Modification of Activated Sludge Cohesion by Enzymatic Catalysis Process and Perspectives

Abstract

It is possible to transform the structure of organic compounds so as to modify some of their properties to make them more “elastic”, for example. Many solid-liquid separation processes use the cohesion property of the solid in suspension to increase the performance of the separation system. In this work, we examine some beneficial aspects that enzyme catalysis may reveal when acting on the strength of cohesion of a suspension. The topic concerns the activated sludge (AS) produced by wastewater of urban (or industrial) treatment plants. We used urban sludge and industrial liquid enzymes produced by the firm NOVO. To accelerate the research process, we employed enzyme mixtures (we called “enzyme cocktails”) that highlighted the active mixtures, but until now we have not characterized specifically active enzymes. Despite a significant number of experiences, it is clear that given the number of different enzymes available and the almost infinite possible ratios of cocktails, only a small number of conceivable methods have been tested (and even less optimized). Nevertheless, a few cocktails were active and promising enough to improve solids contact processes in various industrial processes. We have found a range of combinations that increases the sludge cohesion coefficient and considered this enzyme treatment to strengthen the separation by solid contact structures mainly to tackle important hydraulic shock.