Matrix effects on the performance and mechanism of Hg removal from groundwater by MoS₂ nanosheets

Abstract

Mercury (Hg) contamination in groundwater has been recognized as a serious threat to human health and ecological system all over the world. This study demonstrated two-dimensional (2D) molybdenum disulfide (MoS2)...

Effect of natural organic matter (NOM) on the removal efficiency of Hg(ii) by MoS2: dependence on the Hg/MoS2 ratio and NOM properties

“…S6b† demonstrates that the pseudo-second-order kinetic model yielded an excellent fitting with a coefficient R 2 of 0.99, suggesting the chemical nature of Hg adsorption by MoS 2 . 14…”

“…S6b † demonstrates that the pseudosecond-order kinetic model yielded an excellent fitting with a coefficient R 2 of 0.99, suggesting the chemical nature of Hg adsorption by MoS 2 . 14 Upon the addition of 20 mg L −1 NOM, the Hg removal kinetics still displayed a rapid rate during the initial 1 h, followed by a slower rate until equilibrium was reached at 24 h. The removal capacity of Hg(II) was 1952 mg g −1 after 24 h Environmental Science: Nano Paper of reaction, lower than without NOM, indicating that NOM inhibited the removal efficiency of Hg(II) by MoS 2 . Meanwhile, as shown in Fig.…”

“…This reduction process involves the transformation of Hg(II) into Hg 0 and/or Hg 2 Cl 2 , achieved by oxidizing MoS 2 into soluble molybdate ions (MoO 4 2− ) and sulfate ions. 14,15 For instance, Wang et al 14 reported that the reductive removal of Hg(II) by MoS 2 nanosheets enhanced the removal capacity of Hg to 6288 mg g −1 through the formation of Hg 0 and Hg 2 Cl 2 . Similarly, Fausey et al 15 found that MoS 2 coated nanofibrous mats effectively reduced Hg(II) to Hg 0 with 73% Hg(II) removal via the formation of Hg 0 .…”

Sustainable Design of Molybdenum Disulfide Nanocomposites for Silver Recovery

“…A 100 mg L −1 stock solution of silver was prepared by dissolving 78.7 mg of silver nitrate (ACS reagent, Sigma-Aldrich, United States) in 500 mL of DI. Silver working solutions were prepared through dilution of the stock solution to different concentrations (1,4,6, and 10 mg L −1 ). In all batch adsorption experiments, 15 platform particles were added to 50 mL falcon tubes filled with 40 mL of silver working solution.…”

“…Molybdenum disulfide (MoS 2 ) is a two-dimensional (2D) transition metal dichalcogenide with a lamellar structure of molybdenum atoms covalently bound to two outer layers of sulfur atoms. Beyond its use in electronic and catalytic applications, MoS 2 has been recently explored for various environmental applications. , For example, MoS 2 has been suggested as a selective nanoadsorbent of heavy metals through Lewis soft-acid soft-base interactions with exposed sulfur atoms , and has demonstrated exceptional adsorption capacities toward lead, cadmium, silver, and mercury. − …”