Effects of parts of adsorbent, solution pH level, adsorbent dose, particle size, initial dye concentration, temperature, and contact time on the batch adsorption of Reactive Red (RR) 120 on Moringa ...oleifera seed (MOS) was studied. The surface structure of MOS was characterized using a scanning electron microscope and Fourier transform infrared (FTIR) spectroscopy. Significant changes were observed in the surface structures of MOS before and after the RR 120 adsorption. Changes in the peaks and appearance of new bands (between 1200 and 1500 cm−1) revealed on the interactions between RR 120 molecules and functional groups of MOS (e.g., amino, carbonyl and amide groups) play significant roles in this process. The pH at the point of zero charge (pHpzc) of MOS was found to be 4.5. Experimental kinetic data were well described by Logistic and pseudo second order kinetic models. The very fast process reached the equilibrium stage within 30 min. The Freundlich, Langmuir, and Dubinin-Radushkevish isotherms were applied to equilibrium data. Freundlich isotherm having low values of error function and high correlation coefficient, was the best model to describe the adsorption of RR 120 on MOS. The maximum adsorption capacity of RR 120 on MOS was found as 413.32 mg g−1 at pH 1.0 and 323 K. These results indicate that the MOS had enormous potential for the removal of RR 120 as an eco-friendly process.
Journal of Molecular Structure. Adsorption Kinetic and Isotherms of Reactive Red 120 on Moringa oleifera Seed as an Eco-Friendly Process. Abuzer Ahmed Ismail Al-Nuaimi, Hüseyin Bozkurt. Display omitted
•Assessing sorption kinetic and isotherms of Reactive Red 120 on Moringa oleifera.•Surface structures of adsorbents were characterized by using FTIR–ATR and SEM.•Zero-point charge (pHzpc) of MOS was found to be pH 4.5.•The monolayer sorption was found as 413.32 mg g−1•Moringa oleifera seed as an eco-friendly adsorbent had great potential to remove RR 120.
The metal ion-based nanocomposite photocatalysts were accepted to exhibit a wide range of photocatalytic and biological applications. In this paper, we synthesize bare Fe2O3, 1 wt% metal (Ag, Co, and ...Cu) doped Fe2O3 nanoparticles (NPs) using a simple hydrothermal process and wet impregnation method. The as-prepared nanomaterials crystalline structure, shape, optical characteristics, and elemental composition were determined by using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), Energy-dispersive X-ray (EDS) and Transmission electron microscopy (TEM) techniques. Furthermore, the synthesized nanocomposites were utilized as a photosensitizer for the degradation of reactive red (RR120) and orange II (O-II) dyes under sunlight irradiation. The synthesized 1 wt% Ag–Fe2O3 (AgF) NPs samples exhibit a more exceptional catalytic performance of RR120 and O-II dyes (98.32%) within 120 min than the existing Fe2O3, 1 wt% Co–Fe2O3, and Cu–Fe2O3 NPs. The effect of parameters such as exciton formation under solar irradiation, charge recombination rate, and surface charge availability. The metal oxide-doped nanocomposite economic relevance is revealed by their long-term durability and recyclability in photodegradation reactions. The photocatalytic investigations show that the active species O2∙−, HO∙ and h+ play an important role in the dye degradation process. This research might pave the opportunity for the sustainable development of greater photocatalysts for photodegradation and a wide range of environmental applications.
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•Ag–Fe2O3 NPs were prepared using the wet impregnation method.•The prepared NPs were used for photodegradation of Reactive red 120 & Orange – II without using any oxidizing agent.•The optimum photocatalyst exhibited 99% RR120 and 98% O-II dye degradation within 120 min.•Ag-doped Fe2O3 NPs show improved photo-degradation efficiency than pure Fe2O3 and Co, Cu-doped Fe2O3 NPs.
•A crosslinked chitosan-GLA was modified by TiO2 nanoparticles.•A crosslinked chitosan-GLA/TiO2 was used for removal of RR 120 dye.•Adsorption of RR120 follows pseudo-second-order and Freundlich ...isotherm model.•The adsorption capacity for RR120 dye was 103.1 mg/g.
