Process optimization for Ni(II) removal from wastewater by calcined oyster shell powders using Taguchi method

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Waste oyster shells (OSP) present environmental challenges.
• Nickel (Ni(II)) is a toxic heavy metal pollutant.
• Sustainable methods are needed for heavy metal remediation.

Purpose of the Study:

• To optimize nickel removal using calcined oyster shell powders (OSP).
• To identify key factors influencing Ni(II) adsorption efficiency.
• To develop a predictive model for Ni(II) removal.

Main Methods:

• Application of the Taguchi method for experimental design.
• Optimization of controllable factors: pH, calcined temperature, Ni(II) concentration, OSP dose, and contact time.
• Development of a multiple linear regression model for Ni(II) removal prediction.

Main Results:

• pH (64.3%) and calcined temperature (18.9%) were the most significant factors for Ni(II) removal.
• Optimal conditions determined as pH 10 and OSP calcined at 900°C.
• Near-complete Ni(II) removal achieved under optimal conditions due to increased porosity and surface area.

Conclusions:

• Calcined oyster shell powders are effective for nickel remediation.
• The developed regression equation accurately predicts Ni(II) removal efficiency.
• The findings support the practical application of OSP in wastewater treatment for nickel removal.