Hexadecyl Pyridinium Research Articles

Voltammetric Determination of Sudan I for Foodstuff Quality Control

Simple and rapid determination of Sudan I, a synthetic azo dye banned in the food industry over health concerns, is needed to ensure foodstuff safety and quality. In this study, a voltammetric approach based on Sudan I oxidation at the glassy carbon electrode (GCE) modified with manganese dioxide nanorods (MnO2 NRs) dispersed in hexadecyl pyridinium bromide was developed. The effectiveness of MnO2 NRs as a modifier was confirmed by a 7.9- and 9.2-fold increase in the electroactive surface area and the electron transfer rate, respectively, as compared to GCE. The irreversible electrooxidation of Sudan I was found to be accompanied by proton transfer and controlled by both diffusion and surface processes. Differential pulse voltammetry in phosphate buffer pH 6.5 was used for analytical purposes. The linear response of the electrode to Sudan I was shown in the ranges of 0.050–2.5 and 2.5–25 μM, with a detection limit of 13.5 nM. The developed approach was tested on dried and smoked paprika and Atlantic salmon. The obtained recovery values of 99–101% suggest that there is no matrix effect and that the method can be applied in practice.

Influence of water saturation on interlayer properties of HDTMA-, HDTMP-, and HDPy-modified montmorillonite organoclays

Surfactant-modified clay minerals, organoclays, are well-studied and used commercially for removing contaminants from water. Nevertheless, dry organoclay properties are typically used to understand and predict contaminant sorption. In this work, the effects of water saturation on two properties important to contaminant sorption were examined: organoclay interlayer space and surfactant alkyl tail conformational ordering. Montmorillonite was modified to 0.25–3.0 CEC using three surfactants: hexadecyltrimethylammonium (HDTMA), hexadecylpyridinium (HDPy), and hexadecyltrimethylphosphonium (HDTMP). At low surfactant-loadings (< 1 CEC and < 15% fOC), water saturation expanded the maximum organoclay interlayer by 4–8 Å, depending on the surfactant and its loading but had little effect on surfactant tail conformational ordering. At low surfactant loadings, water saturation likely promotes contaminant sorption relative to expectations based on dry organoclay properties, particularly for larger contaminants, due to a relaxation of the physical constraints of the interlayer. At higher surfactant loadings, HDTMA and HDTMP organoclays showed relatively small effects of water saturation, but effects were significant for HDPy organoclays. The maximum interlayer space of the HDPy organoclay at 20.7% fOC expanded 3-fold (+22.3 Å) upon hydration, which is attributed to a substantial rearrangement of the pyridinium headgroup. All HDPy organoclays with fOC > 20% experienced a notable increase in the alkyl tail conformational ordering upon hydration, becoming fully solid-like, even as negligible interlayer expansion occurred at the highest loadings. At high HDPy-loading water saturation would likely restrict sorption of contaminants relative to what might be expected based on dry properties, due to the energetic barrier of cavity formation in the more solid-like interlayer phase. This work provides evidence from three types of organoclays that water-saturated organoclay properties can differ substantially from those of dry organoclays. Characterization of organoclays under water-saturated conditions that are relevant to contaminant sorption will facilitate our understanding and improvement of organoclay performance.

Biocompatibility and biocidal effects of modified polylactide composites.

Polylactide (PLA) materials treated with antimicrobial fillers represent a suitable alternative to the production of medical devices. Their advantage is that they can prevent the growth of microorganisms and the formation of microbial biofilms on the surface and around composites. The work is focused on the evaluation of biocompatibility and biocide effect of PLA composite films filled with vermiculite and graphene oxide modified with silver (Ag+ and Ag nanoparticles), hexadecylpyridinium (HDP) and hexadecyltrimethylammonium (HDTMA) cations and their degradation leachates monitored at 1-3-6-month intervals. The antimicrobial effect of the leachates was detected by microdilution methods on gram-negative (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis), gram-positive (Staphylococcus aureus, Streptococcus salivarius) bacteria and yeast (Candida albicans). The biocidal effect of composites on biofilm formation on the surface of composites was monitored by Christensen method and autoaggregation and motility tests. The biocompatibility of the composite and the leachates was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) cytotoxicity assay. The evaluation of the antimicrobial effect of the leachates demonstrated that leachates of PLA composite filled with graphene oxide and Ag+ showed a stronger antimicrobial effect than leachates of PLA composite filled with vermiculite and Ag+ and Ag nanoparticles. The leachates of PLA composites containing vermiculite with HDP and HDTMA cations had a higher antimicrobial effect on G+ bacteria and yeast than G- bacteria. Bacterial growth, biofilm formation, autoaggregation and motility of the tested bacteria were most inhibited by the composite with vermiculite and Ag+ and Ag nanoparticles. Even after a 6-month degradation of this composite, bacterial growth and biofilm formation continued to be strongly inhibited up to 42 and 91%, respectively. The cytotoxic effect was proved only in the leachate of the composite with vermiculite containing HDP after 6 months of its degradation. Tests evaluating the biocompatibility of materials have shown that the vermiculite is the most preferred carrier and can be used in the future to bind other compounds. The study confirmed that PLA composite filled with vermiculite and Ag+ and Ag nanoparticles was the most stable and effective composite with the best biocompatible and biocidal properties.

