Reduction Of Toxicity Research Articles

Microwave-assisted oxidation of naphthenic acids in aqueous phase

Naphthenic acids (NAs) in oil sands processing wastewater (OSPW) pose a significant environmental risk. This study investigates the effectiveness of three oxidants, hydrogen peroxide (H2O2), persulfate (PS), and percarbonate (PC), in degrading synthetic OSPW containing a commercial mixture of NAs (50 mg/L) via microwave-assisted oxidation catalyzed by graphite (500 mg/L). Initial experiments using stoichiometric oxidant doses revealed that PC led to NAs’ carboxylation, increasing Total Organic Carbon (TOC). H2O2 was only effective at acidic pH (pH: 3), while PS achieved high mineralization (>85 %) in all cases, whilst decreasing the pH to 2.Although PS efficiently mineralized NAs, it generates sulfate, increasing salinity and hindering water reuse or discharge. To address this, a sequential oxidation process was proposed. Firstly PS was employed to initiate degradation and decrease pH, followed by H2O2 for further purification. A combined dose of 30% stoichiometric PS and 70% stoichiometric H2O2 was selected to treat OSPW in both ultrapure and brackish water matrices. The microwave-assisted PS-H2O2 process demonstrated significant potential, achieving 74% TOC removal in 20 min. Furthermore, toxicity assessments using Artemia salina confirmed a reduction in NAs' toxicity after treatment.

Degradation of Micropollutants in Water by O Atoms Produced by an Atmospheric Pressure He/O2 Plasma Jet

ABSTRACTAn atmospheric pressure He/O2 COST reference microplasma jet was used to study interactions of O atoms with four different organic micropollutants used as target compounds treated by plasma in water (atrazine, carbamazepine, 1,7‐α‐ethinylestradiol, and bisphenol A). Various ratios of O2 to He were used to achieve different exposures of reactive oxygen species to the plasma‐treated micropollutants, and their degradation efficiencies were determined. The degradation of all four micropollutants was merely associated with the variable exposure to the O atom, whereas the role of O3 was minimal. A comprehensive investigation was conducted on the degradation pathways and toxicity reduction assessment of atrazine after the treatment by plasma.

Enhanced hydrolytic acidification with Zero-Valent Iron for efficient treatment of comprehensive wastewater from industrial parks: mechanistic insights and toxicity reduction

In this study, a laboratory-scale zero-valent iron (ZVI)-enhanced hydrolytic acidification system was established to treat the comprehensive wastewater from Nanjing Jiangbei New Material Science Technology Park. Results indicated that the ZVI-enhanced hydrolytic acidification system achieved a maximum COD removal efficiency of 95.0%, surpassing the performance of the system without ZVI by 12.2%. Microbial community analysis revealed the enrichment of electrogenic bacterium Bacteroidetes_vadinHA17 and typical hydrogenotrophic methanogen Methanobacterium due to ZVI addition. High-throughput sequencing combined with PICRUSt2 analysis demonstrated acetate production was promoted, and butyrate and propionate production was inhibited. Additionally, Oxygen Uptake Rate-based toxicity assays revealed the hydrolytic acidification system transitioned the wastewater of three enterprises from low toxicity to non-toxic status and two from high to low toxicity. While the ZVI-enhanced hydrolytic acidification system successfully reduced the toxicity of all highly and low toxic wastewaters to non-toxic levels.

Tackling water contamination by oncologic drugs: Supported ionic liquids as sustainable adsorbents for cyclophosphamide removal

Due to the increasing incidence of cancer, the consumption of highly toxic oncological drugs is continuously growing. Given the current lack of efficient technologies to remove/treat these toxic drugs in wastewater treatment plants, the environmental quality is compromised, and aquatic organisms are at risk. To address this critical environmental burden, a new strategy based on supported ionic liquids (SILs) for the simultaneous removal of oncologic drugs and toxicity reduction of aqueous samples is here proposed. Silica-based SILs functionalized with imidazolium-based and quaternary ammonium-based ILs were designed and kinetics and isotherm adsorption studies performed. Aiming to develop an adsorbent able to reduce the toxicity of aqueous samples contaminated with oncological drugs, the toxicity reduction was appraised using the model organism Danio rerio. The obtained results disclose that among the studied SILs, the [Si][N3888]Cl (silica functionalized with propyltrioctylammonium chloride) is the best adsorption material (maximum adsorption capacity, qmax = 67.64 mg g−1), with a fast adsorption rate (<20 min). Furthermore, [Si][N3888]Cl was able to remove the toxicity of the treated aqueous samples towards D. rerio embryos, as assessed by lethal and several sublethal endpoints, demonstrating that this material holds remarkable potential for oncological drugs pollution remediation.

