Graphene oxide triggers mass transfer limitations on the methanogenic activity of an anaerobic consortium with a particulate substrate

The problems related to the transport of gases through nanoporous graphene (NG) and graphene oxide (GO) membranes are considered. The influence of surface processes on the transport of gas molecules through the aforementioned membranes is studied theoretically. The obtained regularities allow finding the dependence of the flux of the gas molecules passing through the membrane on the kinetic parameters which describe the interaction of the gas molecules with the graphene sheets. This allows to take into account the influence of external fields (e.g., resonance radiation), affecting the aforementioned kinetic parameters, on the transport of gas molecules through the membranes. The proposed approach makes it possible to explain some experimental results related to mass transfer in the GO membranes. The possibility of the management of mass transfer through the NG and GO membranes using resonance radiation is discussed.

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Biochemical Methane Potential (BMP) from sugarcane biorefinery residues: maximizing their use by co-digestion

10.1101/2021.02.19.432018 ◽

2021 ◽

Author(s):

Maria Paula. C. Volpi ◽

Livia B. Brenelli ◽

Gustavo Mockaitis ◽

Sarita C. Rabelo ◽

Telma T. Franco ◽

...

Keyword(s):

Mass Transfer ◽

Filter Cake ◽

Biogas Production ◽

Economic Advantage ◽

Small Scale ◽

Biochemical Methane Potential ◽

Production Potential ◽

Methanogenic Activity ◽

Positive Effects ◽

Methane Potential

ABSTRACTThis work evaluated the methane (CH4) production potential from residues of integrated 1st (vinasse and filter cake) and 2nd (deacetylation pretreatment liquor from straw) generation (1G2G) sugarcane biorefinery. The small-scale study provided fundamentals for basing the optimization of co-digestion by assessing the best co-substrates synergistic conditions. Biochemical Methane Potential (BMP) tests showed co-digestion enhanced CH4 yield of isolated substrates, reaching 605 NmLCH4 gVS−1. Vinasse and deacetylation liquor as the only co-substrates increased the BMP by 37.72%, indicating that the association of these two residues provided positive effects for co-digestion by nutritionaly benefeting the methanogenic activity. The filter cake had the lowest BMP (260 NmLCH4 gVS−1) and digestibility (≤40%), being the stirring required to improve the mass transfer of biochemical reactions. The alkaline characteristic of the liquor (pH-prevented alkalinizers from being added to the co-digestion, which could be a relevant economic advantage for the implementation of the process in an industrial scale. The co-digestion system has proven to efficiently maximize waste management in the 1G2G sugarcane biorefineries and potentially enhance their energy generation (by at least in 18%), providing experimental elements for placing the biogas production as the hub of the bioeconomy in the agroindustrial sector.

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Investigation of Anaerobic Removal and Degradation of Organic Chlorine from Kraft Bleaching Wastewaters

Water Science & Technology ◽

10.2166/wst.1991.0480 ◽

1991 ◽

Vol 24 (3-4) ◽

pp. 241-250 ◽

Cited By ~ 15

Author(s):

John F. Ferguson ◽

Eva Dalentoft

Keyword(s):

Microbial Activity ◽

Significant Inhibition ◽

Removal Mechanism ◽

Organic Halide ◽

Methanogenic Activity ◽

Biological Removal ◽

Organic Chlorine ◽

Anaerobic Consortium ◽

Adsorbable Organic Halide

A study of anaerobic removal of adsorbable organic halide (AOX) from kraft bleaching wastes has been conducted, using bottle bioassay techniques. The anaerobic cultures were fed either acetate or hydrogen and were able to remove from 40 to 65% of the AOX. The removal mechanism and the role of an adapted anaerobic consortium has been investigated with results indicating some biological removal, but significant amounts of sorption or degradation that does not seem to require microbial activity. Significant inhibition of methanogenic activity has also been found in some of the tests.

