A device used to inject a chemical solution into wastewater during water treatment.

The charge on an ion, declared by its number of electrons. A Cl- ion is in fact a Cl atom which has acquired an electron, and a Ca++ ion is a Ca atom, which has lost two electrons.

Substance that dissociates into ions when it dissolves in water.

A process that uses electrical currents, applied to permeable membranes, to remove minerals from water.

Process where electrical energy will change in chemical energy. The process happens in an electrolyte, a watery solution or a salt melting which gives the ions a possibility to transfer between two electrodes. The electrolyte is the connection between the two electrodes, which are also connected to a direct current. If you apply an electrical current, the positive ions migrate to the cathode while the negative ions will migrate to the anode. At the electrodes, the cations will be reduced and the anions will be oxidated.

Negatively charged building blocks of an atom that circle around the nucleus.

The distinctive building blocks of matter that make up every material substance.

Freeing sludge of its mother liquor by washing it with water.

A chemical that helps suspending one liquid in another.

Dispersion of one liquid in another liquid, occurs when a liquid in insoluble.

Techniques for water purification that serve the reduction pollutants after they have formed.

When the addition of nutrients, such as nitrogen and phosphorus, from sewage effluent or agricultural runoff to surface water, greatly increases algal growth.

The wearing away of the land surface by wind, water, ice or other geological agents. Erosion occurs naturally from weather or runoff but is often intensified by human land use practices.

Coliform bacterium that is often associated with human and animal waste and is found in the intestinal court. It is used by health departments and private laboratories t measure the purity of water.

Region of interaction between rivers and near-shore ocean waters, where tidal action and river flow mix fresh and salt water. Therefore estuaries mainly consist of brackish water.

Referring to water that is rich in nutrients such as nitrogen and phosphorous.

Enrichment of water, which causes excessive growth of aquatic plants and increasing activity of anaerobic microrganisms. As a result the oxygen levels in the water quickly decline and the water chokes, making life impossible for aerobic water organisms.

The process of the passage of water from liquid to vapour.

Areas where sewage sludge is dumped and dried.

The loss of water from the soil through vaporizing, both by direct evaporation and by transpiration from plants.