Rapid PFOS mineralization with peroxydisulfate activation process mediated by N modified Fe-based catalyst.

As the cheap and efficient catalysts, the iron-based catalysts have been considered as one of the most promising catalysts for peroxydisulfate (PDS) activation and the development of high-performance iron-based catalysts are attracting growing attentions. In this work, a magnetic Fe-based catalysts (Fe/NC-1000) was obtained by using Fe modified ZIF-8 as the precursor and used to activate the PDS for the degradation of perfluorooctane sulphonate (PFOS). Morphology and structure analysis showed that the resulted Fe/NC-1000 catalyst was displayed porous spheres (40-60 nm) and mainly composed of Fe0, FeNx and carbon. When Fe/NC-1000 was employed to activate the PDS (0.1 g/L of catalyst dosage, 0.5 g/L of PDS dosage and at initial pH of 4.6), the Fe/NC-1000/PDS system exhibited excellent efficiency (97.9 ± 0.1) % for PFOS (10 mg/L) degradation within 30 min. The quenching tests and EPR results revealed that the Fe/NC-1000/PDS system degraded PFOS primarily through singlet oxygen (1O2) evolution and electron-transfer process. Besides, based on the degradation byproducts determined by LC-MS-MS, the PFOS first occurred de-sulfonation to form PFOA, and then the resulted PFOA underwent stepwise defluorination in the Fe/NC-1000/PDS system. Density Functional Theory (DFT) calculations and electrochemistry tests strongly confirmed that Fe/NC-1000 exhibited high electron transfer efficiency, resulting in promoted performance on activating PDS. Importantly, the results of Ecological Structure-Activity Relationship (ECOSAR) analysis showed that the intermediates were lowly toxic during the PFOS degradation, manifesting a green process for PFOS removal. This study would provide more understandings for the persulfate activation process mediated by Fe-based catalysts for Perfluorinated alkyl substances (PFAS) elimination.

A biomass fiber adsorbent grafted with phosphate/amidoxime for efficient extraction of uranium from seawater by synergistic effect.

There are approximately 4 billion tons of uranium in the ocean, which is unmatched by the surface. Nevertheless, it's very challenging to extract uranium from the ocean due to the exceedingly low concentration of uranium in the ocean (about 3.3 µg L-1) as well as high salinity level. Current methods are often limited by selectivity, sustainability, economics, etc. Herein, phosphoric acid group and amidoxime group were grafted to skin collagen fibers through " initiated access" to design a new uranium extraction material, abbreviated as CGPA. Through laboratory simulation experiments, it is concluded that the maximum adsorption capacity of CGPA for uranium reaches 263.86 mg g-1. It has high adsorption, selectivity, and reusability for uranium. In the actual seawater extraction experiment, CGPA obtained 29.64 µg of uranium after extracting 10.0 L of seawater, and the extraction rate was 90.1%. The adsorbent has excellent effects in kinetics, selectivity, extraction capacity, renewability, etc. In the extraction of uranium from seawater, and is an economically feasible and industrially expandable adsorbent.

Insights into Enhanced Peroxydisulfate Activation with B and Fe Co-Doped Biochar from Bark for the Rapid Degradation of Guaiacol.

A boron and iron co-doped biochar (B-Fe/biochar) from Masson pine bark was fabricated and used to activate peroxydisulfate (PDS) for the degradation of guaiacol (GL). The roles of the dopants and the contribution of the radical and non-radical oxidations were investigated. The results showed that the doping of boron and iron significantly improved the catalytic activity of the biochar catalyst with a GL removal efficiency of 98.30% within 30 min. The degradation of the GL mainly occurred through the generation of hydroxyl radicals (·OHs) and electron transfer on the biochar surface, and a non-radical degradation pathway dominated by direct electron transfer was proposed. Recycling the B-Fe/biochar showed low metal leaching from the catalyst and satisfactory long-term stability and reusability, providing potential insights into the use of metal and non-metal co-doped biochar catalysts for PDS activation.

