Dodecyl Benzyl Dimethyl Ammonium Chloride Research Articles

Impact of urban pollution on freshwater biofilms: Oxidative stress, photosynthesis and lipid responses

Urban ecosystems are subjected to multiple anthropogenic stresses, which impact aquatic communities. Artificial light at night (ALAN) for instance can significantly alter the composition of algal communities as well as the photosynthetic cycles of autotrophic organisms, possibly leading to cellular oxidative stress. The combined effects of ALAN and chemical contamination could increase oxidative impacts in aquatic primary producers, although such combined effects remain insufficiently explored. To address this knowledge gap, a one-month experimental approach was implemented under controlled conditions to elucidate effects of ALAN and dodecylbenzyldimethylammonium chloride (DDBAC) on aquatic biofilms. DDBAC is a biocide commonly used in virucidal products, and is found in urban aquatic ecosystems. The bioaccumulation of DDBAC in biofilms exposed or not to ALAN was analyzed. The responses of taxonomic composition, photosynthetic activity, and fatty acid composition of biofilms were examined. The results indicate that ALAN negatively affects photosynthetic yield and chlorophyll production of biofilms. Additionally, exposure to DDBAC at environmental concentrations induces lipid peroxidation, with an increase of oxylipins. This experimental study provides first insights on the consequences of ALAN and DDBAC for aquatic ecosystems. It also opens avenues for the identification of new biomarkers that could be used to monitor urban pollution impacts in natural environments.

Mixed light photoperiod and biocide pollution affect lipid profiles of periphyton communities in freshwater ecosystems

Environmental factors, such as light intensity and exposure to contaminants, may significantly influence the lipid composition of algae in periphytic communities. In this study, we investigated the joint effects of dodecylbenzyldimethylammonium chloride (BAC 12), as biocide, and light photoperiods on the polar lipidome of a freshwater biofilm. Exposure to BAC 12 in a microcosm experiment increased the heterotrophic compartment, while phototrophic organisms were severely affected, with corresponding shifts in lipid composition. The overall decrease in polyinsaturated fatty acids suggested a significant impact of the biocide on biofilm microalgae. However, it was difficult to distinguish the influence of light from that of contamination, as there was no observable effect of photoperiod on conventional fatty acid determination. Thus, the molecular species compositions of both glycolipids and phospholipids were explored in additional multivariate analyzes. The results suggested that certain molecular species can serve as more specific markers of light duration at the biofilm scale, independently of the chemical pressure caused by other pollutants.

Quaternary ammonium compounds promoted anoxic sludge granulation and altered propagation risk of intracellular and extracellular antibiotic resistance genes.

Surfactants could influence sludge morphology and disinfectants were linked to antibiotic resistance genes (ARGs). Thus, the response of activated sludge and ARGs to long-term quaternary ammonium compounds (QACs) exposure required further investigation, which is a popular surfactant and disinfectant. Here, three sequencing batch reactors were fed with 5mg/L most frequently detected QACs (dodecyl trimethyl ammonium chloride (ATMAC C12), dodecyl benzyl dimethyl ammonium chloride (BAC C12) and didodecyl dimethyl ammonium chloride (DADMAC C12)) for 180 d. The long-term inhibitory effect on denitrification ranked: DADMAC C12>BAC C12>ATMAC C12. Besides, obvious granular sludge promoted by the increase of α-Helix/(β-Sheet + Random coil) appeared in DADMAC C12 system. Moreover, intracellular ARGs increased when denitrification systems encountered QACs acutely but decreased in systems chronically exposed to QACs. Although replication and repair metabolism in ATMAC C12 system was higher, ATMAC C12 significantly promoted proliferation of extracellular ARGs. It was noteworthy that the propagation risk of extracellular ARGs in sludge increased significantly during sludge granulation process, and intracellular sul2 genes in sludge and water both increased with the granular diameter in DADMAC C12 system. The universal utilization of QACs may enhance antibiotic resistance of bacteria in wastewater treatment plants, deserving more attention.

