High capacity and fast removal of Cr(vi) by alkali lignin-based poly(tetraethylene pentamine-pyrogallol) sorbent.

In this work, a novel alkali lignin-based adsorption material, alkali lignin-based poly(tetraethylene pentamine-pyrogallol) (AL-PTAP), was prepared using a Mannich reaction and catechol-amine reaction for removal of Cr(vi). It was characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effects of tetraethylene pentamine (TEPA) dosage, pyrogallol (PL) dosage, contact time, pH, temperature and other factors on the adsorption behavior of the adsorbent were systematically investigated.