scholarly journals Evaluation of Kinetic and Equilibrium studies for Phytoremediation of Methylene Blue Dye (Triarylmethane) and Congo Red (Diazo) using Trachyspermum Ammi L.

Author(s):  
Navjeet Kaur ◽  
jyotsna kaushal ◽  
Pooja Mahajan

Abstract Phytoremediation developed as a green-clean, solar-driven and innovative technique for the eradication of contaminants from the environment from last two decades. In the present research work, phytoremediation potential of an ornamental plant Trachyspermum ammi L. (T. ammi) was examined for the removal of a triarylmethane-Methylene blue (MB) and di-azo-Congo red (CR) dye. The various parameters such as initial dye concentration, contact time, and pH were focused to explore the dye removal capability of T. ammi. The increase in initial dye concentration affects the decolorization potential of the T. ammi. The decolorization potential of T. ammi found to be reduced with enhancing the initial dye concentration of both the dyes. The plant achieved condition of equilibrium after the 40 h of contact time with both MB and CR dye. The favorable pH for T. ammi for the MB dye was observed as 5 while for CR dye was 6. The kinetics of phytoremediation reaction with both MB and CR dyes were studied with help of pseudo-first order, pseudo-second order, and Elovich models and the results were well appropriated to pseudo-first order with the correlation value R2 ≥ 0.95 for MB and R2 ≥ 0.97 for CR. The Langmuir and Freundlich isotherms studies of phytoremediation reaction found in favor of Freundlich equilibrium isotherm with correlation R2 ≥ 0.99 for both MB and CR dyes. The mechanism of T. ammi for removal of dyes was supported with the help of analytical techniques such as Fourier Transform-Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM).

2020 ◽  
Vol 3 (6) ◽  
pp. 857-870
Author(s):  
Shagufta Zafar ◽  
Muhammad Imran Khan ◽  
Mushtaq Hussain Lashari ◽  
Majeda Khraisheh ◽  
Fares Almomani ◽  
...  

AbstractThe present study investigates the removal of copper ions (Cu (II)) from aqueous solution using chemically treated rice husk (TRH). The chemical treatment was carried out using NaOH solution and the effect of contact time (tc), adsorbent dosage (Dad), initial Cu (II) concentration ([Cu]i), and temperature (T) on the percentage removals of Cu (II) (%RCu) were investigated. Different analytical techniques (FTIR, SEM, and EDX) were used to confirm the adsorption (ads) of Cu (II) onto the TRH. The ads kinetics was tested against pseudo-first-order (PFO) and pseudo-second-order (PSO) models as well as Langmuir and Freundlich isotherms. Treating RH with NaOH altered the surface and functional groups, and on the surface of RH, the ionic ligands with high electro-attraction to Cu increased and thus improved the removal efficiency. The %RCu decreased by increasing the [Cu]i and increased by increasing the ct, Dad, and T. Up to 97% Cu removal was achieved in ct of 30 min using Dad of 0.3 g [Cu]i of 25 mg L−1 and T = 280 K. The ads of Cu on TRH is endothermic, spontaneous, follows Langmuir isotherms, and exhibited a PSO kinetics. Moreover, the TRH was successfully regenerated and used for further adsorption cycles using 1 M HNO3.


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 32 (6) ◽  
pp. 1361-1369
Author(s):  
Patience Mapule Thabede ◽  
Ntaote David Shooto ◽  
Thokozani Xaba ◽  
Eliazer Bobby Naidoo

Carbon from black cumin seeds was modified with 10 and 20% sulfuric acid to obtain the activated adsorbents. Pristine carbon from black cumin seeds, 10 and 20% H2SO4 activated carbon from black cumin seeds were labelled CBC, ACBC-10 and ACBC-20, respectively. The adsorbents were characterized by SEM, XRD, FTIR, TGA and BET. The adsorbents maximum trend for Cd(II) was ACBC-10 > ACBC-20 > CBC. The maximum capacity trend for methylene blue dye was ACBC-20 > ACBC-10 > CBC. The kinetic model best fitted pseudo second order for Cd(II) which gave r2 values of 0.991-0.998. The methylene blue fitted pseudo first order model with r2 values ranging from 0.993-0.997. Pseudo first order suggested that the adsorption mechanism for methylene blue onto adsorbents involved van der Waal forces of attraction. The equilibrium data fitted Langmuir isotherm model for CBC, ACBC-10 and ACBC-20 with r2 of 0.994 to 0.998 for the removal of methylene blue whilst the removal of Cd(II) followed Freundlich with r2 ranging from 0.992 to 0.997. This suggested that the different adsorption processes were involved between the adsorbate and the adsorbents. Gibb′s free energy (ΔGº) for Cd(II) and methylene blue onto CBC, ACBC-10 and ACBC-20 suggested that the reaction was spontaneous. The adsorption of Cd(II) and methylene blue was endothermic, positive values (ΔHº). This suggested that the enthalpy (ΔHº) had a weak interactive force process whose low energy is associated with electrostatic attraction.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1403
Author(s):  
Kashma Sharma ◽  
Shreya Sharma ◽  
Vipasha Sharma ◽  
Pawan Kumar Mishra ◽  
Adam Ekielski ◽  
...  

