Mercury removal from aqueous solution by adsorption on activated carbons prepared from olive stones

Abstract

The textural characterization of a series of activated carbons prepared from olive stones, by carbonization at different temperatures (400, 550, 700 and 850°C) and thermal activation with CO 2 , has been investigated using N 2 adsorption at −196°C and CO 2 adsorption at 0°C. The effect of pre-oxidation of the carbonized precursor has also been studied, using temperature-programmed decomposition (TPD), to evaluate the effect of oxygen content of the chars in the performance of the obtained activated carbons for mercury removal. The adsorption of Hg(II) cations from aqueous solutions at room temperature by the prepared activated carbons was studied. Experimental results show that all samples exhibit a large microporosity (pore diameter below 0.56 nm). The amount of surface oxygen groups increased after pre-oxidation treatment, this enhancing the Hg(II) uptake (up to 72%). It can be concluded that these groups make the support more hydrophilic, thus providing a more efficient adsorption of Hg(II). The formation of a great amount of surface oxide groups such as carboxyl, phenol and lactone alters the surface charge properties of the carbon, this enhancing the surface-Hg(II) interaction.

Polyvinyl chloride composites filled with olive stone flour: Mechanical, thermal, and water absorption properties

“…Different strategies have been reported in the literature to valorize the solid by‐products generated by the olive oil extraction, to reduce the negative environmental impact. The solid waste can be burned to produce electric energy or heat, or turned into activated carbon after a thermal treatment for the removal of poisonous metals from water . The possible use of the solid by‐products as a source of compost material has also been approached .…”

Preparation of Micropore-Containing Adsorbents from Kenaf Fibers and Their Use in Mercury Removal from Aqueous Solution

“…Thus, samples prepared at high temperatures (i.e., 700 and 800 • C), presented the highest mercury uptakes. A number of authors have reported that the mercury adsorption not only depends on textural characteristics but also on the chemical nature of the prepared samples (Ranganathan 2003;Leyva-Ramos et al 2011;Wahby et al 2011). In this case, and according to the textural data (Table 1), it becomes visible that the influence of the adsorbent porous texture in the mercury uptake was relatively important.…”

Adsorption of Pb and Cd in rice husk and their immobilization in porous glass‐ceramic structures

“…[1][2][3][4] Among these processes, the adsorption process is a simple and effective technique for heavy metal removal from waste water. The most important adsorbents include zeolites, [5][6][7] activated carbon, [8][9][10] expanded perlite, 11 and rice husks. [12][13][14][15] Even though activated carbon became the most attractive candidate as an adsorbent, but its cost and the loss of adsorption efficiency after regeneration of the exhausted activated carbon 16,17 moved the investigation toward low-cost green adsorbents.…”