Influence of organic and inorganic precipitators on the efficiency of surfactants extraction from wastewater by flotation

The chemical structure of surfactants causes their accumulation on the surface of water sources and leads to the formation of stable foam, which prevents the access of oxygen to the water and leads to the death of hydrobionts and deterioration in water quality. Therefore, the extraction of surfactants from wastewater is an urgent task. Increase the efficiency of flotation extraction of cationic surfactants, namely hexadecyl pyridinium chloride [C 16 H 33 NC 5 H 5]Cl (CHDP) and surfactants based on it - cetazol, by introducing organic – (sodium alkyl sulfate (SAS), CnH 2n+1 OSO 3 Na, n=10-16), and inorganic - potassium hexacyanoferrate (II, III) precipitators. The solubility of the products of interaction of cationic surfactants with SAS (sublates) was determined, which are extracted from solutions at different temperatures and impurities of electrolytes. The Gibbs free energy (), enthalpy (), and entropy (), which take place in the process of dissolution, are calculated. The low value of the heat of dissolution (2.1-16.6 kJ/mol) indicates a small effect of temperature on the solubility of sublates. The thermodynamic analysis of the process of formation of sublates allows determining the optimal length of the hydrocarbon radical of the precipitator. It is established that the extraction of the studied cationic surfactants should be extracted from water solutions and wastewater by the method of precipitation flotation using organic and inorganic precipitators. The presence of electrolytes and an increase in temperature leads to an increase in the degree of extraction hexadecyl pyridinium alkyl sulphonates sublates.

Adsorption of Aqueous Iodide on Hexadecyl Pyridinium-Modified Bentonite Investigated Using an Iodine–Starch Complex

The sorption affinity of iodide on organo-bentonite, modified with hexadecyl pyridinium (HDPy), was investigated with the iodine–starch method coupled with UV/Vis absorption spectroscopy. The iodine–starch complex method was optimized in terms of the reaction time and sample compositions, based on the UV/Vis absorbance. The batch sorption experiment for iodide on organo-bentonites, modified using two different loading amounts of HDPy, was conducted to analyze the influence of equilibrium time, liquid-to-solid ratio, and temperature, on the iodide sorption affinity. The experimental results regarding the removal capacity were further employed to derive the distribution coefficients of iodide on the organo-bentonites. The novelty of this work lies in the first application of the iodine–starch method coupled with UV/Vis absorption spectroscopy for analyzing the sorption behavior of iodide on modified bentonites. It is expected that the iodide-starch method can be complementarily employed for future research, with respect to the quantification of iodide.

Modification of Ashaka and Tango Bentonites with Tetraphenyl Phosphonium and Hexadecyl Pyridinium Bromides for Possible Use in Polymer-Clay Nanocomposite Preparation

Bentonites from Ashaka (GA) and Tango (GT) of Gombe State, Nigeria were surface modified with Tetraphenyl phosphonium (TPP) and Hexadecyl pyridinium bromides (HDP) by cation exchange method for their possible use in Clay/polymer nanocomposite preparation. The surfaces of the modified products were characterized by means of spectroscopic, diffraction and scanning methods [Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM)]. The basal spacing of the unmodified bentonite samples was 1.52nm and 1.29nm and after modification with TPP + and HDP + it increased to 1.86nm, 1.74nm and 2.15nm, 2.11nm respectively as determined from the X-ray diffraction (XRD) analysis. Results of the SEM images revealed rougher surfaces with uniformly dispersed small particles of grain-like structures characteristic of the organomodified bentonites. Bentonites from Ashaka (GA) and Tango (GT) of Gombe State, Nigeria were surface modifiedwith Tetraphenyl phosphonium (TPP) and Hexadecyl pyridinium bromides (HDP) by cationexchange method for their possible use in clay/polymer nanocomposite preparation. Thesurfaces of the modified products were characterized by means of spectroscopic, diffractionand scanning methods (Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction(XRD) and scanning electron microscopy (SEM)). The basal spacing of the unmodifiedbentonite samples was 1.52 and 1.29 nm and after modification with TPP+ and HDP+ itincreased to 1.86 and 1.74 nm; and 2.15 and 2.11 nm respectively as determined from the Xraydiffraction (XRD) analysis. Results of the SEM images revealed rougher surfaces withuniformly dispersed small particles of grain-like structures characteristic of theorganomodified bentonites.

