scholarly journals Cd(II) and Pb(II) Adsorption Using a Composite Obtained from Moringa oleifera Lam. Cellulose Nanofibrils Impregnated with Iron Nanoparticles

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 89
Author(s):  
Adriana Vázquez-Guerrero ◽  
Raúl Cortés-Martínez ◽  
Ruth Alfaro-Cuevas-Villanueva ◽  
Eric M. Rivera-Muñoz ◽  
Rafael Huirache-Acuña

This work informs on the green synthesis of a novel adsorbent and its adsorption capacity. The adsorbent was synthesized by the combination of iron nanoparticles and cellulose nanofibers (FeNPs/NFCs). Cellulose nanofibers (NFCs) were obtained from Moringa (Moringa oleifera Lam.) by a pulping Kraft process, acid hydrolysis, and ultrasonic methods. The adsorption method has advantages such as high heavy metal removal in water treatment. Therefore, cadmium (Cd) and lead (Pb) adsorption with FeNP/NFC from aqueous solutions in batch systems was investigated. The kinetic, isotherm, and thermodynamic parameters, as well as the adsorption capacities of FeNP/NFC in each system at different temperatures, were evaluated. The adsorption kinetic data were fitted to mathematical models, so the pseudo-second-order kinetic model described both Cd and Pb. The kinetic rate constant (K2), was higher for Cd than for Pb, indicating that the metal adsorption was very fast. The adsorption isotherm data were best described by the Langmuir–Freundlich model for Pb multilayer adsorption. The Langmuir model described Cd monolayer sorption. However, experimental maximum adsorption capacities (qe exp) for Cd (>12 mg/g) were lower than those for Pb (>80 mg/g). In conclusion, iron nanoparticles on the FeNP/NFC composite improved Cd and Pb selectivity during adsorption processes, indicating the process’ spontaneous and exothermic nature.

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Andrea Carolina Landázuri ◽  
Jaime David Cahuasquí Segura ◽  
Andres Sebastián Lagos Estrella

This work explores the technical viability in the use ofMoringa oleifera Lam. seeds produced in Ecuador as an adsorbent medium for copper (Cu), nickel (Ni) and chromium (Cr) present in water that could be implemented in future Water Resource Recovery Facilities in Ecuador. The seeds were prepared following a sequence of washing, drying, crushing, sieving, rewashing, and final drying. Two treatments were performed based on particle size.  Treatment 1 consisted on a mixture of 70% of particles larger than 2 mm and 30% of particles between 1 and 2 mm; while Treatment 2 consisted only on 1 - 2 mm particles. Batch experiments were performed with metal concentrations ranging from 10 to 150 ppm, a dose of 1.00 g of MO per liter, and mechanical stirring for 1 hour. Treatment 2 showed to be more favorable to metal removal and the Langmuir model better characterized adsorption of the three metals.The best kinetic description of the three metals is that of a pseudo first-order reaction where the adsorption capacities are 50.93 mg Cu/g MO, 30.14 mg Ni/g MO, and 40.98 mg Cr/g MO, with removal percentage of 37 - 53 %, 39 - 76%, and 11 - 33%, respectively. 


RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90602-90608 ◽  
Author(s):  
Amir Abdolmaleki ◽  
Shadpour Mallakpour ◽  
Sedigheh Borandeh

A novel magnetic nano-adsorbent containing Fe3O4 nanoparticles functionalized with MCT-β-CD was fabricated and exhibited a remarkable enhancement in heavy metal removal efficiency from aqueous solutions.


2011 ◽  
Vol 383-390 ◽  
pp. 4038-4042 ◽  
Author(s):  
Worathanakul Patcharin ◽  
Kittipalarak Sriamporn ◽  
Anusarn Kanokkan

Bagasse ash is one of the agricultural wastes and valuable biomass by-products in sugar milling. It was treated hydrothermally with hydrochloric aqueous solution at 100 °C and burned at 600°C for 2 hours under oxygen feeding. The obtained white ash was further used as natural silica source instead of silica sol because of highly silica content from an abundant supply of sugar industries in Thailand. Aluminosilicate precursor gel was prepared from alumina source and silica source via sodium silicate preparation. Different crystallization time was studied for the molar ratio of SiO2/Al2O3 = 2 at 100°C crystallization temperature. The phillipsite zeolite synthesized was characterized using various techniques; X-ray diffraction, Scanning electron microscopy, Fourier Transform Infrared Spectroscopy, and BET-N2 adsorption method. The results can be used as value added for bagasse ash utilization, minimize the environmental impact of disposal problems and further application for heavy metal removal.


