Pyrolytic conversion of cattle manure and acid mine drainage sludge into biochar for oxidative and adsorptive removal of the antibiotic nitrofurantoin

Antibiotics in aquatic environments can foster the development of antibiotic-resistant bacteria, posing significant risks to both living organisms and ecosystems. This study explored the thermo-chemical conversion of cattle manure (CM) into biochar and assessed its potential as an environmental medium for removing nitrofurantoin (NFT) from water. The biochar was produced through the co-pyrolysis of CM and acid mine drainage sludge (AMDS) in a N2 condition. The gaseous and liquid products generated during pyrolysis were quantified and characterized. The biochar exhibited both catalytic and adsorptive capability in NFT removal. It effectively activated persulfate to drive oxidative degradation of NFT via radical (SO4•- and •OH) and non-radical (1O2) pathways. NFT adsorption on the biochar involved multiple binding mechanisms, including electrostatic, hydrogen bonds, and π-π EDA interactions, as evidenced by XPS analysis before and after the reaction. Furthermore, the biochar's performance stability was demonstrated through five cycles of reuse and leaching tests. These findings present a viable approach to generate energy from waste by co-pyrolyzing of livestock manure and metal-containing industrial waste, while also producing environmental media capable of removing antibiotics from wastewater through diverse mechanisms.

Incorporating iron oxide nanoparticles in polyvinyl alcohol/starch hydrogel membrane with biochar for enhanced slow-release properties of compound fertilizers

Biochar-based fertilizers show promise in enhancing nutrient utilization and soil health, but their slow-release performance remains a challenge. Herein, hydrogel membranes incorporating iron oxide nanoparticles within a polyvinyl alcohol and starch matrix (Fe/PVA/ST) were synthesized. These membranes were utilized to coat compound fertilizer particles, with biochar powder applied to the outer layer to form what is known as Fe/PVA/ST-BSRFs. The results revealed that Fe/PVA/ST-BSRFs exhibit markedly improved slow-release performance compared to both PVA/ST-BSRFs lacking iron nanoparticles and commercial compound fertilizers. Within a 30-day period, the cumulative leaching ratios of N, P, and K from Fe/PVA/ST-BSRFs with 0.75 % iron content were significantly lower compared to other tested fertilizers, with values of 22.87 %, 34.93 %, and 84.08 %, respectively. Furthermore, the incorporation of iron oxide nanoparticles into the PVA/ST membrane enhanced its swelling and water-retention properties without compromising its biodegradability. Mechanistic investigations revealed that the exceptional slow-release properties of Fe/PVA/ST-BSRFs stem from a combination of nutrient diffusion control outside the membrane and the loose control mechanism of the membrane. Pot tests demonstrated that Fe/PVA/ST-BSRFs effectively promoted the growth of chili plants while ensuring high utilization of N-P-K and improving the nutritional indices of chili fruits. Economic analysis further underscored the promising application prospects of Fe/PVA/ST-BSRFs.

Growth of Oxide and Nitride Layers on Titanium Foil and Their Electrochemical Properties

The surface of titanium foil can be modified by heating in the air, in a N2 flow, and in an NH3 flow. Upon heating in the air, the elemental Ti gradually transforms to Ti3O at 550 °C and to rutile TiO2 at above 700 °C. Treatment in a N2 flow leads similarly to Ti3O at 600 °C and TiO2 at 700 °C, although the overall reaction is slower. Meanwhile, nitridation in the N2 flow is minimal, even at 900 °C. Heat treatment in an NH3 flow produces nitride phases through the ammonolysis of the hexagonal Ti. With an ammonolysis at 900 °C, trigonal Ti2N and cubic TiN form together while, at higher temperatures, TiN is dominant. The TiN layer can also be obtained via the ammonolysis of the TiO2 coating, that is, by the sequential treatments of Ti in the air and then in an NH3 flow. The titanium nitride layers have particulate microstructures and varying degrees of porosity, depending on the ammonolysis temperature and time. The TiO2-derived TiN has a significantly higher capacitance than TiN derived directly from Ti. The optimally prepared TiN specimen exhibits an areal specific capacitance of 66.2 F/cm2 at 0.034 mA/cm2.

Efficient adsorption of ofloxacin in a novel nanocomposite formed by nano-hexagonal boron nitride fused with zeolite imidazolite skeleton-8: Experimental and molecular dynamics simulation studies

With the widespread application of antibiotics in the medical field, associated wastewater pollution has become a critical environmental issue, creating potential risks to ecosystems and public health. This study synthesized three novel nanocomposite materials, ZIF-8@h-BN-X, using an in-situ growth method by adjusting h-BN content. Compared to pure two-dimensional hexagonal boron nitride (h-BN), their adsorption capacities for ofloxacin (OFL) in solution were evaluated. Results showed that zeolitic imidazolate framework-8 (ZIF-8) attached and grew on the h-BN surface, altering surface functional groups and significantly enhancing the nanocomposite's adsorption effect on OFL. Adsorption capacity depended on the initial h-BN content, with lower X content resulting in more active sites and stronger adsorption capacity. Equilibrium adsorption capacities were 145.46, 124.91, and 58.16 mg·g-1 for X values of 29.82 %, 45.93 %, and 62.95 %, respectively. Molecular dynamics simulations revealed interaction energies of -109.13 kcal·mol-1 between ZIF-8@h-BN-X and OFL, compared to -84.78 kcal·mol-1 between pure h-BN and OFL, demonstrating the superior adsorption performance of ZIF-8@h-BN-X. OFL adsorption on ZIF-8@h-BN-X followed the Langmuir isotherm model and pseudo-second-order adsorption kinetics. Thermodynamic parameters indicated that the adsorption process of ZIF-8@h-BN-X was exothermic and spontaneous when compared to h-BN alone. This study highlights the significant potential of ZIF-8@h-BN-X in treating antibiotic-contaminated wastewater, while providing theoretical and practical insights for developing novel, efficient two-dimensional nanocomposite adsorbents.

Bismuth titanate microplates with tunable oxygen vacancies for piezocatalytic hydrogen peroxide production

Piezocatalysis offers an encouraging alternative for the sustainable, on-demand, and decentralized production of hydrogen peroxide (H2O2), underscoring the importance of enhancing piezocatalytic efficiency. Enhancing piezocatalysts through defect engineering has shown considerable potential in boosting H2O2 production efficiency. However, the impact of oxygen vacancies on piezocatalytic activity remains unclear. Herein, we used a chemical probe method to quantify negative charges (q-) and superoxide radicals (O2-) to explore the relation between the oxygen vacancy concentration and piezocatalytic performance of bismuth titanate (Bi4Ti3O12) based catalysts. Results indicate that piezocatalytic H2O2 production in pure water demonstrates a volcanic trend with increasing oxygen vacancy concentration. This trend is attributed to the dual role of oxygen vacancies, which reduce the piezoelectric property of the piezocatalyst while simultaneously increasing the concentration of O2-, which is crucial for H2O2 formation through the O2 reduction pathway. This study provides insights into the interplay between oxygen vacancies, piezoelectric properties, and piezocatalytic activity, offering valuable guidance for the design of piezocatalysts for sustainable H2O2 production.

A review on WO3 photocatalysis used for wastewater treatment and pesticide degradation

The rapid growth in the global population has led to increased environmental pollution and energy demands, exacerbating the issue of environmental contamination. This contamination is significantly impacted by various types of pesticides found in water sources, which pose serious health risks to humans, animals, and aquatic ecosystems. In response, extensive research into water treatment technologies has been conducted, focusing on efficient methods to remove these pollutants, with advanced oxidation processes and the utilization of tungsten trioxide (WO3) as a photocatalyst showing promising results. This paper aims to review WO3-based photocatalytic processes for pesticide degradation, highlighting the potential of modified WO3 structures to improve photocatalytic efficiency and address current environmental challenges. Different WO3 synthesis routes and methods for modification have been discussed. The synthesis of WO3-based photocatalysts encompasses various methods that significantly affect their morphologies, sizes, structures, and thus catalytic performance, cost-effectiveness, and environmental sustainability. Techniques like hydrothermal, solvothermal, co-precipitation, sol-gel, and green synthesis and physical deposition techniques are elaborated, highlighting their unique advantages in producing nanostructures with desired physical and chemical properties. Moreover, enhancement methods aimed at optimizing the photocatalytic activity of WO3 under visible light for pollutant degradation have been discussed. Evaluation of WO3-based photocatalytic systems for pesticide treatment, emphasizing the effectiveness of various catalysts in degrading pesticides including organochlorines, organophosphorus, and chloropyridines have been conducted.

