Removal Of Tetracycline Hydrochloride Research Articles

Montmorillonite-modified stabilizing SA/CMC gel spheres cross-linked by lanthanum for tetracycline hydrochloride removal

In this study, a stable gel sphere was successfully prepared by crosslinking sodium alginate(SA) with sodium carboxymethyl cellulose(CMC) through La and modified by MMT for removing tetracycline hydrochloride (TCH). The obtained materials have been comprehensively characterized using SEM, FTIR, XRD and XPS. The results of batch experiments showed that La@SA/CMC-MMT-0.5 had a high adsorption capacity of TCH, and its maximum adsorption capacity was up to 420.95 mg/g. The adsorption process followed a pseudo-second-order kinetic model and the Freundlich isotherm model. The removal of TCH was a combined process involving both chemisorption and physical adsorption. Hydrogen-bond and complexation played a primary role in removing process, while the role of static electricity was more limited. The MMT modification not only enhanced adsorption capacity of TCH but also improved the thermal stability of the material by creating a temperature barrier and promoting hydrogen-bond. La substitution of metal ions in MMT and electrostatic attraction by MMT-surface negative charges contributed to reducing La-release. In application experiments, the La@SA/CMC-MMT-0.5 showed a high adsorption capacity, strong anti-disturbance performance, and good reusability. Therefore, La@SA/CMC-MMT-0.5 holds great potential for the effective adsorption of TCH in aqueous environments.

Efficient removal of tetracycline hydrochloride by high entropy oxides in visible photo-Fenton catalytic process

ABSTRACT A novel type of oxide material, high entropy oxide (Mn0.2Fe0.2Co0.2Ni0.2Cu0.2)3O4 (MFO) composites with spinel structure were successfully synthesized by a simple solution combustion in this paper, and it was first applied to the degradation of antibiotic organic pollutants in water by photo-Fenton. SEM and BET characterization showed that the composite was porous and had a large specific surface area. XPS results showed that Fe, Mn, Cu, Co and Ni all participated in the redox reaction of the catalytic process. The redox pairs of Mn2+/Mn3+, Cu+/Cu2+, Co2+/Co3+, Ni2+/Ni3+ can accelerate the Fe2+/Fe3+ redox cycling in MFO to activate H2O2 and produce more reactive oxygen species. The catalytic performance of MFO composite was investigated using tetracycline hydrochloride (TC-HCl) as a model pollutant. The results displayed that the degradation rate of TC-HCl by MFO was 92.9% when the initial pH was 4, the dose of H2O2 was 50 mM, and the irradiation time was 60 min. The high entropy oxide MFO composites could build up an internal electric field, which restrains electron–hole recombination, improves the transfer of photogenerated charge carriers and maximize photocatalytic property. In addition, the free radical capture experiment determined that the main active species of the degradation reaction were e−, •O2 − and •OH. The synergistic effect of the five components in the high entropy oxide strengthens lattice distortion and defects, increases oxygen vacancies, and thus has enhanced catalytic effect for TC-HCl degradation. This work shows that high entropy oxides have excellent catalytic performance for tetracycline organic pollutants, and it is speculated that high entropy oxides have good application prospects in the field of advanced oxidation technology for the degradation of organic pollutants.

Nonthermal plasma induced NiS/UiO-66-NH2 for boosting visible-light photo-Fenton degradation of tetracycline hydrochloride