Adsorption of cationic surfactant as a probe of the montmorillonite surface reactivity in the alginate hydrogel composites.

Adsorption of a cationic surfactant allowed to probe the surface reactivity of montmorillonite encapsulated in a composite of alginate hydrogels (A-MMT). Dodecylbenzyldimethylammonium chloride (BAC-12) was the surfactant used for these studies. BAC-12 is part of the widely used surfactant mixture known as benzalkonium chloride. XRD showed that up to three different types of basal spacing (d 001) were present within the composite indicating that as the concentration of adsorbed BAC-12 increases, populations with different adsorption conformational arrangements are present, even unexpanded clay remains. From the SEM-EDS spectra it is observed that the clay is distributed in the whole composite. In addition, the effect of the presence of cationic and anionic biocides on BAC-12 adsorption was studied. Cationic biocides such as tetradecyllbenzyldimethylammonium chlorides (BAC-14) and paraquat (PQ) show a competitive behavior for the clay adsorption sites at BAC-12 low concentration indicating an electrostatic adsorption mechanism. However, the presence of anionic contaminants such as 2,4-D and metsulfuron methyl do not affect surfactant adsorption. In all scenarios is observed an abrupt increase of BAC-12 adsorbed amount reaching values higher than the clay CEC suggesting strong tail-tail interactions. This occurs at concentrations 10 times lower than the CMC of BAC-12 promoted by clay encapsulation in the composite. In these composites the alginate does not affect the surface reactivity of the clay, but the formation of the hydrogel allows it to be easily extracted from aqueous media which makes it an interesting material with a potential use in water remediation.

Occurrences of benzalkonium chloride in streams near a pharmaceutical manufacturing complex in Korea and associated ecological risk

Benzalkonium chloride (BKC) is a commonly used preservative in personal care products and pharmaceutical preparations. However, its ecological risks are not well understood because of lack of monitoring data and ecotoxicological information. In the present study, occurrence of BKC was investigated in the waters near a pharmaceutical manufacturing complex of South Korea and its acute and chronic ecotoxicities were evaluated using Daphnia magna and Japanese medaka (Oryzias latipes). Associated ecological risks were estimated by calculating hazard quotients (HQs). In addition, endocrine disruption potency of BKC was compared with those of other frequently used preservatives using human adrenal (H295R) and rat pituitary (GH3) cells. High concentration of BKC was detected at locations near the pharmaceutical manufacturing plants, i.e., 35.8 μg/L for dodecyl benzyl dimethyl ammonium chloride (BKC–C12), and 21.6 μg/L tetradecyl benzyl dimethyl ammonium chloride (BKC–C14). In Daphnia, 48 h immobilization EC50 and 21 d reproduction NOEC were determined at 41.1 μg/L and ≥10.8 μg/L, respectively. For O. latipes, 96 h LC50 was determined at 246 μg/L while the growth inhibition NOEC was ≥113.4 μg/L following early life stage exposure. BKC significantly up-regulated vitellogenin gene of juvenile fish, indicating its endocrine disrupting potential in fish. Exposure to BKC increased steroid hormone level in H295R cells, and induced cytotoxicity in GH3 cells. HQ values of BKC were determined at greater than one in the ambient water near pharmaceutical manufacturing facilities. Considering high ecological risk and endocrine disrupting potential, long-term consequences of BKC contamination in aquatic ecosystem need to be examined.

