INTERFERENCE OF SOLID PARTICLES IN THE AIR-WATER MASS TRANSFERENCE IN COLUMN OF AERATION

Abstract

In this paper it was studied the mass transfer air-water in column of aeration with a superficial application rate from 21.5 m3/m2.h to 86.1 m3/m2.h. The liquid level varied from 1.0 m to 3.5 m and the flow from 0.5 m3/h to 2.0 m3/h. The studied configurations provided a potential equation where the overall mass transfer coefficient is a function of the aeration flow, with interval from 0.008 s-1 to 0.042 s-1. Regarding the influence of the turbidity through the use of formazine and industrial pownder, independent of the adopted percentage of the transversal section of the solid particle that is adhered to the interfacial area of the bubble, the comparison carried through with and without chemical composition addition showed that, mainly when the comparison is carried through with the formazine, the influence of the turbidity does not exist, due to enormous mobility of the bubbles that do not make possible the adhesion of solid particles. The no-monotonic behavior evidenced for the studies with industrial pownder is that it reduced considerably the efficiency of mass transfer. The methodology of quantification of the reduction superficial contact area proposed has acceptance in column of aeration with reduced superficial application rate associated with not occurrence of coalescence. Keywords: mass transfer air-water, colunm of aeration, contact interfacial area, formazine, industrial powder.