Metal-Organic Frameworks MIL-101(Fe) and MIL-53(Al) as Efficient Adsorbents for Dispersive Micro-Solid-Phase Extraction of Sorafenib in Plasma and Wastewater, Coupled with HPLC-UV Analysis

In the present study, metal-organic frameworks, MIL-101(Fe) and MIL-53(Al), were synthesized under solvothermal conditions and were characterized by Fourier transform infrared spectroscopy, X-ray energy diffraction spectroscopy and scanning electron microscopy. The synthesized metal-organic frameworks were utilized for the purpose of dispersive micro-solid phase extraction of sorafenib in both human plasma and wastewater, which was subsequently followed by high performance liquid chromatography with ultraviolet determination. Parameters affecting extraction efficacy including adsorbent amount, ionic strength, pH, type of elution solvent, adsorption and desorption time were optimized. Under optimal experimental conditions, the linearity in human plasma and wastewater was achieved in the range of 0.25-5.00 and 0.01-0.20 μg/mL, respectively. The extraction recovery for MIL-101(Fe) and MIL-53(Al), respectively, was calculated in human plasma and wastewater and found to be in the range of 86.27-99.47%.

Quantitative investigation of a 3D bubble trapper in a high shear stress microfluidic chip using computational fluid dynamics and L*A*B* color space

Microfluidic chips often face challenges related to the formation and accumulation of air bubbles, which can hinder their performance. This study investigated a bubble trapping mechanism integrated into microfluidic chip to address this issue. Microfluidic chip design includes a high shear stress section of fluid flow that can generate up to 2.7 Pa and two strategically placed bubble traps. Commercially available magnets are used for fabrication, effectively reducing production costs. The trapping efficiency is assessed through video recordings with a phone camera and analysis of captured air volumes by injecting dye at flow rates of 50, 100, and 150 µL/min. This assessment uses L*A*B* color space with analysis of the perceptual color difference ∆E and computational fluid dynamics (CFD) simulations. The results demonstrate successful application of the bubble trap mechanism for lab-on-chip bubble detection, effectively preventing bubbles from entering microchannels and mitigating potential damage. Furthermore, the correlation between the L*A*B* color space and volume fraction from CFD simulations allows accurate assessment of trap performance. Therefore, this observation leads to the hypothesis that ∆E could be used to estimate the air volume inside the bubble trap. Future research will validate the bubble trap performance in cell cultures and develop efficient methods for long-term air bubble removal.

Exploring Innovative Approaches for the Analysis of Micro- and Nanoplastics: Breakthroughs in (Bio)Sensing Techniques

Plastic pollution, particularly from microplastics (MPs) and nanoplastics (NPs), has become a critical environmental and health concern due to their widespread distribution, persistence, and potential toxicity. MPs and NPs originate from primary sources, such as cosmetic microspheres or synthetic fibers, and secondary fragmentation of larger plastics through environmental degradation. These particles, typically less than 5 mm, are found globally, from deep seabeds to human tissues, and are known to adsorb and release harmful pollutants, exacerbating ecological and health risks. Effective detection and quantification of MPs and NPs are essential for understanding and mitigating their impacts. Current analytical methods include physical and chemical techniques. Physical methods, such as optical and electron microscopy, provide morphological details but often lack specificity and are time-intensive. Chemical analyses, such as Fourier transform infrared (FTIR) and Raman spectroscopy, offer molecular specificity but face challenges with smaller particle sizes and complex matrices. Thermal analytical methods, including pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), provide compositional insights but are destructive and limited in morphological analysis. Emerging (bio)sensing technologies show promise in addressing these challenges. Electrochemical biosensors offer cost-effective, portable, and sensitive platforms, leveraging principles such as voltammetry and impedance to detect MPs and their adsorbed pollutants. Plasmonic techniques, including surface plasmon resonance (SPR) and surface-enhanced Raman spectroscopy (SERS), provide high sensitivity and specificity through nanostructure-enhanced detection. Fluorescent biosensors utilizing microbial or enzymatic elements enable the real-time monitoring of plastic degradation products, such as terephthalic acid from polyethylene terephthalate (PET). Advancements in these innovative approaches pave the way for more accurate, scalable, and environmentally compatible detection solutions, contributing to improved monitoring and remediation strategies. This review highlights the potential of biosensors as advanced analytical methods, including a section on prospects that address the challenges that could lead to significant advancements in environmental monitoring, highlighting the necessity of testing the new sensing developments under real conditions (composition/matrix of the samples), which are often overlooked, as well as the study of peptides as a novel recognition element in microplastic sensing.

PFAS biodegradation by Labrys portucalensis F11: Evidence of chain shortening and identification of metabolites of PFOS, 6:2 FTS, and 5:3 FTCA

The biodegradation of three per- and polyfluoroalkyl substances (PFAS), namely perfluorooctane sulfonic acid (PFOS), 6:2-fluorotelomer sulfonic acid (6:2 FTS), and 5:3-fluorotelomer carboxylic acid (5:3 FTCA), were evaluated using Labrys portucalensis F11, an aerobic bacteria known to defluorinate fluorine-containing compounds. Cultures of L. portucalensis F11 were grown in minimal salts media and treated with 10,000 μg/L of individual PFAS as the sole carbon source in separate flasks. In PFOS-spiked media, several metabolites were detected, including perfluoroheptane sulfonic acid (PFHpS), perfluorohexane sulfonic acid (PFHxS), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), perfluorobutanoic acid (PFBA), and perfluoropropanoic acid (PFPrA). After 194-day incubation three de-fluorinated metabolites were identified: PFOS-F (m/z = 480.940, PFOS-2F (m/z = 462.980), and unsaturated PFOS-3F (m/z = 442.943). During the biodegradation of 5:3 FTCA, the following metabolites were observed: PFHxA, PFPeA, PFBA, PFPrA, and two fluorotelomer unsaturated carboxylic acids (5:3 FTUCA and 7:2 FTUCA). The biodegradation of 6:2 FTS was slower, with only 21 % decrease in concentration observed after 100 days, and subsequent formation of 4:2 FTS. On the contrary, 90 % of PFOS and 58 % of 5:3 FTCA were degraded after 100 days. These results indicate that L. portucalensis F11 can be potentially used for PFAS biodegradation in contaminated environments.

Sustainable synthesis of silver nanoparticles from Conocarpus seeds for removal of methylene blue

This study introduces a sustainable biological approach for synthesizing silver nanoparticles (AgNPs) using Conocarpus seeds, aimed at improving the adsorption and photocatalytic degradation of methylene blue (MB) in wastewater treatment. The photocatalytic efficiency of AgNPs, synthesized under varying concentrations of silver nitrate (AgNO3) and pH levels, was evaluated, together with the effectiveness of a photocatalytic reactor. The synthesized samples were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, and atomic force microscopy (AFM). Results showed that MB degradation occurred quickly within the first 50 min, achieving a 99.60% removal efficiency via adsorption and photocatalytic degradation under optimal conditions (pH = 3, 1 g sample) after 1 h. The maximum adsorption capacity reached 49.80 mg·g-1. Furthermore, the AgNPs demonstrated a significant degradation rate of 99.76% within 2 h under UV light, highlighting the synergistic effects of AgNPs in enhancing both adsorption and photocatalysis. This study not only accentuates the potential of Conocarpus seeds as an eco-friendly precursor for AgNP synthesis but also highlights the applicability of AgNPs in wastewater treatment.

Ni-Co doped TiO2 catalyst for efficient photocatalytic degradation of Malachite Green under UV and direct sunlight

In the present study, combustion-synthesized TiO2 nanoparticles were wet impregnated with Ni, Co, and Ni-Co, respectively. The photocatalytic performance of synthesized catalysts was evaluated against Malachite Green dye. The synthesized materials were characterized for crystallite size, surface morphology, elemental composition, and band gap using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and ultra-violet diffused reflectance spectroscopy, respectively. The optimum parameters for maximum degradation were found by examining the effects of catalyst loading, initial dye concentration, and light intensity. A comparative analysis of Ni-doped, Co-doped, and Ni-Co-doped TiO2 photocatalysts was conducted. The results indicate superior photocatalytic activity of Ni-Co doped TiO2 among the catalysts investigated under UV light. The degradation kinetics was studied, and the underlying degradation mechanism was proposed with the help of LC-MS analysis. Furthermore, a comparative study on the degradation under solar radiation using Ni-Co/TiO2 was conducted.

Impact of irradiation conditions on therapy of Lewis lung carcinoma in mice using glucose-ethylenediamine carbon dots

BACKGROUND

nowadays, the photoacoustic imaging is in the mainstream of cancer theranostics. In this study the nanoparticles with previously proven photoacoustic imaging properties, i.e. glucose-ethylenediamine carbon dots (GE-NPs), were tested for photoacoustic cancer therapy.