Degradation of non-oxidizing biocide benzalkonium chloride and bulk dissolved organic matter in reverse osmosis concentrate by UV/chlorine oxidation

Non-oxidizing biocide that is used to inhibit the microorganism growth on RO membrane, are observed to be high concentration and toxic in RO concentrate. The synergistic oxidation process (SOP) of UV/chlorine was investigated to simultaneously reduced the content (60.2 %) and toxicity (57.0 %) of a representative biocide dodecylbenzyldimethylammonium chloride (DDBAC) in real RO concentrate, with a UV fluence 1080 mJ/cm2 and chlorine dose 20 mg/L. Besides eliminating the DDBAC, UV/chlorine reduced the UVA254 and fluorescence of the dissolved organic matters (DOM). The oxidation mechanism was verified to be the radical electrophilic addition rather than the chlorine-electrophilic substitution through the decay of electron-donation moiety and UVA254. As results, high molecular weight fractions of DOM (>2k Da, 79.2 %) was cleaved into low molecular weight fractions (<0.4k Da, 18.4 %) and organic halide was formed. Parallel-factor analysis of the fluorescence components suggested that decomposition of the protein-like fluorophore is most likely to surrogate the biocide removal and organic halide formation compared to other fluorophore components and UVA254. Accordingly, a portable fluorescence probe with 400 nm excitation and 410–600 nm emission wavelengths was developed as an online surrogate for the DDBAC removal and organic halide formation.

A study of synergistic oxidation between ozone and chlorine on benzalkonium chloride degradation: Reactive species and degradation pathway

Ozonation and chlorination are widely used for disinfection or micropollutant elimination in water treatment or reclamation fields. It was found in this study that the presence of free chlorine increased the production of reactive species significantly during ozonation of dodecylbenzyldimethylammonium chloride (DDBAC, quaternary ammonium compound). DDBAC hardly underwent degradation by the chlorination process. However, the removal of DDBAC by ozonation after 10 min increased from 22% to 92%, when the dosage of free chlorine increased from 0 to 112 mg/L. pH affected the synergistic effect of ozone/chlorine oxidation of DDBAC. The promotion effect of free chlorine was greater at acidic conditions than that at basic conditions. The radical quenching experiments suggested that various reactive species formed during ozone/chlorine oxidation of DDBAC. The contributions of ozone, reactive species that could or could not be quenched by tBuOH were 8%, 78% and 13%, respectively. In the mixed system of DDBAC and pCBA, the degradation percentage of DDBAC and pCBA after 15 min increased from 31.0% and 13.1% to 53.8% and 28.3% with the presence of chlorine, respectively. Based on the steady-state concentration assumption, the steady-state concentration of OH during ozone/chlorine oxidation of DDBAC was 2.3 times higher than that during the sole ozonation process, being 7.5 × 10−14 M and 3.3 × 10−14 M, respectively. Ten oxidation products were identified by HPLC-MS/MS during ozone/chlorine oxidation of DDBAC. Three degradation mechanisms were observed: the hydrogen abstraction of the alkyl chain by hydroxyl radical; the cleavage of the benzyl-nitrogen bond of DDBAC; and the addition of hydroxyl radical on the aromatic ring or the alkyl chain.

UV/chlorine as an advanced oxidation process for the degradation of benzalkonium chloride: Synergistic effect, transformation products and toxicity evaluation

Benzalkonium chlorides (BACs), as typical cationic surfactants and biocides widely applied in household and industrial products, have been frequently detected as micropollutants in many aquatic environments. In this study, the combination of UV irradiation and chlorine (UV/chlorine), a newly interested advanced oxidation process, was used to degrade dodecylbenzyldimethylammonium chloride (DDBAC). UV/chlorine showed synergistic effects on DDBAC degradation comparing to UV irradiation or chlorination alone. Radical quenching experiments indicated that degradation of DDBAC by UV/chlorine involved both UV photolysis and radical species oxidation, which accounted for 48.4% and 51.6%, respectively. Chlorine dosage and pH are essential parameters affecting the treatment efficiency of UV/chlorine. The pseudo first order rate constant (kobs, DDBAC) increased from 0.046 min−1 to 0.123 min−1 in response to chlorine dosage at 0–150 mg/L, and the degradation percentage of DDBAC within 12 min decreased from 81.4% to 56.6% at pH 3.6–9.5. Five main intermediates were identified and semi-quantified using HPLC-MS/MS and a possible degradation pathway was proposed. The degradation mechanisms of DDBAC by UV/chlorine included cleavage of the benzyl-nitrogen bond and hydrogen abstraction of the alkyl chain. Trichloromethane (TCM), chloral hydrate (CH), trichloropropanone (TCP), dichloropropanone (DCP) and dichloroacetonitrile (DCAN) were detected using GC-ECD. The formation of chlorinated products increased rapidly initially, then decreased (TCM, TCP, DCP and DCAN) or remained stable (CH) with extended treatment. The actual formation of TCM peaked at 30 min (50.3 μg/L), while other chlorinated products did not exceed 10 μg/L throughout the process. Based on the luminescent bacterial assay, DDBAC solution underwent almost complete detoxification subjected to UV/chlorine treatment for 120 min, which is more effective than UV irradiation or chlorination alone.

