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 N-2 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 degrees 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.