the charge of the mineral surface is neutral. |
Diffuse layer | the soil solution near the mineral surface. In this layer, the cations are more abundant than diffuse anions. These cations are thus not bonded to the surface but are in solution. |
Stern layer | a layer in which cations are sorbed directly at the surface. |
Diffuse double layer | consists of the diffuse layer and the stern layer. Zone near negatively charged surfaces of colloids. |
CEC | Cation Exchange Capacity, the extent to which clay minerals are able to exchange cations. |
AEC | Anion Exchange Capacity, the extent to which clay minerals are able to exchange anions. |
Flocculation | the formation of flocs or aggregates. |
Detritus | undecayed dead plant and animal tissue. |
Humic substances | decomposed detritus by microorganisms. It is amorphous, colloidal, polymeric, dark-brown organic compounds with a high molecular weight. |
Humification | the formation of humic substances. |
Mineralisation | the complete breakdown to inorganic compounds, mainly water and CO2, but also other minerals and nutrients that constitute an essential part of organic matter. |
Humin | the portion of humus that is insoluble in the dilute sodium hydroxide. The part that dissolves in solution consists of humic acid and fulvic acids. Fulvic acids have lower molecular weight than humic acids (= difference). |
DOM | dissolved organic matter, approximately similar to the soluble organic matter present in soils. |
POM | particulate organic matter, consists largely recalcitrant remains and woody terrestrial and aquatic plants. |
Ligands | organic or inorganic ion that can form complexes with metal-ions by two or more contacts. |
Chelation | the formation of a complex between a metal and an organic ligand. |
Denitrification | the process where nitrate is transformed into free nitrogen gas. It is taken through intermediates like nitrite, nitric oxide, and nitrous oxide. |
BOD | biochemical oxygen demand, the amount of dissolved oxygen used up by a water sample in darkness (at room temperature for five days)/ measure for the amount of easily degradable organic matter in water. |
COD | chemical oxygen demand, the amount of oxygen consumed in the complete oxidation of carbonaceous matter. |
SOD | sediment oxygen demand, the rate of the dissolved oxygen consumption in a water body due to the decomposition of sediment organic matter. |
Major dissolved phase constituents | substances that are abundant as dissolved ions in natural waters. |
Stiff diagram | diagram that expresses the concentrations of cations and anions. |
Piper diagram | two triangular graphs that display the relative contribution or various cations and anions to the respective total positive and negative charge and a diamond shaped graph that combines these contributions of cations and anions. |
TIC | total inorganic carbon, consists of carbonic acid (H2CO3), hydrogen carbonate or bicarbonate (HCO3-) and carbonate (CO3 2-). |
Alkalinity | the capacity to neutralize acid. |
Nutrients | the raw materials that are assimilated by living organisms to promote growth, development and reproduction. |
Nutrient cycling | all the processes by which nutrients are transferred from one organism to another. |
Trophic levels | the position of the organism in the food chain of food web. |
Eutrophication | accelerated nutrient cycling due to enhanced external nutrient inputs. |
Ammonium fixation | the process by which clay minerals capture ammonium tightly between the mineral lattices. Mostly irreversibly bonded. |
Nitrogen fixation | the process where bacteria on plants fix nitrogen from the atmosphere. |
Ammonification | The formation of ammonium as a result of the breakdown of organic nitrogen by oxidation. |
Nitrification | the process where autotrophic bacteria oxidise ammonium to nitrate under oxic condition. This process has multiple steps. It requires oxygen to occur. |
Immobilisation | microorganisms utilise substantial quantities or inorganic nitrogen that thereby become part of organic matter. It is the opposite process of mineralization. |
Dry deposition | removal of gases and aerosols from the atmosphere without the interference of precipitation. |
Wet deposition | wash-out of gases and aerosols from the atmosphere in solution by precipitation. |
Occult deposition | removal of gases and aerosols from the atmosphere through diffusion across the interface between air and wet surface, in fog and dew drops. |
Phosphate fixation | the interactions of phosphates with iron, aluminum, sesquioxides and calcium. Adsorption of phosphate to soil or sediment minerals. |
Internal loading | the release of dissolved constituents (mostly nutrients) from lake/river bed sediments. |
Heavy metals | metals and semimetals that have been associated with contamination and potential toxicity or ecotoxicity. |
Coprecipitation | the inclusion of additional species within or on the surface of a precipitate as it is formed. |
Ionising radiation | any radiation which displaces orbital electrons from atoms, so producing ions. |
Isotopes | atoms that have the same number of protons but different numbers of neutrons. |
Alpha radiation | radiation consisting of positively charged helium nuclei. |
Beta radiation | radiation consisting of electrons or positions. |
Gamma radiation | radiation consisting of a discrete quantity of electromagnetic energy without mass or charge. |
Background radiation | the sum of terrestrial radiation, cosmogenic radiation and the portion of cosmic radiation that reaches the Earth’s surface. |
Nuclear fission | the break-up of heavy elements into smaller nuclei through bombardment with neutrons in a nuclear fission reactor. |
Neutron activation | the process of capture of neutrons in the nuclei of elements. |
Organic pollutant | a variety of compounds made up of C, H, O and small amounts of N, P, S and Cl. |
VOC's | volatile organic compounds. Organic pollutant that evaporates readily and completely when exposed to the atmosphere. |
SVOC's | semi volatile organic compounds. Organic pollutants that evaporate slowly and partially when exposed to the atmosphere. |
POP's | persistent organic pollutants. Organic compounds that break down very slowly in the environment. |
Isomers | substances that can be structured spatially in more than one manner. |
Aromatic | compounds containing at least one benzene ring structure. |
Aliphatic | hydrocarbons that are not aromatic. |
LNAPL's | light non-aqueous phase liquids. Less dense than water. |
DNAPL's | dense non-aqueous phase liquids. Denser than water. |
Monocyclic aromatic hydrocarbons | compounds consisting solely of carbon and hydrogen and containing one benzene ring. Also: BTEX (benzene, toluene, ethylbenzene, xylene). |
Polycyclic aromatic hydrocarbons | compounds consisting solely of carbon and hydrogen and containing two or more benzene rings. Also: PAH’s. |
Chlorinated hydrocarbons | hydrocarbons with one or more chlorine substituents. They can consist of aliphatic as well as aromatic structures. |
ESOC's | Emerging Substances Of Concern. Substances that have recently been detected in the environment or recognized as potentially toxic. |
Protonation | adsorption of protons (H+ ions) at the surface of sesquioxides or clay minerals. |
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