Sorption of Chromium(VI), Cadmium(II) Ions and Methylene Blue Dye by
Pristine, Defatted and Carbonized Nigella sativa L. Seeds from Aqueous Solution

Present study reports on the sorption study of chromium(VI), cadmium(II) ions and methylene blue dye by pristine, defatted and carbonized Nigella sativa L. seeds from aqueous solution. The removal of oil from pristine Nigella sativa L. (PNS) seeds was carried out by defatting the Nigella sativa with acetone and N,N-dimethylformamide and then labelled ANS and DNS, respectively. Thereafter the defatted ANS and DNS adsorbents were carbonized at 600 ºC for 2 h under nitrogen and labelled as CANS and CDNS. The results of pristine, defatted and carbonized seeds were compared. The removal of Cr(VI), Cd(II) and methylene blue dye from aqueous solutions was investigated by varying adsorbate concentration, solution pH, reaction contact time and temperature of the solution. The SEM images indicated that the surface morphology of PNS was irregular, whilst ANS and DNS had pores and cavities. CANS and CDNS was heterogeneous and had pores and cavities. FTIR spectroscopy showed that the adsorbents surfaces had bands that indicated a lot of oxygen containing groups. The pH of the solution had an influence on the removal uptake of Cr(VI), Cd(II) and methylene blue. The sorption of Cr(VI) decreased when pH of the solution was increased due to different speciation of Cr(VI) ions whilst the removal of Cd(II) and methylene blue increased when solution pH was increased. Pseudo first order kinetic model well described the adsorption of Cr(VI), Cd(II) and methylene blue onto PNS. On the other hand, the kinetic data for ANS, CANS, DNS and CDNS was well described by pseudo second order. Furthermore, the removal mechanism onto PNS and ANS was better described by Freundlich multilayer model. The CANS, DNS and CDNS fitted Langmuir monolayer model. Thermodynamic parameters indicated that the sorption processes of Cr(VI), Cd(II) and methylene blue was endothermic and effective at high temperatures for all adsorbents. The ΔSº and ΔHº had positive values this confirmed that the sorption of Cr(VI), Cd(II) and methylene blue onto all adsorbents was random and endothermic, respectively. The values of ΔGº confirmed that the sorption of Cr(VI), Cd(II) and methylene blue on all adsorbents was spontaneous and predominated by physical adsorption process. The CANS had highest adsorption capacity of 99.82 mg/g for methylene blue, 96.89 mg/g for Cd(II) and 87.44 mg/g for Cr(VI) followed by CDNS with 93.90, 73.91 and 65.38 mg/g for methylene blue, Cd(II) and Cr(VI), respectively. The ANS capacities were 58.44, 45.28 and 48.96 mg/g whilst DNS capacities were 48.19, 32.69 and 34.65 mg/g for methylene blue, Cd(II) and Cr(VI), respectively. PNS had the lowest sorption capacities at 43.88, 36.01 and 19.84 mg/g for methylene blue, Cd(II) and Cr(VI), respectively.

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Using of modified-bentonite as low-cost sorbent for removal of methylene blue dye from aqueous solution

Association of Arab Universities Journal of Engineering Sciences ◽

10.33261/jaaru.2020.27.2.005 ◽

2020 ◽

Vol 27 (2) ◽

pp. 45-54

Author(s):

Saraa Muwafaq Ibrahim ◽

Ziad T. Abd Ali

Keyword(s):

Aqueous Solution ◽

Methylene Blue ◽

Silanol Group ◽

Infrared Spectrometry ◽

Blue Dye ◽

Ammonium Bromide ◽

Vibration Band ◽

Order Kinetic ◽

Methylene Blue Dye ◽

Modified Bentonite

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.

