INACTIVATION OF MICROBIOLOGICAL INDICATORS WITH OZONE TO WASTEWATER TREATMENT AIMING WATER REUSE

Abstract

This study intends to demonstrate the technical potentiality of the wastewater pre-disinfection (primary treatment effluent) to optimize the indicator pathogen inactivation. The essays were developed with Wastewater Treatment Plant effluent to simulate the method on real conditions, in two stages of disinfection with ozone. Microbiological exams revealed inactivation superior to 1 log to the three species evaluated (Escherichia coli, coliphages and Clostridium perfringens) only introducing 1.0 mgO3/L in the pre-disinfection. Considering the inicial low dosage of germicide agent, the results prove the technical viability promising of the methodology proposed to reach the emission microbiological standards established by the Brazilian regulation and to provide ways to final effluent adequacy in agreement with the guidelines defined by WHO to its reuse in the unrestricted irrigation.

Key‐words: Disinfection, wastewater, ozone, indicator pathogen.