Engineered Biocorona on microplastics as a toxicity mitigation strategy in marine environment: Experiments with a marine crustacean Artemia salina

The marine environment has become a major sink for microplastics (MPs) wastes. When MPs interact with biological macromolecules, the biocorona forms on their surface, which can alter their biological reactivity and toxicity. In this study, we investigated the impact of biocorona formation on the toxicity of aminated (NH2) and carboxylated (COOH) polystyrene MPs towards the marine crustacean Artemia salina. Biocoronated MPs were prepared using cell-free extracts (CFEs) from microalgae Chlorella sp. (phytoplankton) and the brine shrimp Artemia salina (zooplankton). The results revealed that biocorona formation effectively reduced the toxicity of MPs. Pristine NH2-MPs exhibited higher reactive oxygen species production (ROS) (182%) compared to COOH-MPs (162%) in Artemia salina. Notably, NH2-MPs coronated with brine shrimp CFE exhibited a substantial reduction in ROS production (127%) than those coronated with algal CFE, with COOH-MPs showing a similar trend (120%). Biocorona formation also significantly decreased malondialdehyde (MDA) levels and antioxidant activity compared to pristine MPs. Molecular docking and dynamics simulations demonstrated a strong binding between polystyrene and acetylcholinesterase (AChE). In vitro studies indicated that pristine NH2-MPs exhibited more reduction in AChE activity (84%) compared to COOH-MPs (95%). However, no significant reduction in AChE activity was observed upon exposure to MPs coronated with either algal or brine shrimp cell-free extracts. Independent action modeling indicated an antagonistic interaction for MPs coronated with both the CFEs. Pearson correlation and cluster heatmap analysis suggested that the toxicity reduction in Artemia salina might be driven by decreased oxidative stress followed by the corona formation. Overall, this study provides valuable insights into the potential of biomolecules from phytoplankton and zooplankton to reduce MPs toxicity in Artemia salina, while highlighting their role in modulating the toxicity of other marine pollutants.

Modifications of biological membranes, fat globules and liposomes promoted by cavitation processes. Consequences and applications

Cavitation-based technologies, such as ultrasound (or acoustic cavitation, AC) and hydrodynamic cavitation (HC), are gaining interest among green processing technologies due to their cost effectiveness in operation, toxic solvent use reduction, and ability to obtain superior processed products, compared to conventional methods. Both AC and HC generate bubbles, but their effects may differ and it is difficult to make comparisons as both are based on different phenomena and are subject to different operational variables. AC is one of the most used techniques in extraction and homogenization processes at the laboratory level. However, upscaling to an industrial level is hard. On the other hand, HC is based on the passage of the liquid through a constriction (orifice plate, Venturi, throttling valve), which causes an increase in liquid velocity at the expense of local pressure, forcing the pressure around the contraction below the threshold pressure that induces the formation of cavities.Some applications of cavitation technologies, such as the production of liposomes or lipid nanoparticles (LNPs) allow the generation of delivery systems for biomedical applications.Many others (inactivation of pathogenic viruses, bacteria and algae for water purification, extraction procedures, third generation of biofuel production, green extractions) are based on the disruption of lipid membranes. There are also applications aimed at the modification of membranes (like the milk fat globule) for the development of innovative products. Process parameters, such as cavitation intensity, duration and temperature define the impact of the process on the physical, chemical, and biological characteristics of the membranes. Thus, the adequate implementation of cavitation processes requires understanding of interactions and synergistic mechanisms in complex systems and of their effects on membranes at the microscopic or molecular level. In the present work, the use of cavitation technologies for the generation of LNPs or nanostructured lipid carriers, and the effects of AC and HC treatments on several types of membrane systems (liposomes, solid lipid nanoparticles, milk fat globules, algae and bacterial membranes) are discussed, focusing on the structural and chemical modifications of lipidic structures under cavitation.

