Abstract
Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.
Highlights
The wastewater produced by the leather industry is considered to be one of the most contaminated wastes, since there is a considerable amount of organic material and inorganic chemicals
This study provides a comprehensive understanding of membrane fouling in the ultrafiltration process of tanning wastewater and provides guidance for its industrial application
The removal efficiency observed for chemical oxygen demand (COD), fat, SS, and protein were calculated for the distinct UF membranes in different operating conditions
Summary
The wastewater produced by the leather industry is considered to be one of the most contaminated wastes, since there is a considerable amount of organic material (mainly dissolved fat, protein, keratin, etc.) and inorganic chemicals (various salts, such as chloride Sodium, sodium sulfate, calcium hydroxide, sodium sulfide, etc.). The presence of these substances leads to high chemical oxygen demand (COD), biochemical oxygen demand (BOD), suspended solids (SS), conductivity, and so on. Membrane separation has shown to be a promising water reuse technology to achieve zero liquid discharge (ZLD) in the leather industry
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
