Rapid Removal Research Articles

Unrefined and Milled Ilmenite as a Cost-Effective Photocatalyst for UV-Assisted Destruction and Mineralization of PFAS.

Per- and polyfluoroalkyl substances (PFAS) are fluorinated and refractory pollutants that are ubiquitous in industrial wastewater. Photocatalytic destruction of such pollutants with catalysts such as TiO2 and ZnO is an attractive avenue for removal of PFAS, but refined forms of such photocatalysts are expensive. This study, for the first time, utilized milled unrefined raw mineral ilmenite, coupled to UV-C irradiation to achieve mineralization of the two model PFAS compounds perfluorooctanoic acid (PFOA) and perfluoro octane sulfonic acid (PFOS). Results obtained using a bench-scale photocatalytic reactor system demonstrated rapid removal kinetics of PFAS compounds (>90% removal in less than 10 h) in environmentally-relevant concentrations (200-1000 ppb). Raw ilmenite was reused over three consecutive degradation cycles of PFAS, retaining >80% removal efficiency. Analysis of degradation products indicated defluorination and the presence of shorter-chain PFAS intermediates in the initial samples. End samples indicated the disappearance of short-chain PFAS intermediates and further accumulation of fluoride ions, suggesting that original PFAS compounds underwent mineralization due to an oxygen-radical-based photocatalytic destruction mechanism induced by TiO2 present in ilmenite and UV irradiation. The outcome of this study implies that raw ilmenite coupled to UV-C is suitable for cost-effective reactor operation and efficient photocatalytic destruction of PFAS compounds.

Electrospun nanofibrous membranes based on fluorine-free polyimide for swift oil spill cleanup and emulsion separation

The urgent need to mitigate environmental damage caused by oil and organic pollutants in oil production industries and spill accidents necessitates effective removal methods. This study introduces novel nanofibrous membranes composed of fluorine-free polyimide, which was formed by electrospinning of BPADA-TrMPD, produced by polycondensation reaction in one-step and at high temperature using 4,4′-(4,4′-isopropylidenediphenoxy)bis-(phthalic anhydride) (BPADA) and 2,4,6-trimethyl-m-phenylenediamine (TrMPD). The resulting membranes exhibited a hydrophobic nature with a water contact angle of 114° and an oil contact angle of ∼ 0°. The adsorption performance of the nanofibers was explored using Saudi crude oil and non-polar organic solvents (i.e., n-hexane and dodecane). The developed membranes exhibited a crude oil uptake ranging from 35 to 60 g g−1 and demonstrated rapid removal capabilities, reaching equilibrium sorption capacity within a few minutes for crude oil. Moreover, these membranes displayed remarkable flux of 1991, 1508, and 206 L m−2h−1 for dodecane, n-hexane, and crude oil, respectively. The capability of the fluorine-free mats designed for oil spill cleanup was validated through its application in treating actual samples. The durability and recyclability of the membranes were showcased by regenerating them through mechanical treatment.

Performance of flexible CeO2 composite abrasive in force rheological polishing of fused silica glass

Polishing is critical for obtaining high-quality surfaces on fused silica glass components, which are used extensively in numerous civil and military applications. The abrasive used in conventional polishing processes is typically on the microscale or nanoscale. This study prepared a millimeter-scale flexible composite abrasive consisting of a natural rubber (NR) core coated with CeO2 for use in force rheological polishing (FRP), aiming to improve efficiency and material removal selectivity without compromising surface quality. An analysis of the synthesized abrasive indicated that the CeO2 exhibited excellent adhesion to the surface of the rubber core. The results of polishing experiments conducted on fused silica glass workpieces using the proposed composite abrasive indicated that following 20 min of FRP, the surface roughness (Sa) of the workpiece was reduced from 464.2 nm to 2.2 nm and a high material removal rate (MRR) of 337.2 nm/min was achieved with negligible damage to the surface. The utilization of the composite abrasive for FRP effectively promoted the chemical reaction between CeO2 and silica glass to achieve rapid material removal. Furthermore, the material removal selectivity characteristics of the composite abrasive were investigated by polishing micro-grooved surfaces. The resulting groove contours and morphologies revealed that the composite abrasive played a crucial role in selectively removing material from the edges and bottoms of the micro-grooves such that elevated points experienced more extensive material removal, realizing a flatter surface. However, the effectiveness of selective removal diminished as the micro-groove width increased. The results of this study furnish compelling theoretical and experimental evidence supporting the utilization of millimeter-scale flexible composite abrasives in FRP.

