Lead removal from aqueous solutions by raw sawdust and magnesium pretreated biochar: Experimental investigations and numerical modelling.

Lead removal from aqueous solutions by raw cypress (Cupressus sempervirens L.) sawdust (RCS) and its derivative magnesium pretreated biochar (Mg-B) was investigated under static and dynamic conditions through batch and column assays. The Hydrus-1D model was used to estimate the transport parameters of the lead measured breakthrough curves. The batch experiments results showed that Mg-B was very efficient in removing lead compared to RCS and several other previously tested natural and modified materials. The column experiments results indicated that for both RCS and Mg-B, lead breakthrough curves and the related removal efficiencies were mainly dependent on the used initial concentration and the adsorbents bed height. The use of Hydrus-1D showed that the two-site chemical non-equilibrium model describes better the experimental lead breakthrough curves for both RCS and Mg-B as the equilibrium model.