scholarly journals Removal of Acid Blue 158 from Solution by Sunflower Seed Hull

2013 ◽  
Vol 13 (1) ◽  
pp. 25
Author(s):  
Siriwan Srisorrachatr ◽  
Paranee Sriromreun

The removal of Acid Blue 158, acid dye for textile dyeing, from aqueous solution by sunflower seed hull was studied. The extent of adsorption capacity was studied as a function of heating temperature, sulphuric acid treatment, adsorbent size and pH of the solution. Sunflower seed hull was heated at 200, 300 and 400oC in oxygen deficient conditioned furnace. As the results, the sunflower seed hull heated at 200oC was the best absorbent for the dye removal with the maximum value of 30.84% at pH 4. Furthermore, removal ratio of Acid Blue 158 increased when the adsorbent was treated with 2M sulphuric acid. Particle sizes examined in this study were 250-355, 710-2000 and over 2000 micrometer. It was showed that the size of adsorbent affected on the removal capacity, i.e. the removal capacity increased along with the decrease of the size of absorbent. pH of the solution was studied between 1 and 6, and it was found that the optimum pH was pH 2. At the optimum condition, the modified adsorbent showed the removal ability of about 50%. The results obtained under the conditions of pH 4, 2M H2SO4 treatment of sunflower seed hull and the size of 500-710 micrometer at room temperature, the adsorption isotherm was fitted to Langmuir adsorption model, and the maximum adsorption capacity, qm, of 18.52 mg/g and Langmuir adsorption constant, Kl, of 5.25x10-3 L/mg were obtained.

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.


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.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2933
Author(s):  
Edgar Pineda Puglla ◽  
Diana Guaya ◽  
Cristhian Tituana ◽  
Francisco Osorio ◽  
María J. García-Ruiz

This study reports the adsorption capacity of lead Pb2+ and cadmium Cd2+ of biochar obtained from: peanut shell (BCM), “chonta” pulp (BCH) and corn cob (BZM) calcined at 500, 600 and 700 °C, respectively. The optimal adsorbent dose, pH, maximum adsorption capacity and adsorption kinetics were evaluated. The biochar with the highest Pb2+ and Cd2+ removal capacity is obtained from the peanut shell (BCM) calcined at 565 °C in 45 min. The optimal experimental conditions were: 14 g L−1 (dose of sorbent) and pH between 5 and 7. The sorption experimental data were best fitted to the Freundlich isotherm model. High removal rates were obtained: 95.96% for Pb2+ and 99.05. for Cd2+. The BCH and BZM revealed lower efficiency of Pb2+ and Cd2+ removal than BCM biochar. The results suggest that biochar may be useful for the removal of heavy metals (Pb2+ and Cd2+) from drinking water.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1063
Author(s):  
Zuzana Koudelkova ◽  
Zuzana Bytesnikova ◽  
Kledi Xhaxhiu ◽  
Monika Kremplova ◽  
David Hynek ◽  
...  

The removal of selenium from superficial and waste water is a worldwide problem. The maximum limit according to the World Health Organization (WHO) for the selenium in the water is set at a concentration of 10 μg/L. Carbon based adsorbents have attracted much attention and recently demonstrated promising performance in removal of selenium. In this work, several materials (iron oxide based microparticles and graphene oxides materials) and their composites were prepared to remove Se(IV) from water. The graphene oxides were prepared according to the simplified Hummer’s method. In addition, the effect of pH, contact time and initial Se(IV) concentration was tested. An electrochemical method such as the differential pulse cathodic stripping voltammetry was used to determine the residual selenium concentration. From the experimental data, Langmuir adsorption model was used to calculate the maximum adsorption capacity. Graphene oxide particles modified by iron oxide based microparticles was the most promising material for the removal of Se(IV) from its aqueous solution at pH 2.0. Its adsorption efficiency reached more than 90% for a solution with given Se(IV) concentration, meanwhile its maximal recorded adsorption capacity was 18.69 mg/g.