Unveiling the efficiency of peanut shell-derived porous composite for water denitrification: Characterization, kinetic, isotherm and thermodynamic studies

This research investigated the valorization of peanut shell (PS) waste to produce a ZnO-modified activated carbon composite ZnO@PS-AC for water denitrification. The composite was synthesized through chemical activation with ZnCl₂ followed by pyrolysis at 700 °C. Characterization techniques revealed a highly porous structure with over 79 % carbon content and successful ZnO formation, indicating the effectiveness of the synthesis process. Batch adsorption experiments were conducted to evaluate nitrate removal under various conditions. The adsorption process demonstrated rapid kinetics, reaching equilibrium within 60 min. Isotherm studies showed a maximum adsorption capacity of 17.9 mg/g, while kinetic analysis revealed significant nitrate removal within the first 5 min. Phenomenological modelling suggested that adsorption onto active sites was the rate-limiting step in the process. Thermodynamic analysis indicated an exothermic, physical adsorption process, providing insights into the nature of the nitrate-adsorbent interactions. The study highlights ZnO@PS-AC’s potential as an eco-friendly, cost-effective adsorbent for nitrate removal from water. Its porous structure facilitates rapid uptake and efficient removal, making it a promising solution for water treatment applications. These findings demonstrate the viability of valorizing agricultural waste into effective water treatment materials, contributing to both waste management and environmental remediation efforts.

Self-supporting and hierarchical porous membrane of bacterial nanocellulose@metal-organic framework for ultra-high adsorption of Congo red

The widespread use of synthetic dyes has serious implications for both the environment and human health. Therefore, there is an urgent need for the development of novel, high-efficiency adsorbents for these dyes. In this study, a Zirconium-based metal-organic framework (MOF) with controllable morphology was in-situ grown on bacterial nanocellulose (BC) via a solvothermal method. The resulting BC@MOF composite nanofibers have a high specific surface area of 651 m2/g and can be assembled into a self-supported porous membrane (BMMCa) through vacuum filtration with the assistance of calcium ions. The addition of Ca(II) significantly enhanced the mechanical properties of the membrane through dispersion effect and electrostatic interactions, as well as enhancing its adsorption performance through the salting-out effect. The BMMCa membrane, with its hierarchical porous structure and high flux, exhibits high selectivity for Congo red (CR) with an ultra-high adsorption capacity of 3518.6 mg/g. Furthermore, the self-supporting membrane achieved rapid and convenient removal of CR through circulating filtration adsorption. The adsorption mechanism and selectivity were verified through the molecular dynamics simulation calculations by Materials Studio (MS) software. This membrane-based adsorbent, with its ultra-high adsorption capacity, good selectivity, and recycling ability, has great potential for practical wastewater treatment applications.

Adsorptive removal of phosphate from water with biochar from acacia tree modified with iron and magnesium oxides

A novel biochar (BC) from Acaciatortilis trees pruning waste was synthesized and tested for the removal of phosphate from aqueous solutions. The BC was prepared by calcination at 600 °C and doped with Fe3O4 and MgO by hydrothermal process. The presence of iron and magnesium ions in the modified BC was confirmed by EDS analysis and X-ray diffraction (XRD) methods. Both unmodified and doped BCs were tested for phosphate removal from synthetic 1–500 ppm aqueous solutions. While the unmodified BC did not show any significant removal of phosphate from aqueous solutions, the modified BC almost completely removed phosphate from water. The enhancement in removal efficiency is due to an increase in the overall surface charge and surface area of BC as a result of doping with Fe3O4 and MgO salts. The average porosity and BET surface area corresponding to the plain BC increased by more than 20% from 322 to 394 m2/g after modification by impregnation with iron oxide and magnesium oxide. The modificaiton of BC with Fe3O4 and MgO nanoparticles was observed to increase the point of zero electric charge (PZC) from pH 3.4 (corresponding to plain BC) to pH 5.3 (corresponding to modified BC). The adsorption process was very fast and a phosphate removal value of 82.5% was reached only after 30 min of adsorption, while the removal efficiency after 4 h of adsorption was 97.5%. The rapid removal efficiency in short contact time is attributed to the high surface area of BC and strong bonding between the modified BC surface and PO43− ions. The highest adsorption capacity was observed to correspond to 98.5 mg/g which was achieved at PO43− concentration of 500 ppm and pH 8.5. Moreover, after fitting the adsorption data onto four of the most widely used adsorption isotherm models, the adsorption of PO43− onto BC can be better described by the Langmuir isotherm model.

