Activating peroxymonosulfate with Fe-doped biochar for efficient removal of tetracycline: Dual action of reactive oxygen species and electron transfer.

If pharmaceutical wastewater is not managed effectively, the presence of residual antibiotics will result in significant environmental contamination. In addition, inadequate utilization of agricultural waste represents a squandering of resources. The objective of this research was to assess the efficacy of iron-doped biochar (Fe-BC) derived from peanut shells in degrading high concentrations of Tetracycline (TC) wastewater through activated peroxymonosulfate. Fe-BC demonstrated significant efficacy, achieving a removal efficiency of 87.5% for TC within 60 min without the need to adjust the initial pH (20 mg/L TC, 2 mM PMS, 0.5 g/L catalyst). The degradation mechanism of TC in this system involved a dual action, namely Reactive Oxygen Species (ROS) and electron transfer. The primary active sites were the Fe species, which facilitated the generation of SO4•-, •OH, O2•-, and 1O2. The presence of Fe species and the C=C structure in the Fe-BC catalyst support the electron transfer. Degradation pathways were elucidated through the identification of intermediate products and calculation of the Fukui index. The Toxicity Estimator Software Tool (T.E.S.T.) suggested that the intermediates exhibited lower levels of toxicity. Furthermore, the system exhibited exceptional capabilities in real water and circulation experiments, offering significant economic advantages. This investigation provides an efficient strategy for resource recycling and the treatment of high-concentration antibiotic wastewater.

Synergistic integration of ZrO2-enriched reduced graphene oxide-based nanostructures for advanced photodegradation of tetracycline hydrochloride.

The escalating demand for the antibiotic drug tetracycline hydrochloride (TCH) contributes to an increased release of its residues into land and water bodies, which poses risks to both aquatic life and human health. Therefore, it is precedence to effectively degrade TCH residues to protect environment from their long-term impacts. In this aspect, the present study entails the synthesis of zirconia (ZrO2) nanostructures and focuses on the enhancement in the catalytic performance of ZrO2 nanostructures by employing reduced graphene oxide (RGO) as a solid support to synthesize ZrO2-enriched RGO-based photocatalysts (ZrO2-RGO) for the degradation of TCH. The study delves into comprehensive spectroscopic and microscopic investigations and their photodegradation assessments. Powder XRD and HR-TEM studies depicted the phase crystallinity and also displayed uniform distribution of ZrO2 nanostructures with spherical morphology within ZrO2-RGO. This corresponds to high surface-to-volume ratios, providing a substantial number of active sites for light absorption and generation of e--h+ pairs. Moreover, the heterojunctions created between RGO and ZrO2 nanostructures promoted the interspecies electron transfer which prolonged the recombination time of e- and h+ than pure ZrO2 nanostructures, accounted for enhanced degradation of TCH using ZrO2-RGO. The photocatalytic activity of as-synthesized materials were examined under visible and UV light irradiation. The degradation efficiency of ~ 73.82% was achieved using ZrO2-RGO-based photocatalyst with rate constant k = 0.007023 min-1 under visible-light illumination. Moreover, under UV-light, the degradation rate was explicated to be k = 0.01017 min-1 with ~ 85.56% degradation of TCH antibiotics within 180 mins. Hence, the synthesized ZrO2-enriched RGO-based photocatalysts represents a promising potential for the effective degradation of pharmaceutical compounds, particularly TCH under visible and UV-light irradiation.

A novel BiOBr/rGO photocatalysts for degradation of organic and antibiotic pollutants under visible light irradiation: Tetracycline degradation pathways, kinetics, and mechanism insight.

In this study, the BiOBr/rGO nanocomposite photocatalysts are fabricated by a facile solvothermal method. The BiOBr growth on reduced graphene oxide (rGO) sheet could improve BiOBr's photocatalytic activity by increasing its adsorption ability, surface area, and charge carriers' separation efficiency. The prepared nanocomposites were characterized by XRD, Raman, FESEM, EDS, XPS, and UV-visible DRS. The BiOBr/rGO (BRG) nanocomposites showed improved photocatalytic activity for the photodegradation of Rhodamine B (RhB) dye and Tetracycline (TC) under visible light irradiation. Rhodamine B and tetracycline degradation efficiency were about 96% and 73% within 120 min under visible light irradiation. The PL analysis indicates that BiOBr/rGO nanocomposite exhibited maximum separation efficiency of photoinduced charge carriers. The trapping test confirmed that O2- and h+ are significant active photodegradation species. The GC-MS spectra detected the two plausible transformation routes of tetracycline degradation. The current work presented a low-cost and facile approach for fabricating Bi-based composites.

