METHOD FOR WATER TREATMENT BY ELECTROLYSIS OF FLUORINATED COMPOUND

PROBLEM TO BE SOLVED: To provide a method for water treatment by electrolysis of a fluorinated compd. in which catching ability of flock, turbidity and chromaticity can be improved by treating ability of diatomaceous earth. SOLUTION: In a method wherein, when water 1 to be treated is purified by fluorine-electrolysis of a fluorinated compd., about 1-50mg/l-CaF is incorporated into the water 1 to be treated and about 1-10mg/l-diatomaceous earth 4 is also incorporated therein and an electric voltage of at least 3V is applied to form a colloid of the fluorinated compd. and this colloid of the fluorinated compd. is caught with the flock instead of catching with a flocculating agent, the diatomaceous earth 4 is incorporated under a condition finely ground by means of a mortar to improve particle catching ability of flock of the diatomaceous earth 4.