A Transparent Photo/Electrothermal Composite Coating with Liquid-like Slippery Property for All-Day Anti-/De-Icing.

A photo/electrothermal surface can convert sunlight and electricity into heat to solve icing problems. The combination of active photo/electrothermal surfaces with passive slippery surfaces provides a highly efficient strategy for all-day anti/deicing. However, the lack of transparency remains a primary impediment to the widespread application of these anti-icing measures in photovoltaics, windshields, and other fields. Herein, we report a bilayer transparent photo/electrothermal coating with a liquid-like slippery property for all-day anti/deicing. The prepared coating exhibits ultraslippery, low ice adhesion, and enhanced stability properties through covalent grafting of polydimethylsiloxane (PDMS) brushes in a cross-linked skeleton of epoxy. Moreover, the coating demonstrates a visible transmittance of up to 77% and effectively absorbs ultraviolet and near-infrared light due to the addition of ultraviolet and infrared absorbers, resulting in a temperature increase under sun illumination. The bottom indium tin oxide layer is fabricated to provide the composite coating with electrothermal capability, so that it can achieve all-weather deicing. The coupling of photo/electrothermal and slippery properties can promote the rapid removal of grown ice in a short time. The slippery properties and their exceptional durability under mechanical, optical, and thermal conditions render the composite coatings highly promising for engineering applications.

Geochemical drivers of manganese removal in drinking water reservoirs under hypolimnetic oxygenation

Manganese (Mn) is a naturally occurring contaminant commonly found in drinking water supplies. In lakes and reservoirs, water authorities increasingly use in situ treatment by hypolimnetic oxygenation (HOx) systems to remove metals such as Mn from the water column. HOx systems introduce dissolved oxygen (DO) to the bottom waters (hypolimnion) to promote oxidation and subsequent removal of metals from the water column. Previous laboratory studies have shown the importance of individual geochemical drivers (pH, alkalinity, mineral surfaces) on Mn oxidation, but few studies have examined the influence of these drivers of Mn removal in concert. In this study, we conducted field monitoring and laboratory experiments to examine how pH, alkalinity and the presence of mineral particles influence Mn removal at two drinking water reservoirs in southwest Virginia, both with HOx systems: Falling Creek Reservoir (FCR) and Carvins Cove Reservoir (CCR). Both reservoirs have had historical issues with elevated (>0.05 mg/L) Mn concentrations during seasonal stratification (May–October). Watershed geology contributes to differences in pH and alkalinity between the reservoirs, with FCR having lower historical medians of hypolimnetic pH and alkalinity (6.6 and 18 mg/L CaCO3, respectively) than CCR (7.2 and 62 mg/L CaCO3, respectively).Results of laboratory experiments examining the influence of pH on Mn removal showed substantial Mn loss within 14 days only under high pH (10) conditions. Mn removal did not occur at pH 6 or 8 over the same 14-day period. In experiments with pH 10 and alkalinity >70 mg/L CaCO3, near-total Mn removal occurred within 2 h. Mn removal occurred concurrently with precipitation of microscopic (<5 μm) particles, followed by formation of macroscopic (>100 μm) particles. Particles of both size classes were identified as Mn oxides (MnOx). These observations suggest that increasing pH and alkalinity promotes Mn oxidation and subsequent removal from solution. Results of experiments with pH 10 and alkalinity >70 mg/L CaCO3 suggest that heterogeneous oxidation by MnOx partially drives rapid Mn removal. Thus, initial formation of MnOx creates a positive feedback loop that can enhance additional Mn loss. In experiments using water collected from FCR and CCR, we observed rapid Mn removal in unfiltered water (0.002–0.05 d−1) but no significant removal of Mn in filtered water. These results, in combination with results of analysis of particles collected from reservoir water, suggest that minerals present in the water column likely catalyze MnOx formation. Together, our experimental results suggest that heterogenous oxidation is an important process of Mn removal, while pH and alkalinity variations of the range expected in natural freshwaters contribute less to differential Mn removal. The formation of MnOx particles during in situ oxygenation, as well as the presence of suspended minerals that occur naturally in water columns, play an important role in promoting Mn oxidation and should be accounted for in Mn removal treatment strategies.