Heterojunctions constructed from metal organic frameworks (MOF) and metal sulfides are the potential candidates for solar-light driven photo-Fenton elimination of antibiotics from wastewater. To boost the solar-light induced photo-Fenton degradation of tetracycline hydrochloride (TCH) over UiO-66, NH2-functionlized UiO-66 (UiO-66-NH2) was in-situ loaded with NiS (NiS/NU-66) via the nonthermal plasma sulfurization. For comparison to UiO-66-NH2, NiS/NU-66 had the lower adsorption capacity while the higher photo-Fenton activity for TCH removal. The removal efficiency of NiS/NU-66 climbed and then declined with an increase in NiS content, and the best removal efficiency (84.92 ± 2.55 %) for 110 mg L−1 TCH solution was obtained by c-NiS/NU-66 in 150 min. The sulfur and oxygen defects as well as the plentiful functional groups over NiS/NU-66 were favorable for providing the abundant vacant sites of TCH adsorption and photons capture. In addition, the rapid separation and migration of photo-generated e−/h+ pairs were achieved at the tight junction interface between NiS and UiO-66-NH2, enlarging the visible-light absorption capacity. In NiS/NU-66-assisted photocatalytic system, H2O2 was efficiently convert to •OH by e− and Ni2+/Ni3+ couples in solar light region. Hence, •OH, •O2− and h+ played the vital roles in this photo-Fenton system.

Photocatalytic removal of Cr(Ⅵ) and efficient degradation of tetracycline by oxygen-enriched vacancy pie-like NH2-MIL-125(Ti)

The heavy metals hexavalent chromium and tetracycline hydrochloride have caused considerable harm to the ecological environment of water. This has led to unprecedented requirements for the treatment and protection of the water environment. To address this problem, a cake—NH2-MIL-125(Ti)—was synthesised using a straightforward hydrothermal process, and NH2-MIL-125(Ti) catalysts with different oxygen vacancy concentrations (NMTi-OVs-X catalysts) were prepared through heat treatment. Cr(Ⅵ) and tetracycline hydrochloride (TCH) present in water were used as targets to analyse the samples’ ability to remove catalysis under sunlight. The experimental results indicate that the sample calcined at 300 °C for 300 min (NMTi-OVs-300) exhibits the highest catalytic activity. The effectiveness of TCH and Cr(VI) removal are 80 % and 100 % under simulated sunlight, respectively. Additionally, the reaction kinetic constant is 7.8 and 18.9 times higher than that of NH2-MIL-125(Ti). Proper defect sites contribute to the separation of photogenerated charges, enabling NMTi-OVs-300 to display satisfactory stability and excellent photocatalytic performance. The active substances were determined via electron spin resonance, and a photocatalytic reaction mechanism was suggested. This work provides a novel approach for the photocatalytic degradation of organic pollutants and Cr(VI) using a single semiconductor.

Liquid plasma discharge with low pulse voltage for efficient and ultra rapid removal of tetracycline hydrochloride and evaluation of its degradation pathway

Cathode liquid plasma discharge (LPD) is an efficient and ultra rapid method to degrade organic pollutants, mainly because it can produce a large number of strong oxidizing radical species during the process of plasma discharge. In this paper, the LPD process was firstly used to degrade the tetracycline hydrochloride (TCH) in water. The effects of the cathodic materials, pulse voltages, and anode-cathode distances on the degradation efficiency of the TCH were investigated, and the antibacterial activity and cytotoxicity of the degradation products were also evaluated. The results show that the degradation efficiency of the TCH can reach 98.13 % within only 1 min by the LPD process for initial concentration of 100 mg/L, and the TOC removal rate is maintained at over 81 % in 5 min. The Ti electrode performs the lowest ionic dissolution concentration and the solution near the cathode produces a plasma region for the degradation of the TCH, which contains a number of strong oxidizing radical species (such as ∙OH). The primary intermediate products (m/z = 445, 279, 149, and 123) and secondary intermediate products (m/z = 90.5, 81, and 59) are captured, and a possible degradation pathway of the TCH is also proposed. The cytotoxicity results show that the LPD degraded solutions are non-toxic effect on the NIH3T3 cells. The LPD process is a promising method to efficiently eliminate the TCH in wastewater. This work also provides a new experimental basis and reference for the ultra rapid degradation of organic pollutants in wastewater without using catalysts.

