Membrane Polishing of Stabilization-Pond Effluent from a Poultry Slaughterhouse: Microfiltration, Ultrafiltration, and Water Reuse Potential

Background: Poultry slaughterhouses generate large volumes of wastewater, and conventional biological treatment systems may not provide effluents with sufficient quality for water reuse. Objective: This study evaluated microfiltration (MF) and ultrafiltration (UF) as polishing processes for stabilization-pond effluent from a poultry slaughterhouse, considering hydraulic performance, permeate quality, flux-decline and post-cleaning behavior, and non-potable water reuse potential. Methods: Crossflow filtration experiments were performed using a 0.1 µm PVDF MF membrane at transmembrane pressures of 0.5 and 1.0 bar and a 50 kDa PES UF membrane at 0.5, 1.0, and 2.0 bar. Permeate flux, physicochemical characteristics, and microbiological quality were evaluated, and multivariate analysis was applied to identify relationships among membrane type, operating conditions, and permeate quality. Results: MF provided higher permeate fluxes, whereas UF exhibited greater operational stability. Complete turbidity removal and absence of total coliforms and Escherichia coli were achieved under all evaluated membrane conditions. Among the operating conditions, UF at 1.0 bar showed a favorable combination of hydraulic stability and permeate quality, reducing electrical conductivity by 51%, alkalinity by 32%, and chemical oxygen demand by 17%. However, residual organic matter remained relatively high, indicating that additional treatment may be required for more restrictive reuse applications. Hypothetical industrial water-balance scenarios considering 10–50% substitution of the facility water demand were used to illustrate the potential magnitude of potable-water replacement; these scenarios do not represent experimentally determined membrane-system recovery. Conclusion: These findings demonstrate that membrane polishing can improve the reuse potential of stabilization-pond effluents and that membrane selection and operating pressure should consider the trade-off between hydraulic productivity, flux stability, and permeate quality.