Numerical Investigation of the Performance of a Proton Exchange Membrane Water Electrolyzer under Various Outlet Manifold Structure Conditions.

The oxygen discharge process significantly affects the electrochemical performance of a proton exchange membrane water electrolyzer (PEMWE), which requires an optimal structure of the flow field implemented in the bipolar plate (BP) component. In this study, we numerically investigated the two-phase (liquid water and oxygen) flow in the PEMWE's channel region with different outlet manifold structures utilizing the volume of fluid (VOF) model. Then, the oxygen volume fraction at the liquid/gas diffusion layer (L/GDL) surface, i.e., the interface of the channel and L/GDL, obtained by the liquid water and oxygen flow model was incorporated into a three-dimensional (3D) PEMWE model, which made it possible to predict the influence of the outlet manifold structure on the multiple transfers inside the whole electrolyzer as well as the electrochemical performance. The results indicate that the existence of oxygen in the flow field significantly decreased the electrolyzer voltage at a fixed operation current density and deteriorated the uniform distribution of the oxygen amount, current density (corresponding to the electrochemical reaction rate) and temperature in the membrane electrode assembly (MEA), indicating that the rapid oxygen removal from the flow field is preferred in the operation of the electrolyzer. Moreover, slight increases in the width of the outlet manifold were helpful in relieving the oxygen accumulation in the anode CL and, hence, improved the electrolyzer performance with more uniform distribution characteristics.

Potato peel carbon dots produced via fixed bed pyrolysis reactor decorated 1-D TiO2 nanorods for rapid removal of methylene blue, Cr (VI), Escherichia coli, and Aspergillus niger

In this work, new type carbon quantum dots produced from waste of biomass were used as a dopant molecule in order to investigated photocatalytic properties of TiO2 nanorods structures. Low-cost and eco-friendly carbon quantum dots (CQDs) were obtained via slow pyrolysis of potato peels (PP) as a biomass waste without any chemicals by fixed bed pyrolysis. Potato peel quantum dots (P-CQDs) decorated TiO2 nanorods (P-CQDs/TNRs) were synthesized were by utilizing their high specific surface area, good dispersion, abundant surface functional groups. (P-CQDs) were imposed on the surface of the one-dimensional TiO2 nanorods fabricated via chemical impregnation method for P-CQDs/TiO2 nanorods (P-CQDs/TNRs) that TiO2 nanorods have been fabricated by hydrothermal route. Characteristic properties of as-prepared P-CQDs/TNRs photocatalysts were characterized employing TGA, XRD, XPS, FE-SEM/EDS, HRTEM, FTIR, fluorescence and UV–vis spectroscopy, resp. The photocatalytic activity of as-prepared P-CQDs/TNRs were investigated for methylene blue, hexavalent chromium, Escherichia coli and Aspergillus niger under UV-A. The obtained results suggest that the photocatalytic activity of P-CQDs/TNRs composites was slightly enhanced as compared to that of TNRs. The scenario behind the superior photocatalytic activity of P-CQDs/TNRs may be having a synergetic effect between P-CQDs molecules and the surface of TNRs, and also the design of the charge-transfer channel of TNRs. Moreover, the carbon derived from a natural green source possesses the various functional groups such as CC, C-OH, C-O-C, CO, and when these functional groups deposited to the surface of the TiO2 nanorods, newly formed nanocomposites can improve the visible light-driven photocatalytic activity.

