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16 pages, 2818 KiB

Open AccessArticle

Equilibrium and Kinetics Studies of Metal Ions Biosorption on Alginate Extracted from Marine Red Algae Biomass (Callithamnion corymbosum sp.)

by Alina Roxana Lucaci, Dumitru Bulgariu, Iftikhar Ahmad and Laura Bulgariu

Polymers 2020, 12(9), 1888; https://doi.org/10.3390/polym12091888 - 21 Aug 2020

Cited by 41 | Viewed by 2310

Abstract

Biosorption is a viable alternative that can be used to remove heavy metal ions from aqueous effluents, as long as the biosorbent used is cost-effective and efficient. To highlight this aspect in this study, alginate extracted from marine red algae biomass (Callithamnion [...] Read more.

Biosorption is a viable alternative that can be used to remove heavy metal ions from aqueous effluents, as long as the biosorbent used is cost-effective and efficient. To highlight this aspect in this study, alginate extracted from marine red algae biomass (Callithamnion corymbosum sp.) was used as biosorbent for the removal of Cu(II), Co(II) and Zn(II) ions from aqueous media. Biosorption studies were performed in a batch system, and the biosorptive performances of the alginate were examined as function of initial solution pH, biosorbent dosage, contact time, initial metal ions concentration and temperature. The optimal experimental conditions were found: initial solution pH of 4.4, a biosorbent dose of 2.0 g/L and a temperature of 22 °C, when over 88% of Cu(II), 76% of Co(II) and 81% of Zn(II) are removed by biosorption. The modeling of the obtained experimental data show that the Langmuir isotherm model and pseudo-second kinetic model well describe the biosorption processes of studied metal ions. The maximum biosorption capacity (q_max, mg/g) increases in the order: Cu(II) (64.52 mg/g) > Zn(II) (37.04 mg/g) > Co(II) (18.79 mg/g), while the minimum time required to reach the equilibrium is 60 min. Moreover, the regeneration efficiency of alginate is higher than 97% when a 10⁻¹ N HNO₃ solution is used as desorption agent for the recovery of Cu(II), Co(II) and Zn(II) ions. All these characteristics demonstrate that the alginate extracted from marine algae has promising applications in the decontamination of industrial effluent containing metal ions. Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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15 pages, 3094 KiB

Open AccessArticle

Green Flexible Polyurethane Foam as a Potent Support for Fe-Si Adsorbent

by Afiqah Ahmad, Siti Nurul Ain Md. Jamil, Thomas Shean Yaw Choong, Abdul Halim Abdullah, Mohd Sufri Mastuli, Nurhanisah Othman and NurNazurah Jiman

Polymers 2019, 11(12), 2011; https://doi.org/10.3390/polym11122011 - 04 Dec 2019

Cited by 11 | Viewed by 3332

Abstract

This paper describes the preparation, characterisation, and potential application of flexible palm oil-based polyurethane foam (PUF) as a support for iron-silica (Fe-Si) adsorbent. Fe-Si/polyurethane composite (Fe-Si/PUC) was prepared by impregnating Fe-Si adsorbent onto the surface of PUF by using a novel immersion-drying method. [...] Read more.

This paper describes the preparation, characterisation, and potential application of flexible palm oil-based polyurethane foam (PUF) as a support for iron-silica (Fe-Si) adsorbent. Fe-Si/polyurethane composite (Fe-Si/PUC) was prepared by impregnating Fe-Si adsorbent onto the surface of PUF by using a novel immersion-drying method. Morphological analysis of Fe-Si/PUC proved that Fe-Si was successfully impregnated onto the surface of PUF. Compression test and thermogravimetric analysis were carried out to determine the flexibility and thermal stability of Fe-Si/PUC, respectively. The Fe-Si/PUC removed 90.0% of 10 ppm methylene blue (MB) from aqueous solution in 60 min. The reusability study showed that Fe-Si/PUC removed 55.9% of MB on the seventh cycle. Hence, the synthesis of Fe-Si/PUC opens up a new path of implementing palm oil-based PUF to assist in the recovery of an adsorbent for environmental clean-up. The mechanism of physical interaction during the impregnation of Fe-Si adsorbent onto PUF was proposed in this paper. Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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14 pages, 5888 KiB