Underwater bubbling plasma assisted with persulfate activation for the synergistic degradation of tetracycline hydrochloride

The performance and mechanism of persulfate consisting of peroxymonosulfate (PMS) and peroxydisulfate (PDS) activation by underwater bubbling plasma (UBP) for the synergistic removal of tetracycline hydrochloride (TCH) were comparatively investigated. Both PMS and PDS addition significantly promoted the removal of TCH in UBP system, indicating persulfate exhibited highly synergistic effect with UBP. Furthermore, enhancing the persulfate dosage, peak voltage and pulse frequency, as well as reducing initial TCH concentration were favorable for the elimination of TCH. Compared with neutral condition, acidic and alkaline condition were advantageous to TCH removal. The presence of coexisting substances including Cl−, SO42− and humic acid (HA) had an adverse effect on TCH degradation, while Fe2+ could improve the removal of TCH. The degradation of ciprofloxacin and metronidazole proved the applicability for other antibiotics degradation of the reaction system. SO4−·, ·OH, ·O2−, hydrated electrons, O3 and H2O2 were the active substances responsible for TCH removal. The reduction of aqueous O3 concentration and enhancement of H2O2 concentration were observed after persulfate addition. UV–vis spectra and TOC analysis illustrated the addition of PMS or PDS facilitated the degradation and mineralization of TCH. 3D-EEMF spectra visually displayed the degradation process of TCH. Plausible degradation routes were deduced based on LC-MS and the toxicities of TCH and its intermediates were evaluated by Toxicity Estimation Software Tool.

Designing Z-scheme In2O3 @ZnIn2S4 core-shell heterojunctions for enhanced photocatalytic multi-pollutant removal

In water bodies, the coexistence of and interaction between multiple pollutants complicate remediation. In this study, the In2O3 @ZnIn2S4 Z-scheme heterojunction with a stratified core-shell structure was constructed and used to remove multiple pollutants (tetracycline hydrochloride and Cr(VI)). The large number of active sites and the mechanism of photogenerated charge separation ensured the substantially enhanced catalytic activity of this photocatalyst, making it superior to In2O3 nanospheres and pure ZnIn2S4. The optimised In2O3 @ZnIn2S4 nano-flowers (In2O3 @ZnIn2S4 NFs) realised 99.8% removal of tetracycline hydrochloride and 100% removal of Cr(VI) within 60 min under visible-light. The material’s high stability was demonstrated by five experiment cycles. Effects of organics, inorganics, and pH about the photocatalytic performance of the optimised In2O3 @ZnIn2S4 NFs when tetracycline hydrochloride and Cr(VI) coexist were also explored. Finally, the intermediates and degradation pathways were analysed, and the possible photocatalytic mechanism was also investigated by performing density functional theory calculations.

Fe, Mn-Prussian blue analogue@MXene composites for efficient photocatalytic peroxydisulfate-activated degradation of tetracycline hydrochloride and photoelectrochemical desalination

The utilization of wastewater or saline as a source of clean and safe freshwater is a potential solution to address water pollution and scarcity. In this study, we synthesized a composite material, i. e. Fe, Mn-Prussian blue analogue@MXene, which is highly responsive to visible light and serves as an innovative activator for peroxydisulfate (PDS) in the degradation of tetracycline hydrochloride (TCH). The FeMn-PBA@MXene-0.30 composite, with its unique metal-organic framework (MOF) structure, exhibited excellent photocatalytic activity in the degradation of TCH by activating PDS through dual redox cycles of Mn(II)–C≡N–Fe(III) and Mn(III)–C≡N–Fe(II). A remarkable 93.41% removal of TCH can be achieved at a concentration of 30 mg·L−1 within 120 min. The presence of MXene in the composite may facilitate the efficient electron transportation owing to its excellent conductivity. The influences of various reaction conditions are also investigated, such as the concentration of potassium persulfate (KPS), TCH concentration, and solution pH value. Electron spin resonance (ESR) analysis and trapping experiments revealed the presence of reactive species, including 1O2, ∙OH, and h+, in the FeMn-PBA@MXene-0.30/visible light/PDS system. Furthermore, we demonstrated the application of the FeMn-PBA@MXene-0.30 composite as the photoanode of a solar-assisted photoelectrochemical desalination (SA-PED) device, which combines the TCH degradation with photoelectrochemical desalination. This novel approach enabled simultaneous degradation and desalination, resulting in a significant reduction of 4000-ppm brine to 240 ppm (lower than the freshwater threshold of 500 ppm), with a salt removal efficiency (SRE) of 94.00%. Meanwhile, the degradation rate of TCH (900 mg·L−1) reached up to 98.91% under visible light irradiation. This work not only provides valuable insights into the development of PDS-activated catalysts but also explores new avenues for the multifunctional application of photocatalysts in addressing water pollution and scarcity.

