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Onion membrane: an efficient adsorbent for decoloring of wastewater.

Saber-Samandari S, Heydaripour J - J Environ Health Sci Eng (2015)

Bottom Line: Recently, researchers have tried to design synthetic materials by replicating natural materials as an adsorbent for removing various types of environmental pollutants, which have reached to the risky levels in nature for many countries in the world.In this research, the potential of onion membrane obtained from intermediate of onion shells for adsorption of methylene blue (MB) as a model cationic dye was exhibited.Evidently, the high efficiency and fast removal of methylene blue using onion membrane suggest the synthesis of polymer-based membranes with similar physical and chemical properties of onion membrane as a valuable and promising wastewater decoloring agents in water treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Eastern Mediterranean University, TRNC via Mersin 10, Gazimagusa, Turkey.

ABSTRACT

Background: Recently, researchers have tried to design synthetic materials by replicating natural materials as an adsorbent for removing various types of environmental pollutants, which have reached to the risky levels in nature for many countries in the world. In this research, the potential of onion membrane obtained from intermediate of onion shells for adsorption of methylene blue (MB) as a model cationic dye was exhibited.

Methods: Before and after adsorption, the membrane was characterized by Fourier transform infrared spectroscopy (FTIR) and optical and scanning electron microscopy in order to prove its dye adsorption capability. The various experimental conditions affecting dye adsorption were explored to achieve maximum adsorption capacity.

Results: The dye adsorption capacity of the membrane was found to be 1.055 g.g(-1) with 84.45% efficiency after one hour and 1.202 g.g(-1) with 96.20% efficiency after eight hours in contact with the dye solution (0.3 g.L(-1)). Moreover, the kinetic, thermodynamic and adsorption isotherm models were employed to described the MB adsorption processes. The results show that the data for adsorption of MB onto the membrane fitted well with the Freundlich isotherm and pseudo-second-order kinetic models. In addition, the MB adsorption from room temperature to ~50°C is spontaneous and thermodynamically favorable.

Conclusions: Evidently, the high efficiency and fast removal of methylene blue using onion membrane suggest the synthesis of polymer-based membranes with similar physical and chemical properties of onion membrane as a valuable and promising wastewater decoloring agents in water treatment.

No MeSH data available.


Schematic illustration for the adsorption mechanism of MB by onion membrane.
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Sch1: Schematic illustration for the adsorption mechanism of MB by onion membrane.

Mentions: Onions contain protein (with –COOH and –NH2 groups), sugars, carbohydrate, and vitamins A, B6, and C (with –OH groups), minerals, and over 80% water [23]. As can be seen from Scheme 1, the onion membrane has several anionic groups such as –COOH and –OH. On the other hand, MB is a cationic dye consisting of = S– and –N(CH3)2 can become charged species and have ionic and dipole–dipole interactions with anionic groups in the surface of the onion membrane [24]. In addition, the = N– and –N(CH3)2 groups in the structure of MB can have hydrogen bonds with hydrogen atom of –COOH and –OH groups of the onion membrane. Therefore, the adsorbent can uptake MB very fast with high efficiency through the strong electrostatic attraction between the surface groups on the membrane and the cationic MB.Scheme 1


Onion membrane: an efficient adsorbent for decoloring of wastewater.

Saber-Samandari S, Heydaripour J - J Environ Health Sci Eng (2015)

Schematic illustration for the adsorption mechanism of MB by onion membrane.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4374185&req=5

Sch1: Schematic illustration for the adsorption mechanism of MB by onion membrane.
Mentions: Onions contain protein (with –COOH and –NH2 groups), sugars, carbohydrate, and vitamins A, B6, and C (with –OH groups), minerals, and over 80% water [23]. As can be seen from Scheme 1, the onion membrane has several anionic groups such as –COOH and –OH. On the other hand, MB is a cationic dye consisting of = S– and –N(CH3)2 can become charged species and have ionic and dipole–dipole interactions with anionic groups in the surface of the onion membrane [24]. In addition, the = N– and –N(CH3)2 groups in the structure of MB can have hydrogen bonds with hydrogen atom of –COOH and –OH groups of the onion membrane. Therefore, the adsorbent can uptake MB very fast with high efficiency through the strong electrostatic attraction between the surface groups on the membrane and the cationic MB.Scheme 1

Bottom Line: Recently, researchers have tried to design synthetic materials by replicating natural materials as an adsorbent for removing various types of environmental pollutants, which have reached to the risky levels in nature for many countries in the world.In this research, the potential of onion membrane obtained from intermediate of onion shells for adsorption of methylene blue (MB) as a model cationic dye was exhibited.Evidently, the high efficiency and fast removal of methylene blue using onion membrane suggest the synthesis of polymer-based membranes with similar physical and chemical properties of onion membrane as a valuable and promising wastewater decoloring agents in water treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Eastern Mediterranean University, TRNC via Mersin 10, Gazimagusa, Turkey.

ABSTRACT

Background: Recently, researchers have tried to design synthetic materials by replicating natural materials as an adsorbent for removing various types of environmental pollutants, which have reached to the risky levels in nature for many countries in the world. In this research, the potential of onion membrane obtained from intermediate of onion shells for adsorption of methylene blue (MB) as a model cationic dye was exhibited.

Methods: Before and after adsorption, the membrane was characterized by Fourier transform infrared spectroscopy (FTIR) and optical and scanning electron microscopy in order to prove its dye adsorption capability. The various experimental conditions affecting dye adsorption were explored to achieve maximum adsorption capacity.

Results: The dye adsorption capacity of the membrane was found to be 1.055 g.g(-1) with 84.45% efficiency after one hour and 1.202 g.g(-1) with 96.20% efficiency after eight hours in contact with the dye solution (0.3 g.L(-1)). Moreover, the kinetic, thermodynamic and adsorption isotherm models were employed to described the MB adsorption processes. The results show that the data for adsorption of MB onto the membrane fitted well with the Freundlich isotherm and pseudo-second-order kinetic models. In addition, the MB adsorption from room temperature to ~50°C is spontaneous and thermodynamically favorable.

Conclusions: Evidently, the high efficiency and fast removal of methylene blue using onion membrane suggest the synthesis of polymer-based membranes with similar physical and chemical properties of onion membrane as a valuable and promising wastewater decoloring agents in water treatment.

No MeSH data available.