Search

This study developed eco-friendly composite hydrogel based on cellulose and bentonite to remove Pb2+ from wastewater. The composite hydrogel adsorbents' morphology, chemical composition, and structure were characterized using FE-SEM, EDX, FT-IR, and XRD. Furthermore, EDX mapping displayed uniform dispersion of bentonite within the cellulose-based hydrogel (H), leading to enhanced swelling capacity and mechanical strength. To optimize the adsorption process, the effect of experimental conditions on the amount of Pb2+ adsorbed per bentonite/cellulose-based composite hydrogel (BCH3) was investigated. The batch adsorption results showed that the maximum adsorption capacity of Pb2+ onto BCH3 was 110.64 mg g-1. Post-adsorption EDX spectra and FTIR analysis provided evidence of successful Pb2+ uptake by BCH3. The results obtained from these analyses suggest that the primary adsorption mechanism involves the interaction of Pb2+ with nitrogen (NH2) and oxygen (COO-) groups on the BCH3 surface. Kinetics and isotherm data were best described by the pseudo-second-order (R2 = 0.999) and Sips models (R2 = 0.996). The kinetic model indicated that Pb2+ uptake onto the BCH3 was primarily governed by chemisorption involving coordination bonding/electrostatic interactions. The BCH3 adsorbent exhibited selectivity towards Pb2+ compared to Cd2+ and demonstrated good reusability after five adsorption-desorption cycles.

In this study, bentonite/amino-functionalized cellulose composite (BAC) adsorbent was synthesized by intercalating the hexadecyl trimethyl ammonium bromide surfactant (HDTMA) into bentonite followed by exfoliating the HDTMA-modified bentonite (MB) into amino-functionalized cellulose (AC). The physicochemical properties of BAC were evaluated by FTIR, XRD, FE-SEM, EDX, TGA, and Zeta potential measurement. A series of batch mode adsorption experiments were carried out to identify the optimal adsorption conditions as a function of experimental variables such as pH of solution, uptake time, initial Pb2+ concentrations, BAC dosage, and assess both percent removal (%) and Pb2+ uptake (mg g−1). The result demonstrated that the synergetic advantage of combining HDTMA-modified bentonite (MB) and amino-functionalized cellulose (AC) in Pb2+ uptake (69 mg g−1) surpassed that of HDTMA-modified bentonite (12.14 mg g−1) and amino-functionalized cellulose (31.33 mg g−1) alone. Further, Pb2+ uptake onto BAC was higher than the HDTMA-modified bentonite/cellulose composite (BC) (42.12 mg g−1) due to the introduction of the amino group to cellulose through grafting with ethylenediamine (EDA). The adsorption of Pb2+ from aqueous solution by BAC fit well with pseudo - 2nd-order kinetic (R2 = 0.998) and Langmuir isotherm (R2 = 0.999) models. The kinetic study indicated that the active sites in the BAC exhibit heterogeneity and possess different activation energies for chemisorption. The monolayer attachment of Pb2+ onto the BAC surface was realized from the isotherm study, and the maximum predicted adsorption capacity was found to be 71.869 mg g−1. Regeneration studies showed that BAC maintained its good Pb2+ uptake capacity for up to four cycles.

In this work, by loading a chromium Salen complex on amino-functionalized cellulose (AFC-SalenCr), a novel and efficient heterogeneous catalyst was successfully synthesized, and used for the copolymerization of sulfur dioxide (SO2) with cyclohexene oxide for the first time. The catalysts were characterized by FTIR, XPS, ICP-MS and TGA for their physiochemical and thermal properties. The as-prepared AFC-SalenCr showed high catalytic activity for the copolymerization. Under optimal reaction conditions, the molecular weight of the resultant copolymer could reach 40,100 g/mol. Moreover, the catalyst was able to recover facilely and be reused for four cycles without any significant activity loss. In addition, the thermal degradation kinetics of the synthesized copolymer was further studied using Kissinger and Flynn–Wall–Ozawa methods for the first time, which indicated that the activation energy of the thermal degradation was 92.8 kJ/mol and 94.0 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

