scholarly journals Comparison of Heavy Metals Removal from Aqueous Solution by Moringa oleifera Leaves and Seeds

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 508
Author(s):  
Mohamed Abatal ◽  
M. T. Olguin ◽  
Ioannis Anastopoulos ◽  
Dimitrios A. Giannakoudakis ◽  
Eder Claudio Lima ◽  
...  

In this work, biomass obtained from seeds (S-MO) and leaves (L-MO) of the Moringa oleifera plant were used as low-cost biosorbents to remove the Pb(II), Cd(II), Co(II), and Ni(II) from aqueous solutions. The biosorption of the heavy metal ions was done using the batch technique. The effects of contact time (30–1440 min), biosorbent dosage (10–50 g/L) (0.1–0.5 g), and initial concentration of metals (10–500 mg/L) on the sorption capacity of metal ions were investigated. The S-MO and L-MO samples’ characterization was performed using pHpzc, X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). It was found that the pHpzc was notably different between the seeds and leave-derived biosorbents. The removal process’s experimental kinetic data for both S-MO and L-MO were best described by the pseudo-second-order model for all metal ions, with R2 above 0.997 in all cases. Langmuir and Freundlich’s models were also used to analyze the isotherms parameters. Based on the Langmuir model, the maximum sorption capacities (Qm) for L-MO were found as follows: L-MO-Pb > L-MO-Cd > L-MO-Co ≥ L-MO-Ni, and for S-MO, the values of Qm values presented the following order: S-MO-Pb > S-MO-Co > S-MO-Cd > S-MO-Ni.

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.


2019 ◽  
Vol 800 ◽  
pp. 187-192 ◽  
Author(s):  
Halima Delali ◽  
Djilali Redha Merouani ◽  
Hakim Aguedal ◽  
Mustapha Belhakem ◽  
Abdelkader Iddou ◽  
...  

In the present study, the waste shells were used as a new low cost and eco-friendly biosorbant for Orange G anionic dye removal from aqueous solutions. Experiments were conducted in batch mode, and the effect of pH of solution, contact time, and initial dye concentration. X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and ICP-MS analysis for chemical analysis were used to characterize the obtained biosorbent. The results showed that the mussel shells are composed 73% of calcite and 26% of aragonite with some traces of aluminum, magnesium, sodium, silicium and zinc. The biosorption results show that the optimal pH was around 2 for efficient Orange G biosorption. The equilibrium was attained in 60 min. The kinetic analysis showed that the pseudo-second-order model is in good agreement with the experimental data. The biosorption isotherm was well described by Langmuir isotherm model, the maximumbiosorption capacity was 1000mg/g. The thermodynamic study revealed that the biosorption of Orange G onto mussel shell is spontaneous and exothermic.


Molekul ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 28
Author(s):  
Mohammad Jihad Madiabu ◽  
Joko Untung ◽  
Imas Solihat ◽  
Andi Muhammad Ichzan

The research aims to investigate feasibility eggshells as potential adsorbent to remove copper(II) ions from aqueous solution. Eggshells powder was characterized using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Effect of copper(II) initial concentration, adsorbent dosage, and contact time have conducted. The optimum adsorption condition obtained when 0.7 g eggshells applied to 50 mg/L copper(II) solution for 50 minutes. The maximum percentage of copper(II) removal was exceeded more than 85%. Langmuir and Freundlich isotherm model were applied to describe the equilibrium adsorption. Copper(II) kinetics sorption process was fitted to pseudo-second order model with a rate constant equal to 0.516 g/mg.min. The results clearly exhibit that eggshells powder can be effectively used to remove copper(II) ions from aqueous solutions.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
G. P. Kofa ◽  
G. R. Nkoue Ndongo ◽  
M. B. Kameni Ngounou ◽  
M. N. Nsoe ◽  
E. V. Amba ◽  
...  

In this study, Grewia spp. biopolymer was utilized as a biosorbent for elimination of hexavalent chromium from water. Fourier-transform infrared spectrometry (FTIR) and X-ray diffraction (XRD) were performed for characterization of the biosorbent. Experiments were conducted in a batch mode at room temperature (25 ± 2°C) and agitation speed of 100 rpm to determine the influence of biosorbent dose, contact time, Cr(VI) concentration, and initial solution pH. It was found that equilibrium was attained in 50 min. A pseudo-first-order model suited well than a pseudo-second-order model. Biosorption capacity of Grewia spp. biopolymer increased with increase in concentration and depended on the solution pH. Langmuir and Freundlich models described experimental data very well. These findings showed that Grewia spp. biopolymer can serve as a biosorbent for elimination of Cr(VI) from water.


