Chemical perspectives on water treatment

This article was produced based on a workshop on Coagulation and flocculation in water treatment, held at National Days of Chemical Education 13 to 14 April 2012. The workshop dealt with the central unit operation of surface water treatment, coagulation/flocculation. There are interesting chemical phenomena related to coagulation and flocculation, and it is possible to demonstrate them with relatively simple equipment. Demonstration, suitable for classroom environment, is presented in the section discussing surface water treatment. Water treatment is for the most part based on chemical phenomena and acknowledging the significance of them will become increasingly important as the supply of clean water decreases globally. This article provides a general view on the sufficiency of water supply in Finland and internationally, and examines the central chemical phenomena in the treatment processes of surface, ground and wastewater.