Determination of the interaction using FTIR within the components of GPE based on the synthesized grafted polymer

An oxyethylene chain (–CH2–CH2–O–) grafted polymer (P(MMA–MAh)–PEGME) was synthesized by reacting poly(ethylene glycol) monomethyl ether (PEGME) with the copolymer of poly(methyl metacrylate–maleic anhydride) (P(MMA–MAh)) and endcapping the residual carboxylic acid with methanol. Rectorite modified with dodecyl benzyl dimethyl ammonium chloride (OREC) was used as a filler additive to modify gel polymer electrolytes (GPE) that consisted of P(MMA–MAh)–PEGME used as polymer matrix, propylene carbonate (PC) as plasticizer and LiClO4 as lithium ion producer. Characterization of interaction of the polar group of C=O or C–O–C in PC and grafted polymer with Li+ and OH group on OREC surface has been thoroughly examined using Fourier transform infrared (FTIR), respectively. The quantitative analysis of FTIR shows that the absorptivity coefficients (a) of polymer/LiClO4, PC/LiClO4, PC/OREC and polymer/OREC are 0.705, 0.113, 0.430 and 0.500, respectively, which means that the Li+ or OH bonded polar group of C=O and C–O–C is more sensitive than free C=O and C–O–C in FTIR spectra. The limited values of bonded C=O and C–O–C equivalent fraction of polymer/LiClO4, PC/LiClO4, PC/OREC and polymer/OREC are 33%, 94%, 60% and 22%, respectively, which implies that the interaction within the components is reversible and the intensity of interaction is ordered as PC/LiClO4, PC/OREC, polymer/OREC and polymer/LiClO4.

Effect of Fatty Acid Chain of Tweens on the Micellar Behavior of Dodecylbenzyldimethylammonium Chloride

The present work is aimed at studying the interactions between mixed micelles of nonionic surfactants, Tweens (Tween 20, Tween 40, Tween 60, and Tween 80) and cationic surfactant, dodecylbenzyldimethylammonium chloride (C12BzCl), and to draw a comparison between the effect of different Tweens with respect to fatty acid chain present in them. Both from the industrial and research point of view, the present day need for newer materials has been diverted to surfactant-additive systems rather than single surfactant systems because of the great fundamental, technological, and biological importance associated with the mixed micelles. Moreover, Tweens being biocompatible, stable, and relatively nontoxic can be used to enhance the efficacy of benzalkonium (Bz)-based disinfection products. Conductivity and surface tension techniques have been employed to determine various micellar parameters like critical micellar concentration (cmc), degree of counterion binding (β), standard free energy of micellization (ΔGmico), excess free energy of mixing (ΔGexo), interaction parameter (βm) and activity coefficients for the Tweens (f1) and C12BzCl (f2) in the mixed micelles using Rubingh’s, Motomura’s, and Maeda’s approach. The negative values of βm indicate synergism in the mixtures which is highly beneficial as it reduces the total amount of surfactant used in a particular application resulting in reduction of cost and environmental impact. The results have also been discussed in terms of short-range interactions between the two types of surfactants.

