scholarly journals Effective and Simple NaOH-Modification Method to Remove Methyl Violet Dye via Ipomoea aquatica Roots

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yie Chen Lu ◽  
Muhammad Raziq Rahimi Kooh ◽  
Linda Biaw Leng Lim ◽  
Namal Priyantha

In this study, a simple chemical modification was applied to a sustainable and abundantly available resource, kangkong root (KR), to remove methyl violet 2B (MV) dye. The chemically modified adsorbent (NaOH-KR) was obtained using NaOH solution treatment. Batch adsorption experiments were carried out to investigate the effects of pH, ionic strength, contact time, adsorbent dosage, and initial dye concentration. A regeneration experiment was also carried out to assess the potential of reusability. The adsorption process was modelled using various kinetics and isotherm models, whereby the best-fitting models were evaluated by using the coefficient of determination ( R 2 ) and error functions. The Sips ( R 2 = 0.9714 , χ2 =0.16) and pseudo-second-order ( R 2 = 0.9996 , χ 2 = 0.007 ) models were identified to best represent the adsorption process. The Sips model predicted a maximum adsorption capacity at 551.5 mg g-1 for NaOH-KR, which is 55% improvement in performance when compared to nonmodified KR. Lastly, the regeneration experiment showed that NaOH-KR was able to maintain reasonable dye removal even after five consecutive cycles of regenerating and reusing.

2020 ◽  
Vol 10 (12) ◽  
Author(s):  
Tze Ling Kua ◽  
Muhammad Raziq Rahimi Kooh ◽  
Muhammad Khairud Dahri ◽  
Nur Afiqah Hazirah Mohamad Zaidi ◽  
YieChen Lu ◽  
...  

AbstractIpomoea aquatica (IA) was investigated for its potential as a low-cost adsorbent to remove toxic methyl violet 2B (MV2B) dye in aqueous solutions. Optimising parameters such as the effects of contact time, medium pH and ionic strength (using NaCl, NaNO3, KCl and KNO3) were investigated. The results indicated that 150 min were sufficient for the adsorption to reach an equilibrium state and no adjustment of pH medium was necessary. Batch adsorption experiments such as adsorption isotherm, thermodynamics and kinetics were investigated and the experimental isotherm data were fitted to six isotherm models, namely Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Peterson and Sips, with the latter being the best-fit isotherm model showing maximum adsorption capacity (qmax) of 267.9 mg g−1. Thermodynamics studies indicated adsorption of MV2B to be exothermic in nature, occurring spontaneously. The kinetics was best described by the pseudo-second-order model. Regeneration of IA pointed to its reusability, maintaining high adsorption capacity even up until Cycle 5 when treated with acid (HCl) and base (NaOH). Functional groups such as hydroxyl and amine groups which could be involved in the adsorption of MV2B were determined using FTIR spectroscopy, and the point of zero charge of IA was found to be at pH 6.81.


2020 ◽  
Vol 10 (5) ◽  
pp. 1738
Author(s):  
Kay Thwe Aung ◽  
Seung-Hee Hong ◽  
Seong-Jik Park ◽  
Chang-Gu Lee

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.


2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Swarup Biswas ◽  
Umesh Mishra

Calcium pretreatedHevea brasiliensissawdust has been used as an effective and efficient adsorbent for the removal of copper ion from the contaminated water. Batch experiment was conducted to check the effect of pH, initial concentration, contact time, and adsorbent dose. The results conclude that adsorption capacity of adsorbent was influenced by operating parameters. Maximum adsorption capacity found from the batch adsorption process was 37.74 mg/g at pH of 5.6. Various isotherm models like Langmuir, Freundlich, and Temkin were used to compare the theoretical and experimental data, whereas the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied to study the kinetics of the batch adsorption process. Dynamic studies were also conducted in packed-bed column using different bed depths and the maximum adsorption capacity of 34.29 was achieved. Characterizations of the adsorbent were done by Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy.


2021 ◽  
pp. 1761-1778
Author(s):  
Saba Adel Saed ◽  
Donia Aidan

The influence of acid activation of a mixture of illite, kaolinite, and chlorite clays collected from the area of Zorbatiya (east of Iraq) on the adsorption of methyl violet 6B (MV6B) as a cationic dye was studied. The activation was carried out by using 0.25M HCl and 0.25M . Raw and acid-activated clays were analyzed by atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Batch adsorption method was used to study the adsorption of MV6B onto the raw and acid activated clays. The impacts of different factors on the adsorption process were studied, such as clay weight, agitation time, starting MV6B concentration, temperature, ionic strength, and solution pH. The adsorption process was described by using Langmuir, Freundlich, Temkin, and Dubinin- Radushkevich isotherm models. Thermodynamic parameters like  were estimated based on Vanʼt Hoff equation.


