PROCEDE ET DISPOSITIF POUR LA MESURE DE TURBIDITE COLLOIDALE D'UN LIQUIDE

Continuous control process for the operation of a plant for the flocculation of a liq. to be clarified consists in using a turbidimeter with a rotary polarising filter; this allows the determn., at any moment and notably at the start of the treatment, of the amt. of colloids in the liq. which have not been affected by the flocculation treatment. The turbidimeter is linked to an alarm system which operates when the colloidal turbidity attains a given value; it is also linked to an automatic regulating device for the dosing pump of the flocculant. When the value of the colloidal turbidity increases beyond an admissible max., the output of flocculant is modified accordingly. The process can be used for the constant supervision of the flocculation from the start to see whether all the colloidal particles are in fact flocculated. In addition, the rate of the flocculant addition can be adjusted continuously to ensure that all the colloids in the liq. are flocculated. The process and device can be adapted for regulating the flocculation treatment not only by adjusting the rate of addition of the flocculant, but also by controlling the amt. of dissolved oxygen in a biological treatment or of the pH of the medium.