2017 ◽  
Vol 36 (1-2) ◽  
pp. 198-214 ◽  
Author(s):  
Kaiyue Wu ◽  
Jingang Yu ◽  
Xinyu Jiang

Multi-walled carbon nanotubes (MWCNTs) encapsulated by polyaniline (PANI) were synthesized by in situ polymerization. Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and thermal gravimetric analysis (TGA) were used to characterize the synthesized composites (O-MWCNTs/PANI), and the surface area was calculated by the Brunauer–Emmett–Teller (BET) method. The removal capacity of alizarin yellow R (AYR) with O-MWCNTs/PANI was further investigated. Experiments were conducted to optimize the adsorption conditions, including contact time, pH, initial concentration of AYR and temperature. The results showed that the maximum adsorption capacity for AYR was 884.80 mg/g. The adsorption kinetics and the adsorption isotherm could be better described by the pseudo-second-order model and the Langmuir isotherm, respectively. Energy changes revealed that the adsorption process was exothermic and spontaneous in nature. Additionally, the O-MWCNTs/PANI showed higher adsorption capacity than pristine MWCNTs or PANI. Therefore, O-MWCNTs/PANI would be applied as an efficient adsorbent for the removal of dye from water.


2019 ◽  
pp. 268-277
Author(s):  
Srdjan Stankovic ◽  
Tatjana Sostaric ◽  
Mladen Bugarcic ◽  
Aleksandra Janicijevic ◽  
Katarina Pantovic-Spajic ◽  
...  

Annual production of the sunflower seed in Serbia is between 650,000-720,000 tons. Most of this amount is used in vegetable oil industry. Abundant by-products from this processing are sunflower seed husks. Husks are usually incinerated by vegetable oil producers in order to obtain energy, used as an animal feed, or, unfortunately, landed up at some landfills. In order to promote new, added value for this abundant, renewable resource, the investigation presented in this paper was conducted. For that purpose, adsorption of Cu(II) ions from synthetic solution by unmodified sunflower seed husks was examined. ATR-FTIR was used to identify functional groups as potential active sites for Cu(II) sorption. Zeta potential values were determined to reveal the surface charge, while the cation exchange capacity (CEC) was determined to reveal the amount of exchangeable ions on its surface. ATR-FTIR analysis revealed the presence of specific functional groups (hydroxyl, carboxyl, carbonyl, and amine) responsible for removal of Cu(II) ions. The total CEC of sunflower husk is 47.74 meq/100g and Ca(II) and Mg(II) ions are in dominant exchangeable positions. The study of ion-exchange mechanism involvement was done and results confirmed that this mechanism is not the only mechanism which is involved in copper sorption. Also, the results show that the Cu(II) ions have preference for Mg(II) ions substitution. Sorption experiments were conducted in batch system. The effect of operating parameters (pH, contact time, initial concentration of Cu(II) ions and adsorbent dosage) on the adsorption capacity were investigated. The obtained experimental data were fitted by Langmuir and Freundlich isotherm models. The maximum adsorption capacity for Cu(II) ions calculated from Langmuir adsorption isotherm was 34.89 mg/g which is 15 to 35% higher than the capacity that other researchers reported previously for the same material and pollutant. These results are suggesting that sunflower seed husks have a potential to be applied as an effective adsorbent of copper ions from contaminated waters.


Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 178
Author(s):  
Serap Sezen ◽  
Vijay Kumar Thakur ◽  
Mehmet Murat Ozmen

Currently, macroporous hydrogels have been receiving attention in wastewater treatment due to their unique structures. As a natural polymer, alginate is used to remove cationic dyes due to its sustainable features such as abundance, low cost, processability, and being environmentally friendly. Herein, alginate/montmorillonite composite macroporous hydrogels (cryogels) with high porosity, mechanical elasticity, and high adsorption yield for methylene blue (MB) were generated by the one-step cryogelation technique. These cryogels were synthesized by adding montmorillonite into gel precursor, followed by chemical cross-linking employing carbodiimide chemistry in a frozen state. The as-prepared adsorbents were analyzed by FT-IR, SEM, gel fraction, swelling, uniaxial compression, and MB adsorption tests. The results indicated that alginate/montmorillonite cryogels exhibited high gelation yield (up to 80%), colossal water uptake capacity, elasticity, and effective dye adsorption capacity (93.7%). Maximum adsorption capacity against MB was 559.94 mg g−1 by linear regression of Langmuir model onto experimental data. The Pseudo-Second-Order model was fitted better onto kinetic data compared to the Pseudo-First-Order model. Improved porosity and mechanical elasticity yielding enhanced dye removal capacity make them highly potential alternative adsorbents compared to available alginate/montmorillonite materials for MB removal.


