Tosyl-carrageenan/alginate composite adsorbent for removal of Pb2+ ions from aqueous solutions.

The current study effectively designed novel cross-linked tosyl-carrageenan/alginate (Ts-Car/Alg) beads to remove Pb2+ ions from their aqueous solutions. To confirm the structure of the produced matrix, characterization methods such as XRD, SEM, FTIR, and EDX were used. Batch experiments were employed in order to further evaluate the adsorption efficiency of Pb2+ ions. Additionally, various variables, including contact time, solution pH, adsorbent dosage, and initial concentration of Pb2+ ions were investigated using atomic absorption. The results of this study showed that the adsorption equilibrium increased as Pb2+ ions concentration increased at pH = 5.3 after a contact time of 120 min, with 0.3 g of Ts-Car/Alg that having the best adsorption capacity at 74 mg/g. The adsorption progression was further examined using the kinetic and isothermal models. With a correlation coefficient of 0.975, the Freundlich model was thought to better fit Pb2+ ions adsorption from the isotherm investigation. Also, the adsorption kinetics were investigated using a pseudo-second-order model with 1/n ratio of 0.683. This Ts-Car/Alg adsorbent is regarded as an effective candidate to be used for water treatment because the reusability process of produced beads was successfully completed twice, and the adsorbent maintained its ability to remove Pb2+ ions. The prepared Ts-Car/Alg beads are therefore excellent candidates to be used as potent Pb2+ ions adsorbents from their aqueous solutions. The Ts-Car/Alg beads' regeneration and reusability investigation for the removal of heavy metal ions was completed in at least two successful cycles.

Preparation and performance of bionanocomposites based on grafted chitosan, GO and TiO2-NPs for removal of lead ions and basic-red 46.

Wastewater rich in heavy metals and organic compounds represents one of the essential environmental pollutants. Therefore, a practical approach is to fabricate eco-friendly polymer-based systems with a high ability to absorb pollutants. Herein, bionanocomposites consisting of chitosan (Cs) grafted by various monomers, such as acrylamide (Am), acrylic acid (AA), and 4-styrene sulfonic acid (SSA), and hybrid nanoparticles of graphene oxide/titanium dioxide nanoparticles (GO@TiO2-NPs) were fabricated. The prepared nanomaterials and bionanocomposites characterized via various tools. The data illustrated that the prepared GO had a thickness of 10 nm and TiO2-NPs had a diameter of 25 nm. In addition, the grafted chitosan (gCs) using Am and SSA had the largest surface area (gCs2; 22.89 nm) and its bionanocomposite (NC5; 104.79 nm). In addition, the sorption ability of the 0.15 g of prepared bionanocomposites to the (100 mg/L) of lead ions (Pb2+) and (25 mg/L) of basic-red 46 (BR46) under various conditions has been studied. The results showed that gCs3 and NC5 had the highest adsorption of Pb2+ (79.54 %) and BR46 (79.98 %), respectively. The kinetic study results of the sorbents obeyed the Pseudo second-order model. In contrast, the isothermal study followed the Freundlich adsorption model for Pb2+ and the Langmuir adsorption model for BR46.

Preparation of Isopropyl Acrylamide Grafted Chitosan and Carbon Bionanocomposites for Adsorption of Lead Ion and Methylene Blue.

Wastewater, which is rich with heavy elements, dyes, and pesticides, represents one of the most important environmental pollutants. Thus, it has been significant to fabricate environmentally friendly polymers with high adsorption ability for those pollutants. Herein, crosslinked chitosan (C-Cs) was prepared using isopropyl acrylamide and methylene bisacrylamide. Carbon nanoparticles (C-NPs) were also obtained by the treatment of the agricultural wastes, which was used with C-Cs to prepare C-Cs/C-NPs nanocomposite (C-Cs/C-NC). Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscope (TEM) were used to investigate the prepared adsorbent. C-Cs, C-NPs, and C-Cs/C-NC were used in water treatment for the adsorption of lead ions (Pb+2) and methylene blue (MB). The adsorption process occurred by the prepared samples was investigated under different conditions, including contact time, as well as different doses and concentrations of adsorbents. The findings exhibited that the adsorption of Pb+2 and MB by C-Cs/C-NC was higher than C-Cs and C-NPs. In addition, the kinetic and isotherm models were studied, where the results showed that the adsorption of Pb+2 and MB by various adsorbents obeys pseudo-second-order and Langmuir isotherms, respectively.

Grafted TEMPO-oxidized cellulose nanofiber embedded with modified magnetite for effective adsorption of lead ions.

According to the World Health Organization, nearly a billion people do not have incoming to pure drinking water and much of that water is contaminated with high levels of heavy elements. In this study, adsorption of lead ions has been studied by nanocomposites which prepared through acrylic acid grafting and amino-functionalized magnetized (FM-NPs) TEMPO-oxidized cellulose nanofiber (TEMPO-CNF). The amino-functionalized magnetite was acting as a crosslinked. The crystallinity of TEMPO-CNF was 75 with a 4-10 nm diameter range, while the average particle size of FM-NPs was 30 nm. The adsorption studies illustrated that the elimination efficiency of lead ions was 80% by the prepared nanocomposite that includes a minimum amount of crosslinker (1%), which demonstrated that the magnetic grafted oxidized cellulose nanofiber nanocomposite is a promising green adsorbent material to eliminate heavy metal ions and is additionally easy to get rid of due to its magnetic property. The kinetics and isotherms studied found that the sorption reaction follows a pseudo-second-order model (R2 = 0.997) and Freundlich model (R2 = 0.993), respectively, this indicated that the adsorption of lead ion occurs within the pores and via the functional groups present on the nanocomposite.

Biodegradable grafting cellulose/clay composites for metal ions removal.

Biodegradable bi-functional cellulose derivatives were synthesized to remove widespread underground water cations such as; Ca2+, Mg2+, Fe2+, Pb2+, and Cu2+. Firstly, graft copolymerization of cellulose with binary monomers such as acrylic acid (AA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) with acrylamide (Am) were achieved using potassium persulfate as initiator. Then, cellulose/clay composites were prepared by graft copolymerization of cellulose using different montmorillonite concentrations such as 3, 6 and 9% weight/cellulose weight. The obtained Biodegradable grafted cellulose and their composites were used as adsorbents for the removal of Ca, Mg, Fe, Pb, and Cu ions individually from aqueous solutions. A possible reaction mechanism was deduced and the products were characterized by Fourier transfer infrared (FT-IR), scanning electron microscopy (SEM) and thermal degradation by thermogravimetric analysis (TGA). The results obtained from this study revealed that as the content of clay increases, the uptake of cations increasing and the removal order of the composites were Pb2+ > Mg2+ > Fe2+ > Cu2+ > Ca2+. The biodegradability of grafted cellulose was increased by the addition of clay.