Oxidized Black Phosphorus Nanosheets as an Inorganic Antiresorptive Agent

Black phosphorus (BP) is a newly discovered two-dimensional material that has promising applications from bioelectronics to biomedicine. However, facile oxidation of BP leads to changes in surface ...

Synergistic effect of ClO4− and Sr2+ adsorption on alginate-encapsulated organo-montmorillonite beads: Implication for radionuclide immobilization

Perchlorate (ClO4−) and pertechnetate (TcO4−) exhibit similar adsorption characteristics on alkyl quaternary ammonium-modified montmorillonite (Mt), and 99mTcO4− normally coexists with 90Sr2+ in radionuclide-contaminated water. In this study, hexadecyl pyridinium (HDPy)-modified Mt (OMt) was encapsulated in alginate beads to inhibit HDPy release and simultaneously immobilize ClO4− and Sr2+ ions. The release of HDPy was remarkably reduced (78 times) from OMt after alginate encapsulation. Adsorption of ClO4− and Sr2+ on the obtained composite demonstrated synergistic effects, with adsorption capacities reaching 0.542 and 0.484 mmol/g, respectively. Compared to the single-adsorbate system, adsorption capacities of ClO4− and Sr2+ increased significantly. The characterization of solids using X-ray diffraction, Fourier transform infrared spectroscopy, 13C nuclear magnetic resonance, and X-ray photoelectron spectroscopy, as well as the chemical analysis of the aqueous solution, demonstrated that HDPy+–COO− disintegration accounted for the adsorption synergy. HDPy was extracted from the Mt interlayer space during the synthesis of OMt/alginate and then partially re-intercalated back after interacting with ClO4− during the adsorption of ClO4− and/or Sr2+. In the binary-adsorbate system, the synergy-induced adsorption capacity was superior to many previously reported adsorbents, implying that OMt/alginate beads can be a promising adsorbent for the remediation of aqueous solutions contaminated with multiple radionuclides.

Hexadecylpyridinium (HDPy) modified bentonite for efficient and selective removal of 99Tc from wastewater

99Tc is one of the critical fission products in the treatment of wastewater and the nuclear waste repository due to its long half-life (t1/2 = 2.13 × 105 y), high fission yield (~6%), and high mobility in the environment. The development of highly-efficient, low-cost and easily available materials that can rapidly and selectively remove 99Tc is of great significance, but remains a challenge. In this work, bentonite-based materials (HDPy-bent) were obtained through modifying bentonite with hexadecylpyridinium (HDPy) and applied for the remove of TcO4− as well as its surrogate ReO4−. The structure of HDPy-bent (e.g., the values of d001) was evaluated and the maximum loading amount of HDPy on bentonite was found to be 200% CEC. The loaded HDPy+ might replace exchangeable cations in the inter-layer space of bentonite. Batch experiment results show that HDPy-bent could quantitatively remove TcO4− from aqueous solution within 3 min. The distribution coefficient (Kd) of TcO4− in this material is up to 2.1 × 105 mL/g, which is significantly higher than most of the previously tested inorganic adsorbent materials. More importantly, HDPy-bent can selectively remove TcO4− in the presence of large excess (80,000 times) of competitive anions (NO3–, SO42−, CO32−, PO43− and Cl−). This work demonstrates that the HDPy-bentonite is a low cost, and effective adsorbent for removing 99Tc from contaminated water.

