Oxidized Biomass and Its Usage as Adsorbent for Removal of Heavy Metal Ions from Aqueous Solutions

Abstract

Nowadays, very coarse wool fibers are considered waste biomass and are discarded at random or burned. Therefore, it is of actual interest to valorize coarse wool fibers as utile products. In this sense, we report herein an environmentally-friendly process for the preparation of a new material based on oxidized wool fibers and designed for efficient adsorption of heavy metals from wastewater. The morphology and the structure of the obtained product were characterized by scanning electron microscopy (SEM) coupled with an X-ray energy-dispersive module (EDX) and by Fourier-transform infrared spectroscopy (FTIR). Likewise, the performances of the oxidized wool fibers for the adsorption of heavy metal cations (Cu2+, Cd2+, Pb2+) from aqueous solutions were tested. The adsorption kinetics data were analyzed by applying the pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The equilibrium of the adsorption process was investigated by using the Freundlich and Langmuir isotherm models. According to the Langmuir isotherms registered at 300 K, the maximum adsorption capacities of the oxidized wool were found to increase from Cu2+ (9.41 mg/g) and Cd2+ (10.42 mg/g) to Pb2+ (30.71 mg/g). Consequently, the removal efficiency of metal ions was found to vary in the range of 96.8–99.7%. The thermodynamic parameters (e.g., enthalpy, entropy, and Gibbs free energy) were calculated and discussed.

Saccharomyces cerevisiae additions normalized hemocyte differential genes expression and regulated crayfish (Procambarus clarkii) oxidative damage under cadmium stress

“…Bioremediation is an effective, broad, cost-effective, and environmentally acceptable cleanup technology 50 . Over the past several decades, there has been extensive research on cadmium removal by biosorption 51 , 52 . Microorganisms like fungi, algae, or bacteria can remove cadmium during biosorption 53 , 54 .…”

An Eco-Friendly Modification of a Walnut Shell Biosorbent for Increased Efficiency in Wastewater Treatment

“…The use of biosorbents, derived from agricultural waste, represents an ideal lowcost and eco-friendly alternative for the treatment of contaminated waters [5,13]. One of the most readily available agricultural wastes is walnut shells (WS).…”

Yeast—As Bioremediator of Silver-Containing Synthetic Effluents

“…The negative values of the ΔG° obtained for all elements confirm a spontaneous nature of the metal ion biosorption on the S. cerevisiae biomass. It is considered that Gibbs free energy in the range of 0 to −20 kJ/mol indicates physical adsorption, −20 to −80 kJ/mol ion exchange, and −80 to −400 kJ/mol chemisorption [ 68 ]. According to data obtained in the present study, physical adsorption can be suggested as main mechanism of metal ion removal.…”