scholarly journals Impact of Advanced Oxidation Products on Nanofiltration Efficiency

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 541 ◽  
Author(s):  
Renata Żyłła ◽  
Rafał Milala ◽  
Irena Kamińska ◽  
Marcin Kudzin ◽  
Marta Gmurek ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Membrane Filtration ◽  
Main Product ◽  
Membrane Separation ◽  
Negative Impact ◽  
Microscopic Analysis ◽  
Contact Angles ◽  
Oxidation Products ◽  
Acid Oxidation ◽  
Dihydroxybenzoic Acid

The aim of the work was to determine the influence of salicylic acid (SA) oxidation products on the effectiveness of their further removal in the membrane filtration process. Two commercial polyamide-based polymer membranes, HL (GE Osmonics) and TS80 (TriSepTM), were used and characterized by SEM microscopic analysis, contact angles, and free surface energy. The products of salicylic acid oxidation, 2,3- and 2,5-dihydroxybenzoic acid and catechol, were determined and their impact on the removal of unreacted salicylic acid in the nanofiltration process was investigated. It was also checked to what extent and why they were retained or not by the membranes. The results of the research have shown that the main product of salicylic acid oxidation, 2,3-dihydroxybenzoic acid, has a negative impact on the retention of salicylic acid in the nanofiltration stage, while the other product, catechol, improves SA retention. The determined values of contact angles correlate well with solubility (S) of the tested compounds, which increases in the following order SSA < S2,3-DHBA < SCAT, while the contact angle of the membrane decreases. Nevertheless, it has been shown that some oxidation products can penetrate the environment due to poorer membrane separation properties of these products.

scholarly journals Electrochemical oxidation of salicylic acid on the nanostructured electrodes based on nickel with additionally precipitated platinum

2021 ◽  
pp. 73-80
Keyword(s):  
Salicylic Acid ◽  
Electrochemical Oxidation ◽  
Background Electrolyte ◽  
Thermodynamic Characteristics ◽  
Effective Rate ◽  
Heat Of Formation ◽  
Electrochemical Process ◽  
Acid Oxidation ◽  
Dihydroxybenzoic Acid ◽  
Oxidation Potentials

We studied the electrochemical process of salicylic acid oxidation in acidic solutions on the nanostructured anodes prepared on the basis of nickel with additionally precipitated platinum. The investigation was carried out by means of linear and cyclic voltammetry methods in combination with quantum chemical calculations. The results of voltammetry study showed that clearly expressed current maxima were observed in the range of 0.43 V to 1.15 V in the anode sections of the voltammograms, in contrast to the background electrolyte. The oxidation potentials of the depolarizer almost coincided with those typical of a smooth platinum electrode, but the current density was 1.8 times higher on the electrode under study. Based on the analysis of voltammetric curves, the effective rate constants of heterogeneous charge transfer, activation energy and diffusion coefficient were calculated. The calculation of the thermodynamic parameters of the intermediates of salicylic acid electrooxidation showed that the heat of formation of 2,3-dihydroxybenzoic acid is higher than that of 2,5-dihydroxybenzoic acid, which indicates a higher stability of the latter. Analysis of the calculated thermodynamic characteristics of each stage of salicylic acid electrochemical oxidation showed that the process is endothermic, occurs with an increase in entropy and the Gibbs energy decreases. The rate of the overall process is determined by the rate of the first stage.

scholarly journals Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Membrane System ◽  
Coagulation System ◽  
Fouling Control ◽  
Filtration System ◽  
Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

Chlorogenic Acid Oxidation by a Crude Peroxidase Preparation: Biocatalytic Characteristics and Oxidation Products

2009 ◽  
Vol 5 (1) ◽  
pp. 243-251 ◽  
Author(s):  
Ali Osman ◽  
Ayman El Agha ◽  
Dimitris P. Makris ◽  
Panagiotis Kefalas
Keyword(s):  
Chlorogenic Acid ◽  
Oxidation Products ◽  
Acid Oxidation

Biofilms: their structure, activity, and effect on membrane filtration

2005 ◽  
Vol 51 (6-7) ◽  
pp. 181-192 ◽  
Author(s):  
Z. Lewandowski ◽  
H. Beyenal
Keyword(s):  
Membrane Filtration ◽  
Membrane Separation ◽  
Separation Processes ◽  
Membrane Cleaning ◽  
Underlying Assumption ◽  
Structure Activity ◽  
Membrane Biofouling ◽  
Flux Decline ◽  
Cleaning Procedures ◽  
Near Future

The goal of this presentation is to identify biofouling mechanisms that cause undesirable effects to the membrane separation processes of flux decline and pressure drop. The underlying assumption of this presentation is that biofouling is unavoidable and that the operator cannot eliminate it entirely. This premise justifies research efforts toward understanding the mechanisms by which biofouling affects the membrane processes, rather than expecting that technology can entirely eliminate membrane biofouling in the near future. An improved understanding of biofouling mechanisms may lead to better membrane design, better membrane modules, and better membrane cleaning procedures.

scholarly journals Removal of Organic Compounds with an Amino Group during the Nanofiltration Process