Open AccessArticle

Application of Colloidal Dispersions of Bioshell Calcium Oxide (BiSCaO) for Disinfection

by Yoko Sato, Heisuke Ohata, Akinori Inoue, Masayuki Ishihara, Shingo Nakamura, Koichi Fukuda, Tomohiro Takayama, Kaoru Murakami, Sumiyo Hiruma and Hidetaka Yokoe

Polymers 2019, 11(12), 1991; https://doi.org/10.3390/polym11121991 - 02 Dec 2019

Cited by 10 | Viewed by 3288

Abstract

Bioshell calcium oxide (BiSCaO) is a scallop-shell powder heated at a high temperature. BiSCaO is composed mainly of calcium oxide and exhibits broad microbicidal properties. The aim of this study is to evaluate the disinfection and decontamination abilities of BiSCaO colloidal dispersions with [...] Read more.

Bioshell calcium oxide (BiSCaO) is a scallop-shell powder heated at a high temperature. BiSCaO is composed mainly of calcium oxide and exhibits broad microbicidal properties. The aim of this study is to evaluate the disinfection and decontamination abilities of BiSCaO colloidal dispersions with that of commercially available bioshell calcium hydroxide (BiSCa(OH)₂) following the formation of flocculants/precipitates under strongly alkaline conditions (pH 11.5–12.2). Various concentrations of BiSCaO and BiSCa(OH)₂ colloidal dispersions were prepared by mixing with Na-polyPO₄ (PP) and Na-triPO₄ (TP) as flocculating agents. The microbicidal activities, and the degree of flocculation/precipitation of trypan blue, albumin, chondroitin sulfate, heparin, non-anticoagulant heparin carrying polystyrene (NAC-HCPS), and low-molecular-weight heparin/protamine nanoparticles (LMWH/P NPs) were dependent on the pH, the average particle diameter, and the concentration of BiSCaO or BiSCa(OH)₂ and of the phosphate compound. BiSCaO (average particle diameter: 6 μm) colloidal dispersions (0.2 wt.%) containing 0.15 wt.% PP or TP exhibited substantially stronger microbicidal activity and flocculation/precipitation under strongly alkaline conditions. These results suggest that BiSCaO colloidal dispersions together with phosphate compounds have practical applicability for disinfection. Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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17 pages, 3742 KiB

Open AccessArticle

Study on Preparation and Separation and Adsorption Performance of Knitted Tube Composite β-Cyclodextrin/Chitosan Porous Membrane

by Qian Tang, Nana Li, Qingchen Lu, Xue Wang and Yaotian Zhu

Polymers 2019, 11(11), 1737; https://doi.org/10.3390/polym11111737 - 24 Oct 2019

Cited by 20 | Viewed by 2253

Abstract

In order to obtain membranes with both organic separation and adsorption functions, knitted tube composite β-cyclodextrin/chitosan (β-CD/CS) porous membranes were prepared by the non-solvent induced phase separation (NIPS) method using CS and β-CD as a membrane-forming matrix, glutaraldehyde as crosslinking agent to improve [...] Read more.

In order to obtain membranes with both organic separation and adsorption functions, knitted tube composite β-cyclodextrin/chitosan (β-CD/CS) porous membranes were prepared by the non-solvent induced phase separation (NIPS) method using CS and β-CD as a membrane-forming matrix, glutaraldehyde as crosslinking agent to improve water stability, and knitted tube as reinforcement to enhance the mechanical properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle, water flux, bovine serum albumin (BSA) rejection and tensile test were carried out. The FTIR demonstrated that the β-CD and CS had been successfully crosslinked. With the crosslinking time increased, the membrane structure became denser, the contact angle and the rejection rate increased, while the water flux decreased. The strength and elongation at a break were 236 and 1.7 times higher than these of bare β-CD/CS porous membranes, respectively. The strength of crosslinking membranes increased further. The adsorption performance of composite membranes was investigated for the removal of phenolphthalein (PP) from aqueous solution. The adsorption process followed the Langmuir isotherm model, and the kinetic behavior was accorded with the Double constant equation and the Elovich equation. The adsorption mechanism could be explained by the synergistic effect of host-guest interaction from β-cyclodextrin, non-uniform diffusion and porous network capture. Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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16 pages, 2573 KiB

