Novel silica based adsorbent layer-by-layer modified with polyhexamethylene guanidine and Arsenazo reagents for solid-phase extraction of lanthanides from lignites and products of their processing

Abstract

Novel silica-based adsorption materials layer-by-layer modified with polyhexamethylene guanidine and Arsenazo I or Arsenazo III have been proposed for solid-phase extraction of rare earth elements (REE). Silica, modified with Arsenazo I, quantitatively extracted REE at pH 5.5 − 7.0, and silica, modified with Arsenazo III, at pH 2.0–6.0 with distribution coefficients of 2.9 · 103–4.6 · 104 cm3 g−1. The adsorption capacity for REE was 1.25–2.85 mg g−1. Silica, layer-by-layer modified with polyhexamethylene guanidine and Arsenazo III, was used for removal of REE from solutions after digestion of lignites and ashes after their burning.