Surface Modification of Fly Ash by Poly(1,5-Diaminonaphthalene) for Removal of Hexavalent Chromium from Water

The Fly Ash (FA) was treated by NaOH solution in order to transform into the zeolite-like structure. Poly(1,5-diaminonaphthalene) [p(1,5-DAN)] was synthesized via in-situ chemical oxidation on the surface of NaOH-Treated Fly Ash (TFA) to form p(1,5-DAN)/TFA composite. The p(1,5-DAN)/TFA composite was used as a novel sorbent for removal of Cr(VI) ions from aqueous solutions. The maximum adsorption capacity (at pH 2, 298 K) calculated according to Langmuir isotherm model was 4.4 mg/g. This result suggested that p(1,5-DAN)/TFA was a promising adsorbent for Cr(VI) ions in the environmental treatment.