Rapid degradation of p-arsanilic acid and simultaneous removal of the released arsenic species by Co-Fe@C activated peroxydisulfate process.

In this study, a bimetallic composite catalyst (Co-Fe@C) was fabricated with calcination at high temperature (800 °C) by using Co-MIL-101 (Fe) as the precursor. The characterization results showed that the resulted Co-Fe@C composite mainly consisted of carbon, FeCo alloys, Fe3O4, Co3O4 and FeO, and owned evident magnetism. In addition, the Co-Fe@C was employed to activate the peroxydisulfate (PDS) to degrade a representative organic pollutant (p-arsanilic acid, p-ASA) and the main factors were optimized, which involved 0.2 g L-1 of catalyst dosage, 1.0 g L-1 of PDS dosage and 5.0 of initial pH. Under the optimal condition, Co-Fe@C/PDS system could completely degrade p-ASA (20 mg L-1) in 5 min. In the Co-Fe@C/PDS system, SO4-·, Fe(IV) and ·OH were the main species during p-ASA degradation. Under the attack of these species, p-ASA was first decomposed into phenols and then transformed into the organics acids and finally mineralized into CO2 and H2O through a series of reactions like hydroxylation, dearsenification, deamination and benzene ring opening. Importantly, most of the released inorganic arsenic species (93.40%) could be efficiently adsorbed by the catalyst.

Efficient adsorption of diclofenac sodium in water by a novel functionalized cellulose aerogel.

In this work, a novel cellulose aerogel (CNC-PVAm/rGO) was fabricated using cellulose nanocrystalline (CNC) modified with polyvinylamine (PVAm) and reduced graphene oxide (rGO). The resultant CNC-PVAm/rGO was then applied for the adsorption of diclofenac sodium (DCF), a typical non-steroidal anti-inflammatory drug. Characterization using ultra-high-resolution field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and the Brunauer-Emmett-Teller surface area revealed that the obtained CNC-PVAm/rGO displayed an evident 3D porous structure, which had an ultralight weight, good recovery, abundant surface functional groups (e.g., -NH2 and -OH), and rGO nanosheets. In addition, the material presented a stable crystal structure and large specific surface area (105.73 m2 g-1). During the adsorption of DCF, the CNC-PVAm/rGO aerogel showed a rather excellent adsorption performance, with a maximum adsorption capacity (qmax) of 605.87 mg g-1, which was approximately 53 times larger than that of the bare CNC aerogel (11.45 mg g-1). The adsorption performance of CNC-PVAm/rGO was also better than that of other reported adsorbents. The adsorption of DCF to CNC-PVAm/rGO obeyed the Langmuir isotherm and pseudo-second-order kinetic models, and underwent a spontaneous exothermic process. Moreover, DCF was easily desorbed from CNC-PVAm/rGO with sodium hydroxide solution (0.1 mol L-1), and the absorbent could be reused four times. The introduction of PVAm and rGO to the CNC-PVAm/rGO aerogel also greatly enhanced electrostatic interactions, π-π interactions, and hydrophobic effects. These enhancements significantly promoted the hydrogen bonding interactions between the DCF molecules and CNC-PVAm/rGO, thus resulting in a large improvement in the adsorption performance of the aerogel.

Positive effects of bio-nano Pd (0) toward direct electron transfer in Pseudomona putida and phenol biodegradation.

