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Background: Antibiotics play a crucial role in the treatment of infectious diseases in humans and animals. However, their incomplete metabolism in the body often results in their release as active compounds into aquatic systems via domestic wastewater treatment plants. This release poses potential risks of chronic toxicity and significant health and environmental hazards. This study examines the efficacy of Polypyrrole/Titanium Dioxide Composite (PTDC) as an innovative adsorbent for removing Cephalexin (CFX) from aqueous solutions. Materials and Methods: In the batch adsorption experiments, the researchers inspected the influence of solution pH, contact time, adsorbent dosage, and initial CFX concentration. Thermodynamic parameters were calculated, which include standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), standard entropy (ΔS°), and activation energy (A). Results: The biosorption processes are considered spontaneous when the values of ΔG° are negative. The endothermic character of the biosorption processes is suggested by ΔH°>O for the biosorption of CFX. The biosorption capacity of the PTDC increases as the temperature rises, which also supports the endothermic nature of the biosorption processes. The activation energy for the biosorption of every CFX ion was less than 42 kJ/mol at all temperatures, suggesting that each process was diffusion-controlled. Conclusion: The outcomes indicated that PTDC exhibits capability as an adsorbent for removing CFX from water samples to safeguard the environment. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the performance of the Pd@TMU-16 to act as a photocatalyst in degrading the Acid Red 88 (AR88) dye from an aqueous solution, via photocatalysis process, using UV irradiation. The synthesis of this catalyst was performed under conditions of thermal solvent and its characteristic parameters were confirmed using the XRD, Band gap, SEM, BET, pHPCZ, and FTIR methodologies. The influence exerted by the operative parameters on the AR88 degradation, which included the pH, reaction time, radiation intensity, catalyst mass, and initial dye concentration was examined. At the optimum condition of photocatalysis and utilising only 0.75 g of Pd@TMU-16, total degradation of 10 mg/L dye concentration was performed. From the kinetic studies, the dye degradation indicated that it was similar to the pseudo-first-order model, and the dye degradation mechanism had taken place through the hydroxyl (•OH) and superoxide radicals (•O⁻₂). The adsorbent reusability was also studied, and from the results it was evident that the 18% decrease observed after six consecutive cycles of catalyst use, clearly indicated its stability. For radiation intensities of 8, 15, 24, and 36 W, the Energy Consumed per m3 of the treated wastewater was found 20.2, 28.8, 34.1, and 36.9 kWh, respectively. From these results, namely the low energy gap (2.3 eV) and high degradation capacity, it was evident that the Pd@TMU-16 can be useful, under UV light, as a powerful catalyst in the elimination of dyes and other organic contaminants from polluted aqueous media. [ABSTRACT FROM AUTHOR]

In this study, adsorption of Acid Blue 113 dye (AB113) onto the magnetically activated carbon fibre (ACF) with iron oxide nanoparticles (ACF/Fe3O4) was evaluated. Effects of different reaction conditions, e.g. contact time, pH, AB113 ion concentrations, and temperature, were also studied. The batch adsorption studies revealed that the AB113 ions reached equilibrium at 90 min. From the results, it was clear that when the initial AB113 concentration was 10 mg/L and pH was 3, a 100% removal percentage was achieved in the presence of ACF/Fe3O4 (a dosage of 0.8 g/L) at $$30$$ 30. The thermodynamic parameters revealed that the process is endothermic, spontaneous, and thermodynamically favourable. Under the best experimental conditions, the maximum adsorption capacity was obtained to be 121.4 and 112.2 mg. g−1, according to the nonlinear and linear Langmuir model. Adsorbent reuse was performed in six consecutive cycles, and the results showed high adsorbent efficiency in all cycles. Linear and nonlinear forms of six isotherm models and four kinetic models were investigated, and the equilibrium data, in addition to regression coefficient (R2), were matched with four error coefficient models. As a result, due to the high R2 and the lower error coefficient, the equilibrium data follow the Langmuir isotherm and Pseudo-second-order (PSO) kinetic with both linear and nonlinear models. The adsorption mechanism can be explained through π-π bonds, hydrogen bonds, and electrostatic interactions. The prepared ACF/Fe3O4 presented excellent adsorption capacity for the removal of AB113, demonstrating its viability for removing this contaminant from the aqueous medium. [ABSTRACT FROM AUTHOR]