In this work, a novel and high-efficiency scavenger based on amino-functionalized cellulose was designed for sodium cholate sorption in vitro. To estimate the adsorption performance of the amino-functionalized cellulose for sodium cholate, various factors including sodium cholate concentration, contact time and electrolyte were investigated. The results suggested that amino-functionalization for cellulose regarding to hyperbranched polyethylenimine not only induce positive charge surface of cellulose but also provide abundant and special binding sites for sodium cholate sorption. The amino-functionalized cellulose displayed an excellent performance to sodium cholate sorption with a maximum adsorption capacity of 569.7 mg/g, higher than cholestyramine, a synthetic lipid-lowering drug in clinic. And the adsorption behavior was well fitted into the Langmuir isotherm model and pseudo-second-order kinetic model, suggesting a homogeneous monolayer chemisorption. Furthermore, the amino-functionalized cellulose presented the features of excellent anti-interferences, cytocompatibility and facile preparation process. All these results support amino-functionalized cellulose as a promising prospect for cholesterol elimination. [ABSTRACT FROM AUTHOR]

Improving electron transfer rate of Co species and inhibiting aggregation of metal-organic frameworks (MOFs) particles are essential prerequisites for activating advanced oxidation process in wastewater treatment field. Here, we exploit Cu species with variable valence states to accelerate electron transfer of Co species and then to boost the unsatisfactory degradation efficiency for refractory pharmaceuticals via in-situ growth of copper and cobalt species on l -lysine functionalized carboxylated cellulose nanofibers. Utilizing the synergistic interplay of Co sites and deliberately exposed Cu0/Cu1+ atoms, the subtly designed catalyst exhibited a surprising degradation efficiency (~100 %) toward tetracycline hydrochloride within 10 min (corresponding to a catalytic capacity of 267.71 mg/g) without adjusting temperature and pH. Meanwhile, the catalyst displays good recyclability, well tolerance for coexisting ions and excellent antibacterial performance derived from the intrinsic antibacterial property of Cu-MOF. This research provided a novel strategy to construct MOFs-cellulose materials toward degrading various stubborn antibiotic pollutants. [ABSTRACT FROM AUTHOR]

Electroless plating occupies a vital position in the fields of metal anticorrosion while accompanied by a large amount of effluent containing organophosphorus (like phytic acid) and heavy metals ions {like Cu (II) and Ni (II)}. However, it was still remaining great challenges in how to simultaneously remove these organophosphorus and heavy metal ions with simple methods. This work prepared a green, clean and efficient adsorbent amino-functionalized cellulose (AFCA) for simultaneous removal of organophosphorus and metal ions from complex wastewater. Benefitting from its abundant amino groups, AFCA can rapidly remove organophosphorus and metal ions within 10 min. The theoretical maximum adsorption capacities of AFCA could also reach as high as 89.29 mg/g, 79.37 mg/g and 178.57 mg/g, respectively. Most importantly, for the mixed system of organophosphorus and Cu (II), the removal efficiency was increased by 5.66% and 30.23% compared with the individual system, respectively. High simultaneous removal capacity of AFCA was due to the hydrogen bond and electrostatic interactions with organophosphorus and the complexation interactions between abundant amino groups and metal ions. All of these results demonstrate that AFCA has enormous potential for the treatment of actual electroless plating effluents. [Display omitted] • Green, clean and efficient adsorbent AFCA was prepared from waste cellulose. • AFCA has abundant active amino groups with a content of 2.6 mmol/g. • AFCA displayed efficient adsorption of organophosphorus, Cu (II) and Ni (II). • AFCA can simultaneous and synergistic removal of OP and Cu (II) from mixed system. [ABSTRACT FROM AUTHOR]