In this study, tunable Schiff’s base-cross-linked chitosan-glutaraldehyde (CS-GLA) was modified and applied to remove reactive red 120 (RR120) dye from an aqueous solution. Different ratios of TiO2 nanoparticles, such as 25% TiO2 nanoparticles (CS-GLA/TNC-25) and 50% TiO2 nanoparticles (CS-GLA/TNC-50), were loaded into the CS-GLA’s molecular structure. The adsorptive properties of CS-GLA, CS-GLA/TNC-25, and CS-GLA/TNC-50 for the RR120 dye in the aqueous solution were evaluated. CS-GLA/TNC-25 exhibited the best adsorptive property possibly because of the perfect balancing between the surface area and available amine (NH2) groups in the composite formulation. The impact of adsorption key parameters, such as adsorbent dosage (0.01–1.2 g), RR120 dye concentration (30–400 mg/L), solution pH (3–12), and contact time (0–400 min) were explored by batch adsorption mode. The adsorption was well described by the Freundlich model and pseudo-second order kinetic model. The adsorption capacity of CS-GLA/TNC-25 for RR120 dye was 103.1 mg/g at 303K. The adsorption mechanism of RR120 on the CS-GLA/TNC-25 surface can be assigned to various interactions, such as electrostatic attraction, n–π stacking, and H-bonding. Results indicate the potential application of CS-GLA/TNC-25 as environment-friendly biosorbent for removing acid and/or textile dyes, such as RR120, from aqueous environments.
In this research, an attempt to develop zwitterion composite adsorbent is conducted by modifying chitosan (CHS) with a covalent cross-linker (epichlorohydrin, ECH) and an aluminosilicate mineral ...(zeolite, ZL). The zwitterion composite adsorbent of chitosan-epichlorohydrin/zeolite (CHS-ECH/ZL) is performed multifunctional tasks by removing two structurally different cationic (methylene blue dye, MB), and anionic (reactive red 120 dye, RR120) dyes from aqueous solutions. The surface property, crystallinity, morphology, functionality, and charge of the CHS-ECH/ZL are analyzed using BET, XRD, SEM, FTIR, and pHpzc, analyses, respectively. The influence of pertinent parameters namely CHS-ECH/ZL dosage (0.02–0.5 g), solution pH (4–10), temperature (303−323K), initial dye concentration (30–400 mg/L), and contact time (0–600 min) on the MB and RR120 removal are tested. The research findings revealed that the adsorption isotherm at equilibrium well explained in according to the Freundlich isotherm model, and the recorded adsorption capacities of CHS-ECH/ZL are 156.1 and 284.2 mg/g for MB and RR120 respectively at 30 °C. The mechanism of MB and RR120 adsorption onto the CHS-ECH/ZL indicates various types of interactions namely, electrostatic interaction, hydrogen bonding, and Yoshida H-bonding in addition to n-π interaction. Overall, this research introduces CHS-ECH/ZL composite as an eco-friendly zwitterion adsorbent with good applicability towards the two structurally different cationic and anionic dyes from aqueous environment.
The present study focuses on modelling the removal of reactive azo dyes (Reactive Orange 16, Reactive Red 120 and Direct Red 80) by ozonolytic degradation. The process was optimised using One ...Variable at a Time (OVAT) approach followed by Response Surface Methodology (RSM). The operational parameters influencing the process of degradation, i.e. initial dye concentration (mg/L), pH and ozone exposure time were modelled using Central Composite Design (CCD). Under the optimal condition (Initial dye concentration = 2000 mg/L, pH = 11.0, Ozone exposure time = 10 min), the highest desirable response (i.e. Concentration of the degraded dye) for the degradation of RO 16, RR 120 and DR 80 are 1289.35 mg/L, 1224.98 mg/L and 1039.87 mg/L, respectively. The high correlation coefficients, 0.9814 (RO 16), 0.9815 (RR 120) and 0.9685 (DR 80) indicates the closeness of the results predicted by RSM with the experimental results. The rate of degradation for all the three dyes at the optimal condition followed pseudo-first order kinetics with the rate of reaction as 141 mg/L.min, 197.2 mg/L.min and 216.6 mg/Lmin. The predicted model was also evaluated by partial derivative-based equation modelling and experimental approach. The reliability and applicability of the developed process were confirmed by degrading the synthetic mixed dye effluent.
