Project description:Due to large drug consumption, pharmaceutically active compounds (PhACs) can be found as water contaminants. The removal of PhACs is a significant issue, as they can easily overtake traditional purification methods. Because of their surface properties, carbon nanomaterials are among the most efficient materials able to adsorb PhACs. However, their limitation is their recovery after use and their possible leakage into the aquatic system. Consequently, new hybrid supramolecular ionic liquid gels (HILGs) have been designed for the adsorption of some antibiotic drugs (ciprofloxacin and nalidixic acid) from water. The chemical-physical properties of gels, such as the temperature of the gel-sol transition, morphology, and rheology, have been studied for their use as sorbents. These properties influence the gel removal efficiency of PhAC, i.e., the best system is the gel that presents weaker colloidal forces. A fast removal (RE = 51%) is obtained in 3 h for ciprofloxacin, while a slower adsorption process is observed for nalidixic acid (RE = 88% in 24 h). HILGs can be recycled up to seven cycles and regenerated. In addition, they can be used with higher concentrations or volumes of PhAC and in a realistic apparatus like dialysis membranes. These peculiarities suggest that HILGs can be competitive with more complex sorbent systems.
Project description:Reported herein is an entrapment method for enzyme immobilization that does not require the formation of new covalent bonds. Ionic liquid supramolecular gels are formed containing enzymes that can be shaped into gel beads and act as recyclable immobilized biocatalysts. The gel was formed from two components, a hydrophobic phosphonium ionic liquid and a low molecular weight gelator derived from the amino acid phenylalanine. Gel-entrapped lipase from Aneurinibacillus thermoaerophilus was recycled for 10 runs over 3 days without loss of activity and retained activity for at least 150 days. The procedure does not form covalent bonds upon gel formation, which is supramolecular, and no bonds are formed between the enzyme and the solid support.
Project description:Syndiotactic polystyrene (SPS) physical gels containing a large amount of the ionic liquid 1-butylpyridinium bromide ([C4py]Br) were systematically prepared and their physical properties were examined in detail. The gels had stable forms for a long time, having storage elastic modulus values of normal gels. They showed nearly the same values of the electrical conductivity (∼7 mS/cm) as those of the mixed solutions of [C4py]Br, suggesting that the distribution of [C4py]Br was uniform in these gels and that the charge transportation in these SPS gels was not interrupted by a three-dimensional network of SPS fibrils consisting of the SPS δ crystalline phases.
Project description:Endocrine-disrupting chemicals (EDC) are a wide group of chemicals that interfere with the endocrine system. Their similarity to natural steroid hormones makes them able to attach to hormone receptors, thereby causing unfavorable health effects. Among EDC, bisphenol A (BPA), bisphenol S (BPS), and nonylphenol (NP) seem to be particularly harmful. As the industry is experiencing rapid expansion, BPA, BPS, and NP are being produced in growing amounts, generating considerable environmental pollution. White rot fungi (WRF) are an economical, ecologically friendly, and socially acceptable way to remove EDC contamination from ecosystems. WRF secrete extracellular ligninolytic enzymes such as laccase, manganese peroxidase, lignin peroxidase, and versatile peroxidase, involved in lignin deterioration. Owing to the broad substrate specificity of these enzymes, they are able to remove numerous xenobiotics, including EDC. Therefore, WRF seem to be a promising tool in the abovementioned EDC elimination during wastewater treatment processes. Here, we review WRF application for this EDC removal from wastewater and indicate several strengths and limitations of such methods.
Project description:A cationic poly(ionic liquid) (PIL) with pendent butyl imidazolium cations and free bis(trifluoromethylsulfonyl)imide (TFSI) anions and an anionic PIL with pendent TFSI anions and free 1-butyl-3-methylimidazolium cations are synthesized by postpolymerization chemical modification and reversible addition-fragmentation chain-transfer radical copolymerization, respectively. Upon mixing solutions of these two PILs in acetone with stoichiometric amounts of ion pairs, ionic exchanges induce coacervation and, after solvent evaporation, lead to the formation of a dynamic ion gel (DIG) and the concomitant release of free [1-methyl-3-butyl imidazolium]TFSI ionic liquid (IL). A comparison of thermal (Tg), ion conducting (σDC), and viscoelastic (elastic moduli (G')) properties for DIGs and their parent polyelectrolytes, as well as extracted and IL-doped DIGs, demonstrates the formation of ionic cross-links and the ability to easily produce polymer electrolytes with enhanced ionic conductivity (σDC up to 4.5 × 10-5 S cm-1 at 30 °C) and higher elastic moduli (G' up to 4 kPa at 25 °C and 1 rad s-1), making them highly desirable in many electrochemical applications, including supercapacitors, soft robotics, electrochromic devices, sensors, and solar cells.
