Hybrid materials precursor to natural clay in the attenuation of bisphenol A from aqueous solutions

The present study demonstrates the potential use of organo- and inorgano-organo-modified bentonite and locally collected clay to efficiently attenuate bisphenol A (BPA), one of the most important endocrine disrupting chemical) from aqueous solutions. The hybrid materials were obtained by modifying commercial bentonite or locally collected clay with hexadecyltrimethylammonium bromide (HDTMA) to obtain organo-modifed clay samples (named BH or LCH). Aluminum pillared HDTMA modified clay samples were obtained as inorgano-organo-modified clay hybrid materials (named BAH or LCAH). The hybrid materials were characterized using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) methods. Surface morphology of these solids was determined by field emission scanning electron microscope (FE-SEM) images. pHPZC of these solids were obtained by acid and base titrations. These hybrid materials were used as molecular sieve to attenuate BPA from aqueous solutions. Batch reactor studies were conducted for various physico-chemical parameters. The effect of pH, initial BPA concentration, contact time, and background electrolyte concentrations was studied under the batch mode operations. Porous hybrid materials showed substantially higher sorption capacity than virgin clay. Column reactor operations were performed to obtain loading capacity of these solids for BPA under dynamic conditions.