2015 ◽  
Vol 73 (2) ◽  
pp. 396-404 ◽  
Author(s):  
S. Xu ◽  
X. F. Gong ◽  
H. L. Zou ◽  
C. Y. Liu ◽  
C. L. Chen ◽  
...  

In this study, we exhibit the recycling of agriculture wastes of ramie stalk as bioadsorbents for Cd2+ removal. Based on our experimental results, it is realized that Cd2+ adsorption to ramie stalk is highly pH sensitive, indicating the adsorption is driven by surface complexation reaction. The high adsorption capacity of ramie stalk toward Cd2+ (qm = 10.33 mg g−1, 0.09 mol-Cd g−1), which corresponds to around 21.95% of active adsorption sites available of ramie stalk, is believed to be closely related to its high cellulose and lignin content. The inhomogeneous surface of ramie stalk due to the high cellulose and lignin content also accounts for the observation that the adsorption kinetic is described well by the pseudo second order kinetic model. Results from thermodynamic studies suggest that the adsorption process is endothermic and spontaneous. All these properties demonstrate the potential of ramie stalk as a low cost bioadsorbent for the application of heavy metal removal.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2481
Author(s):  
Fahad M. Almutairi ◽  
Haddad A. El Rabey ◽  
Adel I. Alalawy ◽  
Alzahraa A. M. Salama ◽  
Ahmed A. Tayel ◽  
...  

Biopolymers and nanomaterials are ideal candidates for environmental remediation and heavy metal removal. As hexavalent chromium (Cr6+) is a hazardous toxic pollutant of water, this study innovatively aimed to synthesize nanopolymer composites and load them with phycosynthesized Fe nanoparticles for the full Cr6+ removal from aqueous solutions. The extraction of chitosan (Cht) from prawn shells and alginate (Alg) from brown seaweed (Sargassum linifolium) was achieved with standard characteristics. The tow biopolymers were combined and cross-linked (via microemulsion protocol) to generate nanoparticles from their composites (Cht/Alg NPs), which had a mean diameter of 311.2 nm and were negatively charged (−23.2 mV). The phycosynthesis of iron nanoparticles (Fe-NPs) was additionally attained using S. linifolium extract (SE), and the Fe-NPs had semispherical shapes with a 21.4 nm mean diameter. The conjugation of Cht/Alg NPs with SE-phycosynthesized Fe-NPs resulted in homogenous distribution and stabilization of metal NPs within the polymer nanocomposites. Both nanocomposites exhibited high efficiency as adsorbents for Cr6+ at diverse conditions (e.g., pH, adsorbent dose, contact time and initial ion concentration) using batch adsorption evaluation; the most effectual conditions for adsorption were a pH value of 5.0, adsorbent dose of 4 g/L, contact time of 210 min and initial Cr6+ concentration of 75 ppm. These factors could result in full removal of Cr6+ from batch experiments. The composited nanopolymers (Cht/Alg NPs) incorporated with SE-phycosynthesized Fe-NPs are strongly recommended for complete removal of Cr6+ from aqueous environments.


2021 ◽  
Vol 11 (5) ◽  
pp. 13214-13231

An activated carbon was developed from Moringa oleifera seed and modified with iron nanoparticles (AC-Fe) for application in the oils and greases (O&G) adsorption of the produced water. Activated carbon was prepared by pyrolysis and chemical activation using NaOH. Surface modification was performed by the wet impregnation method. AC-Fe was characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller surface area analyzer (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Boehm titration, and point of zero charge (pHPZC). The amount of O&G adsorbed on AC-Fe was sensitive to pH, initial concentration and temperature, but independent of ionic strength. Freundlich isotherm adjusted well, confirming the heterogeneous distribution of active sites and multilayer. The pseudo-second-order kinetic model accurately represents the O&G adsorption process by AC-Fe. Under different temperatures, the maximum amount of O&G adsorption in AC-Fe calculated by the pseudo-second-order kinetic model was 121.95 mg g-1 (298 K), 111.11 mg g-1 (303 K), and 106.38 mg g-1 (308 K). This high adsorption capacity demonstrates the new material potential as a low-cost adsorbent for O&G removal.


