Preparation of Waterborne Polyurethane Foam with Active Carbon and Its Adsorption for Phenol in Aqueous Solution

Concerned about environmental pollution and health safety risks, waterborne polyurethane (WPU) was introduced in place of conventional binders in preparing an active carbon polyurethane foam, active carbon WPU foam (ACWPU foam), through two sequential steps. The scanning electron microscopy and wettability tests showed that the WPU-based process was effective for achieving a higher active carbon content, enhanced pores' wall roughness, and improved hydrophilicity of the foam, which was explained by infrared spectroscopy. Adsorption behavior of the ACWPU foam for phenol in aqueous solutions was investigated by batch experiments. The results showed that the maximum removal capacity of phenol ( foam) with of sorbent was observed at at pH 7. Removals of more than 85% occurred in 2.5h, and the loading half-time was calculated to be only 26.77min. In addition, adsorption kinetic data were described by a pseudo-second-order equation and the equilibrium data fitted very well with the Langmuir and Temkin models. Further, the ACWPU foam could be fully recycled via 0.01M NaOH. In general, WPU as an environmentally friendly binder had excellent application in preparing ACWPU foam. Meanwhile, this foam should be a promising adsorbent in the recovery of phenol.