Loofa egyptiaca as a novel adsorbent for removal of direct blue dye from aqueous solution

Eggshells was used as a natural adsorbent to remove direct blue(DB) dye from aqueous solution and investigating the four factors that affect the adsorption of DB dye ; amount of eggshell rang (0.1 - 1g), initial concentration (10 - 60 mg/L ), time ( 5 - 45 min.) and pH (3 - 11). Central Composition Design with four variables and five levels coupled with response surface method was adopted to get a second order polynomial equation for dye removal percentage as the response, and to obtain the optimum conditions for maximum dye removal percentage ; which reach 84% with optimum point , eggshell (0.835 g) ,time (24min.) , initial dye concentration ( 10 mg/L) , pH (4.2). The most effecting factors on dye removal are pH and initial dye concentration. Langmuir, Freundich model gives good fitting with (R2 ]0.98). The process of adsorption of DB dye on eggshell fitted a pseudo-second order kinetic model.

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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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