2011 ◽  
Vol 695 ◽  
pp. 73-76 ◽  
Author(s):  
An Kai Luo ◽  
Xue Gang Luo ◽  
Xiao Yan Lin

The adsorption of Cd(II) ions from aqueous solution by sodium hydroxide-treated bamboo powder(STB) was studied in a batch adsorption system. Characteristics of STB were investigated by scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS). Factors influencing adsorption such as pH of the solution, adsorbent dosage, cadmium concentration and temperature have been studied. The adsorption process was relatively fast and equilibrium was achieved after 120 min, and the maximum adsorption of Cd(II) ions occurred at around pH 6.5. The equilibrium data were fitted using Langmuir, Temkin and Freundlich isotherm models to calculate isotherm constants. And the adsorption isotherm fitted well Langmuir isotherm, and the maximum adsorption capacity was 8.987 mg/g.


2021 ◽  
Vol 22 (2) ◽  
pp. 199-205
Author(s):  
Iva Yenis Septiariva ◽  
I Wayan Koko Suryawan ◽  
Ariyanti Sarwono

ABSTRAK Umumnya, industri tekstil menggunakan berbagai pewarna sintetis yang menghasilkan air limbah yang sangat berwarna. Oleh karenaitu, air limbah tekstil ini harus diolah sebelum dibuang ke lingkungan. Penelitian ini bertujuan untuk mengetahui penyisihan warna dengan teknik adsorpsi menggunakan karbon aktif. Metode ini dianggap sebagai teknologi berbiaya rendah dan perawatan yang mudah untuk pengolahan air limbah. Proses adsorpsi batch dilakukan dengan waktu kontak yang berbeda yaitu 5–60 menit dan variasi konsentrasi awal yang mengandung Reactive Black 5 (RB-5) sebesar 5 mg/L; 10 mg/L; 15 mg/L; dan 20 mg/L. Azo-Reactive Black-5 adalah material pewarna yang digunakan untuk membuat air limbah artifisial. Hasil penelitian menunjukkan bahwa proses adsorpsi menurunkan kadar konsentrasi warna masing-masing sebesar 86,21%, 85,21%, 84,29%, dan 71,07% selama 60 menit. Peningkatan konsentrasi zat warna dalam air limbah menyebabkan efisiensi penghilangan warna yang rendah. Selain itu, penelitian mengevaluasi efektivitas adsorpsi batch oleh karbon aktif karena efisiensi penghilangan warna dapat mencapai lebih dari 50% setelah waktu kontak 30 menit. Hal ini terlihat pada konsentrasi awal 5 mg/L dan 20 mg/L dengan efisiensi penyisihan sebesar 66,18% dan 53,97%. Kinetika adsorpsi yang sesuai untuk pendekatan pemodelan pada penelitian ini adalah Langmuir isotherm dengan nilai r2 yang lebih besar dan mendekati nilai 1 yaitu 0,9756. Estimasi kapasitas adsorpsi maksimum yang diperoleh dari model sebesar 4,353 mg/g. Kata kunci: Air limbah tekstil, warna, adsorpsi, efisiensi penyisihan   ABSTRACT Generally, the textile industry uses various synthetic dyes that produced a large amount of highly colored wastewater. This research aims to investigate the color removal by adsorption using powdered activated carbon. This method is considered viable due to cost effective and ease of maintenance for wastewater treatment. The batch adsorption process was carried out at different contact times of 5–60 minutes and varied initial dye concentration containing azo-Reactive Black 5 (RB-5) of 5 mg/L; 10 mg/L; 15 mg/L; and 20 mg/L. A synthetic RB-5 was prepared  as the artificial wastewater to simulate the actual wastewater. The adsorption  proceeded initially with higher rates and gradually slowed down until reached a constant value due to the carbon surface's saturation with increasing contact time.The results showed that, at different initial dye concentration, the adsorption process decreased color concentration for 60 minutes by 86.21%, 85.21%, 84.29%, and 71.07% respectively. The increase of initial dye concentration lowers color removal efficiency. Besides, the effectiveness of adsorption by activated carbon was found more than 50% after 30 minute of contact time. The efficiency removal presented initial concentration of 5 mg/ and 20 mg/L was 66.18% and 53.97%, respectively. Langmuir and Freundlich isotherm were also plotted to assess the kinetics of adsorption. Langmuir isotherm gave the best modelling approach for adsorption kinetics as indicated by higher coefficient of determination (r2) of 0.9756. An estimated maximum adsorption capacity obtained from the model was 4.353 mg/g. Keywords: Textile wastewater, color, adsorption, removal efficiency


