Iskanje po katalogu digitalne knjižnice

Opis: In order to ensure efficient wastewater treatment and seawater desalination, adequate modeling and optimization of the forward osmosis (FO) process has the potential to be very helpful. This paper deals with the FO model parameters calibration and FO process optimization by a gradient-based optimization method. For this purpose, an upgraded FO model, which involves temperature- and agent-dependent parameters, was developed. The FO model calibration was done using NaCl as agents in draw solution, while MgCl2 was used for model validation. The agreements between simulated and measured FO performance were satisfactory; relative index of agreement are higher than 0.99. By using the proposed FO model, the optimization of FO process conditions was performed with various definitions of the objective and constraint functions. In case of maximizing the water flux, minimizing reverse solute flux, and fulfilling the required constraints, the ratio of water flux and reverse solute flux increased up to 40 % for NaCl and up to 20 % for MgCl2; meanwhile the effective osmotic pressure difference was improved 2-times for NaCl and up to 3.8-times for MgCl2. The optimization process proved to be stable and efficient and can easily be adapted or upgraded for more complex dynamic FO modeling.
Ključne besede: forward osmosis, modeling, model and process parameters, calibration procedure, gadient-based optimization
Objavljeno v DKUM: 23.08.2024; Ogledov: 67; Prenosov: 18
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Ključne besede: resource reclamation, single cell protein, electrodialysis, forward osmosis, Saccharomyces cerevisiae
Objavljeno v DKUM: 10.05.2024; Ogledov: 180; Prenosov: 18
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Opis: Multicoated magnetite (Fe3O4) magnetic nanoparticles (MNPs) with polyacrylic acid (PAA) as a terminal hydrophilic ligand were synthesized and examined for use as a draw solution (DS) agent in forward osmosis (FO). After coating superparamagnetic iron-oxide MNPs with (3-aminopropyl)triethoxysilane (APTES) the carboxyl groups of PAA were bound to APTES amino groups via the crosslinker 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) forming a peptide bond resulting in stable water-soluble particles (MNP@APTES@PAA) with a concentration-normalised osmotic pressure of 1.56 bar L g−1. The MNP@APTES@PAA solution was evaluated as a DS in two FO filtrations with deionized (DI) water as a feed solution (FS): one using freshly prepared MNP@APTES@PAA and one using magnetically recovered (re-concentrated) MNP@APTES@PAA. The resulting MNP@APTES@PAA nanocomposites exhibit good colloidal stability in aqueous solution with a concentration-normalized osmotic pressure of 1.56 bar L g−1. This is 12-fold higher than that in our previous studies of poly-sodium-acrylate coated MNPs and 3-fold higher than that of citric acid coated MNPs. The water recoveries of the two filtrations were 25.7% and 13.6%, respectively, after 2 h of FO filtration time resulting in a DS osmotic pressure of 2.5 bar with a concentration of 4.3 g L−1 and a DS osmotic pressure of 2.6 with a concentration of 3.7 g L−1 respectively.
Ključne besede: magnetic nanoparticle, forward osmosis, draw solution, osmose
Objavljeno v DKUM: 16.08.2023; Ogledov: 424; Prenosov: 14
Celotno besedilo (1,92 MB)
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Opis: The problem of wastewater is increasing as we face tighter regulations in limiting parameters for discharge into sewers or surface waters. At the same time, the challenge is also how to upgrade existing technology and identify new appropriate technologies for purification of industrial wastewater for re-use. The optimal solution, which can give the appropriate quality of purified water at acceptable operating costs also is not straightforward. However, increasing environmental legislative demands combined with increased fresh water consumption can facilitate implementation of emerging technologies which at the current state are not fully mature. Forward Osmosis (FO) is one such recent achievement which is considered as a promising membrane process and potentially a sustainable alternative to reverse osmosis (RO) process for wastewater reclamation and sea/brackish water desalination. However, there are many limiting parameters (e.g. membrane fouling, draw solutions) in FO process that needs to be studied and improved. To reduce the membrane fouling in FO, many improvements were attempted, e.g. synthesis of different membrane materials, fabrication of membrane modules, membrane coating etc. One of the novelties in membrane development research field is biomimetic membranes incorporate in separation processes. They employ natural proteins known as AQPs (aqpourins) to regulate the flow of water, providing increased permeability and near-perfect solute rejection. Membrane surface characteristics were measured on virgin, used and cleane membrane in order to confirm the resistance to different types of industrial wastewater and sewage.
Ključne besede: biomimetic membrane, forward osmosis, industrial wastewater, reverse osmosis, textile wastewater, ultrafiltration, wastewater reuse
Objavljeno v DKUM: 25.07.2018; Ogledov: 2065; Prenosov: 134
Celotno besedilo (4,64 MB)

Opis: Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of larger biomolecules with often flexible conformations. In this study, transport of two chemically similar peptides with molecular weight (Mw) of 375 and 692 Da across a thin film composite Aquaporin Inside™ Membrane (AIM) FO membrane was investigated. Despite the relative large size, both peptides were able to permeate the dense active layer of the AIM membrane and the transport mechanism was determined to be diffusion-based. Interestingly, the membrane permeability increased 3.65 times for the 692 Da peptide (1.39 × 10−12 m2·s−1) compared to the 375 Da peptide (0.38 × 10−12 m2·s−1). This increase thus occurs for an 85% increase in Mw but only for a 34% increase in peptide radius of gyration (Rg) as determined from molecular dynamics (MD) simulations. This suggests that Rg is a strong influencing factor for membrane permeability. Thus, an increased Rg reflects the larger peptide chains ability to sample a larger conformational space when interacting with the nanostructured active layer increasing the likelihood for permeation.
Ključne besede: forward osmosis, biomimetic, peptides, rejection
Objavljeno v DKUM: 21.06.2017; Ogledov: 1184; Prenosov: 406
Celotno besedilo (2,21 MB)
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