Fallah, Nima, Johari, Tayebeh, Toosi, mohammad, Peyrovi, mohammad hasan. “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.” Journal of Environmental Science and Technology, vol. 22, no. 3, 2020, pp. 98-109. 10.22034/jest.2020.33711.4133