Simultaneous optimization of multiple performance characteristics in coagulation-flocculation process for Indian...

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Industrial Wastewater Management

Background:

• Paper and pulp industry wastewater presents significant environmental challenges due to high organic load and dissolved solids.
• Conventional treatment methods often require optimization to meet stringent discharge regulations.
• Coagulation-flocculation is a critical primary treatment step for industrial effluents.

Purpose of the Study:

• To optimize the coagulation-flocculation process for paper and pulp industry wastewater.
• To identify the most influential process parameters using a robust statistical methodology.
• To enhance the removal efficiency of key pollutants like chemical oxygen demand (COD), total dissolved solids (TDS), and turbidity.

Main Methods:

• Application of the grey relational analysis (GRA)-based Taguchi method for process optimization.
• Systematic variation of process parameters including natural coagulant type and dose, coagulant aid type and dose, and pH.
• Monitoring and analysis of wastewater responses: COD, TDS, and turbidity.

Main Results:

• Analysis of variance (ANOVA) identified coagulant aid type and dose as the most significant parameters influencing treatment efficiency.
• pH and coagulant dose were also significant, while coagulant type showed minimal impact.
• Confirmatory experiments demonstrated significant improvements: 8.2% higher COD removal, 6.35% higher TDS removal, and 26.17% reduction in turbidity.

Conclusions:

• The Taguchi method combined with GRA provides an effective framework for optimizing complex industrial wastewater treatment processes.
• Coagulant aid selection and dosage are critical factors for efficient removal of COD, TDS, and turbidity in paper and pulp wastewater.
• The optimized process offers a practical and improved approach to managing paper and pulp industry effluents.