scholarly journals Adsorption of Congo red from aqueous solution onto shrimp shell powder

2018 ◽  
Vol 36 (5-6) ◽  
pp. 1310-1330 ◽  
Author(s):  
Youzhou Zhou ◽  
Liuqin Ge ◽  
Neng Fan ◽  
Meisheng Xia

Two novel adsorbents derived from shrimp shell were prepared and their adsorption performances on Congo red were investigated. The results suggested that treated shrimp shell powder exhibited a higher adsorption capacity than raw shrimp shell powder. The factors of initial concentration, solution pH, adsorption time, and temperature were investigated. The maximum adsorption capacity of treated shrimp shell powder calculated according to the Langmuir isotherm model was 288.2 mg/g, which is much higher than that of chitin. The adsorption behavior could be fitted well by the pseudo-second-order kinetic model. Intra-particle diffusion model was also used to study the adsorption process. The thermodynamic parameters indicated the spontaneous and endothermic nature of the adsorption. Shrimp shell powder exhibited enough advantages such as large adsorption capacity, low cost, simple processing methods and high specific gravity compared with chitin or chitosan. This work confirmed that the shrimp shell biosorbent had a potential to be applied in dye wastewater treatment area.

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3718
Author(s):  
Mohammad Azam ◽  
Saikh Mohammad Wabaidur ◽  
Mohammad Rizwan Khan ◽  
Saud I. Al-Resayes ◽  
Mohammad Shahidul Islam

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3–88.2% and 81.8–86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.


Author(s):  
Redouane Ouafi ◽  
Anass Omor ◽  
Younes Gaga ◽  
Mohamed Akhazzane ◽  
Mustapha Taleb ◽  
...  

This research investigates the adsorption potential of pine cones powder (PCP) for the removal of copper ions (Cu(II)) from aqueous solutions. The process of adsorption was reasonably fast to be completed within a time of 60 min. The pseudo-second order kinetic model describes properly the Cu(II) adsorption by PCP. The adsorbent was characterised by various instrumental techniques and batch experiments were conducted to investigate the effect of PCP dose, solution pH, particle size and initial Cu(II) concentration on adsorption efficiency. Optimum Cu(II) removal occurred at a slightly acidic pH, with a particle size less than 100 ?m. The effective PCP dose was estimated to be 36 g.L-1. The increase in the initial concentration of Cu (II) was accompanied by a reduction in the rate of its reduction by almost half. The Langmuir model was the best fitting isotherm with a maximum adsorption capacity of 9.08 mg.g-1. The thermodynamic parameters values showed that the Cu(II) adsorption was a spontaneous and endothermic process. The results of this research suggest that Cu(II) could be removed through an environmentally friendly process using PCP as low-cost natural wastes.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3054
Author(s):  
Yiming Zhou ◽  
Te Li ◽  
Juanli Shen ◽  
Yu Meng ◽  
Shuhua Tong ◽  
...  

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.


2014 ◽  
Vol 567 ◽  
pp. 74-79 ◽  
Author(s):  
Asadpour Robabeh ◽  
Nasiman Sapari ◽  
Mohamed Hasnain Isa ◽  
Kalu Uka Orji

Today oil spills generally cause worldwide worry due to their damaging effects on environment. Use of agricultural wastes such as raw and modified mangrove barks (RhizophoraApiculata), as an abundant and low cost adsorbent for oil-products spill cleanup in aquatic systems, has been developed to control these spills. Sorption capacity can improve by modification of adsorbent. The modification significantly increased the hydrophobicity of the adsorbent. The raw mangrove bark was modified using fatty acid (Palmitic acid) to improve its adsorption capacity. Oil sorption capacity of the modified bark was studied and compared with the raw bark. Kinetic tests were conducted with a series of contact time. The kinetic studies show good correlation coefficients for a pseudo-first-order kinetic model. A correlation between surface functional groups of the adsorbent was studied by FTIR spectrum. The results gave the maximum adsorption capacity of 2640.00 ± 2.00 mg/g for Palmitic acid treated bark (PTB). The prepared adsorbent revealed the potential to use as a low-cost adsorbent in oil-spill clean-up.


2018 ◽  
Vol 36 (3-4) ◽  
pp. 1160-1177 ◽  
Author(s):  
Liyun Yang ◽  
Xiaoming Qian ◽  
Zhi Wang ◽  
Yuan Li ◽  
Hao Bai ◽  
...  

This study investigates the removal effectiveness and characteristics of phenanthrene and naphthalene using low-cost steel slag with batch experiments. The adsorption characteristics of steel slag were measured and analysed using X-ray fluorescence, X-ray diffraction, and Fourier transform infrared spectroscopy. The batch experiments investigated the effect of the time gradient, pH, and steel slag dosage gradient on the adsorption of the steel slag. The results show that with time and dosage of steel slag increased, the adsorption capacity of phenanthrene and naphthalene increased and gradually became balanced, but pH had no obvious effect on the adsorption of phenanthrene and naphthalene. The Langmuir isotherm model best describes the phenanthrene and naphthalene removal by the steel slag, which shows the adsorption occurring in a monolayer. The maximum adsorption capacity of the steel slag to phenanthrene and naphthalene is 0.043 and 0.041 mg/g, respectively. A pseudo-first-order kinetic model can better represent the adsorption of phenanthrene and naphthalene by steel slag. The research demonstrates that the steel slag has a certain adsorption capacity for phenanthrene and naphthalene.


Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 749
Author(s):  
Celia Marcos ◽  
Valeria Medoro ◽  
Alaa Adawy

The aim of this study was to investigate the efficiency of removing Cr6+ from aqueous solutions using two exfoliated vermiculite: (1) heated abruptly at 1000 °C and (2) irradiated with microwave radiation. The effects investigated were contact time, adsorbate concentration and initial Cr6+ concentration. The adsorption with both exfoliated vermiculites was well described by the DKR isotherm, indicative of a cooperative process and with the pseudo second order kinetic model. The Kd value for the two exfoliated vermiculites was similar, 0.2 ·1010 μg/Kg. The maximum adsorption capacity of Cr6+ with thermo-exfoliated vermiculite, 2.81 mol/g, was much higher than with microwave irradiated vermiculite, 0.001 mol/g; both values were obtained with 0.5 g of vermiculite in contact with distilled water enriched with 1 ppm of Cr6+ for 24 h. Factors such as ion chemistry, the solution pH and ionic strength, influence the values of capacity, adsorption energy and initial adsorption rate values of the exfoliated vermiculite. In addition, these values depended on the exfoliation process, being the adsorption capacity highest with abrupt heating of vermiculite, while the adsorption energy and rate values showed just a slight increase with microwave irradiation. This aspect is important to select the most suitable vermiculite modification treatment to use it as an adsorbent.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yue Yin ◽  
Gaoyang Xu ◽  
Linlin Li ◽  
Yuxing Xu ◽  
Yihan Zhang ◽  
...  

A more applicable adsorbent was fabricated using industrial wastes such as red mud, fly ash, and riverbed sediments. The heavy metal inside the raw materials created metal hydroxy on the adsorbent surface that offered elevated adsorption capacity for phosphorus. The required equilibrium time for the adsorption is only 10 min. The theoretical maximum adsorption capacity of the adsorbent was 9.84 mg·g−1 inferred from the Langmuir adsorption isotherm. Higher solution pH favored phosphorus adsorption. Kinetics study showed that the adsorption could be better fitted by the pseudo-second-order kinetic model. The presence of coexisting anions had no significant adverse impact on phosphorus removal. The speciation of the adsorbed phosphorus indicated that the adsorption to iron and aluminum is the dominating adsorption mechanism. Moreover, a dynamic adsorption column experiment showed that, under a hydraulic time of 10 min, more than 80% of the phosphorus in the influent was removed and the surplus phosphorus concentration was close to 0.1 mg L−1. The water quality after adsorption revealed its applicability in real treatment. Consequently, the adsorbent synthesized from industrial wastes is efficient and applicable due to the high efficiency of phosphorus removal and eco-friendly behavior in solutions.


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.


2017 ◽  
Vol 75 (6) ◽  
pp. 1399-1409 ◽  
Author(s):  
Xiao-Shui Li ◽  
Yu-Han Fan ◽  
Shou-Wen Zhang ◽  
Shi-Hua Qi

A novel amino-functionalized magnetic silica (Fe3O4@SiO2-NH2) was easily prepared via a one-step method integrating the immobilization of 3-aminopropyltriethoxysilane with a sol-gel process of tetraethyl orthosilicate into a single process. This showed significant improvement in the adsorption capacity of anionic dyes. The product (Fe3O4@SiO2-NH2) was characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, zeta potential and vibrating sample magnetometry. The adsorption performance of Fe3O4@SiO2-NH2 was then tested by removing acid orange 10 (AO10) and reactive black 5 (RB5) from the aqueous solutions under various experimental conditions including initial solution pH, initial dye concentrations, reaction time and temperature. The results indicated that the maximum adsorption capacity of AO10 and RB5 on Fe3O4@SiO2-NH2 was 621.9 and 919.1 mg g−1 at pH 2, respectively. The sorption isotherms fit the Langmuir model nicely. Similarly, the sorption kinetic data were better fitted into the pseudo-second order kinetic model than the pseudo-first order model. In addition, the thermodynamic data demonstrated that the adsorption process was endothermic, spontaneous and physical. Furthermore, Fe3O4@SiO2-NH2 could be easily separated from aqueous solutions by an external magnetic field, and the preparation was reproducible.


2013 ◽  
Vol 639-640 ◽  
pp. 1300-1306
Author(s):  
Zhen Ping Tang ◽  
Hui Ling ◽  
Shui Bo Xie ◽  
S.Y. Li ◽  
J.S. Wang ◽  
...  

Fe-immobilized bentonite, prepared with bentonite and FeCl3 was used for the adsorption of uranium(VI) in this study, solution pH, ion strength, contact time and temperature were investigated, structural characterization of Fe-immobilized bentonite was assayed by X-ray Diffraction and Fourier Transform Infrared Spectroscopy. Results indicated that the adsorption capacity were strongly affected by the solution pH and ion strength, the adsorption efficiency was 91.8% when pH value was 6 and ion strength was 0.01 mol•L-1, higher or lower pH did not favor the U(VI) adsorption. The adsorption mechanism was discussed by the views of reactive kinetics and thermodynamics along with Scanning Electron Microscope. The adsorption kinetics process was fitted well with the second-order kinetic equation, when the initial U(VI) concentration was less than 38.08mg/L, Langmuir equations could describe the adsorption isotherm of U(VI) well with the maximum adsorption capacity of 169.5mg/g at 303K


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