This study constructed a biological-inorganic hybrid system including Pseudomonas putida (P. putida) and bioreduced Pd (0) nanoparticles (NPs), and inspected the influence of bio-nano Pd (0) on the direct electron transfer and phenol biodegradation. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX) showed that bio-nano Pd (0) (~10 nm) were evenly dispersed on the surface and in the periplasm of P. putida. With the incorporation of bio-nano Pd (0), the redox currents of bacteria in the cyclic voltammetry (CV) became higher and the oxidation current increased as the addition of lactate, while the highest increase rates of two electron transfer system (ETS) rates were 63.97% and 33.79%, respectively. These results indicated that bio-nano Pd (0) could directly promote the electron transfer of P. putida. In phenol biodegradation process, P. putida-Pd (0)- 2 showed the highest k (0.2992 h-1), µm (0.035 h-1) and Ki (714.29 mg/L) and the lowest apparent Ks (76.39 mg/L). The results of kinetic analysis indicated that bio-nano Pd (0) markedly enhanced the biocatalytic efficiency, substrate affinity and the growth of cells compared to native P. putida. The positive effects of bio-nano Pd (0) to the electron transfer of P. putida would promote the biodegradation of phenol.

Optimized determination of polybrominated diphenyl ethers by ultrasound-assisted liquid-liquid extraction and high-performance liquid chromatography.

A method based on ultrasound-assisted liquid-liquid extraction and high-performance liquid chromatography has been optimized for the determination of six polybrominated diphenyl ether congeners. The optimal condition relevant to the extraction was first investigated, more than 98.7 ± 0.7% recovery was achieved with dichloromethane as extractant, 5 min extraction time, and three cycles of ultrasound-assisted liquid-liquid extraction. Then multiple function was employed to optimize polybrominated diphenyl ether detection conditions with overall resolution and chromatography signal area as the responses. The condition chosen in this experiment was methanol/water 93:7 v/v, flow rate 0.80 mL/min, column temperature 30.0°C. The optimized technique revealed good linearity (R(2) > 0.9962 over a concentration range of 1-100 µg/L) and repeatability (relative standard deviation < 6.3%). Furthermore, the detection limit (S/N = 3) of the method were ranged from 0.02 to 0.13 µg/L and the quantification limit (S/N = 10) ranged from 0.07 to 0.35 µg/L. Finally, the proposed method was applied to spiked samples and satisfactory results were achieved. These results indicate that ultrasound-assisted liquid-liquid extraction coupled with high-performance liquid chromatography was effective to identify and quantify the complex polybrominated diphenyl ethers in effluent samples.

Enhanced lactic acid production from household food waste under hyperthermophilic conditions: Mechanisms and regulation.

An annual production of about 500 million tons of household food waste (HFW) has been documented, resulting in significant implications for human health and the environment in the absence of appropriate treatment. The anaerobic fermentation of HFW in an open system offers the potential to recover high value-added products, lactic acid (LA), thereby simultaneously addressing waste treatment and enhancing resource recovery efficiency. Most of LA fermentation studies have been conducted under mesophilic and thermophilic conditions, with limited research on the production of LA through anaerobic fermentation under hyperthermophilic conditions. This study aimed to produce LA through anaerobic fermentation from HFW under hyperthermophilic conditions (70 ± 1 °C), while varying pH values (5.0 ± 0.1, 7.0 ± 0.1, and 9.0 ± 0.1), and compare the results with LA production under mesophilic (35 ± 1 °C) and thermophilic (52 ± 1 °C) conditions. The findings of this study indicated that the combination of hyperthermophilic conditions and a neutral pH (pH7_70) yielded the highest concentration of LA, measuring at 17.75 ± 1.51 g/L. The mechanism underlying the high yield of LA at 70 °C was elucidated through the combined analysis of organics dissolution, enzymes activities, and 16S rRNA microbiome sequencing.

Gold Nanoparticles Bioproduced in Cyanobacteria in the Initial Phase Opened an Avenue for the Discovery of Corresponding Cerium Nanoparticles.

The production of isolated metallic nanoparticles with multifunctionalized properties, such as size and shape, is crucial for biomedical, photocatalytic, and energy storage or remediation applications. This study investigates the initial particle formations of gold nanoparticles (AuNPs) bioproduced in the cyanobacteria Anabaena sp. using high-resolution transmission electron microscopy images for digital image analysis. The developed method enabled the discovery of cerium nanoparticles (CeNPs), which were biosynthesized in the cyanobacteria Calothrix desertica. The particle size distributions for AuNPs and CeNPs were analyzed. After 10 h, the average equivalent circular diameter for AuNPs was 4.8 nm, while for CeNPs, it was approximately 5.2 nm after 25 h. The initial shape of AuNPs was sub-round to round, while the shape of CeNPs was more roundish due to their amorphous structure and formation restricted to heterocysts. The local PSDs indicate that the maturation of AuNPs begins in the middle of vegetative cells and near the cell membrane, compared to the other regions of the cell.

