Ultrapure Water Production by a Saline Industrial Effluent Treatment

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Industrial Wastewater Management

Background:

• Canned food industry effluent poses challenges due to high salinity and mineral content.
• Existing treatment methods may not be cost-effective or efficient for producing ultrapure water from such sources.
• Membrane scaling and fouling are significant issues in treating saline industrial wastewater.

Purpose of the Study:

• To develop and evaluate a membrane system for ultrapure water production from saline canned food industry effluent.
• To assess the effectiveness of reverse osmosis (RO) with antiscalant and ion exchange resins (IEXRs) for water purification.
• To determine the feasibility of reusing treated brine and the cost-effectiveness of the process.

Main Methods:

• A two-stage treatment process combining reverse osmosis (RO) and ion exchange resins (IEXRs).
• Application of hexametaphosphate as an antiscalant during the RO stage to prevent mineral scaling.
• Utilizing anionic and mixed cationic-anionic resins for deionization to achieve ultrapure water quality.

Main Results:

• The optimized antiscalant dose of 6 mg/L resulted in 65-70% clean water efficiency from RO permeates with minimal fouling.
• RO treatment achieved 20% total dissolved solids (TDS) removal, effectively reducing salt concentration.
• Ion exchange resins removed 99.8% of chloride ions and other monovalent salts, producing ultrapure water with electrical conductivity below 3.3 µS/cm.
• The estimated cost for ultrapure water production was 2.62 USD/m³.

Conclusions:

• The combined RO and IEXR system is effective for producing high-purity water from saline industrial effluent.
• Hexametaphosphate successfully mitigated membrane scaling, enhancing the efficiency of the RO process.
• The treated brine has potential for reuse in food industry applications, contributing to a circular economy approach.