2D/1D ZnIn2S4/attapulgite hybrid materials for enhanced photocatalytic performance under visible light

The 2D/1D structure of ZnIn2S4/attapulgite was constructed by anchoring ZnIn2S4 nanosheets on the surface of attapulgite nanorods for the removal of tetracycline hydrochloride (TC) and rhodamine B (RhB). The 2D ZnIn2S4 was closely combined with the 1D attapulgite, and ZnIn2S4/attapulgite had a higher BET surface area (83.6 m2/g) than pure ZnIn2S4 (13.6 m2/g). The combination of ZnIn2S4 and attapulgite promoted pollutant adsorption by providing more exposed active sites and a larger contact area, which also contributed to enhanced photocatalytic performance. Under visible light irradiation, the as-prepared ZnIn2S4/attapulgite composites exhibited enhanced photocatalytic activity when compared with pure ZnIn2S4. After 9 min (50 min) of irradiation, the optimized ZnIn2S4/attapulgite photocatalyst removed about 99.9% RhB (82.1% TC). In addition, the ZnIn2S4/attapulgite photocatalyst demonstrated excellent photostability and availability. Compared with other photocatalysts, the samples in this work used natural minerals as the carrier, which significantly improved the dispersibility and adsorption performance of the catalyst, and was conducive to the improvement of catalytic performance. This work contributed to the development of photocatalysis for the removal of environmental liquid-phase pollutants.

Activation of peroxymonosulfate by biochar-supported Fe3O4 derived from oily sludge to enhance the oxidative degradation of tetracycline hydrochloride

Carbon materials used for catalysis in advanced oxidation processes tend to be obtained from cheap and readily available raw materials. We constructed a carbon material, OSC@Fe3O4, by loading Fe3O4 onto the pyrolyzed hazardous waste oily sludge. OSC@Fe3O4 was then used to activate peroxymonosulfate (PMS) for the removal of tetracycline hydrochloride (TTCH) from water. At 298 K, 0.2 g⋅L−1 of catalyst and 0.3 g⋅L−1 of PMS, the reaction rate constant of the OSC@I-2/PMS system reached 0.079 min−1, with a TTCH removal efficiency of 92.6%. The degradation efficiency of TTCH remained at 81% after five cycles. The specific surface area and pore volume of OSC@I-2 were 263.9 m2⋅g−1 and 0.42 cm3⋅g−1, respectively, which improved the porous structure of the carbon material and provided more active points, thus improving the catalytic performance. N and S were doped into the oily sludge carbon due to the presence of N- and S-containing compounds in the raw oily sludge. N and S doping led to more electron-rich sites with higher negative charges in OSC@I-2 and gave the oily sludge carbon a higher affinity to PMS, thereby promoting its ability to activate PMS. Sulfate radicals (SO4•‾) played a dominant role in the degradation of TTCH, with demethylation and the breaking of double bonds being a possible degradation pathway. A biotoxicity test showed that the microbial toxicity of the degradation intermediates was significantly reduced. This work provides a strategy for the application of PMS-based catalysts derived from waste carbon resources.

