Distribution Coefficient Values Research Articles

Synthesis and Characterization of a New Ion Exchange Cellulose -1- Butane Sulphonic Acid (CBSA) Resin and its Application for Removal of Hazardous Metal Ion (Pb2+) from Industrial Waste Water by Batch Method

Objective: The purpose of this work is to develop and evaluate a new cellulose-1-butane sulphonic acid resin and use it for the elimination of hazardous metallic ions from textile industry effluent. Method: In the laboratory, a new cellulose-based resin containing 1- Butane sulphonic acid group has been synthesized. 1-Butane sulphonic acid group has been introduced into cellulose matrix through modified Porath’s method. Findings: Development of cellulose-1-butane sulphonic acid resin based on natural polysaccharides for the removal of lead ions, a dangerous metal, from industrial wastewater. Cellulose -1-Butane sulphonic acid resin's adsorbed metal ions were efficiently eluted using varying strengths of HCl solution. The resin could then be washed with pure, acidic distilled water to restore it to its H+ cationic exchanger state ten times. The hazardous metal ion Pb2+ can be specifically extracted from industrial waste water using the cellulose-1-Butane Sulphonic Acid (CBSA) resin. Novelty: Ion exchange capacity, pH titration, FTIR spectra, elemental analysis, and moisture levels were used to characterize the CBSA resin. At various pH levels, the distribution coefficient value (Kd) of lead metal ions has been methodically investigated using the batch method. Keywords: Effluent, Distribution Coefficient, Resin, Waste Water, Polysaccharide

Impact of low molecular weight organic acids on heavy metal(loid) desorption in biochar-amended paddy soil.

Low molecular weight organic acids (LMWOAs) are important soil components and play a key role in regulating the geochemical behavior of heavy metal(loid)s. Biochar (BC) is a commonly used amendment that could change LMWOAs in soil. Here, four LMWOAs of oxalic acid (OA), tartaric acid (TA), malic acid (MA), and citric acid (CA) were evaluated for their roles in changing Cd and SB desorption behavior in contaminated soil with (S1-BC) or without BC (S1) produced from Paulownia biowaste. The results showed that OA, TA, MA, and CA reduced soil pH with rising concentrations, and biochar partially offset the pH reduction by LMWOAs. The LMWOAs reduced Cd desorption from the soil at low concentrations but increased Cd desorption at high concentrations, and CA was the most powerful in this regard. The LMWOAs had a similar effect on Sb desorption, and CA was the most effective species of LMWOAs. Adding BC to the soil affects Cd and Sb dynamics by reducing the Cd desorption but increasing Sb desorption from the soil and increasing the distribution coefficient (Kd) values of Cd but lowering the Kd values of Sb. This study helped understand the effects of LMWOAs on the geochemical behavior of Cd and Sb in the presence of biochar, as well as the potential risks of biochar amendment in enhancing Sb desorption from contaminated soil.

Remarkable enhancement in radio-cesium uptake from acidic feeds into an extraction chromatography resin containing a calix[4]arene-mono-crown-6 ligand

An extraction chromatography resin, prepared by the impregnation of bis-octyloxy-calix[4]arene-mono-crown-6 (BOCMC)onto an acrylic ester based polymeric support material, gave excellent uptake data for the removal of radio-cesium (Cs-137) from nitric acid feed solutions. The weight distribution coefficient (Kd) value of >300 obtained during the present study at 3 M HNO3 was the highest reported so far while using a calix-crown-6 based extraction chromatographic resin material. Analogous resin reported previously has yielded a Kd value <100 at comparable feed conditions. The sorbed metal ions could be efficiently desorbed with de-ionized water. Kinetic modeling of the uptake data indicated that both the film and the intra-particle diffusion mechanism are simultaneously operating in the sorption of Cs+ion onto the BOCMC resin. The metal ion sorption data were fitted to the sorption isotherm models and did not conform to the chemisorptions of physisorption models and indicated a pi-pi interaction between the benzene rings of the calix-crown-6 ligand and the Cs+ ion. The reusability of the resins was quite satisfactory after 5 cycles and the radiation stability of the resin material was very good upto an absorbed dose of 500 kGy. The results of column studies were quite encouraging with 15 mL (9 bed volumes) as the breakthrough volume while the elution was complete in about 12 bed volumes of de-ionized water.

