Author(s)

A. Tijero, A. Moral, J. Tijero, A. Blanco & C. Negro

Abstract

The objective of this work is the on-line control of the solid-liquid separation process in a water treatment plant using a focused beam reflectance measurement sensor (FBRM) in order to improve the coagulation, precipitation and flocculation of this plant. A previous study of the system is carried out in order to analyze the possible influence of the external variables on the floc mean chord size though of the monitorization of the flocculation tank. The formation of particle aggregates is the product of the addition of an inorganic flocculant (FeCl3) with a subsequent treatment with an organic synthetic flocculant (anionic polyacrilamide) that determine the formed floc properties. The FBRM study of the variations of the mean chord size realised after the changes in the system show an improvement in flocculant diffusion and a greater phase contact. The final objective is to improve the calcium carbonate precipitation conditions, to reduce the membrane fouling and avoid the deposit formation in the plant surface. The trials carried out a characterization of the waters before and after changes in the system in order to establish whether the final properties of the water fulfil the parameters required for its posterior use. The results obtained show that the measurement system FBRM is an on-line sensor that is good enough to be used as a control and prediction method in the water treatment industries. Furthermore, the relations between the data obtained by the sensor and the properties of the water after the depuration allow control of the outlet water. Keywords: flocculation, coagulation, FBRM control on-line, river water treatment.

Keywords

flocculation, coagulation, FBRM control on-line, river water treatment