Porous covalent organic framework nanofibrous membrane for excellent enrichment and ultra-high sensitivity detection of trace organochlorine pesticides in water.

Developing adsorbents with high performance and long service life for effective extracting the trace organochlorine pesticides (OCPs) from real water is attracting numerous attentions. Herein, a self-standing covalent organic framework (COF-TpPa) membrane with fiber morphology was successfully synthesized by using electrospun nanofiber membranes as template and employed as solid-phase microextraction (SPME) coating for ultra-high sensitivity extraction and analysis of trace OCPs in water. The as-synthesized COF-TpPa membrane exhibited a high specific surface area (800.83 m2 g-1), stable nanofibrous structure, and excellent chemical and thermal stability. Based on the COF-TpPa membrane, a new SPME analytical method in conjunction with gas chromatography-mass spectrometry (GC-MS) was established. This proposed method possessed favorable linearity in concentration of 0.05-2000 ng L-1, high sensitivity with enrichment factors ranging from 2175 to 5846, low limits of detection (0.001-0.150 ng L-1), satisfactory precision (RSD < 10 %), and excellent repeatability (>150 cycles), which was better than most of the reported works. Additionally, the density functional theory (DFT) calculations and XPS results demonstrated that the outstanding enrichment performance of the COF-TpPa membrane was owing to synergistic effect of π-π stacking effects, high specific surface area and hydrogen bonding. This work will expect to extend the applications of COF membrane to captures trace organic pollutants in complex environmental water, as well as offer a multiscale interpretation for the design of effective adsorbents.

Performance and mechanistic studies of rapid atenolol degradation through peroxymonosulfate activation by V, Co, and bamboo carbon catalyst.

Developing the Co-based catalysts with high reactivity for the sulfate radical (SO4-·)-based advanced oxidation processes (SR-AOPs) has been attracting numerous attentions. To improve the peroxymonosulfate (PMS) activation process, a novel Co-based catalyst simultaneously modified by bamboo carbon (BC) and vanadium (V@CoO-BC) was fabricated through a simple solvothermal method. The atenolol (ATL) degradation experiments in V@CoO-BC/PMS system showed that the obtained V@CoO-BC exhibited much higher performance on PMS activation than pure CoO, and the V@CoO-BC/PMS system could fully degrade ATL within 5 min via the destruction of both radicals (SO4-· and O2-··) and non-radicals (1O2). The quenching experiments and electrochemical tests revealed that the enhancing mechanism of bamboo carbon and V modification involved four aspects: (i) promoting the PMS and Co ion adsorption on the surface of V@CoO-BC; (ii) enhancing the electron transfer efficiency between V@CoO-BC and PMS; (iii) activating PMS with V3+ species; (iv) accelerating the circulation of Co2+ and Co3+, leading to the enhanced yield of reactive oxygen species (ROS). Furthermore, the V@CoO-BC/PMS system also exhibited satisfactory stability under broad pH (3-9) and good efficiency in the presence of co-existing components (HCO3-, NO3-, Cl-, and HA) in water. This study provides new insights to designing high-performance, environment-friendly bimetal catalysts and some basis for the remediation of antibiotic contaminants with SR-AOPs.

Efficient dispersive solid phase extraction of trace nitrophenol pollutants in water with triazine porous organic polymer modified nanofiber membrane.