Two Lactones Non-toxic to Humans Are Effective Repellents for the German Cockroach.

Lactones are cyclic esters of hydroxy carboxylic acids, present in several fruits and animals consumed by humans. There is evidence that some lactones modify insect behavior. The aim of the present study was to evaluate the repellent effect of four lactones (γ- and δ-nonalactone, and γ- and δ-dodecalactone) in first instar nymphs of the German cockroach, Blattella germanica (Linnaeus). To assess repellency, a nymph was placed on a circle of filter paper, half of which had been treated with lactone dissolved in acetone and the other half with acetone alone. The behavior of the nymph was recorded and the time the nymph spent in each half of the paper was quantified using Ethovision XT 10.1 software. Values of Distribution Coefficient (DC) were calculated: DC = (Tt - TA) / Tt, where Tt is the experimental time and TA is the time the nymph spent in the area treated with the repellent agent. DC can vary between 0 and 1. Values significantly higher than 0.5 indicate repellency. N,N-diethyl-meta-toluamide (DEET) was used as a positive control. DEET, δ- and γ-nonalactone caused repellency as from 77.9µg/cm2, whereas γ- and δ-dodecalactone had a repellent effect starting at 779.0µg/cm2. The values of DC for these concentrations were 0.89 (DEET), 0.86 (γ-nonalactone), 0.87 (δ-nonalactone), 0.83 (γ-dodecalactone), and 0.72 (δ-dodecalactone). To our knowledge, this is the first report of repellency produced by lactones in the German cockroach. This work allowed to identify two lactones that have a repellent effect similar to DEET.

Desorption and migration of dissolved organics from oil sands tailings to capped water: Demonstration pit lake

Rate and mechanism of organic compounds desorption from fluid fine tailings (FFT) deposits into the capped water are crucial to understand the geochemical stability of end pit lakes. Specifically, the intricate interplay between electrolyte concentrations and seasonal fluctuations along with their impact on the persistence of organic constituents remains insufficiently elucidated. This study utilized PASS-treated FFT (i.e., permanent aquatic structure storage) from Lake Miwasin to address these questions. Experiments were conducted to investigate the desorption of organics from FFT into lake water under different conditions, including FFT dosage, contact time, temperature, and ionic strength. Results revealed that higher FFT dosage and lake water organic matter led to increased desorption of dissolved organic carbon (DOC), while temperature and conductivity of the lake water had minimal effects. The presence of electrolytes regulated the equilibrium desorption capacity of DOC, with cations (K+ and Ca2+) significantly affecting the desorption process from negatively charged treated FFT particles. Temkin isotherms displayed that desorption dynamics followed physically favorable patterns whereas the Intraparticle diffusion kinetic model suggested the equilibrium desorption capacity of DOC as 0.65 mg/g of PASS-treated FFT. A small percentage (5.82 %) of the DOC and less than half of naphthenic acids (NAs) (39.1 %) in PASS-treated FFT were potentially released. The distribution coefficient value of DOC and NAs was comparably high, indicating that DOC and NAs were mostly stable within the PASS-treated FFT deposition. The study reflects considerable stability of PASS-treated FFT about the physical and chemical conditions of the lake water, making them a promising alternative in FFT management.

ZIF-8 Used for the Selective Recovery of Heavy Rare Earth Elements from Mining Wastewater.

