Adsorption of bisphenol A in aqueous solution by composite bentonite with organic moity

Bisphenol A (BPA) is a pollutant in the sewage of petroleum and petrochemical field, which is difficult to be treated efficiently. In this work, the composite modified Bentonite (CPAB/EGIS/B) was prepared by using ester-containing gemini imidazolium surfactant (EGIS) and cationic polyacrylamide (CPAB) as modifiers, CPAB/B and EGIS/B were also prepared. The samples were characterized by XRD, EA, FT-IR, SEM, and N2 Physical adsorption and desorption, the changes of composition and structure of modified bentonite were studied. The adsorption performance of samples was tested by BPA, which shows that CPAB/EGIS/B has the strongest adsorption capacity for BPA solution. Under the conditions of initial pH, at 30 °C, the best adsorption effect was obtained when the dosage of the composite was 2.5 g/L for 180 min, the theoretical maximum adsorption capacity was 119.88 mg/g. CPAB and EGIS formed a more affinity organic micro-environment between bentonite layers and establish a nice structure-activity relationship with BPA. The adsorption of BPA onto CPAB/EGIS/B matched well with the pseudo-second-order model. The obtained isotherms data were described well by the Langmuir model and the adsorption is a spontaneous exothermic process. [Display omitted] •Composite bentonite with ester imidazolium surfactant and cationic polyacrylamide.•A novel organic moity micro-environment between bentonite layers formed.•Composite bentonite shows high adsorption capacity to bisphenol A in aqueous solution.•The adsorption mechanism, kinetics, isotherms, and thermodynamics were studied.•Structure-activity relationship was established between composite bentonite and bisphenol A.