A Simple Low-Cost Method to Prepare Lignocellulose-Based Composites for Efficient Removal of Cd(II) from Wastewater

Abstract

The fabrication of functional lignocellulose-based materials has drawn considerable attention because it acts as a green separation/absorption material owing to its multi-porous mesostructure. In this study, a surface functionalized lignocellulose-based adsorbent for the highly efficient capture of Cd(II) ions was prepared through facile in situ co-deposition of wood waste-derived saw powder (SP) in the presence of tannic acid (TA) and aminopropyltriethoxysilane (APTES) mixed aqueous solution. The SP was first modified using TA-APTES coating to synthesize the functional SP substrate (SP-(TA-APTES)). The SP-(TA-APTES) hybrids served as reactive platforms, which enabled further decoration with amino-rich polyethylenimine (PEI) due to the outstanding secondary reactions of the TA-APTES layer. The surface morphology of the resulting SP-(TA-APTES)-PEI (SP-TAPI) composites were investigated using Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Significantly, the combined advantages of the lignocellulosic skeleton, the layer-particle structure, and the hybrid coating contributed to the enhanced adsorption capacity of Cd(II) (up to 22.66 mg/g at pH = 5.0). This removal capacity was higher than that of most reported agricultural waste-based or lignocellulose-based materials. The Cd(II) adsorption mechanism of the surface-modified SP-TAPI composites was studied in detail. These results provide new insights into the high value-added utilization of agricultural waste for water purification applications.

Lignocellulose Nanofiber Media for the Enhanced Removal of Copper From Aqueous Solutions

“…Carboxylate and phosphate groups are the resulting negative carrier groups (30). Increased absorption with an increase in pH, due to the availability of negatively charged groups, was at the adsorbent level in the metal absorption process (10) so that at a pH of 6, the yields were eliminated and the adsorption capacity reached 99.3% and 9.93 mg/g, respectively. Then, efficiency and adsorption capacity decreased at pH values of 7 and 8 because of the alkalinity of the environment by increasing the pH of the solution and the OH-solution, leading to metal deposition and reduced adsorption (15).…”

“…Temperature is one of the important and effective parameters in the process of adsorption absorption because of its effect on the number of active sites on the adsorbent surface or due to its effect on the analysis molecules on the adsorbent surface. Moreover, temperature shows whether the process is endothermic or exothermic (10). Fig.…”

“…Different approaches have been suggested for the recycling of heavy metals from wastewater, including chemical filtration, membrane processes, electrochemical treatment, ion exchange, evaporation, reverse osmosis, and coagulation (10). Of the most important disadvantages of the above-mentioned methods are their high cost and the production of secondary effluents.…”

“…The data further corroborated with Elovich kinetic, Langmuir, and Freundlich isotherms, and the reaction was endothermic (19). Wen et al also removed Cd using lignocellulose and reported the high ability of the adsorbent to remove this metal due to the high absorption capacity of this adsorbent (10). Moreover, Sun et al removed Cu using lignin.…”

Enhanced heavy metal removal from an aqueous environment using an eco-friendly and sustainable adsorbent

“…There is growing concern regarding the environmental contamination of water bodies worldwide and its health effects on mankind 1 . In recent decades, the widespread release and leaching of heavy metals have resulted in contamination of the aqueous environment 2 .…”