In this study, a sample of 2-methylimidazole zinc salt (ZIF-8) demonstrated high selectivity for the recovery of heavy rare earth elements (REEs) from real rare earth mining wastewater. Results show that the distribution coefficient values of Y3+ (4.02 × 104 mL·g-1), Gd3+ (7.8 × 104 mL·g-1), and Dy3+ (6.8 × 104 mL·g-1) are orders of magnitude higher than those of K+ (359.51 mL·g-1), Mn2+ (266.67 mL·g-1), Ca2+ (396.42 mL·g-1), and Mg2+ (239.48 mL·g-1). Moreover, the desorption efficiency of heavy REEs exceeded 40%. Advanced characterizations and density functional theory (DFT) calculations were utilized to elucidate that the heavy REEs were more likely to bind to the nitrogen atoms of imidazole groups on ZIF-8 compared to non-REEs. Furthermore, the adsorption and desorption of heavy REEs primarily depend on the chemical interaction confirmed by adsorption kinetics, isotherm model, and thermodynamic analysis, which involves the dissociation of water and the formation of REE-O bonds. Finally, the ZIF-8 exhibits a remarkable recovery efficiency of over 40% for heavy REEs in column tests conducted over 7h. The findings reported here provide new insights into the selective recovery of heavy REEs from real mining wastewater.

Optimizing a radiochemical separation of 26Al from an acidic V-rich matrix

Sorption and desorption of Al(III) on a series of different extraction resins (LN, LN2, LN3, TK100, TK101, TK201) in acidic HNO3 media containing high concentrations of V(IV,V) was investigated. Static batch studies were conducted as a way of obtaining preliminary distribution coefficient (Kd) values that were further used to develop dynamic tests on real samples. It was shown that a complete separation and recovery of Al(III) from V(V) under acidic conditions (pH = 2) is possible by utilizing LN resin. Active “hot” dynamic studies with 26Al (≈10 Bq) as a radiotracer and real waste samples were conducted to further investigate and confirm the results of the inactive “cold” experiments. Utilizing this separation procedure, we have successfully removed all traces of 26Al (∼10−9 g) radiotracer from the bulk vanadium matrix.

Experiment and microscopic analysis for the separation of isopropanol‐water using hydrophobic deep eutectic solvents

AbstractIn this study, a method for separating isopropanol from wastewater using hydrophobic deep eutectic solvents (DESs) synthesized from terpenes and capric acid was proposed. The distribution coefficient and selectivity value of isopropanol (IPA) in the solvents were determined by liquid–liquid extraction experiments, and the extraction performances of the solvents at different molar ratios and temperatures were studied. From the perspective of molecular dynamics simulations, the experimental results were verified by mechanism analysis, the contribution of hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs) to the selective separation of isopropanol was explained. The interaction energies, radial distribution functions, normal density distribution, and mean square deviations between the atoms were used to analyze the interactions between the components of the DESs and IPA/water. It was observed that the DESs have a good extraction effect on IPA, which verifies the good application prospects of DESs in wastewater solutions containing alcohol compounds.

Maximizing methyl red dye removal efficiency: a targeted parameter approach

AbstractBACKGROUNDLiquid–liquid extraction plays a crucial role in the chemical industry for obtaining valuable products. This research focuses on optimizing key parameters, namely dye removal percentage, solvent capacity and distribution coefficient, in the liquid–liquid extraction of methyl red dye from its aqueous solution using benzene as the extractant. The study investigates the influence of key variables, including feed dye concentration (20–100) ppm, extraction time (10–30) min and dye solution‐to‐solvent ratio (1–3) mL mL−1. The experiments are conducted at a constant pH of 3 and controlled temperatures of 27 ± 2 °C.RESULTSBy strategically controlling various parameters, this investigation aims to achieve superior outcomes, surpassing prior achievements in similar experimental conditions. Utilizing the Box–Behnken design for optimization, the research attains a remarkable recovery efficiency of 84.61%. The achieved optimal values for dye removal, distribution coefficient and solvent capacity are (84.61 ± 5.07)%, 5.22 ± 0.31 and (5.17 ± 0.94) ppm, respectively, at a feed dye concentration of 20 ppm, an extraction time of 27.994 min and a dye solution‐to‐solvent ratio of 3 mL mL−1.CONCLUSIONThese findings underscore the potential for maximizing methyl red dye extraction efficiency and surpass previously reported efficiency levels using the presented parameters with the same input data. The study contributes to advancements in liquid–liquid extraction technology and provides a deeper understanding of the optimization process with technical precision. © 2024 Society of Chemical Industry (SCI).

