Efficient Removal of Hg(II) by Polymer-Supported Hydrated Metal Oxides from Aqueous Solution

Effective elimination of Hg(II) from water bodies with acid-modified magnetic biomass spent coffee grounds: conditional optimization and application

To maximize the efficiency of biomass waste utilization and waste management, a novel acid-modified magnetic biomass spent coffee grounds (NiFe2O4/SCG) was obtained by pyrolysis at 473 K and co-precipitation methods and employed to eliminate bivalent mercury (Hg(II)) in water bodies. The prepared NiFe2O4/SCG adsorbent exhibits remarkable magnetism with a strength of 45.78 emu/g and can easily be separated from water via a magnetic force. The adsorption of Hg(II) over the NiFe2O4/SCG has an optimal conditions of pH = 8, T = 39 ℃, and dosage of 0.055 g/L, and the maximal adsorption capacity for Hg(II) is 167.44 mg/g via Response Surface Methodology optimization. The removal of Hg(II) over NiFe2O4/SCG primarily involves ion exchange, electrostatic attraction, and chelation; conforms to the pseudo-second-order kinetic and Langmuir models; and is an endothermic reaction. Additionally, the magnetic biomass NiFe2O4/SCG has good regeneration capability and stability. The application research reveal that inorganic salt ions, nitrogen fertilizer urea, humus, and other contaminants in different actual water bodies (river water, lake water, and the effluent of sewage treatment plant) have little effect on the adsorption of Hg(II) over the NiFe2O4/SCG. The prepared adsorbent NiFe2O4/SCG has practical application value for removing Hg(II) from water bodies.

Removal of mercury by adsorption: a review

Due to natural and production activities, mercury contamination has become one of the major environmental problems over the world. Mercury contamination is a serious threat to human health. Among the existing technologies available for mercury pollution control, the adsorption process can get excellent separation effects and has been further studied. This review is attempted to cover a wide range of adsorbents that were developed for the removal of mercury from the year 2011. Various adsorbents, including the latest adsorbents, are presented along with highlighting and discussing the key advancements on their preparation, modification technologies, and strategies. By comparing their adsorption capacities, it is evident from the literature survey that some adsorbents have shown excellent potential for the removal of mercury. However, there is still a need to develop novel, efficient adsorbents with low cost, high stability, and easy production and manufacture for practical utility.