Limits...
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.


Adsorption kinetics of MB on membrane by (a) pseudo-first-order and pseudo-second-order, and (b) intra-particle models kinetic was plotted. In this experiment, dye molecules from a 0.3 g.L−1 dye solution (250 ml) with a pH of 7.1 at 20°C were taken up by 0.06 g of the membrane.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig4: Adsorption kinetics of MB on membrane by (a) pseudo-first-order and pseudo-second-order, and (b) intra-particle models kinetic was plotted. In this experiment, dye molecules from a 0.3 g.L−1 dye solution (250 ml) with a pH of 7.1 at 20°C were taken up by 0.06 g of the membrane.

Mentions: where t is the time (min) and qe, qt, (g.g−1) and qe2 are the amounts of MB adsorbed by the onion membrane at equilibrium, at time t, and at maximum adsorption capacity, respectively. k1 (min−1), k2 (g.g−1.min−1), and k3 (g.g−1.min−0.5) are the adsorption rate constants of the pseudo-first-order, pseudo-second order and the intra-particle diffusion models, respectively. In addition, Ci (g.g−1) is the intra-particle diffusion constant, which is directly proportional to the boundary layer thickness. As shown in Table 1, the theoretical equilibrium adsorption capacity (1.3166 g.g−1) using the pseudo-second-order model compared well with the experimental data (1.2025 g.g−1), with a better R2 value. Moreover, Figure 4a shows the agreement between the experimental adsorption capacities with the calculated values of pseudo-second-order, which were obtained using the data in Table 1. Therefore, the agreement between experimental data and pseudo-second-order can prove the physical adsorption of MB on a highly heterogeneous onion membrane.Table 1


Onion membrane: an efficient adsorbent for decoloring of wastewater.

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

Adsorption kinetics of MB on membrane by (a) pseudo-first-order and pseudo-second-order, and (b) intra-particle models kinetic was plotted. In this experiment, dye molecules from a 0.3 g.L−1 dye solution (250 ml) with a pH of 7.1 at 20°C were taken up by 0.06 g of the membrane.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig4: Adsorption kinetics of MB on membrane by (a) pseudo-first-order and pseudo-second-order, and (b) intra-particle models kinetic was plotted. In this experiment, dye molecules from a 0.3 g.L−1 dye solution (250 ml) with a pH of 7.1 at 20°C were taken up by 0.06 g of the membrane.
Mentions: where t is the time (min) and qe, qt, (g.g−1) and qe2 are the amounts of MB adsorbed by the onion membrane at equilibrium, at time t, and at maximum adsorption capacity, respectively. k1 (min−1), k2 (g.g−1.min−1), and k3 (g.g−1.min−0.5) are the adsorption rate constants of the pseudo-first-order, pseudo-second order and the intra-particle diffusion models, respectively. In addition, Ci (g.g−1) is the intra-particle diffusion constant, which is directly proportional to the boundary layer thickness. As shown in Table 1, the theoretical equilibrium adsorption capacity (1.3166 g.g−1) using the pseudo-second-order model compared well with the experimental data (1.2025 g.g−1), with a better R2 value. Moreover, Figure 4a shows the agreement between the experimental adsorption capacities with the calculated values of pseudo-second-order, which were obtained using the data in Table 1. Therefore, the agreement between experimental data and pseudo-second-order can prove the physical adsorption of MB on a highly heterogeneous onion membrane.Table 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.