Research on military-civilian collaborative innovation of science and technology based on a stochastic differential game model.

The construction of an integrated national strategic system and capability is an essential goal of implementing the strategy of military-civilian integration in the contemporary era. And the collaborative innovation of military-civilian S&T is an inevitable choice to achieve this goal. Due to the dynamic, complex, and stochastic characteristics of military-civilian S&T collaborative innovation, the level of S&T innovation is highly volatile. This paper takes the internal and external stochastic disturbance factors of military-civilian S&T collaborative innovation as the perspective, studies the strategy selection problem of military-civilian S&T collaborative innovation under military domination, constructs a differential game model to explore the innovation strategies under the non-cooperative model without military subsidies, the non-cooperative model with military subsidies, and the collaborative model. Finally, we use numerical experiments to verify the validity of the conclusions. The study shows that: (1) Within a reasonable range of values of the benefit distribution coefficient, the system can achieve the Pareto optimum, and the collaborative model is conducive to improving the S&T innovation level and the optimum benefit level of the system. (2) Military subsidies can increase the benefits of the system and the parties involved to achieve Pareto improvement. (3) The level of S&T innovation under the collaborative model has dynamic evolutionary characteristics of maximum expectation and variance. As the intensity of disturbance increases, the stability of the system may be destroyed. Risk-averse civil enterprises prefer the cooperative mode, whereas risk-averse civil enterprises prefer the non-cooperative model.

Effective Biosorption of Cesium and Strontium Ions from Aqueous Solutions Using Silica Loaded with Aspergillus brasiliensis

In this study, the batch technique was used for the sorption of Sr(II) and Cs(I) onto silica loaded with Aspergillus brasiliensis (AB@S). The precipitation technique was used to synthesize the AB@S bio-sorbent, which was then evaluated using several analytical instruments such as XRD, FT-IR, and SEM. The results of this investigation revealed that the sorption process had a short equilibrium time (40 min). The distribution coefficient values have a sequence order Sr(II) ˃ Cs(I). AB@S sorbent has saturation capacity for Sr(II) and Cs(I) 72.2 and 26.1 mg g−1, respectively. The reaction kinetics follow the pseudo-second-order model with capacity values of 5.01 and 3.53 mg g−1 for Sr(II) and Cs(I), respectively. Applicability of Langmuir isotherms has capacity values of 66.3 and 23.38 mg g−1 for Sr(II) and Cs(I), respectively. Thermodynamics data are endothermic and spontaneous. The AB@S is a promising bio-sorbent for the removal of 85Sr and 134Cs from simulated radioactive waste (SRW). The investigation proved that the AB@S is suitable to adsorb Sr(II) and Cs(I) from aqueous solutions and could be considered potential material for the purification of effluent contaminated with these ions.

Impact of aquatic habitat environment on the elemental composition and shell shape variability of the Beringian freshwater mussel Beringiana beringiana (Bivalvia, Unionidae)

Concentrations of the chemical elements were analyzed in the shells of a bivalve mollusk species (Beringiana beringiana), water, and bottom sediments from seven lakes located on the Kamchatka Peninsula, the Kurile Islands, Sakhalin Island, and Primorsky Krai (Northeast Asia). A principal component analysis allowed to determine three factors those were related to environments in the waterbodies. We revealed two groups of samples corresponding to large geographical regions using the determined factors. Statistically significant differences were found between geographical groups of samples, and higher values of element distribution coefficients were determined for samples from lakes on the Kamchatka Peninsula. The highest concentrations of lithophilic elements were measured in the shells from Lake Kurazhechnoye (Kamchatka Peninsula). The highest concentrations of Al and Mg were detected in shells from Lake Peschanoye (Kunashir Island). In Lake Chernoye (Sakhalin Island), the highest concentrations of Sr and Sb in the shells were detected. Zn, Fe, Pb, and rare earth elements were present in large concentrations in the shells from Lake Vaskovskoye, Primorsky Krai. The shells of the Beringian freshwater mussel show large phenotypic plasticity, and their shape demonstrates significant relationships with various environmental parameters, that were assessed based on the geochemical indicators.