2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Theresa C. Umeh ◽  
John K. Nduka ◽  
Kovo G. Akpomie

AbstractDeterioration in soil–water environment severely contributed by heavy metal bioavailability and mobility on soil surface and sub-surface due to irrational increase in wastewater discharge and agrochemical activities. Therefore, the feasibility of adsorption characteristics of the soil is paramount in curbing the problem of micropollutant contamination in the farming vicinity. Soil from a farming site in a populated area in Enugu, Nigeria was collected and tested to measure the lead and cadmium contents using atomic absorption spectrophotometer (AAS). The adsorption potency of the ultisol soil was estimated for identifiable physicochemical properties by standard technique. The mean activity concentration of Pb2+ and Cd2+ was 15.68 mg/kg and 3.01 mg/kg. The pH, temperature, metal concentration and contact time adsorptive effect on the Pb2+ and Cd2+ uptake was evaluated by batch adsorption technique. The Langmuir, Freundlich and Temkin models were fitted into equilibrium adsorption data and the calculated results depict a better and satisfactory correlation for Langmuir with higher linear regression coefficients (Pb2+, 0.935 and Cd2+, 0.971). On the basis of sorption capacity mechanism of the soil, pseudo-second-order model best described the kinetics of both metal ions retention process. The results of the present study indicated that the soil being a low cost-effective adsorbent can be utilized to minimize the environmental risk impact of these metal ions.


2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.


2013 ◽  
Vol 65 (1) ◽  
Author(s):  
Norzita Ngadi ◽  
Chin Chiek Ee ◽  
Nor Aida Yusoff

Dyes contain carcinogenic materials which can cause serious hazards to aquatic life and the users of water. Textile industry is the main source of dye wastewater which results in environmental pollution. Many studies have been conducted to investigate the use of low cost adsorbent as an alternative technique for the adsorption of dye. The objective of this study is to determine the potential of eggshell powder as an adsorbent for methylene blue removal and find out the best operating conditions for the color adsorption at laboratory scale. The adsorption of cationic methylene blue from aqueous solution onto the eggshell powder was carried out by varying the operating parameters which were contact time, pH, dosage of eggshell powder and temperature in order to study their effect in adsorption capacity of eggshell powder. The results obtained showed that the best operating condition for removal of methylene blue was at pH 10 (78.98 %) and temperature 50°C (47.37 %) by using 2 g of eggshell powder (57.03 %) with 30 minutes equilibrium time (41.36 %). The kinetic studies indicated that pseudo-second-order model best described the adsorption process.


2020 ◽  
Vol 24 (1) ◽  
pp. 562-579
Author(s):  
Asma Behilil ◽  
Driss Lancene ◽  
Brahim Zahraoui ◽  
Meriem Belhachemi ◽  
Houcine Benmehdi ◽  
...  

Abstract Research and scientific work continue to develop low-cost treatment processes in terms of improving water quality and environmental protection. Oxide of zinc supported in natural clay is synthesized by impregnated method. The role of this modification is to increase the adsorption capacity of a basic dye (Methylene Blue) compared with calcined and natural clays. These samples are characterized by several analytical methods, X-Ray Diffraction (XRD), Thermogravimetric Analysis/Differential Thermal Analysis (TGA/TDA) and Brunauer, Emmett and Teller (BET) theory. The results show that these clays contain three phases, Sericite 2M1, Clinochlore, quartz and the presence of a new phase for the modified clay named zincite. The measured cation exchange capacity (CEC) is 9 cmolc/kg and the BET analysis shows the increase of surface area for these clays, from 9 to 30 m2 g−1. The findings show also that the impregnated clay has a better affinity than others when the kinetics data were well fitted by the pseudo-second-order. The adsorption capacities calculated using Langmuir equation of MB onto natural, calcined and impregnated clays are 154.0, 139.6 and 158.1 mg/g, respectively. The thermodynamic data showed that the adsorption of MB on these samples were exothermic. From this study, it can be concluded that these clays are efficacious materials for cationic dye removal from wastewater.


2017 ◽  
Vol 82 (4) ◽  
pp. 449-463 ◽  
Author(s):  
Sanja Marinovic ◽  
Marija Ajdukovic ◽  
Natasa Jovic-Jovicic ◽  
Tihana Mudrinic ◽  
Bojana Nedic-Vasiljevic ◽  
...  

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0?8.5, the amount of adsorbed Sr2+ was almost constant but 2?3 times smaller than at pH ?11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin?Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.


Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.


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