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•Ozonolytic degradation of Reactive and Direct class of dyes were investigated.•Equation simulation modelling was compared with Factorial statistical modelling.•Degradation kinetics was established with the residence time of the pollutant.•The developed process was investigated for the simulated mixed effluent.
Lead (Pb) substituted ZnO nanoparticles were prepared using the ultrasonic-assisted co-precipitation method to enhance the degradation efficiency of reactive red 120 and zone of inhibition of ...pathogens. The structural, optical, and morphological properties of different concentrations of Pb substituted ZnO nanoparticles were characterized. The result confirmed the formation of Pb: ZnO from the structural, optical, and morphological characterization. The dynamic light scattering spectra show that prepared particles were in the range of 50-110 nm. Scanning electron microscopic image exhibited the formation of hexagonal and spindle-like particles with a size less than 100 nm for a 5% Pb substituted sample. The reflectance and bandgap energy of the Pb substituted ZnO nanoparticles decreased with increasing the Pb concentration. The photocatalytic dye degradation of 5% Pb substituted ZnO nanoparticles showed a higher degradation rate of reactive red 120, and it degraded within 120 min. The antibacterial activity of the 5% Pb substituted samples has higher zone of inhibition of 13 mm. The antibacterial, photocatalytic dye degradation, and antibacterial activity results confirmed that 5% Pb substituted ZnO nanoparticles will be the efficient photocatalyst for the degradation of reactive red 120 and commercial use.
Water contamination by reactive dyes is a serious concern for human health and the environment. In this study, we prepared high efficient SnO2/CuO/rGO nanocomposites for reactive dye degradation. For ...structural analysis of SnO2/CuO/rGO nanocomposites, XRD, UV–Vis DRS, SEM, TEM-EDAX, and XPS analysis were used to characterize the physicochemical properties of the material. The characterization results confirmed great crystallinity, purity, and optical characteristics features. For both Rhodamine B (RhB) and Reactive Red 120 (RR120) degradation processes, SnO2/CuO/rGO nanocomposites were tested for their photocatalytic degradation performance. The SnO2/CuO/rGO nanocomposites have expressed the degradation rate exposed to 99.6% of both RhB and RR120 dyes. The main reason behind the photocatalytic degradation was due to the formation of OH radical's generation by the composite materials. Moreover, the antibacterial properties of synthesized SnO2/CuO/rGO nanocomposites were studied against E. coli, S. aureus, B. subtilis and P. aeroginosa and exhibited good antibacterial activity against the tested bacterial strains. Thus, the synthesized SnO2/CuO/rGO nanocomposites are a promising photocatalyst and antibacterial agent. Furthermore, mechanisms behind the antibacterial effects will be ruled out in near future.
•Fabrication of SnO2/CuO/rGO nanocomposites was discussed herein.•XRD, EDAX and XPS was utilized as fingerprinting techniques to confirm the synthesized nanocomposites.•The synthesized nanocomposites has excellent antibacterial properties.•The dye degradation potency of nanocomposites was reported.