Impact of anaerobic zone on biodegradation of micropollutants: Comparison of micropollutants’ removal efficiencies in lab-scale anaerobic bioreactor and in full-scale anaerobic zone

To predict the fate of micropollutants (MPs) in the anaerobic zone at the lab and full-scale levels, anaerobically biological removal (adsorption and biodegradation) of 40 MPs was performed. Among the 40 MPs in the full-scale anaerobic tank, estriol and acetaminophen showed the highest total removal efficiencies in the anaerobic zone (∼100 %). In batch tests, five MPs belonging to estrogens (estriol and 17b-estradiol), parabens (ethyl paraben and propyl paraben), and iopromide were completely removed within 12 h. Meanwhile, MPs belonging to perfluorinated compounds and nitrosamines were infrequently removed (<20 %) within 12 h. The obtained solid-water distribution coefficient (Kd) and biodegradation rate constants (Kbiol) values were used for predictive modeling of residual MPs’ concentrations in the full-scale anaerobic zone and were compared with Kbiol obtained from the oxic zone. Most MPs had similar Kbiol values regardless of redox conditions (oxic or anaerobic); however, caffeine, ibuprofen, naproxen, trimethoprim, and iopromide showed different values depending on the redox conditions. Differences in the efficiencies of total MP’ removal were noted between that predicted via modeling and actually observed (-37 % [iopromide] to 49 % [caffeine]) under altered conditions such as levels of dissolved oxygen (DO) and introduction of the primary or returned sludge. This implies that strictly anaerobic conditions are required for the degradation of specific MPs. The Kd and Kbiol values obtained in this study could help predict changes in the concentration of MPs in the anaerobic zone.

Determination of transport parameters of soils around Solt

A complex labor investigation was performed to determine the adsorption properties of soils around Solt. After collection of samples firstly the soil type was determined as a pre-information of adsorption tests. Two type of test were performed to know the adsorption performance of soils: batch test and breakthrough curve test. In both investigation two type of soil (SD, SV) and two type of heavy metals were investigated. In batch test the Langmuir and the Freundlich isotherms were used to determine the adsorption constants. According to our results the fitting of Freundlich isotherm was better for both soil, and the adsorption of Mn (Kf,SD=2.28, Kf,SV=1.74) was more intensive than Zn (Kf,SD=1.27, Kf,SV=0.84). After performance of static adsorption test, dynamic adsorption test, breakthrough curve test was also performed. The characteristic of adsorption was the same like in case of batch test. The value of distribution coefficient was higher in case of soil SD, and the adsorption was more intensive for Mn.

Removal of Low-Content Impurities from Pure Al by Supergravity Combined with Semi-Solid Method

Recently, the purification technology for high-purity aluminum (Al) has become the focus and difficulty of the majority of researchers. In this study, a novel approach for removing iron (Fe) impurities from pure Al via combining the supergravity field and semi-solid refining was proposed. Various separation temperatures (T), holding times (th), and separation times (ts) were applied within a gravitational field to explore their impact on the purification process and its underlying mechanisms. The optimal conditions were achieved at T = 653 °C, th = 40 min, ts = 3 min, and a gravity coefficient G = 1000, with the loss rate of purified Al reaching up to 4.1% and the removal rate of Fe reaching 81.9%. The Fe content in pure Al was reduced from 0.32 wt.% to 0.06 wt.%. Moreover, the purified mechanism of supergravity in a semi-solid method was reported for the first time. It was concluded that supergravity could decrease the value of the effective distribution coefficient (ke), thereby promoting the continuous migration of Fe impurities at the solidification interface into the liquid phase. The Fe-rich phase in the Al melt was completely filtered to the lower part of the crucible in the supergravity field, completing the further purification of the pure Al.

