scholarly journals Removal of methylene blue dye from aqueous solution using a superabsorbant hydrogel the polyacrylamide: isotherms and kinetic studies

2019 ◽  
Vol 9 (5) ◽  
pp. 337-346
Author(s):  
Imane Lebkiri ◽  
Brahim Abbou ◽  
Lamya Kadiri ◽  
Abdelkarim Ouass ◽  
Youness Essaadaoui ◽  
...  

The present work aims the elimination of an organic dye Methylene Blue (MB) by adsorption on the polyacrylamide (PAAM) hydrogel. Several experiments series were then carried out in order to study the influence on the adsorption capacity of certain parameters such as the mass of the adsorbent, the pH, the contact time, the initial dye concentration and the temperature. The maximal capacity is 1620 mg/g it was obtained at T = 25°C, pH = 6, [BM] = 200 ppm and 0.013g of the adsorbent. The adsorption kinetics of the dye on the support is well described by the first-order model. The adsorption isotherms of the adsorbent/adsorbate systems studied are satisfactorily described by the Langmuir mathematical model. On the other hand, the thermodynamic study revealed that adsorption is spontaneous and endothermic.

2020 ◽  
Vol 23 (10) ◽  
pp. 370-376
Author(s):  
Thamrin Azis ◽  
La Ode Ahmad ◽  
Keke Awaliyah ◽  
Laode Abdul Kadir

Research on the equilibrium and adsorption kinetics of methylene blue dye using tannin gel from the Tingi tree (Ceriops tagal) has been carried out. This study aims to determine the capacity and adsorption kinetics of tannin gel against methylene blue dye. Several parameters, such as the effect of contact time, pH, and methylene blue dye concentration on adsorption, were also studied. Based on the research results, the optimum adsorption process is a contact time of 30 minutes and a pH of 7. The adsorption capacity increased to a concentration of 80 mg/L with a maximum adsorption capacity (qm) of 49.261 mg/g. The adsorption process follows the pseudo-second-order adsorption kinetics model and the Langmuir isotherm model.


Author(s):  
Conrad Kenechukwu Enenebeaku ◽  
Nnaemeka John Okorocha ◽  
Uchechi E. Enenebeaku ◽  
Benedict Ikenna Onyeachu

The adsorption of methylene blue (MB) dye on bush cane bark powder has been studied by analyzing the effect of contact time, initial dye concentration, adsorbent dose, pH, and temperature on the amount of the MB dye adsorbed per unit mass of the bush cane bark powder adsorbent. An optimum adsorption could be achieved during 80 min contact time but, thereafter, decreased with contact time beyond 80 min. The adsorption of the methylene blue dye increased with increasing the initial dye concentration, temperature and pH. However, the amount of methylene blue adsorbed decreased with increasing the dosage of the adsorbent; a phenomenon attributed to a plausible agglomeration of the adsorbent and blocking of the preferred adsorption sites with increasing adsorbent dosage. The adsorption mechanism of the dye obeyed the Freundlich isotherm. Kinetic studies showed that the methylene blue adsorption onto bush cane bark powder adsorbent followed a second order reaction kinetics. The adsorbent was characterized by Fourier transform infra-red spectrophotometer and scanning electron microscope analysis.


2020 ◽  
Vol 32 (6) ◽  
pp. 1352-1360
Author(s):  
J. Prakash ◽  
S. Vedanayaki ◽  
K. Karthick

The studies open up an innovative approach and investigate porous, efficient raw carbon from Zephyranthes citrina bulb, which was used as an adsorbent to remove organic dyes. The well-dried and finely powdered Zephyranthes citrina bulb was carbonized at 900 ºC. The carbonized crude Z. citrina sample was characterized by FT-IR, UV-visible, scanning electron microscopy (SEM), BET, X-ray diffraction (XRD) techniques and their adsorption potential to remove the basic methylene blue dye from an aqueous sample. Adsorption studies comprise both adsorption isotherm and kinetic methods. The processes were carried out with diverse adsorbate concentrations and adsorbent quantities at various time intervals in the batch process. Kinetic models of Lagergren first order, pseudo-second order and intra particle diffusion were used to assess the kinetics and adsorption mechanism. The results revealed that the adsorption process follows the first order kinetic model of Lagergren. The BET isotherm model confirmed that it has an excellent adsorption capacity in an adsorption process. Based on the results obtained, the maximum removal (81%) of dye was achieved in a solution containing 50 mg of 50 mL dye at 3 h for methylene blue. The results indicated that the bulb of Zephyranthes citrina carbon is a proficient adsorption material and is also used as a cost effective alternative that can adsorb dye from an aqueous solution without activation treatment.


