Dithiocarbamate functionalized lignin for efficient removal of metallic ions and the usage of the metal-loaded bio-sorbents as potential free radical scavengers

Abstract

Lignin-based dithiocarbamate (LDTC) was synthesized by anchoring the chelating agent of dithiocarbamate to the ortho sites of phenol hydroxyl groups in the alkaline lignin matrix. The LDTC biomaterial was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and elemental analysis. Due to the cross-linked polymer matrix, high content of dithiocarbamate groups and excellent complex ability, the LDTC was used as a new bio-adsorbent for the removal of metallic ions from aqueous solution. The influences of pH, LDTC dosage, contact time, and initial metallic ion concentration on adsorption capacity and competitive adsorption of multi metallic ions have been investigated. The regeneration of LDTC was also studied. The results demonstrated that LDTC showed fast adsorption, higher adsorption capacity and feasible regeneration compared to other lignin-based bio-adsorbents even activated carbon. The adsorption kinetics and adsorption isotherms were fitted well by a pseudo second-order model and D-R model, respectively. Moreover, the resultant metal-loaded solid bio-sorbents (LDTC-M) were firstly estimated as free radical scavengers due to the inherent merits of naturally occurring polyphenols which therefore could provide a potential way for value-added usage of the LDTC-M.

Adsorptive separation of Pb(II) and Cu(II) from aqueous solutions using as-prepared carboxymethylated waste Lyocell fiber

“…The adsorption isotherm experiments in this study were conducted in single solutions of Cu(II) and Pb(II) at the respective pH values of 4 and 5 and in binary metal solutions at pH 4. These pH conditions were found suitable for effective adsorption of the two metals without precipitations, based on previous studies (Bediako et al 2015b;Ge et al 2014;Li et al 2015;Liu et al 2008). From the present data, the maximum uptakes, affinities, and intensities of adsorption were estimated by fitting the data to the Langmuir, Freundlich, and Redlich-Peterson isotherm models (Table 1).…”

“…They are among the list of metallic elements that are considered toxic to the environment and humans, especially on long-term exposure. They are classified as priority hazardous substances by various agencies including the Agency for Toxic Substances and Disease Registry (http://www.atsdr.cdc.gov/ SPL/; Dong et al 2013;Ge et al 2014). They are found in the effluents from construction and mining industries, metal processing industries, lead batteries, pigments, printing products, and automobiles (Bailey et al 1999;Ge et al 2014;Liu et al 2008).…”

Adsorption of Pb(II) ions from aqueous solution using lignin from Hagenia abyssinica

“…Removal efficiency (R E ) and equilibrium adsorption capacity (q e , mg g -1 ) of the batch experiments were calculated using Eq. (1) and (2) [7].…”

“…Excessive levels of heavy metals in water are an environmental hazard because of their toxicity, accumulation in the food chain and persistence in nature [1][2][3]. Water contamination by heavy metals such as Cr, Cd, Hg, Cu, Ni, As and Pb, is a big environmental concern and it requires significant attention [4][5][6][7][8]. The major sources of heavy metal pollution are municipal waste, metal plating facilities, mining operations, fertilizer industries, tanneries, batteries and paper industries [9][10][11][12].…”

A Novel Gallic Acid-Grafted-Lignin Biosorbent for the Selective Removal of Lead Ions from Aqueous Solutions

“…Pseudo-first-order and pseudo-second-order models were utilized to evaluate the experimental kinetic data (Ge et al 2014b), which are given in Eq. 4 and Eq.…”