Corrigendum to “Efficient adsorption-photocatalytic performance of La2S3/MgO-modified biochar in the removal of tetracycline hydrochloride at a low optical density” [Mater. Sci. Semicond. Process. 165 (2023) 107690

Corrigendum to “Efficient adsorption-photocatalytic performance of La2S3/MgO-modified biochar in the removal of tetracycline hydrochloride at a low optical density” [Mater. Sci. Semicond. Process. 165 (2023) 107690

Efficient adsorption-photocatalytic performance of La2S3/MgO-modified biochar in the removal of tetracycline hydrochloride at a low optical density

Efficient adsorption-photocatalytic performance of La2S3/MgO-modified biochar in the removal of tetracycline hydrochloride at a low optical density

Adsorption characteristics of tetracycline hydrochloride and oxytetracycline by a MOF-525(Co) metal organic framework

Metal organic frameworks (MOFs) has attracted significant scientific interest due to the advantages of high porosity, special porous structure, large specific surface area, open metal sites and modifiable pore size. In this study, the adsorptive performances of tetracycline hydrochloride (TCH) and oxytetracycline (OTC) are evaluated with three Zr-MOFs (MOF-545, MOF-525(Zn), and MOF-525(Co)). Results show that MOF-525(Co) is the optimal adsorbent when the initial antibiotic concentration of 100 mg L-1. The removal efficiency for TCH and OTC is 89.4% and 84.2% at 15 min; moreover, 100% for TCH or OTC is obtained at 60 min. The optimal adsorption pH is 9.0 for TCH and 5.0 for OTC, and the adsorption capacity of TCH by MOF-525(Co) is decreased while that of OTC is increased with the increasing of NaCl concentration from 0 to 1.0 mol L−1. It is revealed that the pseudo-second-order kinetic model (PSOK) fits much better for describing the antibiotics adsorption processes; It is also further suggested that Langmuir is better fitted for TCH, while Freundlich is better fitted for OTC; the adsorption process of both TCH and OTC can be illustrated as spontaneous, endothermic, and with positive entropy by thermodynamics data. Furthermore, the spectroscopy results (including X-rayphotoelectron spectra (XPS) and fourier transform infrared spectroscopy (FT-IR)) indicate that the adsorption mechanisms of both TCH and OTC by MOF-525(Co) are belonging to the π-π interactions, electrostatic interactions, hydrogen bonds, and pore-filling. These results may provide new insights into the potential application of MOF-525(Co) as adsorbent for simultaneous removal of TCH and OTC from aqueous solution.

Efficient peroxymonosulfate activation by Aurivillius phase Bin+1Fen-3Ti3O3n+3(n = 4, 5, 6) for wastewater purification

Aurivillius phase layered perovskites, Bin+1Fen-3Ti3O3n+3(n = 4, 5, 6), have been deemed as promising photocatalysts for degrading organic pollutants in wastewater. However, the inferior photocatalytic performance has greatly limited its application. Here, Bin+1Fen-3Ti3O3n+3 (n = 4, 5, 6) nano-shelves were fabricated and applied as heterogeneous photocatalysts in peroxymonosulfate (PMS) activation for tetracycline hydrochloride degradation. Compared with Bin+1Fen-3Ti3O3n+3(n = 4, 5, 6), the Bin+1Fen-3Ti3O3n+3(n = 4, 5, 6)/PMS system demonstrated an excellent enhancement for tetracycline hydrochloride removal under visible light illumination. Among the synthesized photocatalysts, Bi7Ti3Fe3O21/PMS showed the highest catalytic activity, with the calculated kinetic constant reaching as high as 0.0394 min−1, which was about 78.8 higher than that of Bi7Ti3Fe3O21. The improved tetracycline hydrochloride degradation performance of Bi7Ti3Fe3O21/PMS is attributed to the presence of abundant oxygen vacancies in Bi7Ti3Fe3O21, which can not only boost the separation of electron-hole pairs but also facilitate PMS activation and radical generation. Besides, the scavenging experiments and electron spin resonance analysis showed that sulfate radicals, superoxide radicals, hydroxyl radicals, and holes could effectively degrade tetracycline hydrochloride. Overall, these findings are beneficial for understanding the mechanism of PMS activation by Aurivillius phase layered perovskites-based catalysts and are helpful for the practical application of sulfate-based technology for wastewater purification.