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.


2021 ◽  
Vol 7 (2) ◽  
pp. 188-195
Author(s):  
Nurhasni Nurhasni ◽  
Sariana Harahap ◽  
Ahmad Fathoni ◽  
Hendrawati Hendrawati

The ability of bagasse adsorbents to adsorb methylene blue without activation using 0.5 M H2SO4 solution was examined. Methylene blue is widely used in the textile industry because it produces bright colors, and the dyeing process is fast and easy. This research aims to determine the optimum adsorption conditions, namely the variations in contact time, dye concentration, adsorbent mass, and pH effect on methylene blue, which were carried out using the batch method. Furthermore, the adsorbents were characterized by FT-IR and SEM. The optimum state of the bagasse adsorbent to adsorb methylene blue dye has a mass of 0.5 grams, a contact time of 30 minutes, a concentration of 50 ppm, and a pH of 5. The character of the adsorbent after activation with H2SO4 was better than without activation. The highest adsorption efficiency of methylene blue dye in the batch method was 99.67%. The FTIR spectrum of the bagasse adsorbent showed OH, C-H, C=O, C=C, and C-O functional groups. The adsorption isotherm model for methylene blue dye follows the Langmuir isotherm since the graph obtained is linear with the correlation coefficient (R2) = 1, where the adsorbent has a homogeneous surface.


2020 ◽  
Vol 309 ◽  
pp. 113171 ◽  
Author(s):  
Mehmet Harbi Calimli ◽  
Mehmet Salih Nas ◽  
Hakan Burhan ◽  
Sibel Demiroglu Mustafov ◽  
Özkan Demirbas ◽  
...  

2019 ◽  
Author(s):  
Getasew Nibret ◽  
Shadab Ahmad ◽  
Dubasi Govardhana Rao ◽  
Imran Ahmad ◽  
Mohamed Ashfaq Mohamed Usman Shaikh ◽  
...  

2019 ◽  
Vol 44 (4) ◽  
pp. 307-315 ◽  
Author(s):  
Xueya Dai ◽  
Hua Song ◽  
Hualin Song ◽  
Jing Gong ◽  
Feng Li ◽  
...  

A nickel phosphide hydrodeoxygenation catalyst (Ni2P-O/MCM-41) was prepared using a new synthetic method. The as-prepared catalyst was evaluated in the hydrodeoxygenation of benzofuran, and the effects of reaction temperature, pressure, and the H2/liquid ratio were investigated. A pseudo first-order model was employed to describe the reaction kinetics of benzofuran hydrodeoxygenation over the Ni2P-O/MCM-41 catalyst. The reaction rate constants ( k1– k5) at different temperatures were determined according to this model. At 533 K, the conversion of 2-ethylphenol in to ethylbenzene began to increase dramatically, and the yield of O-free product, ethylcyclohexane, started to increase rapidly. At 573 K, 3.0 MPa, and a H2/liquid ratio of 500 (V/V), the conversion of benzofuran over Ni2P-O/MCM-41 reached 93%, and the combined yield of O-free products was 91%. Contact time analysis indicated that demethylation was not favored over the Ni2P-O/MCM-41 catalyst.


2013 ◽  
Vol 716 ◽  
pp. 368-372
Author(s):  
Hui Xu ◽  
Jian Wei Xing

Polyaniline (PANI)/zinc oxide (ZnO) nanocomposites have been synthesized by in-situ polymerization of aniline monomer with ZnO nanomaterials. The PANI/ZnO nanocomposites were used as photocatalyst in the photodegradation of methylene blue dye (MB) molecules in aqueous solution. The results showed that PANI/ZnO nanocomposite greatly enhanced photocatalytic activities compared with pristine polyaniline might due to high photoexcited electronhole pairs charge separation. The photocatalytic activities of PANI/ZnO nanocomposites increased with increasing ZnO content, however, further increasing ZnO content over 50% induced the formation of more agglomerates, which could act as recombination centers of photoexcited electronhole pairs, leading to decreased photocatalytic activity. The kinetics of photodegradation of MB dye using PANI/ZnO(ZnO content 50 % ) nanocomposites photocatalyst was found to be of the first order.


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