Abstract

Ultraflocculation can be defined as: flocculation performed in a highly non-uniform hydrodynamic field (epsilon > 1 [J/kg.s], G > 10(3) [s(-1)]) in a short period of time (t < 10 [s]), which is used mainly to aggregate fine particles in dispersed, and diluted systems. In this study, four hydraulic ultra-flocculation reactors were tested, UF1, UF2, UF3 and UF4 with tangential inlets/outlets and a cylindrical body, the inside of which varies by reactor. Model flocculated fine quartz slurries were employed as material. Based on a comparison of the three flocculation process indicators - initial settling velocity, supernatant turbidity, and sludge volume - in general the reactors present better performance than that in the base case. There was an average improvement in settling velocity of 300[%], turbidity remains below 100 [NTU], and sludge volume values indicated a higher possibility of water recirculation. Additionally, it was observed that the ultra-flocculation process could be used in relatively concentrated suspensions (phi > 10(-2)) with treatment times below to 5 [s].