scholarly journals Removal of Cd(II) from water using zero valent iron/copper functionalized spent tea

2020 ◽  
Vol 82 (11) ◽  
pp. 2552-2561
Author(s):  
Khan Malook ◽  
Hamayun Khan

Abstract Zero valent Fe/Cu functionalized spent tea adsorbent was prepared for the decontamination of Cd(II) contaminated water. The synthesized material was characterized for structural and morphological characteristics using various analytical techniques. The material was used as adsorbent for the adsorption of Cd(II) from aqueous solutions in batch study experiments. The effect of initial pH, adsorbent dosage, contact time and adsorbate concentration was investigated. The obtained data well followed the Langmuir adsorption isotherm model and pseudo-second order rate model with maximum adsorption capacity of 89.686 mg·g−1. Based on Langmuir separation factor (R), having a value of 0.706–0.194, the adsorption process was confirmed to be favorable. The adsorbent was used in the form of a column for the sorption of Cd(II) from a running solution with satisfactory results. The spent material was regenerated and reutilized with reduction of adsorption capacity by 1.48% only. Overall, the current adsorbent can be efficiently utilized for the removal of aqueous Cd(II).

SAINTIFIK ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 104-115
Author(s):  
Agusriyadin Agusriyadin

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.


2018 ◽  
Vol 78 (7) ◽  
pp. 1615-1623 ◽  
Author(s):  
N. Priyantha ◽  
H. K. W. Sandamali ◽  
T. P. K. Kulasooriya

Abstract Although rice husk (RH) is a readily available, natural, heavy metal adsorbent, adsorption capacity in its natural form is insufficient for certain heavy metal ions. In this context, the study is based on enhancement of the adsorption capacity of RH for Cu(II). NaOH modified rice husk (SRH) shows higher extent of removal for Cu(II) ions than that of heated rice husk (HRH) and HNO3 modified rice husk (NRH). The extent of removal of SRH is increased with the concentration of NaOH, and the optimum NaOH concentration is 0.2 mol dm−3, used to modify rice husk for further studies. The surface area of SRH is 215 m2 g−1, which is twice as much as that of HRH according to previous studies. The sorption of Cu(II) on SRH obeys the Langmuir adsorption model, leading to the maximum adsorption capacity of 1.19 × 104 mg kg−1. Kinetics studies show that the interaction of Cu(II) with SRH obeys pseudo second order kinetics. The X-ray fluorescence spectroscopy confirms the adsorption of Cu(II) on SRH, while desorption studies confirm that Cu(II) adsorbed on SRH does not leach it back to water under normal conditions.


2017 ◽  
Vol 36 (1-2) ◽  
pp. 762-773 ◽  
Author(s):  
Xingmei Guo ◽  
Sihan Tang ◽  
Yan Song ◽  
Junmin Nan

The adsorptive removal of Ni2+ and Cd2+ at concentrations of approximately 50 mg L−1 in wastewater is investigated using an agricultural adsorbent, longan hull, and the adsorptive mechanism is characterized. The maximum adsorption capacity of approximately 4.19 mg g−1 Cd2+ was obtained under the optimized conditions of room temperature, pH 5.0, and a solid-to-liquid ratio of 1:30 in approximately 15 min. For Ni2+, the maximum adsorption capacity of approximately 3.96 mg g−1 was obtained at pH 4.7 in approximately 20 min. The adsorption kinetics for both metal ions on the longan hull can be described by a pseudo second-order rate model and are well fitted to the Langmuir adsorption isotherm. The adsorption mechanism of the longan hull to Ni2+ and Cd2+ ions is shown to be a monolayer adsorption of metal ions onto the absorbent surface. Thereinto, the longan hull adsorbent contains N–H, C–H, C=O, and C=C functional groups that can form ligands when loaded with Ni2+ and Cd2+, which reduces the fluorescence of the dried longan hull material.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhongmin Li ◽  
Peng Zou ◽  
Junzhou Yang ◽  
Miaoyang Huang ◽  
Linye Zhang ◽  
...  

AbstractA novel functionalized tannin-chitosan bentonite composite (TCBC) was successfully synthesized. The formation of the composite was confirmed by the X-ray diffraction (XRD) patterns and Fourier transform infrared spectroscopy (FT-IR) analysis. The pHpzc of TCBC was 3.38. The influences such as pH, dosage of TCBC, temperature and initial Cr(VI) concentration on adsorption capacity were investigated. The experimental data indicated that the almost saturated adsorption of the TCBC towards Cr(VI) in 100 min. The maximum adsorption capacity was 262.08 mg/g at 333 K with initial pH = 2.5. The adsorption kinetics of Cr(VI) on TCBC followed the pseudo-second-order kinetics model. The isothermal data were well described by the models of Langmuir, Freundlich and Temkin. The results revealed that the adsorption of Cr(VI) on TCBC existed comprehensive effects and mainly belong to the chemisorption. The TCBC could keep good performances (qe = 192.17 mg/g) in five runs, 1 M NaOH was used as eluent for desorption, which showed a high desorption efficiency. Studies showed TCBC prepared with low cost and green raw materials, and simple green preparation technology had high adsorption capacity, good reusability and acidic tolerance. By exploring the Cr(VI)-Cr(III) hybrid system, part of Cr(VI) was reduced to Cr(III) and adsorbed by TCBC. The optimal adsorption pH of Cr(III) was 5.0.