Mathematical modeling framework enhances clinical trial design for maintenance treatment in oncology

Clinical trials are costly and time-intensive endeavors, with a high rate of drug candidate failures. Moreover, the standard approaches often evaluate drugs under a limited number of protocols. In oncology, where multiple treatment protocols can yield divergent outcomes, addressing this issue is crucial. Here, we present a computational framework that simulates clinical trials through a combination of mathematical and statistical models. This approach offers a means to explore diverse treatment protocols efficiently and identify optimal strategies for oncological drug administration. We developed a computational framework with a stochastic mathematical model as its core, capable of simulating virtual clinical trials closely recapitulating the clinical scenarios. Testing our framework on the landmark SOLO-1 clinical trial investigating Poly-ADP-Ribose Polymerase maintenance treatment in high-grade serous ovarian cancer, we demonstrate that managing toxicity through treatment interruptions or dose reductions does not compromise treatment’s clinical benefits. Additionally, we provide evidence suggesting that further reduction of hematological toxicity could significantly improve the clinical outcomes. The value of this computational framework lies in its ability to expedite the exploration of new treatment protocols, delivering critical insights pivotal to shaping the landscape of upcoming clinical trials.

Deciphering the biodegradation mechanism of 3,6-dichlorocarbazole using a novel isolate for its implication in bioaugmentation

This study reported a newly isolated strain, Streptomyces sp. FW-32, which showed good ability to degrade 3,6-dichlorocarbazole (3,6-DCCZ). The maximum degradation efficiency of 3,6-DCCZ reached 86.78 % within 5 d at pH of 7.6, glucose concentration of 5.0 g/L, temperature of 33 °C, and 3,6-DCCZ initial concentration of 1.0 mg/L. In total, five biodegradation products were detected, indicating that 3,6-DCCZ was mainly transformed via dechlorination, oxidation, and aromatic ring cleavage. Proteomic analysis suggested that haloacid dehalogenase, glutathione S-transferase family protein, cytochrome P450s, pentachlorophenol monooxygenase, hydroxylase, and several dioxygenases were involved in 3,6-DCCZ biotransformation. Glutathione peroxidase, catalases, catalase − peroxidase, thioredoxin, thioredoxin reductase, and thioredoxin-dependent peroxiredoxin were induced to resist 3,6-DCCZ stress. Molecular docking revealed that 3,6-DCCZ exhibited an affinity for the potential proteins involved in 3,6-DCCZ biodegradation and stress response. Furthermore, the biotreatment of 3,6-DCCZ with the strain FW-32 might have contributed to the reduction in the aquatic toxicity of 3,6-DCCZ. The strain FW-32 efficiently synergized with certain indigenous microorganisms, consequently accelerating the removal of 3,6-DCCZ from the water–sediment system. Overall, these findings shed a new light on the mechanisms underlying the microbial transformation of 3,6-DCCZ, suggesting that Streptomyces sp. FW-32 exhibits considerable potential for the bioaugmentation of 3,6-DCCZ-contaminated aquatic environments.

Formulation and evaluation of cetuximab functionalized phospholipid modified nanocrystals of paclitaxel for non-small cell lung cancer therapy

Present work aims to prepare Soluplus stabilized, phospholipid-modified, and cetuximab-conjugated paclitaxel nanocrystals (NCs) as stable nanocarriers for targeted drug delivery. The NCs, prepared using concurrent antisolvent precipitation cum cold crystallization method followed by probe sonication, were found to be monodispersed particles with sub-200 nm size. The microscopic analysis uncovered rod and spherical anisotropy for Soluplus stabilized (PTX-NCs) and phospholipid modified (Lipid/PTX-NCs) nanocrystals, respectively. The formation of amorphous PTX-NCs and subsequent coating with phospholipid was confirmed by solid-state characterization using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform Infrared Spectroscopy (FTIR). X-ray Photoelectron Spectroscopic (XPS) analysis, indicated successful conjugation of cetuximab on NCs surface. Lipid coating rendered a sustained drug release behaviour to NCs at physiological pH. In vitro cell line studies confirmed the improved cellular internalization and better apoptosis induction capability of NCs, consequently resulting in enhanced efficacy of PTX against A549 cancer cells. Moreover, in Benzo[a] pyrene-induced lung cancer model, Cmab/Lipid/PTX-NCs showed significant improvement in tumor inhibition potential in comparison to pure PTX. The prepared Cmab/Lipid/PTX-NCs also exhibited improved pharmacokinetics performance, avoided off-target distribution, and showed a reduction in systemic toxicity. The findings of this study indicate the promising potential of the prepared cetuximab-functionalized phospholipid-coated paclitaxel nanocrystals in lung cancer therapy.