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Renata Żyłła ◽  
Magdalena Foszpańczyk ◽  
Magdalena Olak-Kucharczyk ◽  
Joanna Marszałek ◽  
Stanisław Ledakowicz
Keyword(s):  
Organic Compounds ◽  
Natural Organic Matter ◽  
Oxidation Product ◽  
Membrane Filtration ◽  
Separation Efficiency ◽  
Ph Value ◽  
Oxidation Products ◽  
Low Molecular Weight ◽  
Amino Group ◽  
Amino Groups

The research covered the process of nanofiltration of low molecular weight organic compounds in aqueous solution. The article presents the results of experiments on membrane filtration of compounds containing amino groups in the aromatic ring and comparing them with the results for compounds without amino groups. The research was carried out for several commercial polymer membranes: HL, TS40, TS80, DL from various manufacturers. It has been shown that the presence of the amino group and its position in relation to the carboxyl group in the molecule affects the retention in the nanofiltration process. The research also included the oxidation products of selected pharmaceuticals. It has been shown that 4-Amino-3,5-dichlorophenol—a oxidation product of diclofenac and 4-ethylbenzaldehyde—a oxidation product of IBU, show poor separation efficiency on the selected commercial membranes, regardless of the pH value and the presence of natural organic matter (NOM). It has been shown that pre-ozonation of natural river water can improve the retention of pollutants removed.

scholarly journals Low- and High-Pressure Membrane Separation in the Production of Process Water for Coke Quenching

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 937
Author(s):  
Anna Trusek ◽  
Maciej Wajsprych ◽  
Andrzej Noworyta
Keyword(s):  
High Pressure ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Coke Oven ◽  
Industrial Plant ◽  
Operating Pressure ◽  
Permeate Flux ◽  
Final Treatment ◽  
Stage System ◽  
Pressure Plant

Although the time for operating mines and coking plants in many countries is coming to an end due to climate change, we must still ensure that the pollution generated by this source of the economy is minimized. Despite the several stages of treatment of the coke-oven effluent, completed with nitrification and denitrification processes preceding final sedimentation, the stream obtained does not meet the requirements of water for coke quenching. That is why the stream after biodegradation and sedimentation was treated on membrane units to ensure water reusing in the coking plant. As the subjected stream contained both solid and dissolved pollutants, a two-stage system was proposed: low- and high-pressure membrane filtration. Industrial modules were tested on pilot units operating under industrial plant conditions. In the case of the ultrafiltration process, all the tested ultrafiltration modules fulfilled the primary task. All of them separated almost completely the turbidities present in the stream, which would have disturbed the operation of the high-pressure plant. Considering the decrease in permeate flux and the possibility of cleaning, a PCI membrane made of PVDF tubes with a diameter of 12.5 mm and pore size of 20 μm was selected. Regarding the high-pressure membrane filtration, the reverse osmosis membrane was significantly better in the removal efficiency of both organic and inorganic dissolved substances. An operating pressure of 3 MPa was chosen for the system. Hence, membrane processes, which are not used as stand-alone treatment units for coke-oven effluents, function well as a final treatment stage.

scholarly journals Annurca Apple Polyphenols Ignite Keratin Production in Hair Follicles by Inhibiting the Pentose Phosphate Pathway and Amino Acid Oxidation

Nutrients ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1406 ◽  
Author(s):  
Nadia Badolati ◽  
Eduardo Sommella ◽  
Gennaro Riccio ◽  
Emanuela Salviati ◽  
Dimitri Heintz ◽  
...  
Keyword(s):  
Pentose Phosphate Pathway ◽  
Hair Growth ◽  
High Resolution Mass Spectrometry ◽  
Negative Impact ◽  
Adult Population ◽  
Pentose Phosphate ◽  
Hair Follicles ◽  
Acid Oxidation ◽  
Healthy Human ◽  
Nucleotide Synthesis

Patterned hair loss (PHL) affects around 50% of the adult population worldwide. The negative impact that this condition exerts on people’s life quality has boosted the appearance of over-the-counter products endowed with hair-promoting activity. Nutraceuticals enriched in polyphenols have been recently shown to promote hair growth and counteract PHL. Malus pumila Miller cv. Annurca is an apple native to Southern Italy presenting one of the highest contents of Procyanidin B2. We have recently shown that oral consumption of Annurca polyphenolic extracts (AAE) stimulates hair growth, hair number, hair weight and keratin content in healthy human subjects. Despite its activity, the analysis of the molecular mechanism behind its hair promoting effect is still partially unclear. In this work we performed an unprecedented metabolite analysis of hair follicles (HFs) in mice topically treated with AAE. The metabolomic profile, based on a high-resolution mass spectrometry approach, revealed that AAE re-programs murine HF metabolism. AAE acts by inhibiting several NADPH dependent reactions. Glutaminolysis, pentose phosphate pathway, glutathione, citrulline and nucleotide synthesis are all halted in vivo by the treatment of HFs with AAE. On the contrary, mitochondrial respiration, β-oxidation and keratin production are stimulated by the treatment with AAE. The metabolic shift induced by AAE spares amino acids from being oxidized, ultimately keeping them available for keratin biosynthesis.

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