scholarly journals Fabrication of MNPs/rGO/PMMA Composite for the Removal of Hazardous Cr(VI) from Tannery Wastewater through Batch and Continuous Mode Adsorption

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6923
Author(s):  
Rahman Ullah ◽  
Waqas Ahmad ◽  
Muhammad Yaseen ◽  
Mansoor Khan ◽  
Mehmood Iqbal Khattak ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
High Efficiency ◽  
Fixed Bed ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Tannery Wastewater ◽  
Order Kinetic ◽  
Batch Mode ◽  
Industrial Level

Herein, we report the synthesis of magnetic nanoparticle (MNP)-reduced graphene oxide (rGO) and polymethylmethacrylate (PMMA) composite (MNPs/rGO/PMMA) as adsorbent via an in situ fabrication strategy and, in turn, the application for adsorptive removal and recovery of Cr(VI) from tannery wastewater. The composite material was characterized via XRD, FTIR and SEM analyses. Under batch mode experiments, the composite achieved maximum adsorption of the Cr(VI) ion (99.53 ± 1.4%, i.e., 1636.49 mg of Cr(VI)/150 mg of adsorbent) at pH 2, adsorbent dose of 150 mg/10 mL of solution and 30 min of contact time. The adsorption process was endothermic, feasible and spontaneous and followed a pseudo-2nd order kinetic model. The Cr ions were completely desorbed (99.32 ± 2%) from the composite using 30 mL of NaOH solution (2M); hence, the composite exhibited high efficiency for five consecutive cycles without prominent loss in activity. The adsorbent was washed with distilled water and diluted HCl (0.1M), then dried under vacuum at 60 °C for reuse. The XRD analysis confirmed the synthesis and incorporation of magnetic iron oxide at 2θ of 30.38°, 35.5°, 43.22° and 57.36°, respectively, and graphene oxide (GO) at 25.5°. The FTIR analysids revealed that the composite retained the configurations of the individual components, whereas the SEM analysis indicated that the magnetic Fe3O4–NPs (MNPs) dispersed on the surface of the PMMA/rGO sheets. To anticipate the behavior of breakthrough, the Thomas and Yoon–Nelson models were applied to fixed-bed column data, which indicated good agreement with the experimental data. This study evaluates useful reference information for designing a cost-effective and easy-to-use adsorbent for the efficient removal of Cr(VI) from wastewater. Therefore, it can be envisioned as an alternative approach for a variety of unexplored industrial-level operations.

scholarly journals Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

2021 ◽  
Vol 13 (15) ◽  
pp. 8421
Author(s):  
Yuan Gao ◽  
Jiandong Huang ◽  
Meng Li ◽  
Zhongran Dai ◽  
Rongli Jiang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Efficiency ◽  
Low Cost ◽  
Chemical Activation ◽  
Cost Effective ◽  
Coal Gangue ◽  
Order Kinetic ◽  
Practical Applications ◽  
Detailed Structural Analysis ◽  
Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

Graphene Oxide as a Substrate for Biosensors: Synthesis and Characterization

2021 ◽  
Vol 324 ◽  
pp. 87-93
Author(s):  
Mohamed Adel ◽  
Abdel Hady A. Abdel-Wahab ◽  
Ahmed Abdel-Mawgood ◽  
Ahmed Osman Egiza
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Acidic Solution ◽  
Cost Effective ◽  
Sem Analysis ◽  
Visible Spectroscopy ◽  
Sem Images ◽  
Hummers Method ◽  
Uv Visible ◽  
Modified Hummers Method

Graphene oxide (GO) is an oxidized nanosheets of graphite with a 2D planar structure. GO could be readily complexed with bio-entities as it possesses many oxygen-containing functionalities on its surface. The preparation process is fast, easy, and cost-effective. It was prepared using modified Hummers’ method in acidic solution as a primary solvent and potassium permanganate as an oxidizing agent. Afterwards, it was successfully characterized by FTIR, UV-visible spectroscopy, as well as XRD and Raman spectroscopy, and finally, SEM analysis. It was observed that the formed GO is mainly composed of carbon and oxygen elements rich in oxygen functional groups. Furthermore, the existence of (001) plane in XRD interprets the complete oxidation of graphite with d-spacing 9 Å. Moreover, Raman spectroscopy displayed the sp3 carbon hybridization, besides, the ID/IG ratio is found to be 0.84, which confirms the disorder between graphene oxide layers. The SEM images also pointed out that graphene oxide sheets were regularly stacked together as flake-like structures. Accordingly, the richness of oxygen-containing functionalities was confirmed. Hence, it is appropriate to be used as a base transducer for biosensing applications.