Detecting trace endocrine disruptors in water is crucial for evaluating the water quality. In this work, a innovative modified polyacrylonitrile@cyanuric chloride-triphenylphosphine nanofiber membrane (PAN@CC-TPS) was prepared by in situ growing triazine porous organic polymers on the polyacrylonitrile (PAN) nanofibers, and used in the dispersive solid phase extraction (DSPE) to enrich trace nitrobenzene phenols (NPs) in water. The resluted PAN@CC-TPS nanofiber membrane consisted of numerous PAN nanofibers cover with CC-TPS solid spheres (∼2.50 µm) and owned abundant functional groups, excellent enrichment performance and good stability. In addition, the method based on PAN@CC-TPS displayed outstanding capacity in detecting the trace nitrobenzene phenols, with 0.50-1.00 µg/L of the quantification, 0.10-0.80 µg/L of the detection limit, 85.35-113.55 % of the recovery efficiency, and 98.08-103.02 of the enrichment factor, which was comparable to most materials. Meanwhile, when PAN@CC-TPS was adopted in the real water samples (sea water and river water), the high enrichment factors and recovery percentages strongly confirmed the feasibility of PAN@CC-TPS for enriching and detecting the trace NPs. Besides, the related mechanism of extracting NPs on PAN@CC-TPS mainly involved the synergistic effect of hydrogen bonding, π-π stacking and hydrophobic effect.

Protein extraction from chlorella pyrenoidosa microalgae: Green methodologies, functional assessment, and waste stream valorization for bioenergy production.

C. pyrenoidosa, a species of microalgae, has been recognized as a viable protein source for human consumption. The primary challenges in this context are the development of an efficient extraction process and the valorization of the resultant waste streams. This study, situated within the paradigm of circular economy, presents an innovative extraction approach that achieved a protein extraction efficiency of 62 %. The extracted protein exhibited remarkable oil-water emulsifying performances, such as uniform morphology with high creaming stability, suggesting a sustainable alternative to conventional emulsifiers. Additionally, hydrothermal liquefaction technique was employed for converting the residual biomass and waste solution from the extraction process into biocrude. A biocrude yield exceeding 40 wt%, characterized by a carbon content of 73 % and a higher heating value of 36 MJ/kg, were obtained. These findings demonstrate the promising potential of microalgae biorefinery, which is significant for paving toward circular economy and zero-waste society.

Effectively remove printing ink from plastic surface over quaternary ammonium-modified waste cooking oil.

The printing ink on the plastic surface will greatly reduce the quality of recycled plastic products. In this work, quaternary ammonium-modified waste cooking oil (WCOEQ) was fabricated using waste cooking oil, epichlorohydrin, and trimethylamine aqueous solution as raw materials, through ring-opening esterification and quaternary amination reaction. The synthesis conditions of WCOEQ were optimised, and the structure and properties of WCOEQ were characterised by Fourier transform infrared spectroscopy, zeta potential, and 1H NMR. Furthermore, WCOEQ had excellent emulsifying performance, low kraft point, low critical micelle concentration value, good foaming, and stability, which could effectively reduce the surface tension of water, showing application potential in the field of plastic deinking. Importantly, compared with the waste cooking oil without deinking effect, the WCOEQ had an excellent deinking performance on the ink on the plastic surface, and the deinking efficiency could be improved by increasing the concentration of the deinking agent, the deinking temperature, and prolonging the pre-soaking and stirring time. The results of atomic force microscope, energy-dispersive spectroscopy, optical photos, and Leica microscope showed that the roughness changed significantly and the ink molecules were gradually peeling off. This work highlighted the potential of quaternary ammonium-modified waste cooking oil for excellent removal of printing inks on the plastic surface.

Example of removing printing ink from plastic surface using quaternary ammonium-modified waste cooking oil.

