NOVELTY - A water treatment disinfection and purification system comprises a mechanism for exposing a stream of air to short-wavelength ultraviolet radiation; an electrolysis cell for electrolysis of salt water stream to be disinfected; a mixer for mixing the stream of air with the salt water stream; and a mixer for mixing the resulting stream of water with a stream of water to be disinfected.    USE - For the disinfection of water streams encountered in marine applications and contaminated by the presence of microorganisms and biological contaminants, solids, heavy metals and organic/inorganic compounds (claimed).    ADVANTAGE - The inventive system provides extremely efficient, low maintenance, low energy cost modular water purification and contamination control technology for the non-chemical disinfection and contaminant separation of various types of water or wastewater streams as encountered in the marine industry.    DETAILED DESCRIPTION - A water treatment disinfection and purification system for disinfection of water streams encountered in marine applications and contaminated by the presence of microorganisms and biological contaminants, solids, heavy metals and organic/inorganic compounds, comprises:    (a) a mechanism for exposing a stream of air to short-wavelength ultraviolet radiation, where ions of oxygen and nitrogen are formed in the stream of air;    (b) an electrolysis cell for electrolysis of part(s) of the salt water stream to be disinfected, where chlorine ions are produced in situ in the salt water stream;    (c) a mixer for mixing the stream of air containing ions of oxygen and nitrogen with the part(s) of the salt water stream containing chlorine ions formed in situ, forming a stream of water containing the ions of oxygen, nitrogen and chlorine; and    (d) a mixer for mixing the stream of water containing the ions of oxygen, nitrogen and chlorine with the stream of water to be disinfected.    INDEPENDENT CLAIMS are included for the following:    (a) A method for the disinfection of water encountered in marine applications as above, comprising exposing a stream of air to short-wavelength ultraviolet (UV) radiation; electrolyzing salt in part(s) of stream of water to be disinfected; mixing the stream of water containing chlorine ions with the stream of air containing ions of oxygen and nitrogen, forming a stream of water containing ions of oxygen, nitrogen and chlorine; and mixing the stream of water containing ions of oxygen, nitrogen and chlorine with the stream of water to be disinfected, where the microorganisms and biological contaminants are destroyed;    (b) An apparatus for the disinfection of water encountered in marine applications and contaminated by the presence or microorganisms and biological contaminants, and for removal of destroyed organisms and other solids, comprising a mechanism for exposing a stream of air to short-wavelength UV radiation; a vessel having a lower settling zone, and an upper electrolysis zone; parallel spaced plates of conductive material in an electrolysis zone of the vessel; and a source of discreet current connected to alternating plates so that an electric field exists between alternating pairs of plates.    The brine in the vessel is electrolyzed, releasing ionized chlorine. The ionized chlorine and the ions of oxygen and nitrogen destroy microorganisms and biological contaminants in the water. The destroyed microorganisms and biological contaminants are agglomerated on the plates, together with other solids in the water stream. The direct current applied to alternating plates is reversed in polarity from time to time. The lighter portions of the destroyed microorganisms and biological contaminants and other solids tend to float upwardly and form a foam on the surface of water in the vessel. The heavier portions of the destroyed microorganisms and biological contaminants and other solids tend to fall downwardly and settle in the settling zone of the vessel.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of a water treatment system incorporating the water treatment disinfection and purification system.