Treatment of industrial effluent by bench-scale microfiltration aiming at water reuse

Abstract

Objective – To evaluate the bench-scale microfiltration process for the treatment of industrial effluent generated from the CIP (Clean in Place) system of a brewery, analyzing color, turbidity, and pH as quality parameters, and verifying the effect of centrifugation as a pretreatment step aiming at non-potable water reuse.

Methodology –  The study was carried out at a bench scale, employing centrifugation as a preliminary stage and microfiltration using glass fiber membranes with pore size < 1.0 µm. Color (Pt-Co), turbidity (NTU), and pH analyses were performed in triplicate, following AWWA (2012) standards. Five tests were conducted: three with raw effluent (50, 100, and 150 mL) and two with centrifuged effluent (50 mL with a new membrane and 50 mL with a reused membrane).

Originality/Relevance – The study explores the combination of centrifugation and microfiltration for treating CIP effluent, a scarcely investigated approach in brewery wastewater management. It provides a low-cost and practical alternative for industrial water reuse, aligned with the Sustainable Development Goals.

Results – Centrifugation promoted approximately 82% color and 95% turbidity removal, proving to be an effective pretreatment. Microfiltration applied directly to raw effluent showed early membrane fouling and removals below 30%. Conversely, microfiltration of the centrifuged effluent reduced color to 128 ± 2.5 Pt-Co and turbidity to 112 ± 2.0 NTU, achieving removals above 85%. Membrane reuse showed decreased color removal efficiency due to fouling accumulation.

Theoretical/Methodological Contributions – This study enhances the understanding of membrane fouling during the treatment of alkaline effluents and provides a reproducible experimental model for comparative future studies.

Social and Environmental Contributions – The research reinforces the feasibility of water reuse in non-potable brewery processes, contributing to water resource conservation and the reduction of industrial effluent discharge.