Synthesis of Eco-Friendly Biopolymer, Alginate-Chitosan Composite to Adsorb the Heavy Metals, Cd(II) and Pb(II) from Contaminated Effluents

Abstract

Efficient removal of Cd(II) and Pb(II) from contaminated water is considered a fundamental point of view. Synthetic hydrogel biopolymers based on chitosan and alginate (cost-effective and eco-friendly) were successfully designed and characterized by highly efficient removal contaminants. The sorbents are characterized by FTIR, SEM-EDX, TGA, XPS analyses and textural properties which are qualified by N2 adsorption. The sorption properties are firstly investigated by the effect of pH, sorption isotherms, uptake kinetics, and selectivity from multi-metal solution with equi-molar concentration. The sorbent with 1:3 ratios (of chitosan and alginate respectively) is the most effective for metal removal (i.e., 0.81 mmol Cd g−1 and 0.41 mmol Pb g−1). Langmuir and Sip’s models fitted better the adsorption isotherms compared to the Freundlich model. Uptake kinetics was well fitted by pseudo-first-order rate equation, while the saturation was achieved within 40 min. The sorbent shows good reproducibility through duplicate the experiments with negligible decreasing efficiency (>2.5%). The sorbent was applied for water treatment on samples collected from the industrial area (i.e., 653 and 203 times over the MCL for Cd(II) and Pb(II) respectively according to WHO). The concentration of Cd and Pb was drastically decreased in the effluents as pH increased with removal efficiency up to 99% for both elements at pH 5.8 and SD equivalent 1 g L−1 for 5 h.

Enhanced Antimicrobial, Cytotoxicity, Larvicidal, and Repellence Activities of Brown Algae, Cystoseira crinita-Mediated Green Synthesis of Magnesium Oxide Nanoparticles

“…The X-ray photoelectron spectroscopy (XPS) analysis was accomplished by ESCALAB 250XI + instrument (Thermo Fischer Scientific, Inc., Waltham, MA, USA) connected with monochromatic X-ray Al Kα radiation (1,486.6 eV). The analysis was conducted under the following conditions: the size of the spot was 500 μm, the samples were prepared under a pressure adjusted at 10 –8 mbar, the energy was calibrated with Ag3d 5/2 signal (∆BE: 0.45 eV) and C 1s signal (∆BE: 0.82 eV), and the full and narrow-spectrum pass energies were 50 and 20 eV, respectively ( Hamza et al, 2021a ).…”

Fabrication, Characterization and Evaluation of an Alginate–Lignin Composite for Rare-Earth Elements Recovery

“…There are different sorbent materials used for the REEs removal from the aqueous solutions such as, Sargassum biomass [ 12 ], granular hydrogel composite [ 13 ], cysteine-functionalized chitosan magnetic particles [ 14 ], modified red clays [ 15 ], and modified silica gels [ 16 ]. As an example of effective biosorbents with significance in the rare earth elements or heavy metal ions removal are alginate salts or their composites [ 17 , 18 , 19 ]. For example, Khotimchenko et al [ 17 ] investigated the ability of calcium alginate and sodium alginate to remove yttrium ions from the aqueous solutions.…”

Grafting of Thiazole Derivative on Chitosan Magnetite Nanoparticles for Cadmium Removal—Application for Groundwater Treatment

“…Ion exchange and chelating resins are the most suitable tools for the recovery of metal ions from low concentrate solutions such as waste effluents and wastewater (either surface or underground water) [ 6 , 7 , 8 , 9 ]. This technique has received prominent attention in recent decades [ 10 , 11 , 12 , 13 ] with either a bio-sorbent (renewable resources) structure, a structure fabricated as nanoparticles and synthetic resins [ 14 , 15 , 16 , 17 ], or magnetic composite micro sorbents [ 18 ].…”