Spatial-Potential-Color-Resolved Bipolar Electrode Electrochemiluminescence Biosensor Using a CuMoOx Electrocatalyst for the Simultaneous Detection and Imaging of Tetracycline and Lincomycin.

A spatial-potential-color-resolved bipolar electrode electrochemiluminescence biosensor (BPE-ECL) using a CuMoOx electrocatalyst was constructed for the simultaneous detection and imaging of tetracycline (TET) and lincomycin (LIN). HOF-101 emitted peacock blue light under positive potential scanning, and CdSe quantum dots (QDs) emitted green light under negative potential scanning. CuMoOx could catalyze the electrochemical reduction of H2O2 to greatly increase the Faradic current of BPE and realize the ECL signal amplification. In channel 1, CuMoOx-Aptamer II (TET) probes were introduced into the BPE hole (left groove A) by the dual aptamer sandwich method of TET. During positive potential scanning, the polarity of BPE (left groove A) was negative, resulting in the electrochemical reduction of H2O2 catalyzed by CuMoOx, and the ECL signal of HOF-101 was enhanced for detecting TET. In channel 2, CuMoOx-Aptamer (LIN) probes were adsorbed on the MXene of the driving electrode (DVE) hole (left groove B) by hydrogen-bonding and metal-chelating interactions. LIN bound with its aptamers, causing CuMoOx to fall off. During negative potential scanning, the polarity of DVE (left groove B) was negative and the Faradic current decreased. The ECL signal of CdSe QDs was reduced for detecting LIN. Furthermore, a portable mobile phone imaging platform was built for the colorimetric (CL) detection of TET and LIN. Thus, the multiple mode-resolved detection of TET and LIN could be realized simultaneously with only one potential scan, which greatly improved detection accuracy and efficiency. This study opened a new technology of BPE-ECL sensor application and is expected to shine in microchips and point-of-care testing (POCT).

Physicomechanical characterizations and in vitro release studies of electrospun ethyl cellulose fibers, solvent cast carboxymethyl cellulose films, and their composites.

Frequent change of wound dressings introduces wound inflammation and infections. In this study, we electrospun phenytoin (PHT) loaded ethyl cellulose (EC) microfibers and solvent cast tetracycline hydrochloride (TCH) loaded carboxymethyl cellulose (CMC) films with the aim to demonstrate tailorable in vitro drug release behaviors suitable for long-term use of wound dressings. Results from tensile testing showed a significant decrease in average elastic moduli from 8.8 ± 0.6 to 3.3 ± 0.3 MPa after incorporating PHT into EC fibers. PHT-loaded EC fibers displayed a slow and zero-ordered release up to 80 % of the total drug at 48 h, while TCH-loaded CMC films demonstrated a rapid and complete release within 30 min. Furthermore, drug-loaded EC/CMC composites were fabricated into fiber-in-film and fiber-on-film composites. Fiber-in-film composites showed stage release of TCH and PHT at 8 h, while fiber-on-film composites demonstrated simultaneous release of PHT and TCH with a prolonged release of TCH from CMC films. In general, electrospun PHT-loaded EC microfibers, solvent cast TCH-loaded CMC films, and their composites were studied to provide a fundamental scientific understanding on the novelty of the ability to modulate drug release characteristics based on the composite designs.

Effects of tire-road wear particles on the adsorption of tetracycline by aquatic sediments.

Tire-road wear particles (TRWPs) are formed by friction between the tire and the road. TRWPs are ubiquitous across the globe, especially in sediments. However, the possible effects of TRWPs on tetracycline (TC) in aquatic sediments are unknown. To investigate the potential role of TRWPs as carriers of co-pollutants, this study investigated the pore surface properties and TC adsorption behavior of TRWP-contaminated sediments and explored the TC behavior in water sediments, as well as the role of aging processes and TRWPs abundance. The results showed that the surface morphology of TRWP-contaminated sediments changed and the adsorption capacity of sediments to TC increased. The TC adsorption capacity of sediments contaminated by 2% TRWPs increased from 3.15 to 3.48 mg/g. Moreover, the surface physical and chemical properties of TRWPs after UV aging changed, which further increased the TC adsorption capacity. The TC adsorption capacity of the sediments contaminated by aged TRWPs increased from 3.48 to 3.65 mg/g. Changing the proportion of aged TRWPs, we found that the adsorption capacity of sediments contaminated by different proportions of TRWPs for TC was 2% > 1% > 0.5% > 4% > blank sediment. These results may contribute to predicting the potential environmental risks of TRWPs in aquatic sediments.