Project description:The removal of TcO4 - from aqueous solutions has attracted more and more attention recently, and ReO4 - has been widely used as its natural analog. In this work, polymeric ionic liquid gel adsorbents, PC2-C12vimBr, with high adsorption capacity and selectivity towards ReO4 - were synthesized by radiation-induced polymerization and crosslinking. PC2-C12vimBr was composed of two monomers: a hydrophobic unit, 1-vinyl-3-dodecylimidazolium bromide for high selectivity, and a hydrophilic unit, 1-vinyl-3-ethylimidazolium bromide for improved kinetics. A gel fraction up to 90% could be achieved under 40 kGy with varied monomer ratios. The adsorption of PC2-C12vimBr gels for ReO4 - was evaluated by batch adsorption. The PC2-C12vimBr gel containing 20 mol% hydrophilic unit (named PC2-C12vimBr-A) could significantly improve the adsorption kinetics, which had an equilibrium time of ca. 24 h. The adsorption capacity obtained from the Langmuir model was 559 mg g-1 (Re/gel). The selective factor against NO3 - was 33.4 ± 1.9, which was more than 10 times higher than that of PC2vimBr, and it could maintain ReO4 - uptake as high as 100 mg g-1 in 0.5 mol kg-1 HNO3. The ΔHΘ and ΔSΘ of the NO3 -/ReO4 - ion-exchange reaction of PC2-C12vimNO3-A were -16.9 kJ mol-1 and 29 J mol-1 K-1, respectively, indicating physical adsorption. The adsorption mechanism of ReO4 - onto PC2-C12vimBr-A gel was ion-exchange, and it could be recovered using 5.4 mol kg-1 HNO3.
Project description:Filtration is an established water-purification technology. However, due to low flow rates, the filtration of large volumes of water is often not practical. Herein, we report an alternative purification approach in which a magnetic nanoparticle composite is used to remove organic, inorganic, microbial, and microplastics pollutants from water. The composite is based on a polyoxometalate ionic liquid (POM-IL) adsorbed onto magnetic microporous core-shell Fe2 O3 /SiO2 particles, giving a magnetic POM-supported ionic liquid phase (magPOM-SILP). Efficient, often quantitative removal of several typical surface water pollutants is reported together with facile removal of the particles using a permanent magnet. Tuning of the composite components could lead to new materials for centralized and decentralized water purification systems.
Project description:In the current era of human life, we have been facing an increased consumption of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). Nevertheless, NSAIDs are not completely metabolized by humans and are further excreted into domestical effluents. Several studies have been showing that a wide variety of pharmaceuticals are present in water effluents and are thus a matter of serious concern in the public health. Although treatment plants use sophisticated technologies for pollutants/contaminants removal, none of these processes was particularly designed for NSAIDs. In this perspective, this work addresses the use of a liquid-liquid extraction approach, employing ionic liquids (ILs), for the removal of NSAIDs from aqueous media. In particular, aqueous biphasic systems (ABS) composed of ILs and aluminium-based salts, which are already used in water treatment plants, were tested for the removal of diclofenac, ibuprofen, naproxen and ketoprofen. With these systems, extraction efficiencies of NSAIDs up to 100% were obtained in a single-step. The recovery of NSAIDs from the IL medium and the recyclability of the IL-rich phase were then ascertained to guarantee the development of a more sustainable and cost-effective strategy. Based on the remarkable increase in the solubility of NSAIDs in the IL-rich phase (from a 300- to a 4100-fold when compared with pure water), water was then studied as an effective anti-solvent, and where single-step recovery percentages of NSAIDs from the IL-rich phase up to 91% were obtained. After the "cleaning" of the IL-rich phase by the induced precipitation of NSAIDs, the phase-forming components were recovered and reused in four consecutive cycles, with no detected losses on both the extraction efficiency and recovery of NSAIDs by induced precipitation. Finally, an integrated process is here proposed, which comprises the (i) removal of NSAIDs from aqueous media, (ii) the cleaning of the IL-rich phase by the recovery of NSAIDs by induced precipitation, and (iii) the phase-forming components recycling and reuse, aiming at unlocking new doors for alternative treatment strategies of aqueous environments.
Project description:A large amount of industrial wastewater containing pollutants including toxic dyes needs to be processed prior to its discharge into the environment. Biological materials such as sugarcane bagasse (SB) have been reported for their role as adsorbents to remove the dyes from water. In this study, the residue SB after fermentation was utilized for the dye removal. A combined pretreatment of NaOH and methyltrioctylammonium chloride was given to SB for lignin removal, and the pretreated SB was utilized for cellulase production from Bacillus aestuarii UE25. The strain produced 118 IU mL-1 of endoglucanse and 70 IU mL-1 of β-glucosidase. Scanning electron microscopy and FTIR spectra showed lignin and cellulose removal in fermented SB. This residue was utilized for the adsorption of an azo dye, congo red (CR). The thermodynamic, isotherm and kinetics studies for the adsorption of CR revealed distinct adsorption features of SB. Untreated SB followed Langmuir isotherm, whereas pretreated SB and fermented SB obeyed the Freundlich isotherm model. The pseudo-second-order model fitted well for the studied adsorbents. The results of thermodynamic studies revealed spontaneous adsorption with negative standard free energy values. Untreated SB showed a 90.36% removal tendency at 303.15 K temperature, whereas the adsorbents comprised of pretreated and fermented SB removed about 98.35% and 97.70%, respectively. The study provided a strategy to utilize SB for cellulase production and its use as an adsorbent for toxic dyes removal.
Project description:This study synthesized a highly efficient KOH-treated sunflower stem activated carbon (KOH-SSAC) using a two-step pyrolysis process and chemical activation using KOH. The resulting material exhibited exceptional properties, such as a high specific surface area (452 m2/g) and excellent adsorption capacities for phenol (333.03 mg/g) and bisphenol A (BPA) (365.81 mg/g). The adsorption process was spontaneous and exothermic, benefiting from the synergistic effects of hydrogen bonding, electrostatic attraction, and stacking interactions. Comparative analysis also showed that KOH-SSAC performed approximately twice as well as sunflower stem biochar (SSB), indicating its potential for water treatment and pollutant removal applications. The study suggests the exploration of optimization strategies to further enhance the efficiency of KOH-SSAC in large-scale scenarios. These findings contribute to the development of improved materials for efficient water treatment and pollution control.