removal of pb (ii) from aqueous solutions using mixtures of bamboo biochar and calcium sulphate, and hydroxyapatite and calcium sulphate

Sorption characteristics of Pb(II) from aqueous solutions through a low-cost adsorbent mixture comprising of Bamboo biochar (BB) and Calcium Sulphate (CS), and a more expensive mixture of Hydroxyapatite (HAP) and Calcium Sulphate (CS), were investigated. The effects of equilibrium contact time, and adsorbate concentration conducted in batch experiments were studied. Adsorption equilibrium was established in 40 (min). The adsorption mechanism of Pb(II) from these two adsorbent mixtures was carried out through a kinetic rate order. A pseudo second-order kinetic model was applied for the adsorption processes. The model yielded good correlation (R2 >0.999) of the experimental data. Adsorption of Pb(II) using (BB&CS) and (HAP&CS) correlated well (R2 >0.99) with both the Langmuir and Freundlich isotherm equations under the concentration range studied. Hence, the effectiveness of an inexpensive natural material (BB&CS) mixture in Pb(II) removal is established, and is promising for use in other heavy metal adsorptions.