Insight into the key factors and mechanism of excellent tetracycline adsorption on amorphous cobalt carbonate nanosheets.

The extensive use of tetracyclines (TCs) has led to their widespread distribution in the environment, causing serious harm to ecosystems because of their toxicity and resistance to decomposition. Adsorption is presently the principal approach to dispose of TCs, and the development of excellent adsorbents is crucial to TC removal. Herein, a novel amorphous cobalt carbonate hydroxide (ACCH) was successfully prepared by a one-step solvothermal method, which was identified as Co(CO3)0·63(OH)0.74·0.07H2O. The ultimate adsorption capacity of ACCH for TC reaches 2746 mg g-1, and the excellent adsorption performance can be maintained over a wide pH (3.0-11.0) and temperature (10-70 °C) range. Moreover, ACCH also exhibits a wonderful adsorption performance for other organic contaminants, such as ciprofloxacin and Rhodamine B. The TC adsorption process can be reasonably described by the pseudo-second-order kinetic model, intraparticle model and Langmuir isothermal model. The experimental results in this work suggest that the excellent adsorption performance of ACCH is ascribed to the large specific surface area, alkaline characteristics and numerous functional groups of ACCH. Accordingly, this work provides a promising strategy for the development of highly-efficient adsorbents and demonstrates their application prospects in environmental remediation.

Facile fabrication of Ag decorated MnFeO3 catalyst: Comparative analysis of visible light driven antibiotic reduction and antibacterial performance.

Photocatalysis is an effective method with the potential to eliminate pharmaceutical compounds from water sources. Manganese ferrite (MnFeO3), a type of multiferroic perovskite catalyst, has attracted significant attention due to its small band gap, however its application was limited due to its high recombination rate and low quantum efficiency. It was therefore aimed to improve the properties of MnFeO3 by doping silver (Ag)-particles. In this study, Ag-MnFeO3 photocatalysts with different Ag content (1-3 mmol%) were synthesized by performing a facile hydrothermal method. The as-prepared samples were characterized using x-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (DRS), photoluminescence spectroscopy (PL), electrochemical impedance spectroscopy (EIS) and Brunauer-Emmett-Teller (BET) method, showing successful addition of Ag-particles with the MnFeO3 structure. Then, the as-synthesized materials were investigated as: (i) photocatalysts for degradation tetracycline (TC) antibiotic and (ii) antibacterial agents for bacteria. The Ag-MnFeO3 catalyst demonstrated superior catalytic performance (95.7%), which was 1.6 times higher than that of pristine MnFeO3 (59.7%). The positive effect was ascribed to oxygen vacancies, enhanced light absorption ability, and lower recombination rate. The Ag-MnFeO3 catalyst also showed satisfactory removal performances in real water matrices. Furthermore, radical trapping tests depicted that the superoxide radicals played a dominant role in the photodegradation system. In addition, Box-Behnken design (BBD) was performed to determine the optimum conditions, which were determined as catalyst dosage of 0.45 g/L, initial TC concentration of 5.10 mg/L, and initial solution pH value of 3.69. In terms of antibacterial tests, the incorporation of Ag into the MnFeO3 structure greatly increased the antimicrobial resistance against bacteria. Our findings disclose that the incorporation of Ag into the MnFeO3 structure can be regarded as a feasible and promising approach to improve both photocatalytic degradation and antibacterial performances.

Unveiling activation mechanism of persulfate by homologous hemp-derived biochar catalysts for enhanced tetracycline wastewater remediation.

Advancements in biochar activating persulfate advanced oxidation processes (PS-AOP), have gained significant attention. However, the understanding of biochar-based catalysts in activating PS remains limited. Herein, biochar (BC) and N-doped biochar (NBC) were synthesized from hemp for activating PS to treat tetracycline (TC) wastewater and analyzed their mechanisms separately. Surprisingly, N-doped in biochar leads to a change in the activation mechanism of PS. The BC-PS system operates mainly through a radical pathway, advantageous for treating soil organic pollution (68%) with pH adaptability (less than 10% variation). Nevertheless, the NBC-PS system primarily employs an electron transfer non-radical pathway, demonstrating stability (only 7% performance degradation over four cycles) and enhanced resistance to anionic interference (less than 10% variation) in organic wastewater treatment. This study provides a technical reference and theoretical foundation for enhancing biochar activation of PS in the removal of organic pollutants from aquatic and terrestrial environments.

