Hyperbranched Dithiocarbamate-Modified Biochar: A Promising Adsorbent for Selective Removal of Pb(II) from Wastewater

Herein, dithiocarbamate-modified biochar (BC-HDTC) was successfully synthesized with nitric acid (HNO3), thionyl chloride (SOCl2), branched PEI and carbon disulfide (CS2). The effective anchoring of amine dithiocarbamate groups onto the surface proven by SEM, FTIR, XPS, N2 adsorption–desorption experiment. batch experiments demonstrated BC-HDTC can selectively remove 98% Pb(II) within multi-metals solution when pH = 5, T 30 °C. impact variations on were researched (pH, contact duration, original concentration).The sorption kinetics (pseudo-first-order, pseudo-second-order, intra-particle diffusion model) isotherm modeling (Langmuir, Freundlich, tempkin models) investigated. adsorption process depicted to attain equilibrium in less than 20 min fit Langmuir isotherms pseudo-2nd-order satisfactorily. complexation functional HDTC (amine/imine dithiocarbamate) as well ion exchange between Na(I) are main mechanisms. endothermic spontaneous, according thermodynamic parameters. After 4 consecutive adsorption-desorption cycles, Pb removal efficiency BC- remained over 90%. This work revealed significant potential for contamination BC-HDTC, a valuable reusable adsorbent.