List of Articles Recycling the Spent Catalyst Open Access Article Abstract Page Full-Text 1 - Recycling the Spent Catalysts of Claus Unit in Natural Gas Refineries and Their Application for Synthesis of Composite Adsorbents Coated by Polypyrrole for the removal of lead ions Nima Fallah Tayebeh Johari mohammad Toosi mohammad hasan Peyrovi 10.22034/jest.2020.33711.4133