Novel dual modified alkali lignin based adsorbent for the removal of Pb2+ in water

In the present study, a dual - modified lignin (DML) adsorbent, which exhibits a high adsorption capacity for Pb2+, was prepared through the reaction of alkaline lignin with ClCH2COOH and CS2. The main objective of the present was to prepare a biomass-based adsorbent that is suitable for scavenging heavy metals from wastewater. The DML was characterized using Fourier transform-infrared Spectroscopy (FT-IR), Elemental Analysis, Conductivity titration, Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The results show that carboxyl and -CSS- components are introduced into the DML, and the corresponding concentrations were 1.3 mmol/g and 30.5 %, yielding an adsorbent with a specific surface area of 3.13 m(2)/g. The rough aggregated porous structure of the DML enhances the adsorption of Pb2+. An adsorption experiments reveal that the Pb2+ adsorption by the DML is adequately represented by a pseudo - second-order kinetic equation, and these produced a maximum Pb2+ adsorption capacity of 208.3 mg/g. XPS (X-ray photoelectron spectroscopy) results demonstrates that complexation and electrostatic attraction constitute the Pb2+ adsorption mechanisms associated with the DML. The adsorbent produced in the present study is valuable for protecting water quality and the environment, and provides another avenue for the utilization of lignin.

Automated summary

A dual - modified lignin (DML) adsorbent with high adsorption capacity for Pb2+ was prepared in this study for scavenging heavy metals from wastewater. The results showed that the Pb2+ adsorption mechanism of DML mainly consists of complexation and electrostatic attraction. This adsorbent is valuable for protecting water quality, the environment, and provides a new avenue for lignin utilization.