Effects of dissolved organic carbon on potentially toxic element desorption in stormwater bioretention systems

Stormwater runoff contains dissolved organic carbon (DOC) and potentially toxic elements (PTEs). Interactions between DOC and PTEs can impact PTE speciation and mobility, but are not fully understood. Soil samples were collected from a vegetated bioretention bed to investigate the effects of DOC (0, 15, and 50 mg-C/L) on the desorption of 10 PTEs captured by the soil media: Mn, Fe, Co, Cu, Zn, As, Cd, Sn, Sb, and Pb. In the absence of DOC, the desorbed PTE concentration from bioretention media into the aqueous phase ranking was as follows: Fe > Mn ∼ Zn > Cu > Pb > Sb > As > Co > Sn ∼ Cd. Increased DOC concentrations resulted in a reduction of the soil-water distribution coefficient (Kd) values. The greatest shift in Kd was observed for Cu and lowest for Sb. The PTE sorption capacities were lower for surficial soil samples (lower Kd) compared to the deep soil samples. Overall, the desorbed PTE (average midchannel 55.7 μg/g) fraction accounted for <1.1 % of the total extracted PTEs (5364 μg/g), and while this is a small percentage of the total, this is the fraction that is mobile. The extracted PTE fractions revealed that DOC reduced the organic matter-bound and carbonate-bound fractions. The PTE desorption trends suggest that reducing DOC in stormwater runoff could be an effective measure to mitigate the release of PTEs into the environment.

Surface structure regulating of silica adsorbent for the selective adsorption of heavy rare earth

Rare earth element (REE) is a strategic metal resource, heavy REE owns higher economic and strategic value compared with light rare earth elements. However, it is a great challenge for the separation of heavy rare earth ion efficiently in the solution with mixed rare earth ions due to the similar physicochemical properties of heavy and light REE. In this paper, the diglycolamide (DGA) modified silica adsorbents were prepared and applied to the selective adsorption of heavy earth ion Dy3+. The structure of DGA on the silica surface was regulated during the modifying processes to obtain DGAb-SiO2 and DGAs-SiO2 adsorbent, which was verified by FTIR and NMR characterization results. The adsorption results showed that the DGAb-SiO2 adsorbent owned a much higher distribution coefficient (Kd) value for the selective adsorption of Dy3+ than the DGAs-SiO2 adsorbent. The higher adsorption selectivity is likely due to the fixed carbon chain of the DGA group on the surface of DGAb-SiO2 adsorbent formed rigid spatial structures of the oxygen atoms, which will be favorable for the selective coordination of Dy3+. Besides its effectiveness in adsorption behavior, the DGAb-SiO2 adsorbent displayed excellent stability. The Kd value of DGAb-SiO2 for Dy3+ selective adsorption maintained a high level after four successive recycling runs. The adsorption kinetics results displayed that the adsorption of Dy3+ followed pseudo-second-order kinetic, and the adsorption process fitted the Langmuir isotherm model. Additionally, the same adsorption rules for the rare earth ions were observed over DGA-KIT-6 adsorbent, indicating the high universality of the surface modification to the adsorbent support, which will provide an intentional reference for the surface modification to other adsorbent support.

