Removal of methyl violet from aqueous solution by perlite

Area of Science:

• Environmental Science
• Materials Science
• Water Treatment

Background:

• Methyl violet is a common industrial dye posing environmental concerns.
• Effective removal of methyl violet from aqueous solutions is crucial for water purification.
• Perlite, a natural volcanic glass, is explored as a low-cost adsorbent material.

Purpose of the Study:

• To investigate the efficacy of perlite for methyl violet removal from aqueous solutions.
• To determine the influence of operational parameters (concentration, pH, temperature) on adsorption.
• To evaluate the adsorption mechanism and isotherm models for methyl violet onto perlite.

Main Methods:

• Batch adsorption experiments were conducted using perlite and methyl violet solutions.
• Adsorption equilibrium, isotherms, and kinetic studies were performed.
• The effects of varying pH, temperature, and initial dye concentration were analyzed.

Main Results:

• Adsorption equilibrium was achieved within 1 hour.
• Perlite's adsorption capacity increased with higher pH and temperature.
• Adsorption capacity decreased with perlite expansion and acid activation; Langmuir model best described the data.
• Physical adsorption was indicated by the heat of adsorption, and unexpanded perlite was more effective.

Conclusions:

• Perlite is a viable adsorbent for methyl violet removal from aqueous solutions.
• Physical adsorption is the primary mechanism for methyl violet onto perlite.
• Unexpanded perlite offers superior performance for methyl violet adsorption compared to expanded or acid-activated perlite.