Mercury is a highly toxic and hazardous pollutant even in trace quantity which poses a major threat to the ecosystem on deposition in the environment. Removal of mercury from aqueous systems has been a subject of immense interest for researchers. The synthesis of highly cross-linked cellulose beads embedded with ferric oxide for removal of Hg(II) ions from aqueous systems has been investigated. The beads were synthesized by solution polymerization technique. The impact of solution pH, ferric oxide content, and initial concentration of Hg(II) ions on the uptake of Hg(II) ions revealed that maximum adsorption occurs at pH 6.0 with beads having 10？wt% Fe2O3 content. Equilibrium adsorption of Hg(II) ions followed the Langmuir isotherm model. Adsorption was observed to follow pseudo second-order kinetic model and intraparticle diffusion model. 1. Introduction Heavy metals such as mercury are considered as toxic and their accumulation over the period of time in human bodies causes serious health hazards, possessing major threats to human health. Heavy metal pollution can arise from various sources but is highly common from purification of metals, for example, smelting of copper and preparation of nuclear fuels. Unlike organic pollutants, heavy metals do not biodegrade which is the largest problem associated with the persistence of heavy metals which has the potential of bioaccumulation and biomagnification entering the food chain causing heavier exposure and hence biological disorders. Mercury affects the central nervous system, kidneys [1], and liver. Compared to other heavy metals, mercury even at low concentrations is highly neurotoxic [2]. Various conventional methods such as chemical precipitation, membrane filtration, ion exchange, lime softening, coagulation-flocculation, photoreduction [1, 3, 4], and electrochemical treatment have been employed for removal of mercury from aqueous systems. Adsorption is the most effective technique for removing heavy metal ions from aqueous solutions. The important aspect of the adsorption process is easy regeneration ability and less operational cost, simple design, easy operation, and free or less generation of toxic substances [5]. Adsorption techniques have proven successful in removing colored organic species and the choice of the adsorbent is one of the key factors determining the effectiveness of any adsorption process. The adsorption process at solid/liquid interface has been extensively employed for several reasons, mainly due to its efficiency and economy [6]. Physical adsorption because of its low cost, high
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