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad Khairud Dahri ◽  
Muhammad Raziq Rahimi Kooh ◽  
Linda B. L. Lim

One of the major contaminants of water bodies is dye pollutants that come from textile, paper, and leather industries. In this study, Casuarina equisetifolia needle (CEN) is used to remove methyl violet 2B (MV) from aqueous solutions. Batch experiments were done to investigate the contact time, effect of pH, initial dye concentrations, and temperature. Langmuir and Freundlich isotherm models were used to describe the interaction between the adsorbate and adsorbent. The sorption mechanism was described using Lagergren 1st order, pseudo 2nd order, and Weber-Morris intraparticle diffusion models. FTIR spectroscopy was used to analyze the functional groups of CEN before and after sorption with MV. Optimal conditions were found to be at room temperature with 2 h contact time and no pH adjustment was needed. Experimental data was best fitted onto Langmuir model with maximum adsorption capacity of 164.99 mg/g, while pseudo 2nd order best described the experimental data for the kinetics study. Thermodynamic parameters such as change in Gibbs free energy (), enthalpy (), and entropy () were also investigated.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 63
Author(s):  
Maria Harja ◽  
Gabriela Buema ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
Dumitru Daniel Herea ◽  
...  

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area, and vibrating sample magnetometer (VSM). Batch adsorption experiments were employed in order to investigate the effects of adsorbent dose, initial Cu (II) concentration and contact time over adsorption efficiency. The experimental isotherms were modeled using Langmuir (four types of its linearization), Freundlich, Temkin, and Harkins–Jura isotherm models. The fits of the results are estimated according to the Langmuir isotherm, with a maximum adsorption capacity of 17.39 mg/g. The pseudo-second-order model was able to describe kinetic results. The data obtained throughout the study prove that this novel material represents a potential low-cost adsorbent for copper adsorption with improved adsorption capacity and magnetic separation capability compared with raw fly ash.


2019 ◽  
Vol 32 (1) ◽  
pp. 73-78
Author(s):  
P. Janaki ◽  
R. Sudha ◽  
T.S. Sribharathi ◽  
P. Anitha ◽  
K. Poornima ◽  
...  

The adsorption performance of sulphuric acid treated low cost adsorbent synthesized by using Citrus limettioides peel as an effective raw material for the removal of cadmium(II) from water. The batch adsorption method was carried out to optimize some parameters like contact time, pH and adsorbent dose. The nonlinear isotherm equations were used to calculate the different isotherm constant of five isotherm models namely Freundlich, Langmuir, Dubinin-Radushkevich, Redlich-Peterson and Sips. The Langmuir monolayer adsorption capacity of chemically modified Citrus limettioides peel was found to be 287.60 mg g-1. The negative values of ΔGº and ΔHº showed that the adsorption process is spontaneous and exothermic.


Author(s):  
L. Salami ◽  
D. O. Olumuyiwa ◽  
E. A. Alfred ◽  
O. S. Olakanmi

Dumpsite leachate has the potential to pollute ground and surface water as well as vegetation within the vicinity of the dumpsite.  Its treatment therefore needs adequate attention. The aim of this work is to study the adsorption of Soluos dumpsite leachate treatment using Musa sapientum peel as biosorbent with a view of establishing the adsorption isotherm model. Musa sapientum peels sourced from Ayetoro market in Epe area of Lagos State, Nigeria were used to prepare the adsorbent. Batch adsorption was carried out with various dosage of the prepared absorbent in leachate collected from Soluos dumpsite in Lagos. The adsorption data obtained were fitted into Linear, Freundlich, Langmuir, Temkin and Hasley isotherm models. The results showed that the concentration of total dissolved solids (TDS) in the dumpsite leachate decreased as the adsorbent dosage increased. At adsorbent dosage of 10 g/L, the concentration of TDS in the leachate was 485.7 mg/L which was less than the 500 mg/L stipulated by National Environmental Standard and Regulatory Agency (NAESRA) for the discharge of wastewater. The coefficient of determination (R2) values for Linear, Freundlich and Hasley, Langmuir and Temkin isotherm models were 0.9944, 0.9936, 0.8562 and 0.9723 respectively. Linear isotherm model was jettisoned because the plot did not pass through the origin and Freundlich isotherm model was ignored as a result of N value which was less than unity hence Hasley isotherm model was adopted in this work. A good correlation existed between the experimental and predicted values, having a R2 value of 0.9965 which further validated the Hasley isotherm model as the best adsorption model for the treatment of Soluos dumpsite leachate using Musa sapientum peel as biosorbent. It was concluded that Musa sapientum peel as biosorbent can be used for treatment of Soluos dumpsite leachate.


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