Influence of the pre-dispersion of montmorillonite on organic modification and the adsorption of perchlorate and methyl red anions

Abstract In this study, hexadecyl pyridinium chloride (HDPy-Cl) was applied to modify powdery and dispersed montmorillonite (pMt and dMt, respectively). Then, perchlorate (ClO4−) and methyl red (MR) were selected as representatives of hazardous inorganic and organic pollutants, respectively, to investigate the influence of the dispersion of Mt on their adsorption using the obtained composites (pMt/HDPy and dMt/HDPy). Based on the X-ray diffraction patterns and water chemistry results, pre-dispersion of Mt resulted in a lower crystallinity of the obtained composite with slightly higher contents of HDPy+ (0.93 mmol/g-Mt) and HDPy-Cl (1.41 mmol/g-Mt) compared to the original powdery Mt (0.85 and 1.36 mmol/g-Mt). Moreover, as supported by thermogravimetry results, the amount of HDPy distributed on the external surface of dMt/HDPy was greater than that on pMt/HDPy, which was opposite of the HDPy content in the interlayer space. The adsorption kinetic of ClO4− and MR on two composites was studied and the results were fitted by three models, where the intra-particle diffusion model fitted the experimental data best. Similar adsorption capacities were obtained, and the slight differences in the adsorption kinetics as supported by the intra-particle diffusion model were ascribed to the differences in the HDPy contents and configuration. The pre-dispersion of Mt is not necessary when a modified composite is planned for use as an adsorbent of pollutants, but it would be beneficial to the synthesis of clay/polymer nanocomposites.

Selective adsorption of inorganic anions on unwashed and washed hexadecyl pyridinium-modified montmorillonite

Abstract Fourteen anions were selected to investigate their adsorption capacities and affinities to unwashed and washed hexadecyl pyridinium (HDPy)-modified montmorillonite (HDPy/Mt). Correlations between adsorption characteristics and anionic properties including radius and hydration energy were determined. With the exception of IO 3 − , H 2 AsO 4 − , and CrO 4 2− , monovalent anions showed higher adsorption capacities and affinities to unwashed or washed HDPy/Mt than divalent anions, because the latter possess higher hydration energies. Unwashed HDPy/Mt demonstrated higher selectivity toward poorly hydrated monovalent anions because it presented a more hydrophobic environment, whereas strongly hydrated divalent anions more readily intercalate into the less hydrophobic washed HDPy/Mt. Hydration of the counter ion (Cl − ) is the driving force for anion adsorption on HDPy/Mt. Higher energy consumption required to dehydrate divalent anions accounts for their lower affinity. Selectivity of HDPy/Mt to anions depends not only on anion size in different phases (from r 1 in aqueous solution to r 2 in the organic solvent-like HDPy/Mt), but also the dielectric constant of HDPy/Mt ( e 2 ) after HDPy release.

Synergistic effect of Sr2+ and ReO4− adsorption on hexadecyl pyridinium-modified montmorillonite

Simultaneous adsorption of Sr2+ and ReO4−, which are surrogates of 90Sr2+ and 99mTcO4−, on hexadecyl pyridinium (HDPy+)-modified montmorillonite (HDPy/Mt) was investigated. When the amount of HDPy+ corresponding to 0.92 times the cation exchange capacity (CEC) of Mt was added, the obtained composite (HDPy/Mt–0.92) showed considerable adsorption capacities for Sr2+ and ReO4−. Some HDPy+ desorbed from the Mt layer in the presence of ReO4−, providing negatively charged sites on the Mt surface for Sr2+ adsorption. The desorbed HDPy+ interacted with ReO4− and was trapped in the composite in the form of HDPy–ReO4, resulting in adsorption of ReO4−. At high initial concentrations of ReO4−, the HDPy configuration changed after adsorption because of the desorption–adsorption process, which was supported by X-ray diffraction. Based on the results of X-ray photoelectron spectroscopy, in the binary system (i.e., Sr2+ and ReO4−), Sr2+ uptake occurred in the interlayer space, while adsorption of ReO4− occurred on the external surface and probably in the interlayer space. Desorption–adsorption and ion exchange account for Sr2+ uptake, while adsorption of ReO4− was mainly attributed to desorption–adsorption. Compared with the one-adsorbate system, a synergistic effect of simultaneous adsorption of Sr2+ and ReO4− was found in the two-adsorbate system.

