Study on the high-efficiency adsorption mechanism and performance of cetyltrimethylammonium bromide and hydroxy-iron pillared modified montmorillonite granules for Cr(VI) in water
Year: 2026
Type: article
Abstract: Water pollution control is critical, with hexavalent chromium (Cr(VI)) posing severe threats. Adsorption technology is widely adopted for its operational simplicity. This study developed a high-efficiency adsorbent by modifying montmorillonite (MMT) with cetyltrimethylammonium bromide (CTAB) and hydroxyl-iron (OH/Fe) pillaring, and the resulting CTAB-OH/Fe-MMT powder was then engineered into robust granules(SA-CTAB-OH/Fe-MMT) by mixing with a sodium alginate(SA) solution and solidifying with calcium chloride. Materials were characterized using SEM, BET, XRD, and FT-IR. Effects of adsorbent dosage, pH, time, and initial Cr(VI) concentration were investigated. Dynamic adsorption evaluated flow rate, bed height, and initial Cr(VI) concentration on SA-CTAB-OH/Fe-MMT granules, fitted with Thomas and Yoon-Nelson models. Results demonstrate optimal preparation: mass ratio 0.5:1 for CTAB:OH/Fe-MMT and 1 %(w/v) sodium alginate. Granules exhibited smooth surfaces and expanded interlayer spacing. Under optimized conditions (pH=4, dosage=6 g/L, T = 120 min, initial Cr(VI)= 10 mg/L), Cr(VI) removal reached 91.5 %. Breakthrough time decreased with increasing flow rate/initial concentration but extended with bed height. Adsorption followed pseudo-second-order kinetics and Langmuir isotherm (max capacity=11.629 mg/g), confirming an endothermic process. Both models effectively described adsorption. This provides a novel material for efficient Cr(VI) removal, offering insights for functionalizing layered minerals.
Authors: Zhili Lu, Yan Shi, Chaoyang Yue, Xin Wang
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,650
Award: G4396384011
OpenAlex ID: W7129052898