METHODS

nanoparticle biocompatibility was analyzed in cell toxicity and neurotoxicity experiments ex vivo. Biochemical parameters were analyzed in animal experiments in vivo after intramuscular implantation of Lewis Lung carcinoma cells into the C57/Black mouse line.

RESULTS

GE-NPs at concentrations of 0.1-1.0 mg/ml did not change the extracellular level, exocytotic and transporter-mediated release, as well as the initial rate of uptake and accumulation of L-[14C]glutamate in isolated rat brain nerve terminals. GE-NP-treated mice had evidence of the probable protection of the liver and attenuating the systemic consequences of tumor growth, as evidenced by normalization of serum aspartate aminotransferase (ASAT), and lactate dehydrogenase (LDH) levels, compared to vehicle-dosed tumor-bearing animals. According to hematological analysis, treatment with GE-NPs caused an increase in red blood cells and hematocrit up to the healthy control levels. When a combination of GE-NPs (1 mg/ml) is injected into a mouse tumor and the tumor is irradiated by a laser beam, it leads to an increase in mice survival by more than 30% compared to GE-NPs-treated non-irradiated mice, and a decrease in the growth rate of the cancerous tumor. The observed therapeutic effect can be related to the photoacoustically-induced destruction of cancer cells significantly enhanced by the presence of the incorporated GE-NPs, because the laser-induced localized heating of mice skin has not exceeded 2 °C.

CONCLUSIONS

the efficiency of photoacoustic therapy of Lewis Lung carcinoma in mice using biocompatible carbon dots was demonstrated. Biocompatible GE-NPs own multimodal potential in cancer theranostics, including both photoacoustic imaging and therapy, by applying different irradiation conditions.

Physical and Surface Chemical Analysis of High-Quality Antimicrobial Cotton Fabrics Functionalized with CuOx Grown In Situ from Different Copper Salts: Experimental and Theoretical Approach

The emergence of harmful microorganisms poses a public health challenge. Antimicrobial cotton textiles with semiconductor oxides offer a promising solution to mitigate pathogen spread. Here, we study the physicochemical interactions between copper oxides (CuOx) and cellulose in cotton fiber functionalized with these same oxides for antimicrobial properties. Fabrics were treated by an exhaust dyeing method using a 2% on-weight-of-fiber (owf) copper precursor with acetate, nitrate, and sulfate anions. Nonfunctionalized (NF) fabrics with a yellow hue turned reddish brown after the functionalization with CuOx. Copper (Cu) content in the functionalized fabrics increased by 27-40% compared to 0.009% in the NF fabric. The percentage of Cu exhaustion was higher with the acetate salt than nitrate and sulfate, resulting in darker fabrics according to colorimetry. XPS analysis of cotton suggests a chemical interaction between the hydroxyl groups of cellulose and CuOx. The nature and strength of potential interactions between Cu cations and the cellulose surface were investigated using the quantum theory of atoms in molecules and crystals. Based on topological parameters, the interaction between Cu and the hydroxyl groups of cellulose exhibits a covalent character. Furthermore, the XPS spectrum of functionalized fabrics exhibited peaks corresponding to Cu1+ and Cu2+ ions, assigned to the Cu2O and CuO phases, respectively. Electron diffraction patterns confirmed copper oxide crystalline phases, where Cu2O was indexed in the cuprite system and CuO in the tenorite system. Regarding morphology, no defined forms of CuOx were observed on the cotton surface, regardless of the salt used for treatment. Likewise, all fabrics functionalized with CuOx inhibited the growth of Escherichia coli and Pseudomonas aeruginosa strains by more than 99%. Therefore, cotton fabrics functionalized with a mixture of Cu2O and CuO have excellent antimicrobial properties that can be used in environments with a high bacterial load.

Structurally Stable Hollow-Fiber-Based Porous Graphene Oxide Membranes with Improved Rejection Performance by Selective Patching of Framework Defects with Metal-Organic Framework Crystals

Graphene oxide (GO)-based membranes have demonstrated great potential in water treatment. However, microdefects in the framework of GO membranes induced by the imperfect stacking of GO nanosheets undermine their size-sieving ability and structural stability in aqueous systems. This study proposes a targeted growth approach by growing zeolitic imidazolate framework-8 (ZIF-8) nanocrystals precisely to patch microdefects as well as to cross-link the porous graphene oxide (PGO) flakes coated on the outer surface of the hollow fiber (HF) alumina substrate (named the hybrid PGO/ZIF-8 membrane). This method simultaneously improves their structural stability and size-sieving performance without compromising their water permeance. Various structural and elemental analyses were used to elucidate the targeted growth of the ZIF-8 crystals. The X-ray photoelectron spectroscopy (XPS) analysis confirmed the targeted coordination interaction of oxygen moieties on the edges of PGO nanosheets with metal ions of ZIF-8 crystals, allowing for the precise growth of the ZIF-8 nanocrystals in the PGO membranes. The XPS depth profile analysis revealed the uniform distribution of the ZIF-8 precursor throughout the PGO/ZIF-8 membrane. The resultant membrane showed a water permeance of 4 L m-2 h-1 bar-1 and maintained a very stable performance under pressure and prolonged cross-flow operation. Notably, the molecular weight cutoff (MWCO) improved considerably from 570 to 320 g/mol without sacrificing any water permeance after the targeted growth of ZIF-8. This research paves the way for the preparation of highly selective and stable PGO-based membranes for applications in industrial wastewater treatment.

Effective Nitrate Electroconversion to Ammonia Using an Entangled Co3O4/Graphene Nanoribbon Catalyst

There has been huge interest among chemical scientists in the electrochemical reduction of nitrate (NO3-) to ammonia (NH4+) due to the useful application of NH4+ in nitrogen fertilizers and fuel. To conduct such a complex reduction reaction, which involves eight electrons and eight protons, one needs to develop high-performance (and stable) electrocatalysts that favor the formation of reaction intermediates that are selective toward ammonia production. In the present study, we developed and applied Co3O4/graphene nanoribbon (GNR) electrocatalysts with excellent properties for the effective reduction of NO3- to NH4+, where NH4+ yield rate of 42.11 mg h-1 mgcat-1, FE of 98.7%, NO3- conversion efficiency of 14.71%, and NH4+ selectivity of 100% were obtained, with the application of only 37.5 μg cm-2 of the catalysts (for the best catalyst ─Co3O4(Cowt %55)GNR, only 20.6 μg cm-2 of Co was applied), confirmed by loadings ranging from 19-150 μg cm-2. The highly satisfactory results obtained from the application of the proposed catalysts were favored by high average values of electrochemically active surface area (ECSA) and low Rct values, along with the presence of several planes in Co3O4 entangled with GNR and the occurrence of a kind of "(Co3(Co(CN)6)2(H2O)12)1.333 complex" structure on the catalyst surface, in addition to the effective migration of NO3- from the cell cathodic branch to the anodic branch, which was confirmed by the experiment conducted using a H-cell separated by a Nafion 117 membrane. The in situ FTIR and Raman spectroscopy results helped identify the adsorbed intermediates, namely, NO3-, NO2-, NO, and NH2OH, and the final product NH4+, which are compatible with the proposed NO3- electroreduction mechanism. The Density Functional Theory (DFT) calculations helped confirm that the Co3O4(Cowt %55)GNR catalyst exhibited a better performance in terms of nitrate electroreduction in comparison with Co3O4(Cowt %75), considering the intermediates identified by the in situ FTIR and Raman spectroscopy results and the rate-determining step (RDS) observed for the transition of *NO to *NHO (0.43 eV).

Enhanced bioelectrochemical degradation of Thiabendazole using biostimulated Tunisian hypersaline sediments: kinetics, efficiency, and microbial community shifts

Thiabendazole (TBZ), a recalcitrant fungicide, is frequently applied in postharvest fruit treatment and generates significant volumes of industrial wastewater (WW) that conventional treatment plants cannot handle. This explores a bioelectrochemical system (BES) for TBZ degradation using Tunisian hypersaline sediments (THSs) as inoculum. Four sets of BES, along with biological controls, were tested using THS subjected to different levels of TBZ biostimulation. Sediments underwent one, two, or three biostimulation phases with increasing TBZ concentrations (0, 10, 100, and 300 mg kg-1). Potentiostatic control was applied to BES, polarized at 0.1 V vs. saturated calomel reference electrode (SCE), with a carbon felt working electrode (72 cm2 L-1) and maintained at 25°C. While current production was very low, sediments biostimulated with 100 mg kg-1 kg TBZ produced the highest current density (3.2 mA m-2), a 5-fold increase over untreated sediments (0.6 mA m-2). GC-FID analysis showed >99% TBZ degradation in all reactors. The TBZ half-elimination time from 27 days with biological treatments to 19 days in BES and further to 6 days following biostimulation. Bacterial analysis revealed a substantial microbial community shift after biostimulation, with a reduction in Bacillota (-64%) and an increase in Proteobacteria (+62%), dominated by Pseudomonas (45%) and Marinobacter (16%). These findings provide insight into the selective potential of biostimulation cycles to enhance microbial community composition and improve BES performance for TBZ wastewater treatment.

