Loose and Encased Graphite for Methylene Blue Adsorption: Process Optimization and Principal Component Analysis

Abstract

Graphite is often converted to expanded graphite or graphene for water remediation. However, these processes require extra chemicals and energy. This study tested loose and encased pristine graphite powders for dye removal. The loose graphite exhibited good methylene blue removal (>97 % across pH levels), indicating that π‐π interaction is the governing factor besides electrostatic attraction. Notably, 5 g of loose graphite led to 100 % removal. Langmuir isotherm fitting disclosed a maximum adsorption capacity of 4.7059 mg g−1. Principal component analysis showed that dye concentration and adsorbent dosage had a greater impact than pH and contact time. However, encasing graphite in a tea bag inhibits adsorption; future studies could explore options facilitating adsorbate penetration into tea bags.