The printing ink on the plastic surface greatly reduces the quality of recycled plastic products. In this work, quaternary ammonium-modified waste cooking oil (WCOQE) was fabricated, using waste cooking oil, epichlorohydrin and trimethylamine aqueous solution as raw materials, by ring-opening esterification and quaternary amination reaction. The synthesis conditions of WCOQE were optimized, and the structure and properties of WCOQE were characterized by FTIR, zeta potential and 1H NMR. Furthermore, WCOQE had excellent emulsifying performance, low kraft point, low CMC value, good foaming and stability, which could effectively reduce the surface tension of water, showing application potential in the field of plastic deinking. Importantly, compared with the waste cooking oil without deinking effect, the WCOQE had an excellent deinking performance on the ink on plastic surface, and the deinking efficiency could be improved by increasing the concentration of deinking agent, the deinking temperature, and prolonging the pre-soaking and stirring time. The results of AFM, EDS, optical photos and Leica microscope showed that the roughness changed significantly, and the ink molecules were gradually peeling off. This work highlighted the excellent potential of quaternary ammonium-modified waste cooking oil for the removal of printing inks on the plastic surface.

Ultra-efficient adsorption of diclofenac sodium on fish-scale biochar functionalized with H3PO4 via synergistic mechanisms.

Developing safe and efficient diclofenac sodium (DS) removal technology has become a critical issue. This study synthesized the fish-scale biochar by co-pyrolysis of fish scale and phosphoric acid (H3PO4). In addition to increasing the specific surface area and pore volume of fish-scale biochar, H3PO4 assisted in the formation of Graphitic N and sp2 C, as well as reacting with C═O groups to form a significant number of phosphorus-containing groups. All these functional groups could act as major active sites for DS adsorption. Adsorption data could well fit pseudo-second-order and Langmuir models. The maximum adsorption capacity of FSB600-15 for DS was 967.1 mg g-1, which was much better than that reported in the literature. Under the synergistic effect of various mechanisms (pore-filling effect, electrostatic attraction, H-bonding, π-π, and n-π electron donor-acceptor interactions), the DS ultra-efficient adsorption on FSB600-15 was realized. Meanwhile, the DS adsorption by FSB600-15 was an endothermic, spontaneous, and entropy-increasing process. Furthermore, the DS adsorption capacity was more than 426.5 mg g-1 in the actual water, which was sufficient for practical applications.

Insights to PFOS elimination with peroxydisulfate activation mediated by boron modified Fe/C catalysts: Enhancing mechanism of boron and PFOS degradation pathway.

In this study, the boron-doped iron-carbon composite (Fe@B/C-2) was prepared via a simple solvothermal and secondary calcination process by using iron metal-organic frameworks (Fe-MOFs) as precursor. The obtained Fe@B/C-2 possessed abundant active sites and low iron ion leaching, and exhibited excellent performance on peroxydisulfate (PDS) activation for efficient PFOS (10 mg/L) degradation (94 %) in 60 min, with 0.2 g/L of catalyst dosage, 1.0 g/L of PDS dosage and at 5.0 of initial pH. The radical scavenging and electron paramagnetic resonance (EPR) tests demonstrated that SO4·- and ·OH were the primary active species during PFOS elimination. Under the attack of these species, PFOS was first transformed into PFOA, followed by a sequential defluorination process, and lastly mineralized into CO2 and F-. Notably, DFT results revealed that Fe species, -BC3/-BC2O structures on the carbon matrix performed crucial roles in PDS activation. The extraordinary catalytic activity of Fe@B/C-2 was attributable to the synergistic effects of Fe nanoparticles and the B-doped on carbon matrix. The doped B not only could activate the inert carbon skeleton and provided more catalytic centers, but also could accelerate the electron transfer efficiency, leading to a boost in PDS decomposition.

Fabrication of covalent organic frameworks modified nanofibrous membrane for efficiently enriching and detecting the trace polychlorinated biphenyls in water.