Asemi-Empirical Study of the Adsorption of Some Organic Pollutants on Modified Iraqi Clays

In this work semi–empirical method (PM3) calculations are carried out by (MOPAC) computational packages have been employed to calculate the molecular orbital's energies for some organic pollutants. The long– chain quaternary ammonium cations called Iraqi Clays (Bentonite – modified) are used to remove these organic pollutants from water, by adding a small cationic surfactant so as to result in floes which are agglomerates of organobentonite to remove organic pollutants. This calculation which suggests the best surface active material, can be used to modify the adsorption efficiency of aniline , phenol, phenol deriviatives, Tri methyl glycine, ester and pecticides , on Iraqi Clay (bentonite) by comparing the theoretical results with experimental results achived in previous experimental studies between some organic pollutants and modified bentonite by (1- Hexadecyl pyridinium bromide) (HDPYBr). The theoretical calculation is made by using three surface active materials [1- (Hexadecyl pyridinium bromide) (HDPYBr), (1,12- Dipyridiniododecane dibromide) (DPYDDBr2) and Hexadecyl trimethyl ammonium bromide (HDTMA)]. Using (HDTMA) leads to the best adsorption efficiency for most pollutants involved in this study. The enthalpy of formations, dipole and energy of molecular orbitale HOMO and LUMO energies levels are calculated for all pollutants and the three surface active materials.

Asemi-Empirical Study of the Adsorption of Some Organic Pollutants on Modified Iraqi Clays

In this work semi–empirical method (PM3) calculations are carried out by (MOPAC) computational packages have been employed to calculate the molecular orbital's energies for some organic pollutants. The long– chain quaternary ammonium cations called Iraqi Clays (Bentonite – modified) are used to remove these organic pollutants from water, by adding a small cationic surfactant so as to result in floes which are agglomerates of organobentonite to remove organic pollutants. This calculation which suggests the best surface active material, can be used to modify the adsorption efficiency of aniline , phenol, phenol deriviatives, Tri methyl glycine, ester and pecticides , on Iraqi Clay (bentonite) by comparing the theoretical results with experimental results achived in previous experimental studies between some organic pollutants and modified bentonite by (1- Hexadecyl pyridinium bromide) (HDPYBr). The theoretical calculation is made by using three surface active materials [1- (Hexadecyl pyridinium bromide) (HDPYBr), (1,12- Dipyridiniododecane dibromide) (DPYDDBr2) and Hexadecyl trimethyl ammonium bromide (HDTMA)]. Using (HDTMA) leads to the best adsorption efficiency for most pollutants involved in this study. The enthalpy of formations, dipole and energy of molecular orbitale HOMO and LUMO energies levels are calculated for all pollutants and the three surface active materials.

Poly-γ-glutamate-based Materials for Multiple Infection Prophylaxis Possessing Versatile Coating Performance.

Poly-γ-glutamate (PGA) possesses a nylon-like backbone and polyacrylate-like carboxyl groups, and shows an extraordinary solubility in water. In this study, the effective synthesis and structural analysis of some water-insoluble PGA ion-complexes (PGAICs) using cationic surfactants, hexadecylpyridinium (HDP), dodecylpyridinium, benzalkonium and benzetonium, were examined. We demonstrated their spontaneous coating performance to the surfaces of different materials (i.e., plastics, metals, and ceramics) as potent anti-staphylococcal and anti-Candida agents. The tests against Staphylococcus aureus revealed that, regardless of a variety of materials, PGAICs maintained surface antimicrobial activity, even after the water-soaking treatment, whereas those against Candida albicans indicated that, among PGAICs, PGA/HDP complex is most useful as an anti-fungal agent because of its coating stability. Moreover, the log reduction values against Influenza A and B viruses of PGA/HDP-coated surfaces were estimated to be 5.4 and 3.2, respectively, suggesting that it can be dramatically suppressed the infection of influenza. This is to our knowledge the first observation of PGA-based antiviral coatings.

Synthesis of single crystal-like hierarchically mesoporous titanosilicate Ti-SBA-1

Abstract Hierarchically mesoporous titanosilicate Ti-SBA-1 was synthesized with organic mesomorphous complexes of polyelectrolyte (poly(acrylic acid) (PAA)) and cationic surfactant (hexadecyl pyridinium chloride (CPC)) as template, tetraethylsiloxane as silica source and titanium ethoxide as titanium source. By adjusting the amount of titanium ethoxide in the synthesis, a series of Ti-SBA-1 particles with different Si/Ti ratio (79–180) were prepared. After incorporation of Ti into the silica framework the well-ordered cubic P m 3 ¯ n mesostructure remained, as well as the morphology, particle size. UV–vis DR spectra of the Ti-SBA-1 materials indicated that incorporated titanium species existed in a highly dispersed state and exhibited tetrahedral and octahedral coordination in the silica framework.