Highly efficient hydrophobic nanocomposite in the decontamination of micropollutants and bacteria from aqueous wastes: A sustainable approach.

Micro-pollutants (specifically antibiotics and personal care products) and potential bacterial contamination pose a severe threat to human health and marine life. The study derives indigenous novel fibrous hydrophobic nanocomposite, efficient in decontaminating the micro-pollutants (tetracycline (TC) and bisphenol A (BPA)) and potential pathogens (S. pyogenes and E. coli) from aqueous wastes. A facile method synthesizes the fibrous attapulgite (ATP)- poly(4-vinylpyridine-co-styrene) (PVP) framework decorated in situ with the Ag0 nanoparticles (ATP@PVP/Ag0). A greener method using the Artocarpus heterophyllus leaf extract derives the Ag0(NPs). Various analytical methods extensively characterize the materials. A comprehensive study that includes pH, concentration, background electrolytes, and ionic strength reveals the sorptive removal insights of TC and BPA utilizing the ATP@PVP solid. The elimination of tetracycline (TC) and bisphenol A (BPA) agrees well with the pseudo-second-order kinetics. The pH 3.07 and 6.06 favor removing TC and BPA with the capacity of 10.86 mg/g and 17.36 mg/g at 25 °C. The hydrogen bonding and hydrophobic interactions predominate the sorption mechanism, and the material shows remarkable stability and reusability in repeated sorption/desorption operations. Similarly, the natural water implications and flow-bed system show fair applicability of solid in decontaminating the TC and BPA in an aqueous medium. Further, the material ATP@PVP/Ag0 exhibits very high inhibition of potential pathogens S. pyogenes and E. coli and optimizes the solid dose and solution pH.

Dimension-controlled synthesis of BiOI for efficient visible light photodegradation of tetracycline: role of pore structure.

The transformation of photogenerated charge carriers (PC) in variable dimensional photocatalyst plays a pivotal role in unraveling the generation of reactive species (RS). However, the dimensional structure-activity relationship in photocatalysis remains elusive, with limited insights into its intricacies. Herein, we report a controlled synthesis strategy by using polyvinyl pyrrolidone (PVP)-assisted precipitation method for BiOI photocatalyst. Due to the steric hindrance of PVP, the 3D microsphere (3D-PVP0.5) and porous structure (3D-PVP1) of BiOI catalysts have been successfully prepared at room temperature. The 3D-PVP1 photocatalyst contains abundant mesopores and larger pores, which significantly shorten the diffusion distance of PC. Also, these PC in porous structure is beneficial for transferring from the inner phase to the surface of materials. Combined with optical property and radicals trapping experiments, the recombination rate of PC in porous structure performs a significant decrease, leading to the generation of more dominated ROS (•O2- and h+). The •O2- played a dominated role (86.98% of contribution rate) in photodegradation of tetracycline (TC) in 3D-PVP1 photocatalytic process. Compared with 2D nanosheet of BiOI (16.7% removal rate of TC), the as-prepared 3D porous structure of BiOI catalyst exhibits unique stable and high removal capacities (90.5%) for TC photodegradation under visible light irradiation. The kobs of 3D-PVP1 photocatalyst increased by 5.1 times than that of 2D nanosheet. To investigate its practical application, the effects of inorganic anions and pH have been systematically studied. This work sheds light on the design of variable dimension BiOI catalyst and provides more insight into the transfer mechanism of PC.

Preparation of Activated Biocarbons from Cones and their Potential Application for Adsorption of Antibiotics (Tetracycline).