Innovative Microencapsulation of Polymyxin B for Enhanced Antimicrobial Efficacy via Coated Spray Drying

This study aims to develop an innovative microencapsulation method for coated Polymyxin B, utilizing various polysaccharides such as hydroxypropyl β-cyclodextrin, alginate, and chitosan, implemented through a three-fluid nozzle (3FN) spray drying process. High-performance liquid chromatography (HPLC) analysis revealed that formulations with a high ratio of sugar cage, hydroxypropyl β-cyclodextrin (HPβCD), and sodium alginate (coded as ALGHCDHPLPM) resulted in a notable 16-fold increase in Polymyxin B recovery compared to chitosan microparticles. Morphological assessments using fluorescence labeling confirmed successful microparticle formation with core/shell structures. Alginate-based formulations exhibited distinct layers, while chitosan formulations showed uniform fluorescence throughout the microparticles. Focused beam reflectance and histograms from fluorescence microscopic measurements provided insights into physical size analysis, indicating consistent sizes of 6.8 ± 1.2 μm. Fourier-transform infrared (FTIR) spectra unveiled hydrogen bonding between Polymyxin B and other components within the microparticle structures. The drug release study showed sodium alginate's sustained release capability, reaching 26 ± 3% compared to 94 ± 3% from the free solution at the 24 h time point. Furthermore, the antimicrobial properties of the prepared microparticles against two Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, were investigated. The influence of various key excipients on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values was evaluated. Results demonstrated effective bactericidal effects of ALGHCDHPLPM against both E. coli and P. aeruginosa. Additionally, the antibiofilm assay highlighted the potential efficacy of ALGHCDHPLPM against the biofilm viability of E. coli and P. aeruginosa, with concentrations ranging from 3.9 to 500 μg/m. This signifies a significant advancement in antimicrobial drug delivery systems, promising improved precision and efficacy in combating bacterial infections.

PFAS in landfill leachate: Practical considerations for treatment and characterization

Per- and polyfluoroalkyl substances (PFAS) are widely used in consumer products and are particularly high in landfill leachate. The practice of sending leachate to wastewater treatment plants (WWTPs) is an issue for utilities that have biosolids land application limits based on PFAS concentrations. Moreover, landfills may face their own effluent limit guidelines for PFAS. The purpose of this review is to understand the most appropriate treatment technology combinations for mitigating PFAS in landfill leachate. The first objective is to understand the unique chemical characteristics of landfill leachate. The second objective is to establish the role and importance of known and emerging analytical techniques for PFAS characterization in leachate, including quantification of precursor compounds. Next, an overview of technologies that concentrate PFAS and technologies that destroy PFAS is provided, including fundamental background content and key operating parameters. Finally, practical considerations for PFAS treatment technologies are reviewed, and recommendations for PFAS treatment trains are described. Both pros and cons of treatment trains are noted. In summary, the complex matrix of leachate requires a separation treatment step first, such as foam fractionation, for example, to concentrate the PFAS into a lower-volume stream. Then, a degradation treatment step can be applied to the concentrated PFAS stream.

Mechanisms of nano zero-valent iron in enhancing dibenzofuran degradation by a Rhodococcus sp.: Trade-offs between ATP production and protection against reactive oxygen species

Nano zero-valent iron (nZVI) can enhance pollutants biodegradation, but it displays toxicity towards microorganisms. Gram-positive (G+) bacteria exhibit greater resistance to nZVI than Gram-negative bacteria. However, mechanisms of nZVI accelerating pollutants degradation by G+ bacteria remain unclear. Herein, we explored effects of nZVI on a G+ bacterium, Rhodococcus sp. strain p52, and mechanisms by which nZVI accelerates biodegradation of dibenzofuran, a typical polycyclic aromatic compound. Electron microscopy and energy dispersive spectroscopy analysis revealed that nZVI could penetrate cell membranes, which caused damage and growth inhibition. nZVI promoted dibenzofuran biodegradation at certain concentrations, while higher concentration functioned later due to the delayed reactive oxygen species (ROS) mitigation. Transcriptomic analysis revealed that cells adopted response mechanisms to handle the elevated ROS induced by nZVI. ATP production was enhanced by accelerated dibenzofuran degradation, providing energy for protein synthesis related to antioxidant stress and damage repair. Meanwhile, electron transport chain (ETC) was adjusted to mitigate ROS accumulation, which involved downregulating expression of ETC complex I-related genes, as well as upregulating expression of the genes for the ROS-scavenging cytochrome bd complex and ETC complex II. These findings revealed the mechanisms underlying nZVI-enhanced biodegradation by G+ bacteria, offering insights into optimizing bioremediation strategies involving nZVI.

Exfoliated MoS2 nanosheets immobilized in porous microbeads as recoverable photocatalysts

Molybdenum disulfide (MoS2) is a highly effective visible light photocatalyst when used as well-exfoliated 2D nanosheets. The ability to make effective use of these properties is significantly compromised by the challenge of preventing nanosheet aggregation or restacking in fluid suspensions. We report a strategy for immobilizing chemically exfoliated MoS2 as single- and few-layer nanosheets in porous crosslinked polymers prepared as microbeads. The polymeric support prevents aggregation of the nanosheets while allowing access to the nanomaterial for model organic compounds present in the surrounding fluid. Exposure to visible light results in high degradation yields (>99%) of these organic species in aqueous media, and the MoS2 nanosheets maintain their photocatalytic efficacy through multiple cycles of use. The recoverability of the porous beads and the persistent photocatalytic activity of the polymer-supported MoS2 offer the potential of realizing an effective, environmentally sustainable platform for photocatalytic degradation of dissolved solutes.

Guadua angustifolia biochar/TiO2 composite and biochar as bio-based materials with environmental and agricultural application

Globally, the companies that make commercial use of bamboo culms produce different kinds of solid waste rich in lignocellulosic biomass, which in some cases is not used and is discarded in landfills or incinerated in the open air; losing the possibility of recovering them and using them in other productive sectors. The research objective were to produce a biochar from Guadua agustifolia  Kunth sawdust, evaluate its potential environmental and agricultural use, obtain a biochar/TiO2  composite to inactivate Escherichia coli and use the biochar as a soil conditioner in medicinal plants producing phenolic compounds and flavonoids. Biochar composite (produced at 300 °C for 1 h) involved TiO2 at 450 °C for 1 h for inactivation of E. coli (initial concentration: 6.5 ± 0.3 Log10 CFU mL- 1). For agriculture, 2% biochar was used to evaluate B. pilosa L. and G. angustifolia  plant growth for 90 days. The biochar/TiO2  composite had a high photocatalytic activity on E. coli, generating a final count of 1.97 ± 0.2 Log10 CFU mL- 1 after 60 min. Biochar (2%) increased the total phenol and flavonoid content in the medicinal plant B. pilosa L. and total phenols in G. angustifolia, tested at the nursery stage. This study provides new information on the conversion and use of G. angustifolia sawdust as an alternative for new bio-based materials with environmental and agricultural applications. In addition, obtaining biochar and composite could positively impact the bamboo production chain in Colombia because of renewable and globally accepted alternatives that help capture gaseous emissions causing the greenhouse effect.

