Selective removal of Hg2+ from acidic wastewaters using sulfureted Fe2TiO5: Underlying mechanism and its application as a regenerable sorbent for recovering Hg from waste acids of smelters

Rapid and Selective Removal of Hg2+ by Copper Sulfides under Strongly Acidic Conditions: Mechanism, Kinetics, and Its Application in Recovering Hg from Waste Acids of Smelters

“…This suggests that Cu 2 S may not participate in Hg 2+ removal and HgS formation was mainly attributed to the substitution of Cu + in CuS by Hg 2+ resulting in a release of Cu 2+ . As the strong sulfophile affinity of Hg species, S 0 acted as the adsorption sites for Hg species adsorption. ,, Therefore, the S 2p binding energy at 164.5 eV corresponding to S 0 disappeared after Hg 2+ removal (Figure f).…”

“…The surface of metal oxides and sulfides was generally negatively charged at pH 2.0. 35 Therefore, CuS x /TiO 2 exhibited a strong electrostatic repulsion for isolated Hg 2+ at pH 2.0. However, Hg 2+ presented in the reaction solution with Cl − mainly as HgCl 2(aq) (91%) and HgCl 3 − (8.0%).…”

“…The batch Hg 2+ removal experiments were conducted in a conical flask reactor. 35 Hg 2+ in the reaction solution was obtained by dissolving HgSO 4 in diluted sulfuric acid, followed by dilution with distilled water or 10 mmol L −1 NaCl solution. The initial pH and Hg 2+ concentrations for the batch experiments were 2.0 and 100 mg L −1 , respectively.…”

“…32 As the strong sulfophile affinity of Hg species, S 0 acted as the adsorption sites for Hg species adsorption. 15,35,42 Therefore, the S 2p binding energy at 164.5 eV corresponding to S 0 disappeared after Hg 2+ removal (Figure 1f).…”

“…Meanwhile, spent metal sulfides were difficult to regenerate, and the safe disposal of spent sorbents containing Hg was necessary. In our previous study, FeS 2 was modified on Fe 2 TiO 5 with the sulfuration of gaseous H 2 S, , which was developed as a sorbent to recover Hg 2+ in waste acids . Although the adsorbed Hg 2+ can be recovered as liquid Hg 0 as a co-benefit of the special Hg recovery units in smelters and the spent sorbents can be regenerated with re-sulfuration, its resistance to acid erosion and the rate of Hg 2+ removal were not satisfied.…”