Insight and mechanisms of tetracycline adsorption on sodium alginate/montmorillonite composite beads

The presence of antibiotics in soil and water raises great health concerns because they may increase the development of harmful antibiotic-resistant bacteria. In this study, composite beads prepared from 2:1 or 1:1 ratios of montmorillonite (Mt) and sodium alginate (SA) were used to adsorb tetracycline hydrochloride (TC), an antibiotic commonly found in aqueous systems. The equilibrium time for TC adsorption onto the Mt/SA was 8 h, and the kinetic data were consistent with the pseudo-second-order model. The adsorption isotherm was described with the Langmuir equation. The maximum amounts of TC adsorbed were 745, 689, and 445 mg g−1 for the 2:1- and 1:1-Mt/SA and the original Mt, respectively. The Mt/SA composite beads exhibited porous structures; however, this did not play a key role in TC removal, as previously reported. Cation exchange was the major adsorption mechanism, and electrostatic attraction and hydrogen bonding between the SA and TC also contributed to TC adsorption on the Mt/SA composite beads. In addition, the migration of a small amount of TC into the inner spaces of the beads led to the intercalation of the TC in the Mt interlayers and enhanced TC adsorption by the Mt/SA composite beads.

Bifunctional organic cobalt phosphonates nanoplates with efficient photocatalytic peroxymonosulfate activation and electrocatalytic water oxidation

The exploration of efficient and inexpensive transition metal phosphonates-based materials with multifunctional applications has increasingly urgent and meaningful. Herein, the organic cobalt phosphonates nanoplates (CoPPA) catalyst was achieved via a solvothermal process without employing any additives. The CoPPA catalyst proceeds nanoplates architecture with minimal sheet thickness, which not only reduce the transfer distance for charge carriers to the surface of catalyst and realize the separation of the charge carriers, but also provide numerous active sites for surface reaction. As a result, the optimal CoPPA catalyst not merely accelerated the photocatalytic activation of peroxymonosulfate (PMS) for tetracycline hydrochloride removal in CoPPA/PMS/Vis system, but also effectively electric-catalyze the oxygen evolution reaction. This work provides fresh insights for exploring high-efficiency dual-functional transition metal phosphonates-based materials and is expected to contribute to purify recalcitrant contaminants and energy conversion.

Zeolitic imidazolate framework-8 modified bacterial cellulose/sodium alginate composite aerogel for efficient removal of tetracycline hydrochloride

Antibiotics released in the water pose a serious threat to human and ecological health. Therefore, it is of great importance to effectively remove antibiotics from wastewater. In this study, recyclable bacterial cellulose/sodium alginate/zeolitic imidazolate framework-8 (BC/SA/ZIF-8) aerogel composites were prepared by chemical cross-linking and in situ growth in freeze-drying. The successful preparation of the composite aerogel was confirmed by scanning electron microscope (SEM), Fourier Transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. The results reveal that BC/SA/ZIF-8 aerogel composite has significantly high BET specific surface area of 165.24 m2/g than that of BC/SA at 7.39 m2/g. The BC/SA/ZIF-8 composite aerogel exhibited excellent adsorption performance for tetracycline hydrochloride, with a maximum adsorption capacity of 746.27 mg/g. The adsorption process followed the pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Moreover, the reusability test on BC/SA/ZIF-8 composite aerogel revealed an insignificant decline in adsorption after six cycles. Therefore, BC/SA/ZIF-8 composite aerogel has a high potential as a novel and recyclable adsorbent for efficient removal of tetracycline hydrochloride from water.