Improving the power production efficiency of microbial fuel cell by using biosynthesized polyanaline coated Fe3O4 as pencil graphite anode modifier

A microbial fuel cell (MFC) is a modern, environmentally friendly, and cost-effective energy conversion technology that utilizes renewable organic waste as fuel, converting stored chemical energy into usable bioelectricity in the presence of a biocatalyst. Despite advancements in MFC technology, several challenges remain in optimizing power production efficiency, particularly regarding anode materials and modifications. In this study, low-cost biosynthesized iron oxide nanoparticles (Fe3O4 NPs) were coated with a polyaniline (PANI) conducting matrix to synthesize hybrid Fe3O4/PANI binary nanocomposites (NCs) as modified MFC anodes via an in-situ polymerization process. Characterization techniques, including UV-Vis, XRD, SEM, and FT-IR, revealed the successful synthesis of green-routed nano-scaled materials with altered optical properties after matrix coating, high crystallinity in the iron oxide phase, rougher surface morphology, and characteristic Fe-O peaks at 594 cm⁻1. Additionally, the electrochemical behavior of the prepared nano-materials was characterized by cyclic voltammetry (CV), where low ΔEp values (0.473 V) for Fe3O4/PANI NCs indicated the presence of reversible charge transfer mechanisms at the electrode surface, reflecting a high rate of electron transfer. The synthesized nanocomposite was used to modify pencil graphite anodes to construct four single-chamber MFCs: bare pencil graphite anodes, pencil graphite anodes modified with Fe3O4, PANI, and Fe3O4/PANI nanocomposites. The maximum open circuit voltage (OCV) value was 645 ± 24.50 mV, with a high power output of 424.51 ± 6.86 mW/m2 and current density of 2475.01 ± 1.23 mA m-2 produced by the Fe3O4/PANI NCs modified pencil graphite electrode, which is more than six times the efficiency in terms of power density compared to the unmodified pencil graphite electrode (PGE). These results demonstrate that the synthesized nanocomposite plays an effective and value-added role in modifying traditional carbon anode electrodes within an MFC energy conversion device system.

Recovery and purification of acetic acid from extremely diluted solutions using a mixed bed ion exchange resin - technical feasibility

A downstream process for the recovery and purification of acetic acid (AA) from an extremely diluted solution (100 mg L-1) also containing a mixture of contaminating inorganic salts in the form of bicarbonates, phosphates, sulfates and chlorides (DPM medium) has been developed, showing its technical feasibility. The process involves two successive steps based on the use of a mixed bed ion exchange (IEX) resin. The first step, a demineralization treatment to remove the inorganic anions that could potentially interfere with the recovery and purification of AA, involves a combined treatment of calcium precipitation, acidification with the Amberlite IR-120 resin and treatment with the Amberlite MB20 mixed bed resin. This treatment allows the total removal of phosphate and sulfate (and likely bicarbonate) and 90% removal of chloride, while still retaining 91% of AA in solution. In the second step the demineralized medium is treated again with the Amberlite MB20 mixed bed resin in batch to completely remove AA and chloride remaining in solution and, finally, the anion-loaded resin is step-eluted with a low volume of diluted H2SO4 to selectively elute AA, obtaining a purified (68.5-82.2% recovery yield and 96.9-99.2% purity) and concentrated (>1500 mg L-1) solution of the acid.

Cutting-Edge Developments in Metal Halide Perovskites Core/Shell Heterocrystals: from Photodetectors to Biomedical Applications

In recent years, the performance of metal halide perovskite (MHP)-based detectors (photon, biomedical, and X-ray detection) has significantly improved, resulting in higher carrier mobilities, longer carrier diffusion lengths, and excellent absorption coefficients. However, the widespread adoption of halide perovskites has been hindered by issues related to their stability and toxicity. Various strategies have been adopted to address these challenges, focusing on enhancing ambient stability and reducing toxicity by encapsulating MHPs within stable and robust host materials, such as silicon compounds, metal oxides, chalcogenides, and lead-free perovskites. This review focuses on recent developments in hybrid nanostructure-based detectors (photon, biomedical, and X-ray), particularly core/shell architectures, and provides a comprehensive analysis of techniques for mitigating degradation due to light and oxygen exposure, UV irradiance, and thermal effects. This review enhances the understanding of current advancements in core/shell-based detectors.

Degradation of micropollutants in water matrices using light activated - Persulfate: A review

The escalating challenge of eliminating persistent micropollutants from aquatic environments acted as a driving force for the development of innovative Advanced Oxidation Processes (AOPs). Among various AOPs, Light-Activated Persulfate (LAP) stands out for its efficacy due to its homogeneous nature and the potential for coupling with renewable sources, leading to enhanced sustainability. From this perspective, this review summarizes the research on LAP for the degradation of micropollutants over the previous six years. It examines the effect of operational parameters such as persulfate concentration, light type and intensity, and pH, with particular emphasis on the effect of water matrices consisting of inorganic ions and organic matter and the application in environmentally relevant water matrices. Particular emphasis was given to the investigation of toxicity variation during the treatment. In addition, some elements of a preliminary estimation of the energy and cost needed are included. Finally, this comprehensive review includes some indicative hybrid systems that achieve dual activation of persulfate with enhanced efficiency and provides suggestions for the intensified future research needed for the transition from the lab scale to industrial application.

Food packaging solutions in the post-per- and polyfluoroalkyl substances (PFAS) and microplastics era: A review of functions, materials, and bio-based alternatives

Food packaging (FP) is essential for preserving food quality, safety, and extending shelf-life. However, growing concerns about the environmental and health impacts of conventional packaging materials, particularly per- and polyfluoroalkyl substances (PFAS) and microplastics, are driving a major transformation in FP design. PFAS, synthetic compounds with dual hydro- and lipophobicity, have been widely employed in food packaging materials (FPMs) to impart desirable water and grease repellency. However, PFAS bioaccumulate in the human body and have been linked to multiple health effects, including immune system dysfunction, cancer, and developmental problems. The detection of microplastics in various FPMs has raised significant concerns regarding their potential migration into food and subsequent ingestion. This comprehensive review examines the current landscape of FPMs, their functions, and physicochemical properties to put into perspective why there is widespread use of PFAS and microplastics in FPMs. The review then addresses the challenges posed by PFAS and microplastics, emphasizing the urgent need for sustainable and bio-based alternatives. We highlight promising advancements in sustainable and renewable materials, including plant-derived polysaccharides, proteins, and waxes, as well as recycled and upcycled materials. The integration of these sustainable materials into active packaging systems is also examined, indicating innovations in oxygen scavengers, moisture absorbers, and antimicrobial packaging. The review concludes by identifying key research gaps and future directions, including the need for comprehensive life cycle assessments and strategies to improve scalability and cost-effectiveness. As the FP industry evolves, a holistic approach considering environmental impact, functionality, and consumer acceptance will be crucial in developing truly sustainable packaging solutions.

Analysis of microplastic contamination and associated human health risks in Clarias gariepinus and Oreochromis niloticus from Kubanni Reservoir, Zaria Nigeria

Environmental safety has become a major concern in recent years due to the global increase in microplastic pollution. These ubiquitous, tiny, and potentially toxic plastic particles enter aquatic environments through weathering of larger plastics and the release of microbeads. Although numerous studies have focused on microplastic pollution in developed regions, information from developing countries remains limited. This study assessed the presence of MPs and associated oxidative stress responses in two commercial fish species, Clarias gariepinus (Catfish) and Oreochromis niloticus (Nile Tilapia), from Kubanni reservoir, Zaria, Nigeria, over six months spanning both the dry and rainy seasons. Fibers were identified as the most abundant MP particles, followed by fragments, films, and beads, in the order of fibers > fragments > films > beads. The highest fiber concentrations were recorded in the gills, with Clarias garipinus showing 11.5 MP items/individual and Oreochromis niloticus showing 22.5 MP items/individual. Black microplastics were predominant, and the most common ingested MP ranged from 1.0 to 2.0 mm. The primary polymers identified were polypropylene and polyethylene terephthalate. Evidence of oxidative stress and cellular damage was observed in the gills, liver, and dorsal muscles of both fish species, which correlated with MPs ingestion. According to recommendations from the European Food Safety Authority regarding fish consumption by children and adults, individuals consuming Clarias gariepinus and Oreochromis niloticus from the Kubanni reservoir may be exposed to between 70 and 700 MP items/organ. The risk associated with consuming MPs found in fish gills and guts was notably higher, posing significant concerns for human health. This study provides insights into microplastic contamination in commercially important fish from the Kubanni Reservoir and highlights the environmental and public health risks associated with consuming contaminated fish from this ecosystem.