Exploring Sustainable Remediation Options: The Mycodegradation of Halogenated Nitroaromatic Compounds by Caldariomyces fumago

Chlorinated and fluorinated nitrophenols (HNCs) are widely used in agriculture and industry, with a global market valued at USD $25 billion, one which is expected to grow by 5% by 2030. However, these compounds pose significant environmental risks; they are classified as toxic by the International Agency for Research on Cancer (IARC). Existing treatment methods include advanced oxidation, adsorption, and bioremediation, though to date, there has been only limited research on fungal remediation of these halogenated pollutants. This study aims to explore a sustainable approach by using fungi’s potential to degrade HNCs in minimal media. Ten fungi were selected through literature screening; Caldariomyces fumago and Curvularia sp. were highly effective, degrading over 50% of 2-chloro-4-nitrophenol (2C4NP) and 80% of 5-fluoro-2-nitrophenol (5F2NP) within 24 and 48 h, respectively. Additionally, five strains showed degradation potential for fluorinated compounds. Further studies revealed C. fumago could degrade up to 1 mM of chlorinated compounds and 12 mM of fluorinated compounds, far exceeding any known environmental concentrations of HNCs; importantly, ecotoxicology tests demonstrated reductions in toxicity of 77% and 85%, respectively. This work highlights fungi’s underexplored ability to degrade toxic HNCs, offering a sustainable mycoremediation strategy and positioning mycology as a critical tool for future environmental remediation efforts.

Effect of an insecticide, fungicide and plant growth regulator and their mixture on the survival of the springtail Folsomia candida and the potential reduction of toxicity by vitamins

A pesticide-free model soil was pretreated with field-realistic doses/applications of the insecticide, Biscaya 240 OD; the fungicide Tilmor; the growth regulator, Atonik and their mixture. Because Folsomia candida is eyeless, unpigmented, avoids light, and prefers dark, wet and cold conditions, we grew and tested it in the dark and at 18°C. Survival of springtails added to soil at 50 % moisture was assessed after 28 days. The experiments were repeated three times in order to confirm the validity of the test and results. The mixture decreased the survival most significantly. Bayesian statistics showed that pesticide treatment had a greater effect than repeating the experiment. Further tests revealed that the negative effect of the mixture on springtail survival was effectively suppressed by the application of biotin (vitamin B7), whereas riboflavin (vitamin B2) had little effect. Vitamins can reduce the toxicity of agrochemicals in the soil through potential effects on soil biological activity.

Harnessing landfill-derived Bacillus subtilis (LLS-04) for bio-electrodegradation of di-butyl phthalate: Comprehensive toxicity assessment across multiple biological models

Di-butyl phthalate (DBP), a pervasive environmental contaminant, poses significant ecological and health risks due to its persistence and toxicity. This study investigates the potential of a landfill-derived Bacillus subtilis strain (LLS-04) in bio-electrodegradation of DBP, alongside a comprehensive toxicity assessment across multiple biological models. Bio-electrodegradation efficiency was compared to biodegradation and electrodegradation, revealing that bio-electrodegradation achieved a remarkable 98.57 % reduction in DBP concentration significantly outperforming the other methods. This enhanced degradation was attributed to improved microbial activity and enzyme production, as indicated by higher protein content and increased esterase and dehydrogenase activities in the bio-electrodegradation system. The optimized conditions facilitated efficient degradation, with HPLC-MS/MS analysis confirming the breakdown of DBP into non-toxic end products via a proposed metabolic pathway. A comprehensive toxicity assessment, including in-silico analysis, in-vitro cytotoxicity and brine shrimp lethality assays, demonstrated a significant reduction in toxicity of BES treated effluent compared to DBP untreated effluent. Furthermore, in-vivo toxicity studies using animal model supported these findings, demonstrating reduced toxicity in the BES treated effluent compared to the DBP untreated effluent. Overall, these findings highlight the potential application of bio-electrodegradation in bioremediation strategies for phthalate pollution, offering an effective solution for reducing both DBP concentration and its environmental toxicity.