In this study, a biofilm of cross-linked Chitosan- Ethylene Glycol Diglycidyl Ether (Chi-EGDE) was prepared and coated onto glass plate to act as a biosorbent for two structurally different Reactive ...Red 120 (RR120) and Methyl Orange (MO) dyes by applying non-conventional adsorption system without separation and filtration processes. The characterizations reveal that the Chi-EGDE biofilm has a low swelling index, good mechanical strength on glass plate, relatively high content (64.4%) of free amine (-NH2) groups, and pHpzc of ∼6.8 indicating a positive surface charge occurs below pHpzc. The adsorption data of RR120 and MO by the cross-linked Chi-EGDE biofilm were in agreement with Langmuir isotherm at 303 K, with maximum adsorption capacities of 165.3 mg/g and 131.2 mg/g, respectively. The kinetic data were well described by pseudo-second-order kinetic model. The adsorption process was spontaneous and endothermic in nature at cross-linked Chi-EGDE biofilm thickness of 4.24 μm. The mechanism of adsorption included mainly hydrogen bonding interaction, electrostatic attractions, and n-π stacking interaction. This study reveals that the cross-linked Chi-EGDE biofilm as a good candidate for adsorption of two structurally different reactive and acid dyes as it does not require any filtration process and adsorbents recovery during and post-adsorption process.
The worldwide consumption of eggs is very high, leading to about 250,000 tons of eggshell membrane (ESM) waste annually. The present research thus investigated the potential use of ESM as an ...inexpensive and abundant adsorbent for Reactive Red 120 (RR120) in aqueous solutions, a widespread hydrophilic azo dye used in the textile industry. The chemical structure and morphology of ESM were characterized using various spectroscopic methods, including scanning electron microscopy, Fourier transform infrared spectroscopy, and elemental analysis. It was found that natural ESM has a porous structure and surface functional groups that are suitable for the adsorption of the target molecules. The impact of the operating conditions, including the variation in the pH and temperature, on the RR120 sorption capacity and mechanisms of ESM was also analyzed. The maximum monolayer adsorption ability of ESM for RR120 was found to be 191.5 mg/g at 318 K, and the sorption process was spontaneous and endothermic. The adsorption of RR120 onto ESM was significantly influenced by the solution pH and the use of NaOH as eluent, indicating that the driving force for this adsorption was electrostatic attraction. Subsequent desorption experiments using 0.1 M NaOH resulted in satisfactory recovery efficiency. Kinetic, isothermic, and thermodynamic analysis was also conducted to support the experimental findings. The experimental results for the adsorption kinetics of ESM were fitted by a pseudo-second-order model. In conclusion, ESM has the potential to be utilized as an eco-friendly and cost-effective adsorbent for the removal of RR120 from aqueous solutions.
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•Utilized waste egg shell for the adsorption of toxic and sulfonated Reactive Red 120 dye.•Operational parameters, kinetics, thermodynamics and desorption were investigated.•Reusability of the developed egg shell membrane for dye removal increases its applicability.•Egg shell membrane could be utilized as eco-friendly and potential adsorbent for dye containing wastewater.
Chitosan (CS) was physically modified with fly ash (FA) powder and subjected to chemical cross-linking reaction with tripolyphosphate (TPP) to produce a cross-linked CS-TPP/FA composite as adsorbent ...for removal of reactive orange 120 (RR120) dye. Different ratios of FA such as 25% FA particles (CS-TPP/FA-25) and 50% FA particles (CS-TPP/FA-50) were loaded into the molecular structure of CS-TPP. Box–Behnken design (BBD) was applied to optimize the input variables that affected the synthesis of the adsorbent and the adsorption of RR120 dye. These variables included FA loading (A: 0–50%), adsorbent dose (B: 0.04–0.1 g), solution pH (C: 4–10), temperature (D: 30 °C–60 °C), and time (E: 30–90 min). Results revealed that the highest removal (88.8%) of RR120 dye was achieved by CS-TPP/FA-50 at adsorbent dosage of 0.07 g, solution of pH 4, temperature of 45 °C, and time of 60 min. The adsorption equilibrium was described by the Freundlich model, with 165.8 mg/g at 45 °C as the maximum adsorption capacity of CS-TPP/FA-50 for RR120 dye. This work introduces CS-TPP/FA-50 as an ideal composite adsorbent for removal of textile dyes from the aqueous environment.
•Crosslinked chitosan- tripolyphosphate was modified by fly ash (CS-TPP/FA)•The synthesis conditions were optimized by Box–Behnken design•The CS-TPP/FA was used for adsorption of reactive orange 120 (RR120).•The adsorption capacity for RR120 dye was 165.8 mg/g.