2020 ◽  
Vol 12 (7) ◽  
pp. 1078-1089
Author(s):  
Hongna Xu ◽  
Liguo Jin ◽  
Yan Cheng

Metal organic skeleton (MOFs) is a kind of porous material composed of metal ions and organic ligands through coordination, which can be used to absorb a lot of toxic substances from waste water. In this research, UiO-66, UiO-66(Zr) and UiO-66(Zr)–2COOH were synthesized by solvent thermal method, and physical analysis was conducted on the adsorbent properties of the materials by means of XRD, IR, Zeta potential, etc. In the adsorption test of wastewater impurities, UiO-66(Zr)–2COOH was firstly taken as the research object. With the increase of the initial concentration of hydrochloric acid, the adsorption capacity of the organic skeleton was greatly increased. However, when the concentration increases further, the growth rate of adsorption decreases, and with the increase of temperature, the adsorption decreases further. The organic skeleton of Hg(II) adsorption process conforms to the secondary dynamic adsorption model. At the same time, the organic skeleton materials of Hg(II) has strong ability of recognition, the recognition of Hg(II) sex is much stronger than the Ni(II) identification. Uio-66(Zr) and UiO-66(Zr)–2COOH are selected for adsorption of As, and the adsorption process of the two kinds of materials of As is close to the Freundlich model(III). The ability of absorbing As(III) of these materials is stronger than the ability of As(V). At the same time, UiO-66(Zr)–2COOH shows higher adsorption capacity on the As(III), and maximum adsorption capacity is 220 mg/g.


2014 ◽  
Vol 906 ◽  
pp. 112-117 ◽  
Author(s):  
Sanil Sebastian ◽  
Suseeladevi Mayadevi ◽  
Sujata Mandal

Layered double hydroxide (MgAl LDH) and its composites containing different quantities of sodium alginate were synthesized. The adsorption characteristics of these materials were evaluated for the adsorption of Acid Blue 120 (AB 120). The adsorption capacity of the composites for the dye was higher than that of pristine LDH. The adsorption capacity varied with alginate concentration and was the highest when the alginate concentration was 5.9 wt%. The maximum adsorption capacity of the composite enhanced by 40%, compared to pristine MgAl LDH. The rate of adsorption of the dye on the composites was also higher than that of pristine MgAl LDH up to an alginate concentration of 11%. The results reveal that LDH composites are more efficient adsorbents compared to pure LDH. Sodium alginate, being a biopolymer can also improve the biocompatibility of the LDH for biological applications.


2009 ◽  
Vol 4 (2) ◽  
Author(s):  
Nassima Tazrouti ◽  
Moussa Amrani

Activated lignin having surface area of 1023 m2.g-1 has been prepared from sulfate lignin that was treated by 30 % H2O2 and carbonized at 300 °C in order to test the chromium (VI) adsorption from aqueous solution. The influence of contact time, pH, initial concentration of adsorbent and adsorbate and temperature on the adsorption capacity were investigated. The maximum removal of Cr(VI) was found to be 92,36 % at pH=2 and contact time of 80 min. Optimal concentration of lignin and Cr(VI) were found to be 3.8 g.l-1 and 180 mg.l-1, respectively. The adsorption kinetics was tested pseudo-first-order and pseudo-second-order equation. The analytical data were fitted well in a pseudo-second-order equation and the rate of removal of chromium was found to speed up with increasing temperature. Activation energy for the adsorption process was found to be 18.19 Kj.mol-1. The Langmuir and Freundlich adsorption isotherm models were applied to describe the isotherm and isotherm constants for the adsorption of Cr (VI) on lignin. These constants and correlation coefficients of the isotherm models were calculated and compared. Results indicated that Cr (VI) uptake could be described by the Langmuir adsorption model. The maximum adsorption capacity (qm) of Cr (VI) on lignin was 75.75 mg.g-1 at temperature of 40°C. The dimensionless equilibrium parameter (RL) signified a favorable adsorption of Cr (VI) on lignin and was found between 0.0601 and 0.818 (0<RL<1). The thermodynamic parameters like ΔG°, ΔS° and ΔH° were calculated and it has been found that the reaction was spontaneous and endothermic in nature. This study indicates that lignin has the potential to become an effective and economical adsorbent for removal Cr (VI) from the waste water.


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