2019 ◽  
Vol 107 (6) ◽  
pp. 459-467 ◽  
Author(s):  
Shuting Zhuang ◽  
Jianlong Wang

Abstract In this study, phosphate functionalized bacterial cellulose with micro-fibrous structure was prepared, characterized and applied for U(VI) adsorption. The successful grafting of phosphoric functional groups was proved by the FTIR spectra and EDS analysis (P~4.15 wt%), and the porous structure was confirmed by SEM and BET analyses. Furthermore, the effect of initial pH, contact time, initial concentration, and temperature were studied. The as-prepared adsorbent showed a high adsorption capacity at wide pH range (4.0–8.0) and its maximum adsorption capacity was calculated to be 50.65 mg/g. This endothermic adsorption process conformed to the pseudo second-order kinetic model and the Elovich kinetic models and the Langmuir isothermal models. According to the FTIR and XPS analysis, an adsorption mechanism was tentatively proposed, mainly due to the interaction between U(VI) and phosphoric groups.


2021 ◽  
Vol 2 (2) ◽  
pp. 245-256
Author(s):  
Priyanka R. Sharma ◽  
Sunil K. Sharma ◽  
Marc Nolan ◽  
Wenqi Li ◽  
Lakshta Kundal ◽  
...  

Raw wood was subjected to sequential oxidation to produce 2,3,6-tricarboxycellulose (TCC) nanofibers with a high surficial charge of 1.14 mmol/g in the form of carboxylate groups. Three oxidation steps, including nitro-oxidation, periodate, and sodium chlorite oxidation, were successfully applied to generate TCC nanofibers from raw wood. The morphology of extracted TCC nanofibers measured using TEM and AFM indicated the average length, width, and thickness were in the range of 750 ± 110, 4.5 ± 1.8, and 1.23 nm, respectively. Due to high negative surficial charges on TCC, it was studied for its absorption capabilities against Pb2+ ions. The remediation results indicated that a low concentration of TCC nanofibers (0.02 wt%) was able to remove a wide range of Pb2+ ion impurities from 5–250 ppm with an efficiency between 709–99%, whereby the maximum adsorption capacity (Qm) was 1569 mg/g with R2 0.69531 calculated from Langmuir fitting. It was observed that the high adsorption capacity of TCC nanofibers was due to the collective effect of adsorption and precipitation confirmed by the FTIR and SEM/EDS analysis. The high carboxylate content and fiber morphology of TCC has enabled it as an excellent substrate to remove Pb2+ ions impurities.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2295
Author(s):  
Marwa El-Azazy ◽  
Ahmed S. El-Shafie ◽  
Hagar Morsy

Biochars (BC) of spent coffee grounds, both pristine (SCBC) and impregnated with titanium oxide (TiO2@SCBC) were exploited as environmentally friendly and economical sorbents for the fluroquinolone antibiotic balofloxacin (BALX). Surface morphology, functional moieties, and thermal stabilities of both adsorbents were scrutinized using SEM, EDS, TEM, BET, FTIR, Raman, and TG/dT analyses. BET analysis indicated that the impregnation with TiO2 has increased the surface area (50.54 m2/g) and decreased the pore size and volume. Batch adsorption experiments were completed in lights of the experimental set-up of Plackett-Burman design (PBD). Two responses were maximized; the % removal (%R) and the adsorption capacity (qe, mg/g) as a function of four variables: pH, adsorbent dosage (AD), BALX concentration ([BALX]), and contact time (CT). %R of 68.34% and 91.78% were accomplished using the pristine and TiO2@SCBC, respectively. Equilibrium isotherms indicated that Freundlich model was of a perfect fit for adsorption of BALX onto both adsorbents. Maximum adsorption capacity (qmax) of 142.55 mg/g for SCBC and 196.73 mg/g for the TiO2@SCBC. Kinetics of the adsorption process were best demonstrated using the pseudo-second order (PSO) model. The adsorption-desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 66.32% after the fifth cycles.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jhonatan R. Guarín ◽  
Juan Carlos Moreno-Pirajan ◽  
Liliana Giraldo

Currently, there is a great pollution of water by the dyes; due to this, several studies have been carried out to remove these compounds. However, the total elimination of these pollutants from the aquatic effluents has represented a great challenge for the scientific community, for which it is necessary to carry out investigations that allow the purification of water. In this work, we studied the bioadsorption of methylene blue on the surface of the biomass obtained from the algae D. antarctica. This material was characterized by SEM and FTIR. To the data obtained in the biosorption experiments, different models of biosorption and kinetics were applied, finding that the best fit to the obtained data is given by applying the pseudo-second-order models and the Toth model, respectively. It was also determined that the maximum adsorption capacity of MB on the surface of the biomass is 702.9 mg/g, which shows that this material has great properties as a bioadsorbent.


2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.


2020 ◽  
Vol 11 (4) ◽  
pp. 11891-11904

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.


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