The present work demonstrates the development of hydroxyapatite (HA)/gold (Au) nanocomposites to increase the adsorption of methylene blue (MB) dye from the wastewater. HA nanopowder was prepared via a wet chemical precipitation method by means of Ca(OH)2 and H3PO4 as starting materials. The biosynthesis of gold nanoparticles (AuNPs) has been reported for the first time by using the plant extract of Acrocarpus fraxinifolius. Finally, the as-prepared HA nanopowder was mixed with an optimized AuNPs solution to produce HA/Au nanocomposite. The prepared HA/Au nanocomposite was studied by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) analysis. Adsorption studies were executed by batch experiments on the synthesized composite. The effect of the amount of adsorbent, pH, dye concentration and temperature was studied. Pseudo-first-order and pseudo-second-order models were used to fit the kinetic data and the kinetic modeling results reflected that the experimental data is perfectly matched with the pseudo-first-order kinetic model. The dye adsorbed waste materials have also been investigated against Pseudomonas aeruginosa, Micrococcus luteus, and Staphylococcus aureus bacteria by the agar well diffusion method. The inhibition zones of dye adsorbed samples are more or less the same as compared to as-prepared samples. The results so obtained indicates the suitability of the synthesized sample to be exploited as an adsorbent for effective treatment of MB dye from wastewater and dye adsorbed waste as an effective antibacterial agent from an economic point of view.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6343
Author(s):  
Burcu Gunes ◽  
Yannick Jaquet ◽  
Laura Sánchez ◽  
Rebecca Pumarino ◽  
Declan McGlade ◽  
...  

The remarkable adsorption capacity of graphene-derived materials has prompted their examination in composite materials suitable for deployment in treatment of contaminated waters. In this study, crosslinked calcium alginate–graphene oxide beads were prepared and activated by exposure to pH 4 by using 0.1M HCl. The activated beads were investigated as novel adsorbents for the removal of organic pollutants (methylene blue dye and the pharmaceuticals famotidine and diclofenac) with a range of physicochemical properties. The effects of initial pollutant concentration, temperature, pH, and adsorbent dose were investigated, and kinetic models were examined for fit to the data. The maximum adsorption capacities qmax obtained were 1334, 35.50 and 36.35 mg g−1 for the uptake of methylene blue, famotidine and diclofenac, respectively. The equilibrium adsorption had an alignment with Langmuir isotherms, while the kinetics were most accurately modelled using pseudo- first-order and second order models according to the regression analysis. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated and the adsorption process was determined to be exothermic and spontaneous.


2018 ◽  
Vol 83 (1) ◽  
pp. 107-120 ◽  
Author(s):  
Zdravka Velkova ◽  
Gergana Kirova ◽  
Margarita Stoytcheva ◽  
Velizar Gochev

Pretreated waste Streptomyces fradiae biomass was utilized as an eco-friendly sorbent for Congo Red (CR) and Methylene Blue (MB) removal from aqueous solutions. The biosorbent was characterized by Fourier transform infrared spectroscopy. Batch experiments were conducted to study the effect of pH, biosorbent dosage, initial concentration of adsorbates, contact time and temperature on the biosorption of the two dyes. The equilibrium adsorption data were analysed using Freundlich and Langmuir models. Both models fitted well the experimental data. The maximum biosorption capacity of the pretreated Streptomyces fradiae biomass was 46.64 mg g-1 for CR and 59.63 mg g-1 for MB, at a pH 6.0, with the contact time of 120 min, the biosorbent dosage of 2 g dm-3 and the temperature of 298 K. Lagergren and Ho kinetic models were used to analyse the kinetic data obtained from different batch experiments. The biosorption of both dyes followed better the pseudo-second order kinetic model. The calculated values for ?G, ?S, and ?H indicated that the biosorption of CR and MB onto the waste pretreated biomass was feasible, spontaneous, and exothermic in the selected temperature range and conditions.


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.


Author(s):  
Zhiliang Zhang ◽  
Jiaqi Lu ◽  
Bingqian Lv ◽  
Wei Liu ◽  
Shuyuan Shen ◽  
...  

The gas-liquid jet flow was proved to be capable of inducing chemical consequences which can lead to the decomposition of methylene blue (MB). The reaction process follows a pseudo-first-order kinetics....


2020 ◽  
Vol 24 (2) ◽  
pp. 329-333
Author(s):  
D.O. Jalija ◽  
A . Uzairu

The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters. Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order


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