The pine cones (PC), spruce cones (SC) and fir cones (FC) were used for biocarbons preparation. Chemical activation with sodium hydroxide was applied to prepare activated biocarbons. All the materials under investigation were characterized by the N2 adsorption, scanning electron microscopy (SEM), elemental analysis (CHNS), infrared spectroscopy (ATR FT-IR), and the Boehm's titration method. Moreover, pHpzc (the point of zero charge) was determined. It was shown that cones are a good, cheap precursor from which biocarbons with a developed porous structure, characterized by good adsorption properties, can be obtained. All the obtained adsorbents are characterized mainly by a microporous structure. Moreover, they contain both acidic and basic surface functional groups (acidic ones prevail over basic ones). The tested activated biocarbons have large specific surface area values ranging from 578 to 1182 m2 g-1. The efficacy of selected materials in the adsorption of an essential contaminant of increasing concern, tetracycline (TC), was investigated. The experimental data were described using the Langmuir and Freundlich adsorption isotherm models. The maximum adsorption capacity of the tested biocarbons ranges from 200 to 392 mg g-1. Thermodynamic studies proved that adsorption is a spontaneous and endothermic process. In summary, economical and environmentally friendly adsorbents were obtained.

Efficient removal of tetracycline and Cu2+ by honeycomb derived magnetic carbon: Adsorption mechanism and advanced oxidation regeneration mechanism.

The honeycomb magnetic carbons (xFe@HCNs) were prepared by sacrificial template method novelty using polyacrylamide resin (PAAS) as template and ammonium pyrrolidine dithioate/Fe3+ complex (APDC-Fe) as carbon skeleton and metal source. Tetracycline (TC) and copper (Cu2+) as target pollutants were used to investigate the adsorption properties of xFe@HCNs in single or binary TC and Cu2+ systems. The adsorption capacity sequence for TC among the adsorbents was (mmol·g-1): 2Fe@HCNs (0.088) > 8Fe@HCNs (0.061) > HCNs (0.054) > RC (0.036), and for Cu2+ was (mmol·g-1): 2Fe@HCNs (1.120) > 8Fe@HCNs (1.026) > RC (0.792) > HCNs (0.681). 2Fe@HCNs demonstrated notable affinity for adsorbing both TC and Cu2+. Additionally, the influence of hydrochemical factors (i.e., cation species, anion species, and pH) on the adsorption properties of 2Fe@HCNs. Combined with advanced oxidation technology, the regeneration methods of magnetic adsorbent were explored using oxidizing agents (e.g., H2O2 and peroxymonosulfate) as eluents which could increase the adsorption sites of magnetic carbon adsorbents during the regenerating process, which was the novelty of the study. Furthermore, the regeneration mechanisms of H2O2 as eluent were investigated. This study discussed the application and regeneration methods of magnetic adsorbents in water treatment, offering new insights into environmental remediation using magnetic materials.

Photocatalytic degradation of tetracycline using a novel WO3-ZnO/AC under visible light irradiation: Optimization of effective factors by RSM-CCD.

Mitigating pharmaceutical pollution in the global environment is imperative, and tetracycline (TC) is a commonly utilized antibiotic in human and veterinary medicine. The persistent existence of TC highlights the necessity of establishing efficient measures to protect water systems and the environment from detrimental contaminants. Herein, a novel rhubarb seed waste-derived activated carbon-supported photocatalyst (WO3-ZnO/RUAC) was synthesized by combining wet impregnation and ultrasonic methods. The activated carbon (AC) was obtained from rhubarb seed waste for the first time via chemical activation. The function of AC as an electron acceptor and in separating electron-hole pairs was illuminated by characterization analyses that included XRD, FTIR, XPS, SEM, TEM, PL, EIS, TPC, and UV-DRS. Using the response surface methodology-central composite design (RSM-CCD) technique, the synthesis parameters of the composite were systematically optimized. Under ideal conditions, with a TC concentration of 33 mg. L-1, pH of 4.57, irradiation time of 108 min, and catalyst dose of 0.85 g. L-1, the highest degradation efficiency of TC by this composite, achieved 96.5%, and it was reusable for five cycles. Subsequently, trapping tests and electron spin resonance (ESR) analysis were conducted, elucidating that •OH and •O2- radicals played pivotal roles in the photocatalytic degradation of TC. This research offers valuable insights into utilizing the AC-based photocatalyst to degrade pharmaceutical micropollutants effectively.

Comparative study of reactive oxygen species and tetracycline degradation pathways in catalytic peroxodisulfate activation by asymmetric mesoporous TiO2 and the corresponding controlled-release materials.