Open AccessArticle

Macroporous Oil-Sorbents with a High Absorption Capacity and High-Temperature Tolerance Prepared Through Cryo-Polymerization

by Abdul Haleem, Jia-Yun Wang, Hui-Juan Li, Chuan-Shan Hu, Xi-Chuan Li and Wei-Dong He

Polymers 2019, 11(10), 1620; https://doi.org/10.3390/polym11101620 - 07 Oct 2019

Cited by 19 | Viewed by 3584

Abstract

The facile preparation and admirable performance of macro-porous poly(lauryl acrylate)-based oil-sorbents for organic solvents and oils are reported in this manuscript. Cryo-polymerizations of lauryl acrylate (LA) with ethylene glycol dimethacrylate (EGDMA) as the cross-linker were carried out at temperatures below the freezing point [...] Read more.

The facile preparation and admirable performance of macro-porous poly(lauryl acrylate)-based oil-sorbents for organic solvents and oils are reported in this manuscript. Cryo-polymerizations of lauryl acrylate (LA) with ethylene glycol dimethacrylate (EGDMA) as the cross-linker were carried out at temperatures below the freezing point of the polymerization mixture. The polymerization medium and pore-forming agent was 1,4-dioxane. The influences of the total monomer concentration, EGDMA content and cryo-polymerization temperature on the structure of the obtained P(LA-co-EGDMA) cryogels were investigated with the techniques of Fourier transform infrared spectroscopy, scanning electron microscopy, contact angle measurement and thermo-gravimetric analysis. Through the modulation of the crosslinking density and porosity of these cryogels, the P(LA-co-EGDMA) oil-sorbents demonstrated a high absorption capacity for organic solvents and oils, recyclability and high-temperature tolerance. The absorption capacity reached 20–21 and 16–17 g/g for toluene and gasoline oil, respectively. Those fabricated sorbents survived high temperatures up to 150 °C without any change in absorption capacity as well as porosity. Considering the convenient synthesis process and absorption performance, the present work offers a remarkable opportunity to bring polymer cryogels to practical application in waste oil clean-up. Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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14 pages, 2352 KiB

Open AccessEditor’s ChoiceArticle

Surface Energy of Filtration Media Influencing the Filtration Performance against Solid Particles, Oily Aerosol, and Bacterial Aerosol

by Seojin Jung, Jaejin An, Hyungjin Na and Jooyoun Kim

Polymers 2019, 11(6), 935; https://doi.org/10.3390/polym11060935 - 29 May 2019

Cited by 23 | Viewed by 4045

Abstract

Particulate airborne pollutants are a big concern to public health, and it brings growing attention about effective filtration devices. Especially, particulate matters smaller than 2.5 µm can reach the thoracic region and the blood stream, and the associated health risk can be exacerbated [...] Read more.

