A measure of the amount of chlorine which will be consumed by organic matter and other oxidisable substances in a water before a chlorine residual will be found; the difference between the total chlor [..]

The addition of foreign matter to a substance which reduces the value of the substance or interferes with its intended use.

The concentration of residual chlorine present as a dissolved gas, hypochlorous acid or hypochlorite, not combined with ammonia or in other less readily available forms.

Radiation falling upon or striking a surface.

To reduce the number of bacterial contaminant to safe levels as judged by public health requirements. To make clean and free or inactivation of dirt, filth, and conditions injurious to health. General [..]

Component of collector, which absorbs solar radiation.

An essential planar ( flat) from absorber.

The ratio of radiation energy absorbed by a surface to that of the radiation falling on the surface.

The process in which one substance is taken into the body of another substance, termed the absorbent. An example is the absorption of water into the soil.

The quantitative capacity of a water, or water solution, to neutralise an alkali or base. It is usually measured by titration with a standard solution of sodium hydroxide, and expressed in terms of it [..]