Removal and detection of phenols through an SPE-HPLC method using microporous organic networks as adsorbent.

The design and development of a facile synthesis approach to construct novel materials for the rapid adsorption and removal of environmental pollutants are of significant interest. In this work, we report the rational design and facile synthesis of magnetic core-shell-based microporous organic networks, Fe3O4@MON-TBPT-TEB (TTMON, achieved by reacting 2,4,6-tris(p-bromophenyl) triazine and 1,3,5-triethynylbenzene) and Fe3O4@MON-TBPM-DEBP (TDMON, achieved by reacting tetrakis (4-bromophenyl) methane and 4-4'-diethynylbiphenyl). These MONs possessed excellent dispersity, electrostatic attraction as well as plenty of π-π and hydrophobic interaction sites enabled them to efficiently absorb targeted environmental pollutants. TTMON and TDMON exhibited excellent adsorption capacities of 440 and 510 mg g-1, respectively, at 25 °C for 2,4,6-trichlorophenol (TCP). TCP, 2,4-dichlorophenol (DCP), 2-naphthol (2-NT) and 4-nitrophenol (4-NP) from aqueous solution were treated by both MONs, followed by their analysis with high-performance liquid chromatography (HPLC). For TDMON, the proposed SPE-HPLC-UV method showed an LOD of 0.03 μg L-1, LOQ of 0.11 μg L-1, and a wide linear range of 1-1000 μg L-1 for TCP. The adsorption kinetics, thermodynamics, isotherms, effect of pH and humic acid (HA), ionic strength, regeneration, and reusability of the MONs were also studied. The results revealed that the novel-designed MONs have potential applications as efficient adsorbents in sample pretreatment.

Oligo cyc-DEP: On-chip cyclic immunofluorescence profiling of cell-derived nanoparticles.

We present a follow-on technique for the cyclic-immunofluorescence profiling of suspension particles isolated using dielectrophoresis. The original lab-on-chip technique ("cyc-DEP" [cyclic immunofluorescent imaging on dielectrophoretic chip]) was designed for the multiplex surveillance of circulating biomarkers. Nanoparticles were collected from low-volume liquid biopsies using microfluidic dielectrophoretic chip technology. Subsequent rounds of cyclic immunofluorescent labeling and quenching were imaged and quantified with a custom algorithm to detect multiple proteins. While cyc-DEP improved assay multiplicity, long runtimes threatened its clinical adoption. Here, we modify the original cyc-DEP platform to reduce assay runtimes. Nanoparticles were formulated from human prostate adenocarcinoma cells and collected using dielectrophoresis. Three proteins were labeled on-chip with a mixture of short oligonucleotide-conjugated antibodies. The sample was then incubated with complementary fluorophore-conjugated oligonucleotides, which were dehybridized using an ethylene carbonate buffer after each round of imaging. Oligonucleotide removal exhibited an average quenching efficiency of 98±3% (n=12 quenching events), matching the original cyc-DEP platform. The presented "oligo cyc-DEP" platform achieved clinically relevant sample-to-answer times, reducing the duration for three rounds of cyclic immunolabeling from approximately 20 to 6.5h-a 67% decrease attributed to rapid fluorophore removal and the consolidated co-incubation of antibodies.

Rapid adsorptive removal of emerging and legacy per- and polyfluoroalkyl substances (PFASs) from water using zinc chloride-modified litchi seed-derived biochar

The present study successfully synthesized a novel biochar adsorbent (M−L−BC) using litchi seed modified with zinc chloride for PFASs removal in water. M−L−BC greatly enhanced removal of all examined PFASs (>95 %) as compared to the pristine biochar (<40 %). The maximum adsorption capacity was observed for PFOS, reaching 29.6 mg/g. Adsorption kinetics of PFASs followed the pseudo-second-order model (PSO), suggesting the predominance of chemical adsorption. Moreover, characterization and density functional theory (DFT) calculations jointly revealed involvement of surface complexation, electrostatic interactions, hydrogen bonding, and hydrophobic interactions in PFAS adsorption. Robust PFAS removal was demonstrated for M−L−BC across a wide range of pH (3–9), and coexisting ions had limited impact on adsorption of PFASs except PFBA. Furthermore, M−L−BC showed excellent performance in real water samples and retained reusability after five cycles of regeneration. Overall, M−L−BC represents a promising and high-quality adsorbent for efficient and sustainable removal of PFASs from water.