The Electrooxidation of Synthetic Bipyridyl Herbicide Wastewaters with Boron-Doped Diamond Electrodes: A Technical and Economic Study to Boost Their Application for Pollution Prevention in the Agricultural Sector

Boron-doped diamond electrodes (BDDEs) offer a highly efficient pathway to mineralize recalcitrant compounds due to their reduced energy requirements, fewer chemical inputs, and mechanical stability. In this work, the electrochemical degradation of paraquat (PQ) and diquat (DQ) was studied using an undivided cell (Condiacell®-type) at circumneutral pH, and under galvanostatic control. The roles of applied current density, volumetric flow rate, and herbicide concentration were systematically studied through a central composite design (CCD) using a closed-flow reaction setup. Under the best operating conditions (i.e., for PQ: 1.6 mA/cm2, 80 mL/min, and 70 mL/min, and 70 mg/L; and for DQ: 1.5 mA/cm2, 80 mL/min, and 73 mg/L), a spectrophotometric analysis evidenced that the herbicides were satisfactorily removed (ca. 100%) while mineralization degrees were above 90%. Furthermore, the produced effluents yielded significant increases in seed germination and root length, which suggest a reduction in toxicity. Energy consumptions of 0.13 and 0.18 kWh/g of TOC are reported with the electrochemical cells for the PQ and DQ treatments, respectively. The PQ and DQ treatments by electrooxidation are estimated to emit nearly 2.7 and 38.9 kg CO2/m3 of water treated, with a cost around USD 250/m3. Carbon emissions could be greatly decreased for PQ (0.28 kg CO2/m3) and DQ (0.40 kg CO2/m3) if electricity were generated from renewable resources. Although this study suggests that the use of BDDE can be considered as a green alternative for agrochemical removal due to lower carbon emissions, the environmental profile of the process is determined by the degree of renewability of the electrical grid of each country or region.

Computer prediction of acute toxicity of thioderivatives of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenol

This study presents the computational prediction of acute toxicity for new derivatives of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenols and their alkylated analogues. The aim of the work was to evaluate the impact of structural changes, particularly alkylation and chain length extension, on the toxicity levels of new derivatives of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenols and their alkylated analogues. Materials and methods. QSAR methodologies were used to predict toxicity, allowing the evaluation of toxicological properties based on molecular descriptors. Toxicity modeling was performed using computer software, enabling the estimation of toxicity without the need for in vivo experimental studies. Results. The results showed, that alkylation of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenol derivatives does not lead to a significant toxicity reduction. Moreover, an increase in toxicity was observed with the prolongation of the carbon chain in the synthesized compounds. It was also found, that acid derivatives, particularly 2,2’-(((5-hydroxy-1,3-phenylene)bis(4-R-4H-1,2,4-triazol-5,3-diyl))bis(sulfanyl))diacetate acids and 3,3’-((((5-hydroxy-1,3-phenylene)bis(4-R-4H-1,2,4-triazol-5,3-diyl))bis(sulfanyl))bis(methylene))dibenzoyl acids, exhibit toxicity ranging from 521.9 mg/kg to 2232.2 mg/kg, corresponding to toxicity class IV (low toxicity) on the OECD scale. It was found, that molecular structure and hydrophobic properties play a crucial role in determining compound toxicity. This study helps to establish a structure-toxicity relationship and to optimize compound structures for reduced toxicity. Conclusions. These results provide a foundation for further development of potential drug candidates with predicted toxicological properties.

Photocatalytic Degradation of Antiviral Drugs Chloroquine Phosphate and Lamivudine by Bi2O3–TiO2/PAC under a Xe Lamp: Insights into Reactive Oxygen Species’ Action and Toxicity Reduction

Photocatalytic Degradation of Antiviral Drugs Chloroquine Phosphate and Lamivudine by Bi₂O₃–TiO₂/PAC under a Xe Lamp: Insights into Reactive Oxygen Species’ Action and Toxicity Reduction

Oxygen vacancies-enriched spent lithium-ion battery cathode materials loaded catalytic membrane for effective peracetic acid activation and organic pollutants degradation