Effects of Bentonite Modified by Organic Additives on the Physical Stability of Hexaconazole Suspension

Four kinds of quaternary ammonium salt cationic surfactants(dodecyl benzyl dimethyl ammonium chloride(1227),tetradecyl dimethyl benzyl ammonium(1427),hexadecyl trimethyl ammonium bromide(1631) and octadecyl trimethyl ammonium bromide(1831)) were used to modify sodium bentonite(Na-Ben).The prepared organic bentonites(1227-Ben,1427-Ben,1631-Ben,1831-Ben) were characterized by Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD),and used as subsidence-resistance for preparing suspensions containing 5% hexaconazole.The suspension capability of bentonite modified by above four organic additives in water and the effects of these bentonites on the physical stability of suspensions were examined.FT-IR spectra and XRD analysis results showed that these four cationic surfactants were intercalated into the layer of bentonite.Suspension capability results indicated that 1831-Ben has a better suspension than the other three.Subsidence-resistance tests showed that bentonites modified by organic additives could improve the physical stability of suspensions.The water segregation ratio of samples prepared by 1831-Ben was the lowest,while the viscosity,yield value and suspension rate were the highest.So 1831-Ben could be used as a suspension-additive for the preparation of suspensions containing 5% hexaconazole.

Altered ocular absorption and disposition of sodium cromoglycate upon ion-pair and complex coacervate formation with dodecylbenzyldimethylammonium chloride.

Ion-pair formation between the dianionic drug sodium cromoglycate and dodecylbenzyldimethylammonium chloride has been found to alter the extent and rate of corneal penetration of both large ions upon their coadministration. Additionally, using a complex coacervate of the two large ions as the applied dose form (in which the complex is in equilibrium with the ion pairs), a change in the overall disposition of both large ions to the various components of the eye is observed.

Determination of the interaction using FTIR within the composite gel polymer electrolyte

In the previous research, the gel polymer electrolyte (GPE) which consisted of poly(methyl methacrylate) (PMMA) matrix, propylene carbonate (PC), LiClO4 and OREC (Rectorite modified with dodecyl benzyl dimethyl ammonium chloride), achieved satisfactory properties. In the paper, the interaction between components was quantitatively determined. Characterization of interaction of CO in PC and PMMA with Li+ and OH group on OREC surface has been thoroughly examined using FTIR, respectively. The quantitative analysis of FTIR shows that the absorptivity coefficient a of PMMA/LiClO4, PC/LiClO4, PC/OREC and PMMA/OREC is 0.902, 0.113, 0.430 and 0.753, respectively, which means that the Li+ or OH bonded CO is more sensitive than the free CO in FTIR spectra. The limit value of bonded CO equivalent fraction of PMMA/LiClO4, PC/LiClO4, PC/OREC and PMMA/OREC is 17%, 94%, 57% and 20%, respectively, which implies that all the interaction within the components is reversible and the intensity of interaction is ordered as PC/LiClO4, PC/OREC, PMMA/OREC and PMMA/LiClO4.

Determination of quaternary ammonium compounds in seawater samples by solid-phase extraction and liquid chromatography–mass spectrometry

A method for the simultaneous determination of two biocidal quaternary ammonium compounds; didecyldimethylammonium chloride (didecyldimethyl quat) and dodecylbenzyldimethylammonium chloride (benzyl quat), in seawater by solid phase extraction (SPE) followed by liquid chromatography–mass spectrometry (LC–MS) was developed. The optimised procedure utilised off-line extraction of the analytes from seawater using polymeric (Strata-X) SPE cartridges. Recoveries ranged from 80 to 105%, with detection limits at the low parts-per-trillion (ng/l) level for both analytes. To demonstrate sensitivity, environmental concentrations were measured at three different locations along the North East coast of England with measured values in the range 120–270 ng/l.

