Adsorption of Pb2+ in Aqueous Solutions by Biologically Produced Sulfur as a Novel Adsorbent

In the process of biological desulfurization of gases from landfills, huge amounts of biologically produced Sulfur (BPS) were produced as by-products.A study was conducted to find out the possibility of using it as an adsorbent for Pb 2+ .BPS was subjected to an adsorption test in an aqueous solution in the presence of Pb 2+ and compared with the removal efficiency of granular activated carbon (GAC), which is mainly used as an adsorbent for heavy metal.As a result of the Pb 2+ removal experiment using BPS, it was a two-step process in which 54.5% of the initial Pb 2+ was removed within 5 minutes by fast initial adsorption followed by slow adsorption.As a result of the isotherm adsorption experiment, the Pb 2+ adsorption to BPS was fitted the Langmuir isotherm model, and the maximum adsorption capacity of BPS (175.4 mg g -1 ) was about 3 times higher than that of GAC (67.11 mg g -1 ).The data from XPS demonstrated that the main adsorption mechanism was the complexation of Pb 2+ with the sulfide in the BPS.Therefore, it was confirmed that BPS has sufficient value to be recycled as a new adsorbent for Pb 2+ removal in wastewater.