Effects of advanced oxidation process on biological treatment of spent fermentation broth

The present study aimed to establish the feasibility of the wastewater treatment process generated from an oleaginous fermentation plant. Treatment of spent fermentation broth (SFB) poses significant environmental challenges due to its high organic load, recalcitrant compounds, and potential toxicity. The synergistic effects of combining ozone-based advanced oxidation process (O3-AOP) with biological treatment for the efficient degradation of pollutants in spent fermentation broth. O3-AOP aimed to decolorize SFB and improve the biodegradability index (BI). After O3-AOP pretreatment, color, chemical oxygen demand (COD), and biochemical oxygen demand (BOD) were reduced by 92, 22.3, and 4.7%, respectively, with the improvement of BI from 0.59 to 0.72. Furthermore, the anaerobic-aerobic sequential system (AASS), where anaerobic digestion (AD) was followed by an aerobic treatment process (ATP), ~ 93.08 and 91.53% COD and BOD reduction were achieved. In turn, 197 mL of maximum cumulative bio-methane was produced during AD. The inoculum for AASS resulted in color enhancement during the digestion process. O3-AOP post-treatment, after AASS, lowered the color to 80 NTU, with a final 93.6% color removal efficiency. Before and after treatment, the water quality index (WQI) decreased from 12,642.83 to 719.65 (weighted arithmetic WQI), suggesting the unacceptability of the water for portable usage. However, the phytotoxicity analysis of 70% seed germination suggested its nontoxic nature in agricultural field activity. Through the WQI assessment, it was evident that the pollution potential of the SFB was reduced significantly during the treatment process, but the treated stream was not suitable for potable use, and further treatment processes, such as membrane filtration and evaporators, were recommended to re-use the water within the system to reduce the freshwater demand. The findings influence the augmentation of sustainable and environmentally friendly wastewater treatment approaches for the biotechnological industry.

Antiviral effect of oversulfated kappa-carrageenan derivatives against COVID-19 for spray coating application on facemasks

The COVID-19 pandemic caused by SARS-CoV-2 has spurred the urgent need for effective antiviral strategies. In this work, we explored the potential of oversulfated kappa-carrageenan (OSKC) in spray-coated facemasks for SARS-CoV-2 inhibition pathway. The sulfated derivative was synthesized with sulfur trioxide pyridine complex in dimethylformamide solution. The antiviral efficacy of OSKC at different concentrations and spray-coated facemasks was evaluated using betacoronavirus Murine Hepatitis Virus strain 3, revealing a significant reduction in viral load compared to commercial kappa-carrageenan. Furthermore, the characterization techniques assessed the effect of the position of the introduced sulfate groups on the antiviral activity and on the physicochemical characteristics. OSKC is able to bind specific proteins of enveloped viruses, preventing viral attachment into target cells. Overall, this study demonstrates the feasibility and effectiveness of OSKC spray coating for breathable facemasks with antimicrobial properties, offering a promising approach to enhancing personal protective equipment against viral transmission in healthcare and community settings.

Investigation of Real-Time Gaseous Thermal Decomposition Products of Representative Per- and Polyfluoroalkyl Substances (PFAS)

The thermal decomposition of per- and poly fluoroalkyl substances (PFAS) is poorly understood. Here, we present an innovative, comprehensive analytical method to investigate their thermal decomposition, including perfluorocarboxylic acids (PFCAs), alcohol, sulfonates, and GenX (acid dimer), focusing on identifying their breakdown products. In this study, evolved gas analysis-mass spectrometry (EGA-MS) was used for fast real-time screening to determine the significant temperatures to be investigated with the thermal desorption-pyrolysis coupled with gas chromatography-mass spectrometry (TD-Py-GC-MS), which provided detailed information about evolved PFAS and their breakdown products. This approach enabled a systematic study of perfluorocarboxylic acids (PFCAs) ranging from C3 to C9 and GenX showing volatilization, followed by degradation and formation of respective perfluorinated-1-alkenes and C5F10O perfluorinated ether (from GenX). At elevated temperatures (e.g., 600 °C), the products observed included perfluorinated butene and higher molecular-weight products, likely formed by pyrolytic polymerization of perfluorinated radicals. 1H,1H,2H,2H-perfluoro-1-decanol, i.e., 8:2 FTOH, volatilized at 100 °C; however, at higher temperatures, several novel decomposition products were observed, including perfluoro-1-decene and perfluorinated compounds suggesting the presence of the hydroxylic group. Our method offers an alternative approach to studying the thermal behavior of currently regulated and emerging PFAS with a focus on application to a wide range of matrices (laboratory grade standards or environmental samples).

Preparation of magnetic rice husk carbon nanocomposite for efficiently extracting aflatoxin B1 from rice followed by time-resolved fluorescent immunochromatographic assay

An on-site, sensitive, and cost-effective method for determining aflatoxin B1 (AFB1) in rice samples is proposed, combining magnetic solid phase extraction (MSPE) and time-resolved fluorescence immunochromatography (TRFICA) techniques. Cost-effective rice husks were carbonized and combined with nanomaterials to make magnetic nanocomposites that acted as effective adsorbents in MSPE. Under optimal conditions, the entire process was completed in 15 min with a visual detection limit of 0.16 μg/kg. Recoveries ranged from 85.2 % to 109.4 %, with intra- and inter-day precisions below 11.5 %. The proposed MSPE-TRFICA method offers a viable alternative for the rapid and highly sensitive quantitative detection of AFB1 for quality assurance.

Adsorption and flotation in one step: A new method for treating petroleum wastewater

Developing process intensification technologies to treat Petroleum Wastewater (PW) is crucial to maintaining the economic and environmental safety of the process. Therefore, a one-step combination of adsorption and flotation was tested in this study for the first time to remove organic compounds from PW using a biochar-derived composite. High salinity PW samples from Brazilian oil wells were used to test the efficiency of the new method. The tests in synthetic petroleum wastewater found that applying the composite in the combined technique is an efficient alternative for removing organic compounds, presenting better results than using a commercial surfactant. In addition, applying the composite in real-petroleum wastewater showed that it can remove up to 83.89% of oil and grease concentration, even in complex and highly competitive environments. Therefore, its application in batch adsorption and in biosorptive flotation has technical and environmental potential as a viable alternative for treating produced water.

Toward the development of an ML-driven decision support system for wastewater treatment: A bacterial inactivation prediction approach in solar photochemical processes

The design of efficient bacterial inactivation treatment in wastewater is challenging due to its numerous parameters and the complex composition of wastewater. Although solar photochemical processes (PCPs) provide energy-saving benefits, a balance must be maintained between bacterial inactivation efficiency and experimental costs. Predictive decision tools for bacterial inactivation under various conditions would significantly contribute to optimizing PCP design resources. This study evaluated four machine learning algorithms (ML) (i.e., Artificial Neural Network (ANN), Random Forest (RF), Support Vector Machine (SVM), and Extreme Gradient Boost (XGBoost)) for predicting bacterial inactivation behavior, using Escherichia coli, Enterococcus spp., and Salmonella spp. Several oxidant types, bacterial concentrations, and aqueous matrices were evaluated in two scenarios simulating real-world conditions. Results demonstrated that decision tree-based models (RF and XGBoost) outperformed SVM and ANN in accuracy. In Scenario I (prediction of intermediate experimental values over time) the XGBoost model was most effective, achieving a Root Mean Square Error (RMSE) of 0.81, 0.76 and 0.55 and an R2 of 0.84, 0.79, and 0.87 for the three bacteria, respectively. In Scenario II (prediction of full experimental values over time), the RF model excelled for Escherichia coli and Salmonella spp. with an RMSE of 0.88 for both and an R2 of 0.80 and 0.71, respectively. The XGBoost model showed moderate effectiveness for Enterococcus sp. with an RMSE of 1.31 and R2 of 0.50. Overall, the decision tree-based models demonstrated their potential for prediction in tests of a wide range of PCP parameters without requiring additional trials.

Innovative approaches to chemical recycling of polyethylene terephthalate waste: Investigating key components and their emerging applications

Polyethylene Terephthalate, a widely recognized thermoplastic, is used in numerous sectors including packaging, textiles, electronics, construction, and medical due to its lightweight, cost-efficiency, transparency, flexibility, quick drying, durability and excellent gas/moisture barrier properties. However, its non-biodegradable nature poses significant environmental concerns, necessitating effective recycling and reuse methods. Over the past decades, scientists have focused on both mechanical and chemical recycling methods for PET waste to produce new molecules with potential applications. This review provides a comprehensive account of utilizing PET waste as a feedstock for synthesizing new molecules through various recycling techniques. An up-to-date and comparative overview of different chemical recycling techniques, including ammonolysis, aminolysis, glycolysis, alcoholysis, and hydrolysis in terms of reactants, reaction conditions, products, and yields are outlined. Applications of depolymerized end products like terephthalamide, NN'-bisallyl-terephthalamide, terephthalic dihydrazide, NN'-diphenyl-terephthalamide, dimethyl-terephthalate, dimethyl terephthalate, bis-hydroxyethyl-terephthalate (BHET), bis-hydroxy ethylene terephthalamide (BHETA), terephthalic acid etc. are succinctly presented. These products found potential industrial applications including thermostabilizers, surfactants, hardeners, peptisers, photoinitiators, crosslinkers, plasticizers, adsorbents, sealants, catalysts, etc. Additionally, the conversion of these depolymerized end products into other useful compounds like terephthalonitrile, para-xylylenediamine, 1,4-bis(aminomethyl)cyclohexane, lanthanum complexes, acrylates, BHET and BHETA derivatives, oxadiazole derivatives, 2,2'-(1,4-phenylene)-bis(2-oxazoline), 1,4-cyclohexanedimethanol, dyes, dioctyl terephthalate, butylene-adipate-co-terephthalate, terephthaloyl dichloride etc. has also been detailed along with their potential applications.

