Membrane Processes for Remediating Water from Sugar Production By-Product Stream

TL;DR

This study explores using membrane processes to clean and recover water and sugar from wastewater in the sugar industry, offering a sustainable alternative to traditional methods.

Contribution

The study introduces an integrated ultrafiltration–reverse osmosis process to effectively treat sugar industry effluent and reduce membrane fouling.

Findings

A tight ultrafiltration pre-treatment significantly reduced membrane fouling and improved performance.

The process achieved 28% water recovery and 79% sugar recovery with high permeate quality.

SEM, EDS, and FTIR analyses helped understand fouling mechanisms on the membranes.

Abstract

Sugar production generates wastewater rich in dissolved solids and organic matter, and improper disposal poses severe environmental risks, exacerbates water scarcity, and creates regulatory challenges. Conventional treatment methods, such as evaporation and chemical precipitation, are energy-intensive and often ineffective at removing fine particulates and dissolved impurities. This study evaluates membrane-based separation as a sustainable alternative for water reclamation and sugar recovery from sugar industry effluents, focusing on replacing evaporation with membrane processes, ensuring high permeate quality, and mitigating membrane fouling. Cross-flow filtration experiments were conducted on a lab-scale membrane system at 70 °C to suppress microbial growth, comparing direct reverse osmosis (RO) of the raw effluent to an integrated ultrafiltration (UF)–RO process. Direct RO resulted in rapid membrane fouling. A tight UF (5 kDa) pre-treatment before RO significantly mitigated fouling and improved performance, enabling 28% water recovery and 79% sugar recovery, maintaining permeate conductivity below 0.5 mS/cm, sustaining stable flux, and reducing membrane blocking. Additionally, the UF and RO membranes were tested via SEM, EDS, and FTIR to elucidate the fouling mechanisms.

Figures