Advanced oxidation processes combined with membrane filtration technique offer a promising approach for pollution mitigation and catalyst recovery. Herein, a waste ternary lithium-ion battery cathode material of LiNixCoyMnzO2 (LNCM) loaded polytetrafluoroethylene (PTFE) membrane was synthesized for peracetic acid (PAA) activation (LNCM-PTFE/PAA) and 2,4,6-trichlorophenol (TCP) degradation. Such a novel membrane, with a catalyst loading of 10 mg (0.796 mg/cm2) of LNCM achieved 96.4 % removal of TCP (2 mg/L) within 20 min in neutral pH. The redox cycles of surface metals (such as Co3+/Co2+, Ni3+/Ni2+, and Mn4+/Mn3+/Mn2+) in spent LNCM efficiently enhance charge transfer and mediated PAA activation. And intrinsic oxygen vacancies in LNCM facilitated PAA adsorption and its cleavage. The resulting carbon-centered radicals (R-C•, CH3C(O)OO•) and 1O2 are identified as the primary reactive species that collaboratively participate in TCP degradation. Quantitative structure-activity relationship analysis demonstrated a substantial reduction in product toxicity. The successful practical application of the LNCM-PTFE/PAA membrane was exemplified by treating chlorophenol industrial wastewater. This study presents a new LNCM-PTFE/PAA catalytic membrane for high-efficiency water treatment and a novel perspective for green utilization of waste LNCM.

A hybrid system based on the combination of adsorption, electrocoagulation, and wetland treatment for the effective remediation of industrial wastewater from underground coal gasification (UCG)

The study verified the effectiveness of treating post-process underground coal gasification (UCG) wastewater, containing high loads of inorganic and organic pollutants, using constructed wetlands (CW) enhanced by hybrid adsorption and electrocoagulation (EC) techniques. Four different system configurations were tested: wetland, EC/wetland, adsorbent/wetland, and EC/adsorbent/wetland. Each experiment lasted 60 days. The feed and effluents from each treatment step were analysed for their basic physicochemical parameters such as metals and trace elements, phenols, sulphides, cyanides, total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD), benzene, toluene, ethylene, xylene (BTEX), and polyaromatic hydrocarbons (PAHs).Systems with electrocoagulation proved to be effective in the case of metal removal. The best results were obtained for Fe, Ni, Sb and As (up to 96%, 98%, 94% and 82% respectively). The systems were ineffective in removing Mn. All tested systems showed the greatest effectiveness in the treatment of wastewater from phenols, BTEX and CN (almost 100% removal). CWs without preliminary electrocoagulation showed practically 100% effectiveness in removing BTEX after 14 days of treatment. Electrocoagulation was particularly effective in reduction of large quantity of PAH compounds (from 1228 μg/l to below 0.050 μg/l). Effective toxicity reduction from V class to II class after 60 days in comparison with meeting the requirements contained in the Best Available Techniques (BAT) document, showed that all tested systems were favorable in terms of UCG wastewater treatment. A significant decrease in toxicity was observed in just 14 days (around 90% reduction of toxicity measured in TU values for systems without adsorbent and around 75% for systems with adsorbent). The wastewater were still toxic due to the formation of degradation intermediates of organic compounds (BTEX, PAHs, phenol compounds), despite a significant decrease in the concentration of contaminants, therefore toxicity assessment should be one of the evaluation criteria for industrial wastewater treatment.

A highly-efficient peroxymonosulfate activator using a sewage sludge derived biochar supported cobalt oxide: Mechanism and characteristics

