Isotherm parameters for basic dyes onto activated carbon: comparison of linear and non-linear method

Area of Science:

• Environmental Chemistry
• Adsorption Science

Background:

• Wastewater from textile and other industries often contains toxic basic dyes.
• Activated carbon is a widely studied adsorbent for dye removal due to its porous structure and large surface area.

Purpose of the Study:

• To investigate the equilibrium sorption of four basic dyes (Basic Red 9, Basic Violet 3, Basic Brown 1, Basic Violet 10) onto activated carbon.
• To compare the effectiveness of linear and non-linear regression methods for estimating sorption isotherm parameters.

Main Methods:

• Equilibrium sorption experiments were conducted at 305 K.
• Sorption isotherm parameters were estimated using both linear and non-linear regression analyses.
• The adsorption capacity of activated carbon for each dye was determined.

Main Results:

• Non-linear regression analysis was found to be more appropriate for estimating isotherm parameters compared to linear regression.
• The sorption capacity of activated carbon for the tested cationic dyes increased in the order: Basic Red 9 (131 mg/g) < Basic Violet 3 (247 mg/g) < Basic Violet 10 (259 mg/g) < Basic Brown 1 (404 mg/g).

Conclusions:

• Activated carbon demonstrates significant potential for removing basic dyes from aqueous solutions.
• The choice of regression method impacts the accuracy of isotherm parameter estimation, with non-linear methods being superior.
• Basic Brown 1 exhibits the highest affinity for adsorption onto activated carbon among the studied dyes.