Glossary of Water Disinfection Terms

ADI VALUE - "Acceptable Daily Intake" is the highest tolerable daily intake of a substance, expressed in mg/kg bodyweight, which does not represent a health risk over the entire lifespan, calculated on the basis of all currently available data. The wording Tolerable Daily Intake (TDI) is also often used.DISINFECTANTSDisinfectants used to treat water, e.g., ozone, ultraviolet radiation, chlorine dioxide, chlorination, and chloramine.

AOX - Absorbable Organic Halogens is a measurement often used in waste water testing to indicate the overall level of the halogens, fluorine, chlorine, bromine and iodine. This "sum parameter" comes from a standard analytical procedure, which gives no information on the source or nature of halogens present nor on their toxicity. It has the advantage of being simple to measure; alternative methods of measuring levels of individual compounds are complex and require costly equipment.

BATS -Best Available Techniques. BAT Standards are used to judge the performance of industrial processes and to provide a target for improvement plans.

BEPS - Best Environmental Practices. BEP means the application of the most appropriate combination of environmental control measures or strategies in order to reduce the impact of specific substances or applications.

BIOACCUMULATION - Bioaccumulation denotes the accumulation of a substance in a living organism as a result of its intake both in the food and also from the environment. Determination of the B-factor (Bioaccumulation Factor) is extremely important in the risk analysis of a compound.

BIOCONCENTRATION - Accumulation of a substance in an organism by absorption from the environment irrespective of any intake with food. The concept is of particular importance for aquatic life with regard to the absorption of those fat-soluble substances which are only broken down slowly.

BIOMAGNIFICATION - This term denotes the accumulation of substances in a living organism with the food intake. Simple organisms such as algae can absorb minute quantities of a substance which are transferred through the food chain to higher living species such as fish, bird, etc. Biomagnification along a food chain will result in the highest concentrations of a substance being found at the top of the food chain.

BLEACH - Bleach is used for whitening paper, soap, straw and cotton, and for disinfection, water purification and in sanitary cleaners. Archaically, bleach has been produced by reacting chlorine into a dilute sodium hydroxide solution

CARBON TETRACHLORIDE - Carbon tetrachloride is produced by the high temperature chlorination of propylene or methanes. It is used as a feedstock in the production of CFCs and of chlorine to extract nitrogen trichloride, and as a solvent to recover chlorine from tail gas.CHLORINATED AROMATICS
Collective term for chlorinated derivatives of benzene, toluene, phenol, naphthalene and bi-phenyl and other compounds containing at least one benzene ring. Chlorinated aromatics are widely used as intermediates in the manufacture of medicines, agricultural chemicals and paints.
CHLORINATED ORGANIC COMPOUND - (see Organic Chlorine Compounds)

CHLORINATED SOLVENTS - Trichloroethylene, tetrachloroethylene (also known as perchloroethylene), and methylene chloride, are the main solvents in this group. Due to their non-flammability, these compounds have been widely used for cleaning metals in the electronics industry and for dry cleaning of clothes. The use of 1,1,1-trichloroethane was phased out at the end of 1995 under the Montreal Protocol.CHLORINATIONThe process in water treatment of adding chlorine (gas or solid hypochlorite) for purposes of disinfection.

1. Introduction of chlorine into a chemical compound.
2. Sterilisation of drinking and swimming pool water or oxidation of undesirable impurities, using chlorine or its compounds.
3. Exposure of wool to chlorine solutions to prevent unwanted felting.