Gel polymer electrolyte based on poly(methyl methacrylate-maleic anhydride)-poly(ethylene glycol) monomethyl ether and organophilic rectorite clay

AbstractA grafted polymer (P(MMA-MAh)-PEGME)) was synthesized by reacting poly(ethylene glycol) monomethyl ether (PEGME) with copolymer of poly(methyl methacrylate-maleic anhydride) (P(MMA-MAh)and end-capping the residual carboxylic acid with methanol. Natural rectorite (REC) was made organophilic by modification with the surfactant dodecyl benzyl dimethyl ammonium chloride. The organoclay was termed OREC and was used as a filler additive to modify gel polymer electrolytes (GPEs) which consisted of the grafted polymer (used as a polymer matrix), propylene carbonate (PC) as a plasticizer and LiClO4 as a lithium ion producer.The temperature dependence of the ionic conductivity of the GPEs agreed well with the VTF (Vogel-Tamman-Fulcher) relation. 5 phr doses of OREC resulted in the highest ionic conductivity. Using OREC also considerably improved the plasticizer retention levels. As a consequence of OREC occupation of the free volume space in the polymer matrix of GPEs, the bulk resistance of the GPEs was reduced and the glass transition temperature (Tg) increased. From the present research, it can be concluded that the incorporation of PEGME into the copolymer of P(MMA-MAh) produced a great improvement in ionic conductivity, plasticizer retention capability and movement of carrier charge of Li+.

Sorption of quaternary ammonium compounds to municipal sludge

The sorptive behavior of four quaternary ammonium compounds (QACs) – hexadecyl trimethyl ammonium chloride (C 16TMA), dodecyl trimethyl ammonium chloride (C 12TMA), hexadecyl benzyl dimethyl ammonium chloride (C 16BDMA), and dodecyl benzyl dimethyl ammonium chloride (C 12BDMA) – to municipal primary, waste activated, mesophilic digested, and thermophilic digested sludges was assessed at 22 °C. Batch adsorption of all four separately tested QACs to primary sludge reached equilibrium within 4 h. At a nominal, initial QAC concentration of 300 mg/L and a sludge volatile solids concentration of 1 g/L, the extent of adsorption was 13, 88, 67, and 89% for the C 12TMA, C 16TMA, C 12BDMA, and C 16BDMA, respectively, and correlated positively to the QAC hydrophobicity and negatively to their critical micelle concentration. Equilibrium partitioning data were described by the Freundlich isotherm model. The adsorption capacity of the four sludges was very similar. In binary QAC mixtures, QACs with relatively high adsorption affinity and at relatively high aqueous concentrations decreased the adsorption of QACs with a low adsorption affinity. At pH 7, about 40% of the sludge-C 12TMA desorbed, whereas less than 5% of the sludge-C 16BDMA desorbed in 10 days. The effect of pH was negligible on the desorption extent of C 12TMA at a pH range 4–10 over 10 days, whereas increasing the solution pH to 10 resulted in more than 50% desorption of C 16BDMA. Given the fact that approximately 50% of the municipal biosolids are land-applied in the US, the data of this study would help in the assessment of the fate of QACs and their potential effect on human and environmental health.

Effect of Sodium Alkanoates on Micellization of Dodecylbenzyldimethylammonium Chloride in Aqueous Medium

The present study deals with the interaction of sodium alkanoates viz. sodium acetate, sodium propionate, sodium butanoate, sodium hexanoate and sodium benzoate on the micellization of dodecylbenzyldimethylammonium chloride using conductometeric and flourscence quenching experiments carried out at 25°C. The analysis has been made through study of variation of critical micelle concentration (cmc), degree of counterion binding (β), aggregation number (N), and micropolarity with the concentration of these hydrophobic salts. The differentiation between the effects of hydrophobic and inorganic salts was made by comparing the above results with the influence of NaCl on cmc, β, and N.

