Supercritical fluid CO2 extraction accelerates isolation of humic acid from livePilayella littoralis (Phaeophyta)

Radwan, Amal; Willey, Ronald J.; Davies, Geoffrey; Fataftah, Amjad; Ghabbour, Elham A.; Jansen, Susan A.

doi:10.1007/bf02186334

Cited by 10 publications

(3 citation statements)

References 11 publications

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“…Hence there is an urgent need for inert, bioacceptable materials capable of withstanding the strong oxidative environment in vivo. Humic acids (HAs) are biopolymers found in soil, sediments, water, and some plants such as tobacco. − Although their origin is ambiguous, it is speculated that they may have evolved from the auto-oxidation and condensation of lignin and polyphenols during the humification process or are produced during in vivo biosynthesis in plants . Humic acids are deemed as the final product of the biodegradative and oxidative route, with a mean residence time up to 1200 years in soil, and probably will not undergo any further breakdown unless they are exposed to agents they have not previously encountered .…”

Section: Introductionmentioning

confidence: 99%

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

et al. 2001

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Multilayered films of humic acids (HAs) (naturally occurring biopolymers) were investigated as a potential semipermeable membrane for implantable glucose sensors. These films were grown using a layer-by-layer self-assembly process of HAs and oppositely charged ferric ions. The growth of these assemblies exhibited strong dependence on the pH and ionic strength of HAs solutions, which correlated with the degree of ionization of the carboxyl groups and neutralization-induced surface spreading. Quartz crystal microbalance (QCM) and ellipsometric studies have shown repeatable, stepwise increase in mass (as high as 5.63 microg/cm(2)) and in film thickness (ca. 24.3 nm per layer) for these assemblies. The permeability of glucose through these membranes can be regulated by varying the number of self-assembled HAs/Fe(3+) layers. Moreover, a 200 nm thick HAs/Fe(3+) film (in its hydrated state) had a shear modulus of about 80 MPa, implying stability upon implantation. These films were determined to be biocompatible since in vivo studies indicated only mild tissue reaction along with some neovascularization.

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Section: Introductionmentioning

confidence: 99%

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

et al. 2001

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“…These poly functional polymers are formed during early diagenesis of bio matters and occur in soils, peats, sediments, natural water, ocean, sewages, waste effluents of different industries like, food, textile, paper and pulp industries [1]. Literatures reveal that it is not possible to write a molecular structure that can describe the connectivity within molecules of humic substances.…”

Section: Introductionmentioning

confidence: 99%

“…Few studies have been showed to estimate the separation and purification of sludge humic acids for use as fruitful fertilizer in our environment [5]. Ultrasonication followed by acid alkali extraction [6] and super critical fluid extraction [1] were already performed to extract humic substances from different sources. Acid alkali extraction process was evaluated to extract humic acids from vegetable residues [7].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Fouling Characteristics and Flux Decline during Humic Acids Batch Ultrafiltration

Saha¹,

Das²

2015

J Chem Eng Process Technol

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This work focuses on the membrane ultrafiltration technique to separate humic acids from aqueous solution. An unstirred dead end ultrafiltration of synthetic aqueous humic acids solutions of 50, 150 and 250 mg L -1 was performed with Polyethersulfone membrane. To observe the effects of applied transmembrane pressure (TMP) drops during separation, the experiments were carried out at 207, 276, 345 and 414 kPa with 50 kDa molecular weight cutoff (MWCO) membrane. The performance of this process is expressed in terms of volume reduction factor (VRF). To analyze flux decline and pore blocking behavior, Hermia's fouling mechanism models, namely, complete, standard, intermediate and cake filtration models have been studied in search of best fittings in flux decline system. After completion of the experiment with 50 mg L -1 feed solution, the concentration of Humic acids in permeate was 2.9 mg L -1 , revealing 94% rejection during the membrane ultrafiltration. Keywords:

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Isolation of humic acid from the brown algaeAscophyllum nodosum, Fucus vesiculosus, Laminaria saccharina and the marine angiospermZostera marina

et al. 1996

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Supercritical fluid CO2 extraction accelerates isolation of humic acid from livePilayella littoralis (Phaeophyta)

Cited by 10 publications

References 11 publications

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

Analysis of Fouling Characteristics and Flux Decline during Humic Acids Batch Ultrafiltration

Isolation of humic acid from the brown algaeAscophyllum nodosum, Fucus vesiculosus, Laminaria saccharina and the marine angiospermZostera marina

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