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.

中文翻译：

---

用于亚甲基蓝吸附的松散和包裹石墨：工艺优化和主成分分析

石墨通常被转化为膨胀石墨或石墨烯用于水修复。然而，这些过程需要额外的化学品和能源。这项研究测试了松散和包裹的原始石墨粉末的染料去除效果。松散石墨表现出良好的亚甲基蓝去除率（在不同 pH 水平下>97%），表明 π-π 相互作用是除静电吸引力之外的主导因素。值得注意的是，5 克松散石墨导致 100% 去除。Langmuir等温线拟合揭示最大吸附容量为4.7059 mg g ^-1。主成分分析表明，染料浓度和吸附剂用量的影响比 pH 值和接触时间的影响更大。然而，将石墨装入茶袋中会抑制吸附；未来的研究可以探索促进吸附物渗透到茶袋中的选择。