Dense medium plasma environments: a new approach for the disinfection of water.

The levels to which microbial colony forming units are permitted in various waters fit for human contact are carefully regulated. Conventional chemical and physical approaches usually are complex processes with significant limitations due to the generation of toxic side-products. In this contribution a novel plasma reactor--dense medium plasma reactor--is described, and its efficiency for the disinfection of contaminated water is discussed. It has been shown that owing to the intense stirring of the reaction medium (e.g. contaminated water), as a result of the specially designed spinning electrode and gas-flow system, a volume-character discharge is created, which can efficiently kill bacteria. It has been demonstrated that treatment times as low as 20 s are enough for the total inactivation of microorganisms for 200 mL of 10(5) bacteria/mL contaminated water.