Adsorption of azo dyes from aqueous solution by the hybrid MOFs/GO

2016 ◽  
Vol 73 (7) ◽  
pp. 1728-1737 ◽  
Author(s):  
Ling Li ◽  
Zhennan Shi ◽  
Hongyang Zhu ◽  
Wei Hong ◽  
Fengwei Xie ◽  
...  

In this work, a hybrid of chromium(III) terephthalate metal organic framework (MIL-101) and graphene oxide (GO) was synthesized and its performance in the removal of azo dyes (Amaranth, Sunset Yellow, and Carmine) from water was evaluated. The adsorption for azo dyes on MIL-101/GO was compared with that of MIL-101, and it was found that the addition of GO enhanced the stability of MIL-101 in water and increased the adsorption capacity. The maximum adsorption capacities of MIL-101/GO were 111.01 mg g−1 for Amaranth, 81.28 mg g−1 for Sunset Yellow, and 77.61 mg g−1 for Carmine. The adsorption isotherms and kinetics were investigated, showing that the adsorption fits the Freundlich isotherm and the pseudo-second-order kinetic model. The recyclability of MIL-101/GO was shown by the regeneration by acetone. The high adsorption capability and excellent reusability make MIL-101/GO a competent adsorbent for the removal dyes from aqueous solution.

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1053
Author(s):  
Krzysztof Cendrowski ◽  
Karolina Opała ◽  
Ewa Mijowska

In this contribution, the synthesis of the metal−organic framework (MOF) based on lanthanum that exhibits trigonal prism shape is presented. The length of a single side of this structure ranges from 2 to 10 μm. The carbonized lanthanum-based organic framework (CMOF–La) maintained the original shape. However, the lanthanum oxide was reshaped in the form of rods during the carbonization. It resulted in the creation of parallel arranged channels. The unique structure of the carbonized structure motivated us to reveal its adsorption performance. Therefore, the adsorption kinetics of acid red 18 onto a carbonized metal−organic framework were conducted. Various physicochemical parameters such as initial dye concentration and pH of dye solution were investigated in an adsorption process. The adsorption was found to decrease with an increase in initial dye concentration. In addition, the increase in adsorption capacity was noticed when the solution was changed to basic. Optimal conditions were obtained at a low pH. Kinetic adsorption data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order kinetic model and the intraparticle diffusion model. The adsorption kinetics were well fitted using a pseudo-second-order kinetic model. It was found that the adsorption of anionic dye onto CMOF–La occurs by hydrophobic interactions between carbonized metal-organic framework and acid red 18.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Hamid Raza ◽  
Aqsa Sadiq ◽  
Umar Farooq ◽  
Makshoof Athar ◽  
Tajamal Hussain ◽  
...  

Batch scale studies for the adsorption potential of novel biosorbentPhragmites karka(Trin), in its natural and treated forms, were performed for removal of mercury ions from aqueous solution. The study was carried out at different parameters to obtain optimum conditions of pH, biosorbent dose, agitation speed, time of contact, temperature, and initial metal ion concentration. To analyze the suitability of the process and maximum amount of metal uptake, Dubinin-Radushkevich (D-R) model, Freundlich isotherm, and Langmuir isotherm were applied. The values ofqmaxfor natural and treated biosorbents were found at 1.79 and 2.27 mg/g, respectively. The optimum values of contact time and agitation speed were found at 50 min and 150 rpm for natural biosorbent whereas 40 min and 100 rpm for treated biosorbent, respectively. The optimum biosorption capacities were observed at pH 4 and temperature 313 K for both naturalP. karkaand treatedP. karka.RLvalues indicate that comparatively treatedP. karkawas more feasible for mercury adsorption compared to naturalP. karka. Both pseudo-first-order and pseudo-second-order kinetic models were applied and it was found that data fit best to the pseudo-second-order kinetic model. Thermodynamic studies indicate that adsorption process was spontaneous, feasible, and endothermic.


2017 ◽  
Vol 105 (12) ◽  
Author(s):  
Sayed S. Metwally ◽  
Hoda E. Rizk ◽  
Mona S. Gasser

AbstractGreen composites emphasize renewable starting materials for better economy using biomass materials. Therefore, low-cost composite biosorbent was prepared by modification of eggshell material using heteropoly acid for removal of strontium ions from aqueous solution. The resulted composite was characterized and evaluated for the sorption process using the batch technique. Low concentration of strontium ions was used to evaluate the sorption sensitivity of the prepared composite. The obtained experimental results illustrated that the modification process of eggshell material enhanced the percent uptake from 49.9 to 95.7%. From kinetic studies, the sorption of strontium ions follows the pseudo-second-order kinetic model. The isotherm studies indicated that Langmuir is more applicable than Freundlich isotherm. Moreover, Dubinin–Radushkevich isotherm was studied. Thermodynamic studies revealed that the sorption process is spontaneous and has endothermic nature. Strontium ions can be desorbed from the modified eggshell using HNO


2020 ◽  
Vol 26 (5) ◽  
pp. 64-81
Author(s):  
Saraa M. Ibrahim ◽  
Ziad T. Abd Ali

Modified bentonite has been used as effective sorbent material for the removal of acidic dye (methyl orange) from aqueous solution in batch system. The natural bentonite has been modified using cationic surfactant (cetyltrimethyl ammonium bromide) in order to obtain an efficient sorbent through converting the properties of bentonite from hydrophilic to organophilic. The characteristics of the natural and modified bentonite were examined through several analyses such as Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Surface area. The batch study was provided the maximum dye removal efficiency of 88.75 % with a sorption capacity of 555.56 mg/g at specified conditions (150 min, pH= 2, 250 rpm, and 0.5 g/100 ml). The-results-showed that with the Freundlich isotherm model the sorption data was accurately described with (R2≥0.94) in comparison with the Langmuir model under the studied conditions. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules. 