Synthesis of phosphoric acid-based mesoporous geopolymers from tourmaline tailings for effective adsorption of tetracycline hydrochloride in aqueous environment

As a porous material, geopolymers (GPs) have attracted more attention for wastewater purification. Herein, a low-cost and environmentally friendly phosphoric acid-based tourmaline tailings geopolymers (PTMT-GP) were fabricated, and used as adsorbents for removal of tetracycline hydrochloride (TCH) in solution. The morphological and structural evolution of TMT after phosphoric acid attack was confirmed by XRD, SEM and FT-IR. The optimal PTMT-GP0.7 had the largest average pore and specific surface area, which were 3.89 nm and 115.66 m2 g−1, respectively. The observed adsorption process of TCH on PTMT-GP0.7 could be perfectly explained by pseudo-second-order kinetic model, and the maximum theoretical adsorption capacity, obtained from the Langmuir model, was 82.56 mg g−1 at 318 K and pH = 3. Thermodynamics indicated that the adsorption process of TCH on PTMT-GP0.7 was not only endothermic, but also feasible and spontaneous. The removal of TCH in aqueous by PTMT-GP0.7 suggested the combined effect of physical and chemical adsorption, including pore filling, electrostatic, H-bonding and ion exchange interaction. After 5 reuse cycles, PTMT-GP0.7 maintained 86.56% of the first saturated adsorption capacity for TCH, and the adsorption capacity of PTMT-GP0.7 calcined at 400 °C for 2 h decreased by 4.56%. This work will provide a valuable reference for evaluating the adsorption performance of phosphate-based geopolymer materials synthesized from tailings, which are expected to be a low-cost, green and stability adsorbent to remove TCH from wastewater.

Floating metal phthalocyanine@polyacrylonitrile nanofibers for peroxymonosulfate activation: Synergistic photothermal effects and highly efficient flowing wastewater treatment

Highly efficient floating photocatalysis has potential applications in organic pollutant treatment but remains limited by low degradation efficiency in practical applications. By introducing the photothermal effect into a peroxymonosulfate (PMS) coupled photocatalysis system, tetracycline hydrochloride (TCH) degradation could be significantly enhanced using floating metal phthalocyanine@polyacrylonitrile (MPc@PAN) nanofiber mats. MPc@PAN nanofibers with different metal centers showed similar photothermal conversion performance but different activation energies for PMS activation, resulting in metal-center-dependent synergistic photothermal effects, i.e., light-enhanced dominated, thermal-enhanced dominated, and conjointly light-thermal dominated mechanisms. The porous structures and floating ability of the FePc@PAN nanofibers provided a fast mass transfer process, with higher solar energy utilization and superior photothermal conversion performance than the FePc nanopowders. Meanwhile, the FePc@PAN nanofibers showed excellent TCH removal stability within 10 cycles (>92%) and extremely low Fe ion leaching (<0.055 mg/L) in a dual-channel flowing wastewater treatment system. This work provides new insight into PMS activation via photothermal effects for environmental remediation.

Biochar loaded with CoFe2O4 enhances the formation of high-valent Fe(IV) and Co(IV) and oxygen vacancy in the peracetic acid activation system for enhanced antibiotic degradation

Corn straw and sludge-derived biochar composite (BC) loaded with CoFe2O4 was successfully prepared to activate peracetic acid (PAA) for efficient degradation of tetracycline hydrochloride (TCH). Within 60 s, 96 % TCH removal efficiency was achieved through a non-free radical degradation pathway, primarily driven by singlet oxygen (1O2). The mechanism involves the electron-rich groups on the biochar surface, which facilitate the cleavage of the PAA OO bond to generate •O2−/1O2 and provide electrons to induce the formation of high-valent Fe(IV) and Co(IV). The oxygen vacancies on the surface of the CoFe2O4-loaded biochar composite (CFB-2) contribute partially to 1O2 production through their transformation into a metastable intermediate with dissolved oxygen. Moreover, elevated temperatures further enhance PAA activation by CFB-2, leading to increased reactive oxygen species (ROS) production through PAA decomposition, thereby promoting TCH removal. This study offers new insights into the catalysis of metal-loaded biochar for efficient TCH degradation via non-free radical generation.