The removal of trace amounts of antibiotics from water environments while simultaneously avoiding potential environmental hazards during the treatment is still a challenge. In this work, green, harmless, and novel asymmetric mesoporous TiO2 (A-mTiO2) was combined with peroxodisulfate (PDS) as active components in a controlled-release material (CRM) system for the degradation of tetracycline (TC) in the dark. The formation of reactive oxygen species (ROS) and the degradation pathways of TC during catalytic PDS activation by A-mTiO2 powder catalysts and the CRMs were thoroughly studied. Due to its asymmetric mesoporous structure, there were abundant Ti3+/Ti4+ couples and oxygen vacancies in A-mTiO2, resulting in excellent activity in the activation of PDS for TC degradation, with a mineralization rate of 78.6%. In CRMs, ROS could first form during PDS activation by A-mTiO2 and subsequently dissolve from the CRMs to degrade TC in groundwater. Due to the excellent performance and good stability of A-mTiO2, the resulting constructed CRMs could effectively degrade TC in simulated groundwater over a long period (more than 20 days). From electron paramagnetic resonance analysis and TC degradation experiments, it was interesting to find that the ROS formed during PDS activation by A-mTiO2 powder catalysts and CRMs were different, but the degradation pathways for TC were indeed similar in the two systems. In PDS activation by A-mTiO2, besides the free hydroxyl radical (·OH), singlet oxygen (1O2) worked as a major ROS participating in TC degradation. For CRMs, the immobilization of A-mTiO2 inside CRMs made it difficult to capture superoxide radicals (·O2-), and continuously generate 1O2. In addition, the formation of sulfate radicals (·SO4-), and ·OH during the release process of CRMs was consistent with PDS activation by the A-mTiO2 powder catalyst. The eco-friendly CRMs had a promising potential for practical application in the remediation of organic pollutants from groundwater.

Iron­calcium dual crosslinked graphene oxide/alginate aerogel microspheres for extraordinary elimination of tetracycline in complex wastewater: Performance, mechanism, and applications.

Antibiotics have been considered as a group of emerging contaminants for their stable chemical structure, significant pseudo-persistence, and biological toxicity. Tetracycline (TC), as one of the typical antibiotics frequently detected in environmental media, can cause the dissemination and accumulation of antibiotic resistance gene (ARG), ultimately threatening human health and environmental safety. Herein, a novel iron­calcium di-crosslinked graphene oxide/alginate (GO/SA-Fe3+-Ca2+) aerogel was facilely synthesized for TC uptake. It was found that the introduction of GO nanosheets and Fe3+ sites into composite enormously enhanced TC removal. Specifically, TC can be stably and efficiently eliminated over the wide pH range of 5-8. The fitted maximum qe with Liu isotherm model at 308 K reached 1664.05 mg/g, surpassing almost all reported sorbents. The pseudo-second-order kinetic model with chemical sorption characteristics better fitted TC adsorption process, which was endothermic and spontaneous in nature. Multifarious adsorptive sites of GO/SA-Fe3+-Ca2+ synergically participated in TC uptake through multi-mechanisms (e.g., π-π EDA, cation-π bonding, H-bonding, Fe3+-coordination, and electrostatic attraction, etc.). The as-prepared composite showed satisfactory TC removal in several runs of adsorption-desorption operations, high salinity, and model aquaculture wastewater. Moreover, the packed-column could continuously run for >200 h until adsorption saturation was achieved with a dynamic adsorption capacity of 216.69 mg/g, manifesting its scale-up engineering applications. All above merits make as-constructed composite an alternative sorbent for eliminating TC from complex wastewater.

Construction of SU-102 for adsorption and photocatalytic synergistic removal of tetracycline.

Tetracycline (TC) is a significant group of broad-spectrum antibiotics that are frequently employed in medical health and animal husbandry. However, the problem of TC residues has been increasing globally with the large-scale production and widespread use, posing a serious threat to the human health and ecological environment. In this paper, a green plant-based MOF SU-102 was prepared, and the adsorption characteristics of SU-102 on TC were investigated. SU-102 was columnar crystal with considerable specific surface area and pore structure, and it could adsorb TC quickly and effectively. And compared to SU-102-a, the adsorption rate of TC by SU-102-b has increased by nearly four times. The adsorption reaction was a spontaneous, entropy-gaining, heat-absorbing process. The adsorption mechanisms between SU-102 and TC were π-π interaction and hydrogen bonding. In addition, SU-102 also had considerable photocatalytic properties, and its application in adsorbent desorption treatment effectively solved the problem of secondary pollution.

Synergistic cobalt­copper metal-organic framework anchored amino-functionalized cellulose for antibiotic degradation: Interfacial engineering and mechanism insight.