Analysis of the interaction using FTIR within the components of OREC composite GPE based on the synthesized copolymer matrix of P(MMA-MAh)

Poly(methyl methacrylate-maleic anhydride) (P(MMA-MAh)) has been synthesized from methyl methacrylate (MMA) and maleic anhydride (MAh) monomers. The molar ratio of monomers was found to be 1MAh:8MMA. The molecular weight of copolymer was determined in the order 104 (g/mol).Rectorite modified with dodecyl benzyl dimethyl ammonium chloride (OREC) was used as a filler additive to modify gel polymer electrolytes (GPEs) which consisted of P(MMA-MAh) used as polymer matrix, propylene carbonate (PC) as a plasticizer and LiClO4 as lithium ion producer. Characterization of interaction of CO in PC and copolymer with Li+ and OH group on OREC surface has been thoroughly examined using FTIR. The quantitative analysis of FTIR shows that the absorptivity coefficient a of copolymer/LiClO4, PC/LiClO4, PC/OREC and copolymer/OREC is 0.756, 0.113, 0.430 and 0.602, respectively, which means that the Li+ or OH bonded CO is more sensitive than free CO in FTIR spectra. The limit value of bonded CO equivalent fraction of copolymer/LiClO4, PC/LiClO4, PC/OREC and copolymer/OREC is 55, 94, 57 and 26%, respectively, which implies that all the interaction within the components is reversible and the intensity of interaction is ordered as PC/LiClO4, PC/OREC, copolymer/OREC and copolymer/LiClO4.

Interactions in organic rectorite composite gel polymer electrolyte

AbstractRectorite (REC) was modified with dodecyl benzyl dimethyl ammonium chloride (1227) to form an organic-modified rectorite, termed OREC. The OREC was used as a filler additive to modify gel polymer electrolytes (GPEs) which consisted of polymethyl methacrylate (PMMA), propylene carbonate (PC) and LiClO4. Studies of ionic conductivity and viscosity of liquid electrolytes and pure PC, respectively, clearly showed that these properties are greatly influenced by temperature and the amount of OREC added; a consequence of the interactions between the components of CPEs. The Fourier transform infrared (FTIR) spectroscopy results indicated that there were two kinds of interaction: namely (1) a strong hydrogen bond between Si–OH and C=O of PC and (2) a weak interaction between Li+ and C=O. Inverse gas chromatography (IGC) research supported the FTIR interpretation, indicating that the two interactions exist and that the H bond is the stronger of the two. In CPEs, the polymer matrix of PMMA merely supports the active components and does not influence the interactions between them. The OREC greatly increased the crucial plasticizer maintenance property when the amount of clay added was optimum.

Adsorption of phenol with modified rectorite from aqueous solution

Abstract The natural rectorite (REC) was modified with surfactant of dodecyl benzyl dimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide and octadecyl trimethyl ammonium bromide, respectively, to form three kinds of organic-modified rectorite (OREC), termed OREC1, OREC2 and OREC3. Three kinds of ORECs were used as adsorbents for phenol in aqueous solution. Through FTIR and XRD analysis, it confirmed the cation exchange reaction between REC and surfactant. The amount of surfactant exchanged in OREC1, OREC2 and OREC3 were determined as 0.27, 0.51 and 0.62 mmol/g, respectively, through incineration method. Through the research of phenol adsorption, it was found that the removal percentage (%) of phenol increased with the increase in adsorbents dose, whereas the adsorption amount q e (mg/g) decreased. The adsorption efficiency of OREC adsorbents was greatly affected by the initial phenol solution pH value. The thermodynamics study of adsorption process showed that the adsorption of phenol with three adsorbents was carried out spontaneously, and that the process was exothermic in nature. The adsorption kinetic data of phenol with OREC adsorbents were well fitted to the Lagergren rate equation. The Freundlich isotherm model was employed and well represented in the experimental data.