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Removal of methylene blue from aqueous solution by ozone microbubbles

Association of Arab Universities Journal of Engineering Sciences ◽

10.33261/jaaru.2020.27.3.004 ◽

2020 ◽

Vol 27 (3) ◽

pp. 31-40

Author(s):

Ola A. Nashmi ◽

Nada N. Abdulrazzaq ◽

Ahmed A. Mohammed

Keyword(s):

Methylene Blue ◽

Removal Efficiency ◽

Batch Reactor ◽

Generation Rate ◽

Blue Dye ◽

Order Kinetic ◽

Methylene Blue Dye ◽

Solution Ph ◽

Ozone Generation ◽

Order Kinetic Model

In this work, ozone microbubbles (OMBs) technique was used to remove methylene blue dye (MB) from water in a semi- batch reactor. The removal efficiency of methylene blue dye were investigated under various reaction conditions such as effect of initial solution pH, ozone generation rate, initial methylene blue dye concentration and determination of mass transfer coefficient. The removal of methylene blue by Ozonation microbubbles were very high at the acidic media and upon increasing ozone generation rate from 0.498 to 0.83 mg s−1, the removal efficiency dramatically increased from 8 to 98%.The overall rate of the oxidation reaction fitted well a second order kinetic model. The results demonstrated that ozone microbubbles were effective in terms of the elimination of methylene blue concentration and its complete mineralization.

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Sorption Behavior of Methylene Blue From Aqueous Solution By Using PVA/SA/Kaolin Composite

Issue 4 - Journal of Science and Technology ◽

10.46243/jst.2020.v5.i4.pp199-213 ◽

2020 ◽

pp. 199-213

Keyword(s):

Aqueous Solution ◽

Methylene Blue ◽

Metal Ion ◽

Physical Adsorption ◽

Thermo Gravimetric Analysis ◽

Blue Dye ◽

Sorption Behavior ◽

Gravimetric Analysis ◽

Order Kinetic ◽

Batch Mode

This research shows a method of elimination of methylene blue from aqueous solutions using PVA/SA/Kaolin Composite. The prepared was characterized by Fourier transform infra red spectroscopy (FTIR), X-Ray diffractogram (XRD), Thermo gravimetric analysis (TGA) and Scanning electron microscopic (SEM). Furthermore, the analyses of batch mode experiments were performed to study the experimental important parameters such as pH, metal ion concentrations, adsorbent dosages and contact time are discussed. From the experimental data, the adsorption isotherms are well described by Langmuir and Freundlich model, the adsorption of methyleneblue was fitted with Freundlich isotherm confirms the physical adsorption phenomena involved in this process. The kinetic parameter was correlated with the pseudo-second-order kinetic model. From the results, it was concluded that the material of PVA/SA/Kaolin Composite is an excellent adsorbent for the removal of methylene blue dye from aqueous solution.

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Eucheuma cottonii Seaweed-Based Biochar for Adsorption of Methylene Blue Dye

Sustainability ◽

10.3390/su122410318 ◽

2020 ◽

Vol 12 (24) ◽

pp. 10318 ◽

Cited By ~ 1

Author(s):

Anwar Ameen Hezam Saeed ◽

Noorfidza Yub Harun ◽

Suriati Sufian ◽

Ahmer Ali Siyal ◽

Muhammad Zulfiqar ◽

...

Keyword(s):

Methylene Blue ◽

Large Scale ◽

Synthetic Wastewater ◽

Blue Dye ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Methylene Blue Dye ◽

Adsorption Model ◽

Solution Ph ◽

Eucheuma Cottonii

Pollution from dye containing wastewater leads to a variety of environmental problems, which can destroy plant life and eco-systems. This study reports development of a seaweed-based biochar as an adsorbent material for efficient adsorption of methylene blue (MB) dye from synthetic wastewater. The Eucheuma cottonii seaweed biochar was developed through pyrolysis using a tube furnace with N2 gas, and the properties were later improved by sulfuric acid treatment. The adsorption studies were conducted in a batch experimental setup under initial methylene blue concentrations of 50 to 200 mg/L, solution pH of 2 to 10, and temperature of 25 to 75 °C. The characterization results show that the developed biochar had a mesoporous pore morphology. The adsorbent possessed the surface area, pore size, and pore volume of 640 m2/g, 2.32 nm, and 0.54 cm3/g, respectively. An adsorption test for 200 mg/L of initial methylene blue at pH 4 showed the best performance. The adsorption data of the seaweed-based biochar followed the Langmuir isotherm adsorption model and the pseudo-second-order kinetic model, with the corresponding R2 of 0.994 and 0.995. The maximum adsorption capacity of methylene blue using the developed seaweed‑based biochar was 133.33 mg/g. The adsorption followed the chemisorption mechanism, which occurred via the formation of a monolayer of methylene blue dye on the seaweed-based biochar surface. The adsorption performance of the produced seaweed biochar is comparable to that of other commercial adsorbents, suggesting its potential for large-scale applications.

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