Rapid HCV Replication Machinery Removal after Antiviral Treatment with DAA Monitored by Multimodal Imaging

Rapid HCV Replication Machinery Removal after Antiviral Treatment with DAA Monitored by Multimodal Imaging

Shifting to biology promotes highly efficient iron removal in groundwater filters

Rapid sand filters are established and widely applied technologies for groundwater treatment. In these filters, main groundwater contaminants such as iron, manganese, and ammonium are oxidized and removed. Conventionally, intensive aeration is employed to provide oxygen for these redox reactions. While effective, intensive aeration promotes flocculent iron removal, which results in iron oxide flocs that rapidly clog the filter. In this study, we operated two parallel full-scale sand filters at different aeration intensities to resolve the relative contribution of homogeneous, heterogeneous and biological iron removal pathways, and identify their operational controls. Our results show that mild aeration in the LOW filter (5 mg/L O2, pH 6.9) promoted biological iron removal and enabled iron oxidation at twice the rate compared to the intensively aerated HIGH filter (>10 mg/L O2, pH 7.4). Microscopy images showed distinctive twisted stalk-like iron solids, the biosignatures of Gallionella ferruginea, both in the LOW filter sand coatings as well as in its backwash solids. In accordance, 10 times higher DNA copy numbers of G. ferruginea were found in the LOW filter effluent. Clogging by biogenic iron solids was slower than by chemical iron flocs, resulting in lower backwash frequencies and yielding four times more water per run. Ultimately, our results reveal that biological iron oxidation can be actively controlled and favoured over competing physico-chemical routes. The production of more compact and practically valuable iron oxide solids is of outmost interest. We conclude that, although counterintuitive, slowing down iron oxidation in the water before filtration enables rapid iron removal in the biofilter.

Kinetics analysis of PAHs degradation using SiO2–ZnO nanoparticles and evaluating their antibacterial and antibiofilm efficacy

The adsorption of Polycyclic aromatic hydrocarbons (PAHs) using nanoparticles is gaining significant attention due to the rapid removal or treatment rates. In this study, Silicon Dioxide-Zinc Oxide nanoparticles (SiO2–ZnO NPs) were synthesized to adsorb pyrene. Physicochemical characterization of SiO2–ZnO NPs showed plasmon resonance at 323 nm, agglomeration, irregular dispersion, and diameters of 90–100 nm. FT-IR analysis identified major functional groups on SiO2–ZnO NPs, including alkyne, amine, and isothiocyanate. SiO2–ZnO NPs demonstrated significant pyrene adsorption at pH 5, with 10 μg/mL of SiO2–ZnO NPs and 2 μg/mL of PAHs, performing better under UV irradiation. Two isotherm models, adsorption isotherm and kinetics adsorption, were used to analyze the PAHs adsorption by SiO2–ZnO NPs. Additionally, SiO2–ZnO NPs were tested for antibacterial and antibiofilm activities against both Gram-negative and Gram-positive bacteria. At a concentration of 150 μg/mL, SiO2–ZnO NPs produced inhibition zones of 21.57 mm, 20.30 mm, 19.30 mm, and 11.30 mm against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Klebsiella pneumoniae, respectively. They also inhibited and disrupted biofilms of Micrococcus luteus and Acinetobacter baumannii. Furthermore, SiO2–ZnO NPs exhibited photocatalytic degradation of lead, achieving 68.24% degradation within 5 h of treatment. Therefore, SiO2–ZnO NPs are efficient candidates for multiple applications, including pyrene adsorption, bacterial biofilm disruption, and lead degradation under sunlight.