Assessment of Urtica as a low-cost adsorbent for methylene blue removal: kinetic, equilibrium, and thermodynamic studies

2015 ◽  
Vol 69 (7) ◽  
Author(s):  
Mohammad Peydayesh ◽  
Mojgan Isanejad ◽  
Toraj Mohammadi ◽  
Seyed Mohammad Reza Seyed Jafari
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Low Cost ◽  
Cost Effective ◽  
Sem Analysis ◽  
Order Kinetic ◽  
Solution Ph ◽  
Factors Affecting ◽  
Order Kinetic Model ◽  
Mb Adsorption

AbstractMethylene blue (MB) removal using eco-friendly, cost-effective, and freely available Urtica was investigated. The morphology of the adsorbent surface and the nature of the possible Urtica and MB interactions were examined using SEM analysis and the FTIR technique, respectively. Various factors affecting MB adsorption such as adsorption time, initial MB concentration, temperature, and solution pH were investigated. The adsorption process was analysed using different kinetic models and isotherms. The results showed that the MB adsorption kinetic follows a pseudo-second-order kinetic model and the isotherm data fit the Langmuir isotherm well. Thermodynamic parameters, such as ΔG°, ΔH°, and ΔS°, were also evaluated, and the results indicated that the adsorption process is endothermic and spontaneous in nature. The MB adsorption capacity of Urtica was found to be as high as 101.01 mg g

A Cost Effective, Facile Hydrothermal Approach of Zinc Sulfide Decorated on Graphene Nanocomposite for Supercapacitor Applications

2019 ◽  
Vol 19 (11) ◽  
pp. 6987-6994
Author(s):  
Ranjith Balu ◽  
Suresh Sagadevan ◽  
Arivuoli Dakshanamoorthy
Keyword(s):  
Electrode Materials ◽  
Cost Effective ◽  
Xrd Analysis ◽  
High Energy ◽  
Sem Analysis ◽  
Super Capacitor ◽  
Raman Analysis ◽  
Good Potential ◽  
Graphene Nanocomposite ◽  
Hydrothermal Approach

A cost effective, facile hydrothermal method was used for the synthesis of ZnS/graphene (G) nano-composites. The XRD analysis clearly confirmed the presence of cubic sphalerite structure of ZnS which maintained its structure both in pure and composite materials matrix. The spectroscopic investigations like FTIR and FT-Raman analysis, and optical studies of the ZnS and ZnS/G nanocomposite were also carried out. The thermal behaviour of ZnS and ZnS/G nanocomposite showed that ZnS/G have higher thermal stability. The SEM analysis showed the spherical nature of ZnS nanoparticles covered over the surface of the graphene sheets and elemental composition of the GO, ZnS and ZnS/G nanocomposite was analyzed by EDAX analysis. The electrochemical properties of the prepared nanocomposite were investigated using cyclic voltammetry and galvanostatic charge discharge techniques. The specific capacitance of ZnS and ZnS/G nanocomposite was found to be 129.67, 315.1, respectively, at 5 mV/s scan rate. The obtained results are compared with reported results and the results indicate the possibility that, the synthesized sample have a good potential to be used as an electrode materials for high energy super capacitor applications.

Effects of feeding strategies on the performance of an anaerobic discontinuous reactor containing immobilized biomass with circulation system for liquid-phase mixing

2004 ◽  
Vol 49 (11-12) ◽  
pp. 303-310 ◽  
Author(s):  
A.A. Orra ◽  
S.M. Ratusznei ◽  
J.A.D. Rodrigues ◽  
E. Foresti ◽  
M. Zaiat
Keyword(s):  
Liquid Phase ◽  
High Efficiency ◽  
Feeding Strategy ◽  
Current System ◽  
Operating Conditions ◽  
Circulation System ◽  
Feeding Strategies ◽  
Order Kinetic ◽  
Fed Batch ◽  
Batch Mode

Data on the influence of feeding strategy on the performance of a fed-batch anaerobic sequencing reactor containing biomass immobilized on polyurethane foam and subjected to liquid phase circulation are presented and discussed. Six-hour cycles, temperature of 30°C and circulation flow rate of 6 L/h were used. During each cycle 890 mL of synthetic domestic wastewater, with organic matter concentration of 500 mgCOD/L were fed to the reactor. The feeding strategies were implemented using fill times of 6 min (batch mode), 60, 120, 240 (fed-batch/batch mode) and 360 min (fed-batch mode). The system attained high efficiency and stability for all the operating conditions, and the substrate removal efficiency based on filtered samples presented a slight decrease from 85% to 81% when fill time was increased from 6 min to 360 min. A model considering a first-order kinetic equation was fitted to the experimental data. The apparent kinetic parameters for both batch and fed-batch phases were estimated, thus permitting evaluation of the influence of the feeding strategy on the reactor performance. The current system may be considered flexible in terms of the operating conditions it is subjected to.