The application of biochar derived from sewage sludge (BS) in Fenton-like reactions for contaminant removal has attracted considerable attention. Herein, a BS-supported Co3O4 (BS-Co3O4) catalyst was synthesized using a simple two-step hydrothermal-calcination process to achieve highly efficient activation of peroxymonosulfate (PMS). The introduction of biochar effectively inhibited the aggregation of Co3O4 and reduced cobalt leaching. Compared to Co3O4, the mesoporous BS-Co3O4 exhibited an 8-fold increase in specific surface area (SSA) to 111.92 m2∙g−1, and a 46 %-66.4 % reduction in crystal plane size. The interaction between biochar and cobalt oxide resulted in several notable enhancements in the BS-Co3O4 composite. Specifically, there was an increase in sp2 carbon content, a 42.69 % rise in capacitance, and a 79.99 % reduction in charge transfer resistance. These improvements contributed to enhanced PMS activation performance. The BS-Co3O4 also contained a higher content of Co(II), sp2 carbon, and oxygen vacancies (OV). Co(II) played a crucial role in the redox reaction, accelerating the formation of SO4•− and 1O2 during the PMS activation process. Additionally, OV acted as electron capture centers, further promoting the generation of 1O2. Evidence from reactive species investigations and electron paramagnetic resonance (EPR) tests indicated that SO4•− and 1O2 were the main reactive radicals for eliminating tetracycline (TC). Based on the identification of TC intermediates, two potential degradation pathways were proposed, and a reduction in intermediate toxicity was observed. Experiments involving interference and repetition demonstrated that the BS-Co3O4 catalyst was stable and reusable. This work provides a solution with low metal leaching, high recycling performance, and safety for antibiotic wastewater treatment.

Highly dispersed single-atom Fe and Fe3O4 clusters anchored hierarchical-pore carbon as efficient persulfate activation catalyst

The selective removal of Fe particles from carbonized Fe-MOFs presents an intriguing strategy for developing efficient peroxydisulfate (PDS) activators. It is commonly accepted that their outstanding performance is largely attributed to the high specific surface area/pore volume. However, our investigation into the structure–function relationship of these materials has revealed new insights. In this study, a highly dispersed single-atom Fe and Fe3O4 clusters anchored hierarchical-pore carbon (CM88-H) was obtained via post-acid treatment of carbonized MIL-88B (CM88). Various characterizations were comparatively conducted to highlight the beneficial effects of iron dissolution. The CM88-H/PDS system achieved a notable BPA degradation efficiency, with a reaction rate of 0.323 min−1, which is 3.94 times higher than that of the CM88/PDS system. DFT calculations indicate that the Fe3O4 clusters optimize the charge distribution around single-atom Fe, promoting favorable PDS adsorption and facilitating a higher oxidation state of CM88-H. As a result, BPA can be completely degraded within 10 min with 0.1 g L-1 CM88-H and 0.05 g L-1 PDS via both radical and non-radical pathways. The CM88-H/PDS/BPA system performs effectively under various conditions, with a general reduction in toxicity. Furthermore, the CM88-H/PDS system shows broad oxidation activity towards BPA substitutes and pollutants with high ionization potential (IP). Notably, the CM88-H sponge-based fixed-bed catalytic reactor demonstrated satisfactory BPA degradation, highlighting the promising application of CM88-H in water purification. This study provides a sustainable solution for water treatment and accelerates the practical application of powdered nanocatalysts to improve water quality.

Acidic-thermal coupled degradation of tylosin by using magnetic sulfonated resins under microwave irradiation

Acidic- and alkalic-hydrolyses are selective in breaking functional bonds and falling off pharmacological moieties of antibiotics in production wastewater in comparison with advanced oxidation processes. Elevating temperature can accelerate hydrolytic kinetics and improve efficiency. In this work, magnetic sulfonated polypropylene resin (Fe3O4@PS-S) composites were reported for acidic-thermal hydrolysis of tylosin by employing the acidic feature of sulfonic group, the dielectric effect of resin, and the magnetic-loss effect of magnetite under microwave irradiation. As observed, a rapid and complete mitigation 100 mg/L of tylosin was achieved within 15 min by the catalysts. Acidic cleavage of tylosin was fulfilled by sulfonic groups in the composites, and microwave thermal accelerated the hydrolysis reactions due to the dielectric and magnetic-loss effects. Differentiating the dielectric and magnetic-loss effects through electromagnetic analyses indicated that the latter contributed more in converting microwave energy to heat. The interactions under multiple operational conditions were quantitatively fitted using the Behnajady model and visually demonstrated, which indicated that a synergic effect of microwave thermal- and acidic-hydrolyses contributed to the efficient mitigation of tylosin. The transformation products were identified and the pathways were supposed. Cleaving deoxyaminosugars groups and destructing lactone structures led to reduced antibacterial potential and toxicity reduction. The acute toxicity of tylosin and transformation products to fish, daphnia, and green algae were all classified as non-toxic. This work suggested that this synergistic acid-thermal hydrolytic method is attractive and promising in pretreating tylosin production wastewater in field.