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Immobilization of Graphene Oxide on the Permeate Side of a Membrane Distillation Membrane to Enhance Flux

Membranes ◽

10.3390/membranes8030063 ◽

2018 ◽

Vol 8 (3) ◽

pp. 63 ◽

Cited By ~ 11

Author(s):

Worawit Intrchom ◽

Sagar Roy ◽

Madihah Humoud ◽

Somenath Mitra

Keyword(s):

Mass Transfer ◽

Graphene Oxide ◽

Direct Contact ◽

Membrane Distillation ◽

Water Vapor Flux ◽

Vapor Flux ◽

Ptfe Membrane ◽

Direct Contact Membrane Distillation ◽

Water Vapors ◽

Facile Fabrication

In this paper, a facile fabrication of enhanced direct contact membrane distillation membrane via immobilization of the hydrophilic graphene oxide (GO) on the permeate side (GOIM-P) of a commercial polypropylene supported polytetrafluoroethylene (PTFE) membrane is presented. The permeate side hydrophilicity of the membrane was modified by immobilizing the GO to facilitate fast condensation and the withdrawal of the permeate water vapors. The water vapor flux was found to be as high as 64.5 kg/m2·h at 80 °C, which is 15% higher than the unmodified membrane at a feed salt concentration of 10,000 ppm. The mass transfer coefficient was observed 6.2 × 10−7 kg/m2·s·Pa at 60 °C and 200 mL/min flow rate in the GOIM-P.

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Ultrahigh permeance of a chemical cross-linked graphene oxide nanofiltration membrane enhanced by cation–π interaction

RSC Advances ◽

10.1039/c9ra07109a ◽

2019 ◽

Vol 9 (69) ◽

pp. 40397-40403 ◽

Cited By ~ 2

Author(s):

Ruobing Yi ◽

Rujie Yang ◽

Risheng Yu ◽

Jian Lan ◽

Junlang Chen ◽

...

Keyword(s):

Mass Transfer ◽

Graphene Oxide ◽

Water Channels ◽

Cross Linking ◽

Nanofiltration Membrane ◽

Magnesium Ions ◽

Mass Transfer Resistance ◽

Transfer Resistance ◽

Low Mass ◽

Chemical Cross Linking

Chemical cross-linking together with magnesium ions, potentially promoting reasonable cross-linking and improving the water channels of membrane in terms of flatness and surface with low mass transfer resistance.

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Two-particle model of anaerobic solid state fermentation

Water Science & Technology ◽

10.2166/wst.2000.0054 ◽

2000 ◽

Vol 41 (3) ◽

pp. 43-50 ◽

Cited By ~ 29

Author(s):

S. Kalyuzhnyi ◽

A. Veeken ◽

B. Hamelers

Keyword(s):

Mass Transfer ◽

Solid State ◽

Solid State Fermentation ◽

Volatile Fatty Acids ◽

Experimental Studies ◽

Particle Model ◽

Mass Transfer Limitation ◽

Methanogenic Activity ◽

Seed Particles ◽

Gas Interactions

A structured mathematical model of anaerobic solid state fermentation (ASSF) has been developed. Since a stable ASSF requires addition of significant quantities of methanogenic seed sludge and mass-transfer limitation becomes important, the model postulates the existence of two different types of particles inside the fermenting solid mass – so-called “seed” particles with low biodegradability and high methanogenic activity and so-called “waste” particles with high biodegradability and low methanogenic activity. Any particle is assumed to be a completely mixed reactor and mass transfer of solutes between the particles is brought about by diffusion. The model includes multiple-reaction stoichiometry, microbial growth kinetics, material balances, liquid-gas interactions and liquid phase equilibrium chemistry. The theoretical model agrees on the qualitative level with existing experimental studies of ASSF. Hypothetical computer simulations are presented to illustrate the influence of biodegradabilityand mass transfer intensity on the stability of ASSF. On this basis, possible measures are proposed to prevent accumulation of volatile fatty acids inside the “seed” particles beyond their assimilative methanogenic capacity.

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