Enzymatic reactors for the removal of recalcitrant compounds in wastewater

Abstract

Enzymatic treatments based on oxidative enzymes, such as peroxidases, laccases and tyrosinases, have been proposed as an alternative to conventional methods to remove a broad range of contaminants present in wastewater. The aim of this study is to discuss existing technologies for the removal of pollutants based on the use of oxidative enzymes, including a discussion on the most important factors affecting the efficiency of the proposed systems. Factors involved in the catalytic cycle of the enzyme (biocatalyst, substrates and mediators), the addition of certain components to the reaction medium (additives, surfactants or solvents) as well as operational parameters (temperature, pH or agitation) will be discussed. Finally, two types of reactors: one-stage and two-stage enzymatic membrane reactors, especially designed for the treatment of micropollutants present in secondary effluents, will be described in detail.