Influence of composition and drying method of cellulose/bentonite/CTAB composite on the BPA removal

Recent studies on cetyltrimethylammonium bromide (CTAB)-modified biopolymers and clay-cellulose composites for organic pollutant removal have focused exclusively on batch adsorption experiments, lacking systematic evaluation of drying method effects on morphological preservation and performance validation in continuous flow systems. This work addresses these critical gaps by investigating microfibrillated cellulose (MFC) composites with CTAB modified bentonite (B@C) for bisphenol A (BPA) removal, systematically comparing freeze-drying versus oven-drying preparation methods. Mercury intrusion porosimetry revealed that freeze-drying preserved three-dimensional porous architecture (porosity ~93%), whereas oven-drying induced structural collapse (39.2-74.7% porosity). Batch experiments demonstrated that morphological preservation, rather than total CTAB content, determined adsorptive efficiency; freeze-dried MFC/8B@C achieved q max = 98.51 mg/g versus 43.99 mg/g for oven-dried counterparts, a 159% improvement despite similar CTAB loading. Fixed-bed column validation, the first reported for CTAB-modified cellulose systems, demonstrated q₀ = 115.92 mg/g, surpassing literature values by up to two orders of magnitude. Performance evaluation in freshwater versus ultrapure water revealed natural organic matter interference effects (q max = 74.37 mg/g versus 98.51 mg/g), establishing practical applicability limits absent in previous studies. Integrated economic analysis identified MFC/2B@C as achieving optimal cost-effectiveness ($0.25/L) despite lower adsorption capacity, providing essential guidance for large-scale implementation.