Toxics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 74
Author(s):  
Elisa Pandelani Munzhelele ◽  
Wasiu Babatunde Ayinde ◽  
Rabelani Mudzielwana ◽  
Wilson Mugera Gitari

Water is regarded as an important natural resource to sustain life, and its purification is an important criterion that determines its quality and usefulness. In this study, the incorporation of Fe3+ oxide onto a phenylenediamine (pPD) polymer matrix through chemical co-polymerization was prepared, and its arsenite and fluoride removal potentials at optimal conditions from aqueous solution were evaluated. The morphology and structural analysis of the synthesized Fe-doped pPD (Fe-pPD) were comparatively evaluated using the FT-IR, SEM, EDS, and XRD techniques. Fe was successfully incorporated onto pPD matrix as confirmed by different morphological characterizations. The rate of adsorption of F− and As3+ onto the Fe-pPD composite best followed the pseudo-second-order kinetic model. The experimental data for both As3+ and F− onto the Fe-pPD composite better fit the Freundlich isotherm model at different operating temperatures. Overall, the synthesized composite exhibited a strong affinity towards fluoride uptake (96.6%) than arsenite uptake (71.14%) with a maximum capacity of 6.79 (F−) and 1.86 (As3+) mg/g. Additionally, the synthesized adsorbent showed some level of antimicrobial activity against common water-borne bacterial. Therefore, the Fe-doped pPD composite has the potential ability for inorganic metal species pollutants remediation and bacterial disinfection in community-level water purification processes.


2021 ◽  
Vol 11 (5) ◽  
pp. 12831-12842

High amounts of phosphate (PO43–) discharged in receiving water can lead to eutrophication, which endangers life below water and human health. This study elucidates the removal of PO43– from synthetic solution by iron-coated waste mussel shell (ICWMS). The PO43– adsorption by ICWMS was determined at different process parameters, such as initial PO43– concentration (7 mg L−1), solution volume (0.2 L), adsorbent dosage (4, 8, 12, 16, and 20 g), and contact time. The highest efficiency of PO43− removal can reach 96.9% with an adsorption capacity of 0.30 mg g−1 could be obtained after a contact time of 48 h for the use of 20 g of ICWMS. Batch experimental data can be well described by the pseudo-second-order kinetic model (R2 = 0.999) and Freundlich isotherm model (R2 = 0.996), suggesting that chemisorption and multilayer adsorption occurred. The efficiency of PO43– removal from aqueous solution by ICWMS was verified to contribute to applying a new low-cost adsorbent obtained from waste mussel shell in the field of wastewater treatment.


2013 ◽  
Vol 316-317 ◽  
pp. 509-515
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Mei Na Liang ◽  
Rong Rong Lu

In this study, a Fe(III)-impregnated sorbent was prepared from sugarcane bagasse and FeCl3 solution via carbonization/activation in a muffle furnace at 500 °C for 4h. Batch experiments were carried out to determine the capacity of the Fe(III)-impregnated sorbent to adsorb As(V) from aqueous solution. The dynamical data fitted very well with the pseudo-second-order kinetic model and the calculated adsorption capacities of 4.8263, 5.2219 and 7.1225 mg/g were equal to the actual values of the experiments at temperatures of 20, 25, and 35 °C, respectively. The experimental data were modeled by Langmuir and Freundlich isotherm models. The Langmuir isotherm with R2 values of 0.9926-0.9968 could yield better fits than the Freundlich isotherm, and the adsorption was endothermic, indicating monolayer adsorption of As(V).Freundlich isotherm, and the adsorption was endothermic, indicating monolayer adsorption of As(V).


2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4318
Author(s):  
Elie Meez ◽  
Abbas Rahdar ◽  
George Z. Kyzas

The threat of the accumulation of heavy metals in wastewater is increasing, due to their abilities to inflict damage to human health, especially in the past decade. The world’s environmental agencies are trying to issue several regulations that allow the management and control of random disposals of heavy metals. Scientific studies have heavily focused on finding suitable materials and techniques for the purification of wastewaters, but most solutions have been rejected due to cost-related issues. Several potential materials for this objective have been found and have been compared to determine the most suitable material for the purification process. Sawdust, among all the materials investigated, shows high potential and very promising results. Sawdust has been shown to have a good structure suitable for water purification processes. Parameters affecting the adsorption mechanism of heavy metals into sawdust have been studied and it has been shown that pH, contact time and several other parameters could play a major role in improving the adsorption process. The adsorption was found to follow the Langmuir or Freundlich isotherm and a pseudo second-order kinetic model, meaning that the type of adsorption was a chemisorption. Sawdust has major advantages to be considered and is one of the most promising materials to solve the wastewater problem.


2013 ◽  
Vol 726-731 ◽  
pp. 2100-2106 ◽  
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Shou Rui Yuan

Activated carbon prepared from grapefruit peel, an agricultural solid waste by-product, has been used for the adsorption of Cr(VI) from aqueous solution. The effects of adsorbent dosage, pH and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 3. The dynamical data fit very well with the pseudo-second-order kinetic model and the calculated adsorption capacities (23.98, 24.33 and 24.81 mg/g) were in good agreement with experiment results at 20°C, 30°C and 40 °C for the 100 mg/L Cr(VI) solution. The Freundlich model (R2 values were 0.9198-0.9871) fitted adsorption data better than the Langmuir model. The calculated parameters confirmed the favorable adsorption of Cr(VI) on the activated carbon prepared from grapefruit peel.


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