Triflimide Effect in Solvent Extraction of Rare-Earth Elements from Nitric Acid Solutions by TODGA

ABSTRACT Outer-sphere interactions play an important role in the liquid-liquid extraction and separation of metal ions and they could be used to tune the efficiency and selectivity of recovery. Here, we report the extraction behaviour and separation of trivalent rare-earth elements from aqueous nitric acid solutions with N,N,N’,N’-tetra-n-octyl diglycolamide (TODGA), which was preliminarily contacted with an aqueous solution of N-H acid bis[(trifluoromethyl)sulfonyl]imide (triflimide, HTf2N; Tf = CF3SO2) resulting in an adduct TODGA⋅HTf2N. We examined in detail the extraction system composed of TODGA acidified with HTf2N and 1,2-dichloroethane as diluent. The effect of various experimental conditions such as the nature of diluent, aqueous nitric acid concentration, and TODGA⋅HTf2N concentration in the organic phase was studied. It has been found that the distribution coefficient values for metal ions are much greater, especially at low aqueous acidity in the extraction systems with the acidified organic solvent phase. Furthermore, the heavier lanthanides were effectively extracted and the intergroup lanthanide selectivity was greatly improved (separation factors for the Lu/La pair increased by 40 and 2 times for the two systems under study, respectively).

Target recognition and preferential degradation of toxic chemical groups by innovative group-imprinted photocatalyst with footprint cavity

Target recognition and preferential degradation of toxic chemical groups remain critical challenges in photocatalytic degradation of organic contaminant. In this study, the concept of group-imprinting was first proposed, and group-imprinted copolymers of aniline and pyrrole were grafted from the surface of magnetic CuFeO2@MnO2 nanocomposites (MIP-CuFeO2@MnO2) using acrylamide as dummy templates for imprinting the amide group of tetracycline for the first attempt, and the molar ratios of dummy template molecule to functional monomer was optimized. The magnetic MIP-CuFeO2@MnO2 showed high adsorption capacity and good recognition for tetracycline. In mixture solution of tetracycline and ibuprofen, the distribution coefficient (kd) value of MIP-CuFeO2@MnO2 for tetracycline was 0.308 L/g, which is 6.86 times more than for ibuprofen (only 0.045 L/g). The selection factor (α) of MIP-CuFeO2@MnO2 is about 3.2 times that of non-imprinted counterpart, indicating that the imprinting cavities in copolymer layer which match with the amide groups of tetracycline can selectively recognize and adsorb tetracycline. More importantly, MIP-CuFeO2@MnO2 exhibited preferential degradation performance for amide groups, which was confirmed by the intermediates and degradation pathway. The E. coli growth suggests effective toxicity reduction of tetracycline due to the preferential degradation of amide groups by photocatalysis of MIP-CuFeO2@MnO2.

Separation of furfuryl alcohol from water using hydrophobic deep eutectic solvents

Furfuryl alcohol (FA) is an important organic chemical feedstock that must be separated from water to upgrade it into high-value-added products. Since FA forms an azeotrope with water, liquid-liquid extraction is a suitable option for separating both compounds. This work evaluates the separation of FA from water using hydrophobic deep eutectic solvents (DES). Three DES were prepared using menthol, thymol, and octanoic acid by combining them in molar ratio as follows: thymol + octanoic acid (1:2), menthol + octanoic acid (1:2), and thymol + menthol (1:1). Experimental liquid-liquid equilibria (LLE) of ternary systems water + FA + DES measured at 313.15 K and 101.13 kPa were used to determine the distribution coefficient and selectivity values for FA when using each DES. The experimental results were compared with molecular dynamics (MD) using Martini 3 force field and modeled using Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) without any adjustable binary parameters. According to the results, selectivities and distribution coefficients using hydrophobic DES have comparable values to traditional volatile organic compounds (VOCs) used to separate FA from water. In general, DES shows better distribution coefficients compared with typical organic solvents. According to the results, a good alternative would be menthol + octanoic acid (1:2) or thymol + menthol (1:1) to replace typical VOCs. MD and PC-SAFT provide accurate estimations for ternary LLE in the range of examined thermodynamic conditions, which confirms the predictive consistency of both approaches. Microscopic properties computed with MD simulations evidence a surface activity or absolute adsorption of FA in the interfacial region, which is correlated with favorable distribution coefficients and selectivities.