Development of antimicrobial PCL/nanoclay nanocomposite films with enhanced mechanical and water vapor barrier properties for packaging applications

Biodegradable PCL-base d nanocomposites were successfully prepared by melt mixing of the poly(e-caprolactone) with two organo-modified Algerian montmorillonites by the cation exchange reactions with two quaternary ammonium surfactants, namely hexadecyl trimethyl ammonium chloride (OMMT1) and hexadecyl pyridinium chloride (OMMT2), with the aim to elaborate antimicrobial PCL/nanoclay composite films with enhanced properties for food packaging applications. PCL-based nanocomposite films containing either OMMT1 or OMMT2 organoclays have displayed mainly intercalated structures as attested by X-ray diffraction patterns and transmission electron microscope images. Glass transition (T g) and melting (T m) temperatures of these materials, evaluated by differential scanning calorimetry analysis, were remained almost unchanged. In addition, their thermal stabilities, observed by thermogravimetric analysis, were slightly decreased as compared to the neat PCL matrix. The antibacterial performance of PCL/OMMT1 and PCL/OMMT2 composite films against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) was assessed by counting the number of bacteria in the sample. A significant decrease in the number of bacteria is noticed after the addition of 3 wt% of OMMT to the matrix, where a maximum of 94 % of growth inhibition can be reached. Furthermore, these PCL/OMMT nanocomposites have showed an interesting improvement in their several properties that are strategically studied in packaging applications. The Young modulus has increased by 36 and 22 % for (PCL/OMMT1) and (PCL/OMMT2), respectively. Also, the water vapor permeability has decreased by 56 % for (PCL/OMMT1) and 48 % for (PCL/OMMT2).

Effective and Selective Sorption of Iodide by Thin Film of Multilayered MnO2 Intercalated with Cationic Surfactants

We have fabricated a thin film of multilayered MnO2 whose interlayer is occupied with hexadecylpyridinium (HDPy) cations, using a simple anodic approach. The resulting film can effectively sorb iodide anions from aqueous solutions, even in the presence of NaCl or Na2SO4. The maximum sorption capacity was estimated to be 256 mg/g-MnO2, whereas a layered MnO2 film intercalated with K(+) ions showed no significant sorption. The layered structure of the HDPy/MnO2 composite remained unchanged after a sorption experiment. This indicates the incorporation of I(-) ions between MnO2 layers due to their specific affinity toward HDPy.

Valproate effects on chemophysical properties of Human Serum Albumin

Albumin has a fundamental role in human body. Its main tasks in blood are to regulate osmotic blood pressure, maintaining the pH, and transporting metabolites and drugs throughout the vascular system. Pharmacological studies of the interaction of drugs on HSA are important due to structural and functional changes of this vital protein; thus, here in this research the effect of valproate as a common drug for epilepsy disorders is evaluated in the presence of hexadecyl pyridinium bromide (HPB) as a positive surfactant in normal and fever condition. Electrochemical method was used to investigate the binding number of HPB molecules to HSA in the absence and presence of valproate by evaluating the concentration of free HPB in 37oC and 42oC temperatures. HSA affinity for valproate binding studied via ligand binding process for normal and fever temperatures. The findings indicate that, there is a significant difference in valproate binding to albumin at physiological and pathological temperatures. The consequences are the same in the presence of HPB; in other words, HSA binding tendency to HPB in the presence of valproate was totally altered because of HSA major conformational changes in fever condition. In conclusion, corrected dosage of valproate is needed for fever condition relative to normal temperature and the patients under prescription of different medications in fever condition should have different orders due to the interferences of drugs.

Wastewater treatment of raisins processing factory using micellar-enhanced ultrafiltration

In this work, the treatment of raisins processing wastewater using micellar-enhanced ultrafiltration (MEUF) with two cationic surfactants, hexadecyl pyridinium chloride and Cetyl trimethyl ammonium bromide, has been investigated. The effect of process parameters, such as transmembrane pressure (TMP), temperature, and surfactant concentration, on permeate flux and rejection of the wastewater pollutants have been studied. COD, turbidity, TDS, and electrical conductivity were selected as the indicators of wastewater pollution. The obtained results show that rising TMP or temperature led to rejection decrease and flux increase. However, rejection of pollutants increased and flux decreased with increasing surfactant concentration. Applying surfactants enhanced the rejection of the pollutants, thereby a considerable amount of wastewater pollution was omitted and the turbidity of the wastewater was decreased to a high extent through this process. As a result, the MEUF process can be applied as an efficient method for the treatment of raisins factories’ wastewater.