Phenol adsorption by charred sawdust of sheesham (Indian rosewood; Dalbergia sissoo) from single, binary and ternary contaminated solutions

The objective of this work was to evaluate the potential of sheesham sawdust (Indian rosewood; Dalbergia sissoo) charred at 673 K (SSD673) for the removal of phenol from aqueous solution as single contaminant, and competitively from binary and ternary contaminated waters. The experimental observations for removal from single-contaminant water fit well on the Langmuir adsorption model, showing qmax of 344.83 mg phenol/g SSD673 at 45 °C. Adsorption equilibrium was established within 90 min of adsorbate–adsorbent contact and the data obeyed pseudo-second order kinetics model. FT-IR spectroscopy revealed the presence of carbonyl, aldehyde, carboxyl and cellulosic groups that participated in the adsorption of phenol. The adsorption of phenol from binary contaminated system in the presence of methylene blue and Hg2+ was as efficient as from single-contaminant solution, indicating better affinity of SSD673 for phenol. The order of adsorption affinity of SSD673 in the ternary contaminated system was phenol > methylene blue > Hg2+. Studies have revealed that SSD673 has high adsorption capacity and rapid kinetics, while the adsorbent is low-cost and eco-friendly showing potential for use in the treatment of waters containing multiple-contaminants.

► Char prepared from sheesham sawdust (Indian rosewood) at 573, 673 and 773 K were characterized on the basis of physico-chemical properties. ► Adsorption equilibrium for phenol removal by CSD673 was reached in 90 min with qmax of 344.83 mg/g at 45 °C. ► FT-IR revealed the presence of several functional moieties that participate in phenol removal. ► CSD673 showed greater affinity for phenol in the order of phenol > methylene blue > Hg2+, in three contaminated systems, i.e. single, binary, or ternary.