Particulate airborne pollutants are a big concern to public health, and it brings growing attention about effective filtration devices. Especially, particulate matters smaller than 2.5 µm can reach the thoracic region and the blood stream, and the associated health risk can be exacerbated when pathogenic microbials are present in the air. This study aims at understanding the surface characteristics of nonwoven media that influence filtration performance against solid particles (sodium chloride, NaCl), oily aerosol (dioctyl phthalate, DOP), and Staphylococcus aureus (S. aureus) bacteria. Nonwoven media of polystyrene (PS) fibers were fabricated by electrospinning and its pristine surface energy (38.5 mN/m) was modified to decrease (12.3 mN/m) by the plasma enhanced chemical vapor deposition (PECVD) of octafluorocyclobutane (C₄F₈) or to increase (68.5 mN/m) by the oxygen (O₂) plasma treatment. For NaCl particles and S. aureus aerosol, PS electrospun web showed higher quality factor than polypropylene (PP) meltblown electret that is readily available for commercial products. The O₂ plasma treatment of PS media significantly deteriorated the filtration efficiency, presumably due to the quick dissipation of static charges by the O₂ plasma treatment. The C₄F₈ treated, fluorinated PS media resisted quick wetting of DOP, and its filtration efficiency for DOP and S. aureus remained similar while its efficiency for NaCl decreased. The findings of this study will impact on determining relevant surface treatments for effective particulate filtration. As this study examined the instantaneous performance within 1–2 min of particulate exposure, and the further study with the extended exposure is suggested. Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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15 pages, 2077 KiB

Open AccessArticle

Preparation and Characterization of Magadiite–Magnetite Nanocomposite with Its Sorption Performance Analyses on Removal of Methylene Blue from Aqueous Solutions

by Mingliang Ge, Zhuangzhuang Xi, Caiping Zhu, Guodong Liang, Guoqing Hu, Lafifa Jamal and Jahangir Alam S. M.

Polymers 2019, 11(4), 607; https://doi.org/10.3390/polym11040607 - 02 Apr 2019

Cited by 32 | Viewed by 3111

Abstract

The magadiite–magnetite (MAG–Fe₃O₄) nanocomposite has great potential applications in the field of biomaterials research. It has been used as a novel magnetic sorbent, prepared by co-precipitation method. It has the dual advantage of having the magnetism of Fe₃ [...] Read more.

The magadiite–magnetite (MAG–Fe₃O₄) nanocomposite has great potential applications in the field of biomaterials research. It has been used as a novel magnetic sorbent, prepared by co-precipitation method. It has the dual advantage of having the magnetism of Fe₃O₄ and the high adsorption capacity of pure magadiite (MAG). MAG–Fe₃O₄ was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The results showed that Fe₃O₄ nanoparticles were deposited on the interlayer and surface of magadiite. MAG–Fe₃O₄ was treated as an adsorbent for methylene blue (MB) removal from aqueous solutions. The adsorption properties of MAG–Fe₃O₄ were investigated on methylene blue; however, the results showed that the adsorption performance of MAG–Fe₃O₄ improved remarkably compared with MA and Fe₃O₄. The adsorption capacity of MAG–Fe₃O₄ and the removal ratio of methylene blue were 93.7 mg/g and 96.2%, respectively (at 25 °C for 60 min, pH = 7, methylene blue solution of 100 mg/L, and the adsorbent dosage 1 g/L). In this research, the adsorption experimental data were fitted and well described using a pseudo-second-order kinetic model and a Langmuir adsorption isotherm model. The research results further showed that the adsorption performance of MAG–Fe₃O₄ was better than that of MAG and Fe₃O₄. Moreover, the adsorption behavior of MB on MAG–Fe₃O₄ was investigated to fit well in the pseudo-second-order kinetic model with the adsorption kinetics. The authors also concluded that the isothermal adsorption was followed by the Langmuir adsorption isotherm model; however, it was found that the adsorption of the MAG–Fe₃O₄ nanocomposite was a monolayer adsorption. Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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1 pages, 166 KiB

Open AccessErratum

Erratum: Surface Energy of Filtration Media Influencing the Filtration Performance against Solid Particles, Oily Aerosol, and Bacterial Aerosol. Polymers 2019, 11, 935

by Seojin Jung, Jaejin An, Hyungjin Na and Jooyoun Kim

Polymers 2020, 12(5), 1189; https://doi.org/10.3390/polym12051189 - 22 May 2020

Cited by 2 | Viewed by 1461

Abstract

The authors wish to make a change to the published paper [...] Full article

(This article belongs to the Special Issue Polymer-Based Materials as Ecological Adsorbents for Environmental Protection)

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