2021 ◽  
Author(s):  
Magda Akl ◽  
Mohamed A. Ismail ◽  
Mohamed A. Hashem ◽  
Dina A. Ali

Abstract In this work, an attempt was made to modify natural cellulose powder via three steps process; oxidation by potassium periodate followed by condensation with aminoguanidine and eventually reaction with phenyl isothiocyanate. The modified cellulose (PhGu-MC) was characterized by several techniques including Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM), and elemental analysis (EA), Brunauer–Emmett–Teller analysis (BET) and thermogravimetric analysis (TGA). The modified cellulose (PhGu-MC) was used as an adsorbent for Cu2+, Hg2+ and Pb2+ from aqueous solution and environmental water samples. Effects of various factors on the adsorption efficiency were investigated including pH, initial metal concentration, contact time, adsorbent dose, temperature and interfering ions on adsorption was investigated to estimate the optimum adsorption conditions. At optimum adsorption conditions, the adsorption capacities of Cu2+, Hg2+ and Pb2+ were found to be 50, 94 and 55 mg.g−1, respectively. The adsorption process was, well described by the Langmuir model, and it was found to follow the pseudo-second-order kinetic model. The synthesized (PhGu-MC) has revealed significant potential towards heavy metal removal from environmental water samples.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Rajaa Bassam ◽  
Achraf El hallaoui ◽  
Marouane El Alouani ◽  
Maissara Jabrane ◽  
El Hassan El Khattabi ◽  
...  

The aim of this study is the valorization of the Moroccan clays (QC-MC and QC-MT) from the Middle Atlas region as adsorbents for the treatment of water contaminated by cadmium Cd (II) ions. The physicochemical properties of natural clays are characterized by ICP-MS, XRD, FTIR, and SEM techniques. The adsorption process is investigated as a function of adsorbent mass, solution pH, contact time, temperature, and initial Cd (II) ion concentration. The kinetic investigation shows that the adsorption equilibrium of Cd (II) ions by both natural clays is reached after 30 min for QC-MT and 45 min for QC-MC and fits well to a pseudo-second-order kinetic model. The isotherm study is best fitted by a Freundlich model, with the maximum adsorption capacity determined by the linear form of the Freundlich isotherm being 4.23 mg/g for QC-MC and 5.85 mg/g for QC-MT at 25°C. The cadmium adsorption process was thermodynamically spontaneous and exothermic. The regeneration process showed that these natural clays had excellent recycling capacity. Characterization of the Moroccan natural clays before and after the adsorption process through FTIR, SEM, XRD, and EDX techniques confirmed the Cd (II) ion adsorption on the surfaces of both natural clay adsorbents. Overall, the high adsorption capacity of both natural clays for Cd (II) ions removal compared to other adsorbents motioned in the literature indicated that these two natural adsorbents are excellent candidates for heavy metal removal from aqueous environments.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 111 ◽  
Author(s):  
Carolina Rodríguez ◽  
Eduardo Leiva

Due to the unique properties of carbon nanotubes (CNTs), they have attracted great research attention as an emergent technology in many applications including water and wastewater treatment. However, raw CNTs have few functional groups, which limits their use in heavy metal removal. Nevertheless, their removal properties can be improved by oxidation processes that modify its surface. In this study, we assessed the capacity of oxidized and double-oxidized multiwalled carbon nanotubes (MWCNTs) to remove heavy metals ions from acidic solutions. The MWCNTs were tested for copper (Cu), manganese (Mn), and zinc (Zn) removal, which showed an increment of 79%, 78%, and 48%, respectively, with double-oxidized MWCNTs compared to oxidized MWCNTs. Moreover, the increase in pH improved the sorption capacity for all the tested metals, which indicates that the sorption potential is strongly dependent on the pH. The kinetic adsorption process for three metals can be described well with a pseudo-second-order kinetic model. Additionally, in multimetallic waters, the sorption capacity decreases due to the competition between metals, and it was more evident in the removal of Zn, while Cu was less affected. Besides, XPS analysis showed an increase in oxygen-containing groups on the MWCNTs surface after oxidation. Finally, these analyses showed that the chemical interactions between heavy metals and oxygen-containing groups are the main removal mechanism. Overall, these results contribute to a better understanding of the potential use of CNTs for water treatment.


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