Improving electron transfer rate of Co species and inhibiting aggregation of metal-organic frameworks (MOFs) particles are essential prerequisites for activating advanced oxidation process in wastewater treatment field. Here, we exploit Cu species with variable valence states to accelerate electron transfer of Co species and then to boost the unsatisfactory degradation efficiency for refractory pharmaceuticals via in-situ growth of copper and cobalt species on l-lysine functionalized carboxylated cellulose nanofibers. Utilizing the synergistic interplay of Co sites and deliberately exposed Cu0/Cu1+ atoms, the subtly designed catalyst exhibited a surprising degradation efficiency (~100 %) toward tetracycline hydrochloride within 10 min (corresponding to a catalytic capacity of 267.71 mg/g) without adjusting temperature and pH. Meanwhile, the catalyst displays good recyclability, well tolerance for coexisting ions and excellent antibacterial performance derived from the intrinsic antibacterial property of Cu-MOF. This research provided a novel strategy to construct MOFs-cellulose materials toward degrading various stubborn antibiotic pollutants.

Subnano-Fe (Co, Ni) clusters anchored on halloysite nanotubes: an efficient Fenton-like catalyst for the degradation of tetracycline.

Iron-based catalysts are environmentally friendly, and iron minerals are abundant in the earth's crust, with great potential advantages for PMS-based advanced oxidation process applications. However, homogeneous Fe2+/PMS systems suffer from side reactions and are challenging to reuse. Therefore, developing catalysts with improved stability and activity is a long-term goal for practical Fe-based catalyst applications. In this study, we prepared Fe-HNTs nanoreactors by encapsulating a nitrogen-doped carbon layer with one-dimensional halloysite nanotubes (HNTs) using the molten salt-assisted method. Subsequently, Fe (Co, Ni) nanoclusters were anchored onto the nitrogen-doped carbon layer at a relatively low temperature (550℃), resulting in stable and uniform distribution of metal nanoclusters on the surface of HNTs carriers in the form of Fe-Nx coordination. The results showed that the dissolution of the molten salt and leaching of post-treated metal oxides generated numerous mesopores within the Fe-HNTs nanoreactor, leading to a specific surface area more than 10 times that of HNTs. This enhanced mass transfer capability facilitates rapid pollutant removal while exposing more active sites. Remarkably, Fe-HNTs adsorbed up to 97% of tetracycline within 60 min. In the Fe-HNTs/PMS system, the predominant reactive oxygen species has been shown to be 1O2, and the added tetracycline was degraded by more than 98% within 5 min. The removal of tetracycline was maintained above 96% in the presence of interfering factors such as wide pH (3-11) and inorganic anions (5 mM Cl-, HCO3-, NO3-, and SO42-). The investigated mechanism suggests that efficient degradation and interference resistance of the Fe-HNTs/PMS system is attributed to the synergistic effect between the rapid adsorption of porous structure and the non-radical (1O2)-dominated degradation pathway.

Amino-functionalized cellulose composite for efficient simultaneous adsorption of tetracycline and copper ions: Performance, mechanism and DFT study.

A novel cellulose composite (denoted as PEI@MMA-1) with porous interconnected structure was prepared by adsorbing methyl cellulose (MC) onto microcrystalline cellulose (MCC) and cross-linking polyethyleneimine (PEI) with MCC by the action of epichlorohydrin, which had the excellent adsorption property, wettability and elasticity. The performances of PEI@MMA-1 composite for removing tetracycline (TC), Cu2+ and coexistent pollutant (TC and Cu2+ mixture) were systematically explored. For single TC or Cu2+ contaminant, the maximum adsorption capacities were 75.53 and 562.23 mg/g at 30 °C, respectively, while in the dual contaminant system, they would form complexes and Cu2+ could play a "bridge" role to remarkably promote the adsorption of TC with the maximum adsorption capacities of 281.66 and 253.58 mg/g for TC and Cu2+. In addition, the adsorption kinetics, isotherms and adsorption mechanisms of single-pollutant and dual-pollutant systems have been thoroughly investigated. Theoretical calculations indicated that the amide group of TC molecule with the assistance of Cu2+ interacted with the hydroxyl group of PEI@MMA-1 composite to enhance the TC adsorption capacity. Cycle regeneration and fixed bed column experiments revealed that the PEI@MMA-1 possessed the excellent stability and utility. Current PEI@MMA-1 cellulose composite exhibited a promising application for remediation of heavy metals and antibiotics coexistence wastewater.