Enriching and detecting the trace pollutants in actual matrices are critical to evaluating the water quality. Herein, a novel nanofibrous membrane, named PAN-SiO2@TpPa, was prepared by in situ growing ß-ketoenamine-linked covalent organic frameworks (COF-TpPa) on the aminated polyacrylonitrile (PAN) nanofibers, and adopted for enriching the trace polychlorinated biphenyls (PCBs) in various natural water body (river, lake and sea water) through the solid-phase micro-extraction (SPME) process. The resulted nanofibrous membrane owned abundant functional groups (-NH-, -OH and aromatic groups), outstandingly thermal and chemical stability, and excellent ability in extracting PCBs congeners. Based on the SPME process, the PCBs congeners could be quantitatively analyzed by the traditional gas chromatography (GC) method, with the satisfactory linear relationship (R2>0.99), low detection limit (LODs, 0.1∼5 ng L-1), high enrichment factors (EFs, 2714∼3949) and multiple recycling (>150 runs). Meanwhile, when PAN-SiO2@TpPa was adopted in the real water samples, the low matrix effects on the enrichment of PCBs at both 5 and 50 ng L-1 over PAN-SiO2@TpPa membrane firmly revealed the feasibility of enriching the trace PCBs in real water. Besides, the related mechanism of extracting PCBs on PAN-SiO2@TpPa mainly involved the synergistic effect of hydrophobic effect, π-π stacking and hydrogen bonding.

Effectively remove p-arsanilic acid from water over amphiphilic amino modified collagen fiber.

Efficient and rapid removal of p-arsanilic acid (p-ASA) in water is very important in environmental protection and human health, however it is still a severe challenge in actual engineering. Herein, a novel sorbent (CF-PEI) was successfully fabricated by simply modifying the amphiphilic skin collagen fiber (CF) substrate with Polyethylenimine (PEI). The as-prepared CF-PEI exhibits high-efficiency adsorption for negatively charged p-ASA with aromatic rings due to the introduction of amino groups and the existence of hydrophobic bands, and the maximum adsorption capacity of CF-PEI for p-ASA was high up to 285.71 mg g-1. In addition, the adsorption mechanism of CF-PEI on p-ASA mainly includes electrostatic interaction, hydrogen bond and amphiphilicity. The multi-level all-fiber structure of CF makes it mainly focus on surface mass transfer with short mass transfer distance, and its capillary drainage effect can realize large flow and rapid separation. CF-PEI based on CF can realize the ability to separate low-concentration p-ASA with high flow rate and high efficiency. The effective processing volume was 12.5 L g-1 when the separation flux reached as high as 9931.27 L m-2 h-1. Notably, the p-ASA adsorbed on CF-PEI was almost completely eluted by NaOH (0.5 mol L-1). The adsorbent is convenient to prepare, recyclable, high in efficiency, and has a great application prospect in removing organic micro-pollutants.

Preparation of amino-modified cellulose aerogels and adsorption on typical diclofenac sodium contaminant.

A new functional cellulose aerogel (Cell@PEI) with high adsorption efficiency was prepared for the removal of diclofenac sodium (DCF) by ammonification cross-linked polyethyleneimine (PEI) with the surface of cellulose. The fabricated Cell@PEI adsorbent was characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), etc. The results demonstrated that the Cell@PEI exhibited a distinct three-dimensional cell structure and was rich in functional groups, i.e., -OH, C = O, -NH2, and C = C. The Cell@PEI presented a stable crystal structure and large specific surface area (241.41 m2·g-1), which was approximately 42 times as much as bare cellulose aerogel (5.82 m2·g-1). In addition, a series of adsorption experiments showed that the adsorbent had good adsorption performance for DCF with a maximum adsorption capacity of 294.12 mg·g-1. Furthermore, the adsorption of DCF on Cell@PEI was well corresponded with the Langmuir isotherm and pseudo-second-order adsorption model. Thermodynamic study proved that adsorption was a spontaneous exothermic reaction. Moreover, the introduction of PEI into Cell@PEI aerogel enhanced the electrostatic interaction and hydrogen bonding, promoting DCF adsorption. Importantly, the Cell@PEI aerogel could be reused up to five times desorbed by NaOH (0.5 mol/L). Considering the above results, the fabricated aerogel material can be applied to remove organic pollutants.