Cyclic CO2 Capture Behavior of Limestone Modified by Qinghai Lake Salt During Long-Term Calcium Looping Cycles

2017 ◽  
Author(s):  
Yongqing Xu ◽  
Haoran Ding ◽  
Cong Luo ◽  
Ying Zheng ◽  
Qiyao Wang ◽  
...  
Keyword(s):  
Co2 Capture ◽  
Large Scale ◽  
Salt Water ◽  
Fixed Bed ◽  
Cost Effective ◽  
Sem Analysis ◽  
Fixed Bed Reactor ◽  
Qinghai Lake ◽  
Impregnation Method

A modified sorbent was prepared by a novel hydration-impregnation method. Results indicated that hydrating with salt water can obtain enhanced capacity of the sorbents during multiple calcination/carbonation reactions. After 40 cycles, the modified limestone sorbent doped with 2wt% lake salt remained a CO2 capture capacity of 0.34 g of CO2 of sorbent, which was 150% higher than that of natural limestone. XRF and XRD were tested for analyzing the chemical component of the sorbents. A Fixed-bed reactor was applied to test the absorption characteristics of those sorbents. SEM analysis revealed that macropores in this novel sorbent were relatively stable during long-term cycles. A preliminary economic analysis of different modified calcium-based sorbents was conducted, and the results demonstrated that limestone modified by lake salt is a promising scheme for large-scale sorbent production, which is a well cost-effective and pollution free scenario suitable for industrial promotion. (CSPE)

scholarly journals Facile preparation and highly efficient sorption of magnetic composite graphene oxide/Fe3O4/GC for uranium removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aili Yang ◽  
Zhijun Wang ◽  
Yukuan Zhu
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Maximum Adsorption Capacity ◽  
Magnetic Composite ◽  
Order Kinetic

AbstractIn this work, we reported for the first time a novel magnetic composite graphene oxide/Fe3O4/glucose-COOH (GO/Fe3O4/GC) that was facilely prepared from glucose through the hydrothermal carbonization and further combination with graphene oxide (GO). The chemical and structural properties of the samples were investigated. By the batch uranium adsorption experiments, the magnetic composite GO/Fe3O4/GC exhibits an excellent adsorption performance and fast solid–liquid separation for uranium from aqueous solution. GO/Fe3O4/GC (the maximum adsorption capacity (Qm) was 390.70 mg g−1) exhibited excellent adsorption capacity and higher removal rate (> 99%) for U(VI) than those of glucose-COOH (GC) and magnetic GC (MGC). The effect of the coexisting ions, such as Na+, K+, Mg2+, Ca2+, and Al3+, on the U(VI) removal efficiency of GO/Fe3O4/GC was examined. The equilibrium sorption and sorption rate for the as-prepared adsorbents well fit the Langmuir model and pseudo second-order kinetic model, respectively. The thermodynamic parameters (ΔH0 = 11.57 kJ mol−1 and ΔG0 < 0) for GO/Fe3O4/GC indicate that the sorption process of U(VI) was exothermic and spontaneous. Thus, this research provides a facile strategy for the preparation of the magnetic composite with low cost, high efficiency and fast separation for the U(VI) removal from aqueous solution.

scholarly journals Removal of arsenate using graphene oxide-iron modified clinoptilolite-based composites: adsorption kinetic and column study

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Meltem Bilici Baskan ◽  
Seçil Hadimlioglu
Keyword(s):  
Graphene Oxide ◽  
Fixed Bed ◽  
Order Kinetic ◽  
Breakthrough Time ◽  
Column Studies ◽  
Column Study ◽  
Treated Water ◽  
Order Kinetic Model ◽  
Arsenate Adsorption ◽  
Modified Clinoptilolite

AbstractIn this study, graphene oxide (GO), iron modified clinoptilolite (FeZ), and composites of GO-FeZ (GOFeZA and GOFeZB) were synthesized and characterized using SEM, EDS, XRF, FTIR, and pHpzc. The arsenate uptake on composites of GOFeZA and GOFeZB was examined by both kinetic and column studies. The adsorption capacity increases with the increase of the initial arsenate concentration at equilibrium for both composites. At the initial arsenate concentration of 450 μg/L, the arsenate adsorption on GOFeZA and GOFeZB was 557.86 and 554.64 μg/g, respectively. Arsenate adsorption on both composites showed good compatibility with the pseudo second order kinetic model. The adsorption process was explained by the surface complexation or ion exchange and electrostatic attraction between GOFeZA or GOFeZB and arsenate ions in the aqueous solution due to the relatively low equilibrium time and fairly rapid adsorption of arsenate at the beginning of the process. The adsorption mechanism was confirmed by characterization studies performed after arsenate was loaded onto the composites. The fixed-bed column experiments showed that the increasing the flow rate of the arsenate solution through the column resulted in a decrease in empty bed contact time, breakthrough time, and volume of treated water. As a result of the continuous operation column study with regenerated GOFeZA, it was demonstrated that the regenerated GOFeZA has lower breakthrough time and volume of treated water compared to fresh GOFeZA.

Sign in / Sign up

Export Citation Format

Share Document