Upgrade constructed wetlands wastewater quality by solar-driven photochemical quaternary treatments in raceway pond reactor at pilot plant scale

This study explores the potential application of solar photochemical processes (SPPs) for simultaneous disinfection and decontamination of urban wastewater (UWW) when combined with constructed wetlands (CWs). Two SPPs based on the addition of low concentrations of hydrogen peroxide and peroxymonosulfate (PMS) were evaluated. SPPs were carried out at pilot plant scale using low-cost solar open photoreactors (Raceway Pond Reactor (RPR)) under natural sunlight. The performance of the SPPs was analyzed by monitoring naturally occurring bacteria (Escherichia coli, Enterococcus spp. and Salmonella spp.) and Contaminants of Emerging Concern (CECs), such as pharmaceutical products, pesticides, antibiotics and their metabolites, simultaneously. SPP best operating conditions were determined by testing a wide range of oxidant concentrations (0-5.9 mM, 0-3.0 mM) and liquid depths (5, 10 and 15 cm) in the RPR. SPP treatment efficacy was tested on the actual inlet and outlet of the CW system, showing the high influence of their different physicochemical characteristics on the oxidants' performance. H2O2/solar SPP in the actual inlet of the CWs showed slightly higher inactivation kinetics when increasing H2O2 concentration at both water depths (5 and 10 cm), while no significant CECs degradation rates were obtained. However, much higher efficacy was obtained with PMS/solar process attaining high bacteria inactivation under dark conditions and 79 % CEC degradation at 3.0 mM after only 10 min of reaction time. SPPs assessment on the outlet of the CWs also showed better efficacy of the PMS as oxidant compared to the H2O2 for the simultaneous CECs removal (95 % at 1.0 mM of PMS, after only 5 min of treatment) and bacteria inactivation (confirming the no-regrown after 24 h). SPPs have demonstrated to be a low-cost and eco-sustainable polishing alternative to regenerate CW effluents complying with the actual European regulation on the minimum water quality requirements for reusing treated UWW in agriculture.

Recent advances in metal-catalysed oxidation reactions

Oxidation reactions are vital tools in synthetic organic chemistry. Oxidation of organic species such as alcohols, phenols, aldehydes and ketones provides synthetically valuable organic compounds, especially synthetic intermediates for several biologically active compounds. Some of these synthetic intermediates have shown their synthetic utility in the total synthesis of natural products. Several classical and modern synthetic approaches have been used to achieve these oxidation reactions. In this review article, various oxidation reactions achieved by metal catalysis are highlighted.

A review of functions and mechanisms of clay soil conditioners and catalysts in thermal remediation compared to emerging photo-thermal catalysis

High temperatures and providing sufficient time for the thermal desorption of persistent organic pollutants (POPs) from contaminated clay soils can lead to intensive energy consumption. Therefore, this article provides a critical review of the potential additives which can improve soil texture and increase the volatility of POPs, and then discusses their enhanced mechanisms for contributing to a green economy. Ca-based additives have been used to reduce plasticity of bentonite clay, absorb water and replenish system heat. In contrast, non-Ca-based additives have been used to decrease the plasticity of kaolin clay. The soil structure and soil plasticity can be changed through cation exchange and flocculation processes. The transition metal oxides and alkali metal oxides can be applied to catalyze and oxidize polycyclic aromatic hydrocarbons, petroleum and emerging contaminants. In this system, reactive oxygen species (•O2- and •OH) are generated from thermal excitation without strong chemical oxidants. Moreover, multiple active ingredients in recycled solid wastes can be controlled to reduce soil plasticity and enhance thermal catalysis. Alternatively, the alkali, nano zero-valent iron and nano-TiN can catalyze hydrodechlorination of POPs under reductive conditions. Especially, photo and photo-thermal catalysis are discussed to accelerate replacement of fossil fuels by renewable energy in thermal remediation.

Sorption of tetracycline antibiotics by microplastics, associated mechanisms, and risk assessments

In this study, we selected polyvinyl chloride (PVC), polyethylene (PE), and polystyrene (PS) as representative microplastics (MPs) to systematically investigate the sorption behavior of tetracycline (TC) antibiotics by MPs. Scanning electron microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, and adsorption experiments were applied to assess the sorption behavior of MPs. The results demonstrated that the sorption of TC by MPs was most favorable under neutral conditions, where a modest increase in the salt ion concentration enhanced the adsorption of TC by MPs. The saturation adsorption capacities for PVC, PE, and PS for TC were determined as 121.95 μg/g, 81.301 μg/g, and 178.57 μg/g, respectively. The strength of TC sorption by MPs followed the order of: PS > PVC > PE. Analysis of the sorption behavior of TC by MPs showed that the adsorption of TC by PE was weak and it readily desorbed, and thus their interaction will not lead to excessive compound pollution. By contrast, the adsorption of TC was high by PVC and PS, and they were not readily desorbed.

Nanofiber Applications From Hijiki Macroalgae: Antibacterial and Cytotoxicity Properties in Biocompatible Polymers

One of the current biotechnological applications is nanofiber applications made from algae using the electrospinning technique. Nanofibers containing poly-caprolactone (PCL) extracted from the brown seaweed Hijiki (Sargassum fusiforme) were prepared using electrospinning technique. Water extraction was performed to preserve the integrity of Hijiki components, ensuring their efficacy in subsequent electrospinning and characterization. The morphology and chemical composition of the nanofibers were characterized using field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) analyses. Hijiki was found to combine well with electrospun biocompatible polymers and effectively provide the common properties of these materials. The cytotoxicity of algae-doped PCL nanofibers was examined in vitro using liver cancer and liver healthy cell lines (HepG2 and The-2). Among hepatic tumor cell lines, the HepG2 cell line has been preferred due to its wide range of scientific applications. Although the nanofibers caused a 28% decrease in liver cancer cell lines viability (HepG2), the decrease in healthy liver cell viability (The-2) was 12%. Algae-doped PCL nanofiber applied to bacteria showed antibacterial effect. Based on the findings, Hijiki macroalgae nanofibers show great promise for tissue regeneration and band-aid applications in the medical industry.

A chemometric approach to the interaction of hydrogen peroxide and thermally activated persulfate in the removal of aromatic compounds

This study evaluates the combined use of H₂O₂ and thermally activated S₂O₈2⁻ (T-PDS) for the degradation of phenolic compounds (PhOH) in wastewater, aiming to limit or eliminate sludge production. Phenolic compounds are common in industrial effluents, and their effective removal is crucial for reducing environmental impact. The study employs Response Surface Methodology (RSM) and Principal Component Analysis (PCA) to optimise critical variables such as temperature, pH, and oxidant concentrations. Optimal conditions were determined to be a temperature of 70 °C, pH 5, and a H2O2/S2O82- molar ratio of 1:6. Under these conditions, the system achieved an 89% PhOH degradation efficiency, reducing the concentration from 10 to 1.2 mg L-1 after 120 min of treatment. The kinetic analysis revealed a rapid initial reduction in PhOH concentration by 38% (from 10 to 6.2 mg L-1) within the first 15 min, followed by a slower degradation phase. This suggests a complex reaction mechanism, likely influenced by oxidant consumption and intermediate formation. The model demonstrated high precision, with R2 values of 0.99 for PhOH and S2O82-and slightly lower for H₂O₂ (R2 = 0.98). A brief cost analysis estimated the treatment cost at €6.86 per cubic meter of wastewater, showing the economic viability of the process. Additionally, eliminating sludge formation reduces operational costs related to sludge management and disposal, making the H2O2/T-PDS system a promising solution for large-scale industrial applications in sustainable wastewater treatment.

