Matrix-enhanced adsorption removal of trace BPA by controlling the interlayer hydrophobic environment of montmorillonite

•Systematic relation of adsorption of trace amount of BPA to gallery hydrophobicity•Complete removal of trace BPA by longer (n > 12) chain surfactant intercalation•Matrix organic substances enhanced adsorption of trace BPA in organoclay.

There is an increased concern recently toward Bisphenol A (BPA), a typical phenolic type estrogenic endocrine disruptor compound, because of its potential impact toward both human beings as well as wildlife at a trace concentration level. In this research, the surfactant-modified montmorillonite materials were used aiming at the complete removal of trace BPA in water environment. Through a detailed examination on the intercalation properties of alkyltrimethylammonium ions, the interlayer hydrophobic environment properties of the clay minerals, and their relationship with the BPA equilibrium adsorption, it is concluded that BPA at a trace concentration level can be completely removed through increasing the chain length of the surfactant intercalates. Sufficient interlayer hydrophobicity, realized by near or excess cation exchange capacity intercalation of longer chain surfactants, is found significant to the enhancement of selective adsorption of BPA while coexisting with matrix organic substances, which is substantially instructive to the removal of other kinds of non-ionic emerged organic contaminants.

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