# Performance Evaluation of Polymeric Tubular Membranes for Wastewater from Rubber Production

## TL;DR

This study evaluates how well polymeric membranes can treat rubber production wastewater, showing high initial efficiency but reduced performance over time.

## Contribution

The study provides empirical data on membrane performance and regeneration in rubber industry wastewater treatment.

## Key findings

- Tubular membranes reduced turbidity by over 95% and showed high initial separation efficiency for contaminants.
- Membrane performance declined significantly after several hours of operation due to fouling.
- Chemical cleaning recovered about 70% of initial performance for PES membranes and 60% for PVDF membranes.

## Abstract

The purpose of this study was to assess the suitability of tubular polymeric ultrafiltration membranes for use in a closed-loop water system within a rubber manufacturing plant. This research focused on determining the transport and separation properties of polymeric tubular membranes during the ultrafiltration of wastewater generated from washing vulcanised rubber hoses. The tests were conducted using the installation of the UF-1 membrane supplied by APEKO Sp. z o.o. This study evaluated the performance of modified PES membranes with a molecular weight cut-off (MWCO) of 4 kDa and PVDF membranes with MWCO of 100 kDa in the wastewater treatment process, as well as the effectiveness of membrane regeneration. Given the characteristics of wastewater, the key parameters for evaluating ultrafiltration performance included the determination of contaminant separation coefficients (R, %) for non-ionic surfactants (NIS) and chemical oxygen demand (COD), as well as turbidity reduction. The results demonstrated that the tested membranes substantially improved the visual quality of the wastewater by reducing turbidity by more than 95% and exhibited high separation efficiency for the analysed contaminants, with initial values of RNIS = 95% and RCOD = 85% at the beginning of the ultrafiltration cycle, decreasing to RNIS < 10% and RCOD < 10% after several hours of operation. During closed-loop filtration, when a twentyfold concentration of contaminants in the retentate was reached, membrane fouling occurred, significantly reducing filtration performance. Chemical cleaning enabled the recovery of approximately 70% of the initial performance for modified PES membranes and 60% for PVDF membranes.