Utilizing urban and agricultural waste for sustainable production of mesoporous hybrid nanocomposites in synthetic dye removal and antimicrobial activity

The discharge of untreated dye waste from various industrial sectors into wastewater poses significant environmental and health risks. This study presents an innovative approach by developing a cost-effective and eco-friendly hybrid mesoporous nanocomposite, silver nanoparticles@mesoporous mango peel-derived carbon (AgNPs@MMC), synthesized from agricultural waste (mango peels) and urban waste (X-ray film waste). The core objectives of this work are: (i) recycling agricultural and urban waste to produce valuable materials; (ii) achieving effective removal of methyl violet 10B (MV10B) through simultaneous adsorption and photocatalytic degradation; and (iii) evaluating the antimicrobial properties of the developed material. The findings for identifying the optimal parameters for the adsorption and photodegradation process showed that 25 mg of AgNPs@MMC can remove >98% of the MV10B dye in 30 min at pH of 7. Furthermore, the nanocomposite maintained its high efficiency for five reuse cycles without significant loss in performance. This work highlights the dual functionality of AgNPs@MMC, combining adsorption and catalytic degradation, while also showcasing its potential for practical wastewater treatment applications. The nanocomposite's structural stability in water and its superior antibacterial activity against Gram-negative bacteria, such as Escherichia coli, Pseudomonas vulgaris, and Vibrio parahaemolyticus, further confirm its environmental suitability.

Potential health, environmental implication of microplastics: A review on its detection

Microplastic contamination of terrestrial and aquatic environment has gained immense research attention due to their potential ecotoxicity and biomagnification property when enterer into food chain. Heterogenous nature of microplastics coupled with their ability to combine with other emerging pollutants have increased the severity of this crisis. Existing detection methods often fails to accurately quantify the amount of microplastic components present in environmental and biological samples. Thus, a great deal of research gap always exists in our current understanding about microplastics including the limitations in screening, detection and mitigation. This review work presents a comprehensive out look on the impact of microplastics on both terrestrial and aquatic environment. Furthermore, an in-depth discussion on various microplastic detection techniques recently used for microplastic quantification along with their significance and limitations is summarised in this review. The review also elaborates various physical, chemical and biological methods used for the mitigation of microplastics from environmental samples.

Synthesis of ternary geopolymers using prediction for effective solidification of mercury in tailings

This study used steel slag, fly ash, and metakaolin as raw materials (SFM materials) to create silica-alumina-based geopolymers that can solidify Hg2+ when activated with sodium-based water glass. The experiments began with a triangular lattice point mixing design experiment, and the results were fitted, analyzed, and predicted. The optimum SFM material mass ratio was found to be 70% steel slag, 25% fly ash, and 5% metakaolin. The optimum modulus of the activator was identified by comparing the unconfined compressive strength and solidifying impact on Hg2+of geosynthetics with different modulus. The SFM geopolymer was then applied in the form of potting to cure the granulated mercury tailings. The inclusion of 50% SFM material generated a geosynthetic that reduced mercury transport to the surface soil by roughly 90%. The mercury concentration of herbaceous plant samples was also reduced by 78%. It indicates that the SFM material can effectively attenuate the migration transformation of mercury. Finally, characterization methods such as XPS and FTIR were used to investigate the mechanism of Hg2+ solidification by geopolymers generated by SFM materials. The possible solidification mechanisms were proposed as alkaline environment-induced mercury precipitation, chemical bonding s, surface adsorption of Hg2+ and its precipitates by the geopolymer, and physical encapsulation.

Optimization of anthracene biodegradation by indigenous Trichoderma lixii and Talaromyces pinophilus using response surface methodology

Two indigenous fungal strains, Trichoderma lixii FLU1 (TlFLU1) and Talaromyces pinophilus FLU12 (TpFLU12) showed potential to biodegrade anthracene. Response Surface Methodology (RSM) employing Box-Behnken Design (BBD) and Central Composite Design (CCD) methods optimized crucial physicochemical parameters like pH, temperature, biomass, substrate concentration and media composition. BBD maximized anthracene biodegradation efficiency by predicting 98.7-103.2 %. Analysis of Variance confirmed the model's accuracy with a significant F-value of 51.0 at p<0.0001 while the quadratic regression model showed a high R² value 0.9808. CCD predicted 100 % degradation efficiency which were validated for TlFLU1 and TpFLU12 respectively on day 8 and 12 at pH 4 and 5, temperatures 30°C and 25°C, with 20 mm biomass size and 200 mg/L anthracene. 9,10-anthraquinone and phthalic acid were detected as metabolites formed during the anthracene degradation by TlFLU1 and TpFLU12 after validation of the optimization process. Acute toxicity tests showed that the degradation media toxicity reduced as evidenced by increased in survival rate (log CFU/mL) of Vibrio parahaemolyticus after 6 h exposure. Despite reduced toxicity, both strains were classified as harmful based on effective concentration (EC50) and toxicity unit (TU) (20.92±1.32 mg/L and 4.78 % for TlFLU1 and 35.29±1.55 mg/L and 2.83 % for TpFLU12). This systematic optimization approach supported by robust statistical analyses and a deep exploration of biodegradation mechanisms holds the promise of more efficient and sustainable methods for remediating PAH-contaminated environments.

Triboelectric Nanogenerator Drives Electrochemical Water Splitting for Hydrogen Production: Fundamentals, Progress, and Challenges

Currently, triboelectric nanogenerators (TENGs) are drawing significant attention owing to their potential in harvesting wave and wind energy from environment as well as their capability for driving electrochemical water splitting for hydrogen fuel production. This review aims to summarize the recent progress of ocean wave and wind energy harvesting TENGs and TENG-driven electrochemical water splitting processes for hydrogen evolution reaction. For better understanding, this review begins from the fundamentals of TENG and electrochemical water splitting. And then the working principle of TENGs and mechanism of electrochemical (EC) water splitting for hydrogen evolution reaction (HER) are introduced. Subsequently the progress of output performance enhancement in ocean wave and wind energy harvesting TENGs are systematically discussed including structure design, triboelectric material selection and power management all of which are important for output performance enhancement and the integration of TENGs with electrochemical water splitting cell. Although this review focus on the promotion strategies of TENG-driven electrochemical water splitting processes for HER, challenges for water splitting are also highlighted. While envision that this review provides a deep insight and direction to the design of TENG-driven electrochemical system for promoting the hydrogen fuel production in an active, economical manner.

Smart and advanced nanocomposites of rGO-based Ni-doped Co3O4/TiO2 for next-level photocatalysis and gas sensing application

The rGO-based 5% Ni-doped Co3O4/TiO2 (GNCT) p-n heterojunction nanocomposite was synthesized using hydrothermal method. The resulting nanocomposite's morphology, structure, surface area, elemental composition, electrical and optical properties were thoroughly examined using a variety of techniques. The GNCT nanomaterial achieved an impressive 99.11% degradation within 40 min, while GPCT closely followed with a 96.6% efficiency. Its smart nanomaterial also excels as a n-butanol sensor, with GNCT showing a sensitivity of 91.51%, and GPCT registering 86.51%. This dual-functionality highlights its potential as an advanced material for environmental and sensing applications. Additionally, GNCT exhibited excellent stability across multiple cycles, underscoring its potential for gas sensing and environmental applications. The remarkable performance of GNCT is a result of the synergistic effects of its morphology (nanosheet), surface area (540.215 m2/g), band gap (1.93 eV), and photosensitivity (36.92%), which collectively make it an ideal candidate for the photocatalytic and gas sensing applications.

Adsorption and biodegradation of butyl xanthate in mine water by Pseudomonas sp. immobilized on yak dung biochar

The butyl xanthate (BX) in mining wastewater poses significant environmental challenges due to its toxicity and persistence. This study aimed to evaluate the effectiveness of Pseudomonas sp. immobilized on yak dung biochar (Ps.@YDBC600) for BX degradation, emphasizing the synergistic effects of biochar adsorption and microbial degradation. BX removal efficiency of free Pseudomonas sp. cells was assessed under various environmental conditions, with optimal degradation observed at 30 °C and an initial pH of 5.0. Yak dung biochar prepared at 600 °C (YDBC600) was selected due to its high surface area, porosity, and favorable adsorption properties, enhancing the immobilization and activity of Pseudomonas sp. The absorption of BX by biochar followed a two-compartment first-order kinetic model and primarily involved hydrogen bonding, hydrophobic interactions, and pore filling. The primary crystalline mineral component of YDBC600 and Ps.@YDBC600 before and after the adsorption and degradation of BX was SiO₂. The Ps.@YDBC600 was shown to significantly enhance BX removal efficiency compared to free Pseudomonas sp. cells or biochar alone. Molecular studies indicated that biochar facilitated BX degradation by providing a stable environment for Pseudomonas sp. and optimizing metabolic resource allocation. The primary by-products, including CS₂, HS-, ROCOS-, ROCSSH and (ROCSS)₂ were effectively minimized (each by-product was reduced more than 80%), reducing secondary pollution. These findings demonstrated the potential of Pseudomonas sp. immobilized on biochar as an effective approach for treating BX-contaminated mining wastewater, offering a sustainable approach to environmental remediation and management.