Adsorption of Cr(VI) and Cd(II) on charcoal from alep pine: Effects of Simple Chemical and Thermal Post Treatments

In the present work we report the adsorption of heavy metals Cr (VI) and Cd (II) on an adsorbent made up from rough charcoal of Pin of Alep. The charcoal prepared traditionally (dehydrated at 100°C and carbonised at 280°C) is crushed and sieved to Ø < 0.25 mm in diameter. The raw charcoal shows a specific area of 410 m²/g. The characterisation of surface functional groups of charcoal after chemical post treatments by distilled water, hydrochloric acid, sodium hydroxide or by thermal treatment at 600°C shows the presence of carboxylic acid, phenolic, lactone and carbonyl functional groups. The adsorption capacities of the different charcoals were determinate and the modelling of the isotherms was done according to Langmuir and Freundlich models. The samples CHRS (treated by NaOH solution) and CHRT (heat treatment till 600°C) present promising adsorptive properties. On the basis of the obtained results, it is possible to conclude that the charcoal of pine of Alep can be used for the elimination of the mineral pollutants such as chromium and cadmium in water with moderate capital costs.