Surface hydroxyl-riched ultrasmall monodispersed CuO nanoparticles for rapid degradation of tetracycline by peroxymonosulfate activation

The activation of peroxymonosulfate (PMS) is viewed as a highly prospective strategy to address antibiotic abuse issues. In this work, surface hydroxyl-riched ultrasmall (3–5 nm) monodispersed CuO nanoparticles (NPs) are firstly applied in the degradation of tetracycline (TC) by PMS activation. The ultrasmall CuO NPs facilitate rapid degradation of TC, achieving approximately 90 % degradation within 1 min and 97 % degradation within 15 min. Furthermore, the degradation efficiency of TC remains 90 % after five cycles. The CuO/PMS system not only exhibits outstanding anti-interference properties toward various anions and organics, and high catalytic activity in a wide pH range, but also could efficiently degrade other common organic pollutants, possessing higher practical application value. Mechanistic experiments elucidated that singlet oxygen (1O2) is the main active substance for TC degradation. This work provides a newly developed and highly effective catalyst for rapid removal of persistent organic contaminants from wastewater by the activation of PMS.

Rapid removal of polycyclic aromatic hydrocarbons from water using sulfonated mesoporous polymeric adsorbents

Polycyclic aromatic hydrocarbons (PAHs) are potential hazards and are often found in aquatic environments through industrial effluents. Herein, we report sulfonated modified mesoporous thermoplastic polymers to remove potentially carcinogenic PAHs from water rapidly. Mesoporous structures of the thermoplastics (polystyrene, polysulfone, and polycarbonate) were attained using nano-crystallization induced phase separation by flash-freezing route. Sulfonation reactions carried out hydrophilic surface modifications of the polymers. Their ion exchange capacity (IEC) values determined the degree of sulfonation. The sulfonated mesoporous polymers were characterized using Fourier-Transform Infra-Red spectroscopy (FT-IR) for functional groups, Field-Emission Scanning Electron Microscopy (FE-SEM) for mesoporous structures, Brunauer-Emmet-Teller method for specific surface area, and Barrett-Joyner-Halenda method for pore size distributions. The IEC values for the sulfonated mesoporous polymers range from 1.13 – 1.15 × 10-2 meq. g−1. The sulfonated mesoporous polymers showed high specific surface areas (176–185 m2/g) with pore sizes ranging from 5 nm to 9 nm. The sulfonated mesoporous polymers rapidly adsorb PAHs from nearly saturated water solutions within 60 min with % removal of over 98 %. The adsorbents can also be easily regenerated by simple washing with methanol and are found to be recycled up to 10 cycles with only a marginal reduction in adsorption capacities.

Engineered Fe3 Triangle for The Rapid and Selective Removal of Aromatic Cationic Pollutants

Heydays, water pollution is proliferating due to widespread industrialization and in- proper planning of its waste, consisting of aromatic hazards [1]. Most industries dispose of the wastewater in their neighborhood areas of the cities, which is directly in touch with several groundwater sources. The wastewater pollutant (specialties the aromatic ones) can easily enter the underground water which in turn contaminants the surface water and consequently harm the human and environment [2-5].

Rapid and selective removal of bisphenol S from environmental samples by surface-imprinted polymer synthesized based on metal-organic framework MIL-101(Cr)

In this study, a novel, surface-imprinted polymer (MIL-101@MIP) was successfully synthesized using the metal-organic framework MIL-101(Cr) with a large specific surface area as a carrier, which achieved rapid and selective removal of bisphenol S (BPS) from environmental samples. The structure and morphology of MIL-101@MIP were characterized using SEM, XPS, FTIR, TGA, BET, and XRD techniques. The results show that MIL-101@MIP has rough surface morphology and good thermal stability. The large specific surface area (1251.6 m2 g−1) of MIL-101@MIP provides more imprinting sites in MIL-101@MIP; thus, the maximum adsorption capacity of BPS reached 87.76 mg g−1 with good imprinting factor 2.08, and equilibrium was achieved in only 10 min. Moreover, the process of BPS adsorption onto MIL-101@MIP followed the pseudo-second-order kinetics and Langmuir isothermal adsorption models. In addition, the MIL-101@MIP was utilized as an adsorbent for a solid phase extraction column to determine BPS in seven environmental samples using HPLC, achieving recovery of 89.20–105.78%. The developed MIL-101@MIP is a promising and efficient adsorbent for rapid and selective removal of BPS from the environment.