In this study, titanium dioxide nanoparticles (TiO2) were loaded on graphene oxide (GO) by hydrothermal method and used as a photocatalyst for the degradation of bisphenol A (BPA). The optimum photocatalytic conditions were evaluated by studying the effect of operating parameters such as initial pH, photocatalyst dosage, radiation intensity, and initial BPA concentration. Under optimal conditions, 88.9% BPA degradation and 65% BPA mineralisation were obtained after 60 min of UV radiation. The presence of anions such as chloride, nitrate, carbonate, and bicarbonate in the reaction reactor significantly reduced the degradation efficiency and the constant kinetic rate by producing reactive species with weaker oxidation potential. The kinetic rate emphasised that the integrated TiO2 and GO nanoparticles have a high degradation activity (0.31 min−1) in the presence of UV compared to the alone process of UV (0.003 min−1) and adsorption (0.007 min−1). The radical trapping experiments showed that h+, •OH, O2•-, and e− are present in the reaction system, and the h+ and •OH species play a major role in the degradation process. The system energy consumption for different concentrations of BPA (10–100 mg/L) was in the range of 23.06–99.96 kWh/m3. The reusability results showed that the activity of GO-TiO2 in the degradation of BPA did not change significantly even after five cycles, which indicates its excellent photocatalytic stability. To evaluate the performance of GO-TiO2, the photocatalytic activation, oxidants such as H2O2, persulphate, and peroxymonosulfate were evaluated, and the results showed complete degradation of the contaminant at low concentrations of oxidants. The performance of the system for BPA removal in various real solutions such as drinking water, raw water, and treated wastewater was found to be 85.52, 79.52%, and 55.65%, respectively. Based on comparative experiments and trapping of reactive species, the photocatalytic degradation mechanism of BPA by GO-TiO2/UV was proposed. [ABSTRACT FROM AUTHOR]

Despite the importance of breastfeeding, complementary or complete feeding with infant formula is performed worldwide. Metal contaminants, especially lead and cadmium, have many toxic and adverse effects, especially in children. Therefore, this work was conducted to investigate the levels of lead and cadmium in infant formula and baby foods. This study was performed on 18 samples of infant formula and 7 samples of baby food. Random sampling was performed among the best-selling and most consumed brands available in the Zahedan market, and elements were measured by atomic absorption spectroscopy using a graphite furnace. Moreover, Estimated Daily Intake (EDI) and health risk index (HRI) were calculated for the average of the total data. The mean concentrations of lead in infant formula and baby food samples were 14.7±0.98 and 13.77±1.51 µg/kg, respectively; lead was observed in all samples, although the difference between the amount of lead in samples no. 2 and no. 9 and its standard amount was significant (p<0.05). The average concentrations of cadmium in infant formula and baby food samples were 0.097±0.016 and 0.705±0.12 µg/kg, respectively; it was observed in 22% of infant formula samples and 57% of baby food samples, but the difference in cadmium concentrations in the samples was not significant compared to the standard concentration (p>0.05). The highest EDI for lead in infant formula for ages of 0 to six months was 0.22 µg/kg.day.bw. Also, the HRI for all samples was much less than one, which indicates that the baby's food and infant formula are healthy in terms of daily intake of cadmium and lead. Finally, it can be concluded that the amount of cadmium and lead in the infant formula and baby food samples, according to some indicators, is less than the standard level. [ABSTRACT FROM AUTHOR]

Introduction: This research introduces an innovative photocatalytic reactor designed to address challenges in wastewater treatment, with a focus on enhancing dye degradation and reducing Chemical Oxygen Demand (COD). Methods: The reactor is designed with counter-rotational movements of discs to enhance hydrodynamics and mass transfer, along with a 3D-printed, interchangeable component system to boost efficacy. TiO2 nanoparticles, composed of 80% anatase and 20% rutile, are thermally immobilized on glass discs. The effectiveness of various treatment variables was assessed through a Central Composite Design (CCD), guided by a Response Surface Methodology (RSM) model. Results: The RSM analysis reveals that the linear, quadratic, and interactive effects of the counter-rotational movements significantly influence the efficiency of dye and COD removal. The RSM model yields coefficients of determination (R2) values of 0.9758 and 0.9765 for the predictive models of dye and COD removal, respectively. Optimized parameters for dye removal include a pH of 6.05, disc rotation speed of 22.35 rpm, initial dye concentration of 3.15 x 10-5 M, residence time of 7.98 h, and the number of nanoparticle layers set at 3.99, resulting in 96.63% dye removal and 65.81% COD removal under optimal conditions. Discussion: Notably, the reactor demonstrates potential for efficient treatment within a near-neutral pH range, which could reduce costs and resource use by eliminating the need for pH adjustments. The implementation of discs rotating in opposite directions marks a significant advancement in the process of dye removal. [ABSTRACT FROM AUTHOR]

This study involved the preparation of magnetized activated carbon (Fe3O4–HSAC) by first activating hazelnut shell waste, followed by coating it by Fe3O4 nanoparticles. The Fe3O4–HSAC thus prepared was evaluated as an adsorbent possessing the potential for fluoride to elimination, under a variety of conditions. From the findings, it is evident that by using the Fe3O4–HSAC as an adsorbent 100% fluoride removal could be accomplished under the optimum conditions cited (adsorbent dose = 0.75 g/L; pH = 3–5; and temperature = 323 K). The Halsey and Freundlich isotherm models both concurred strongly with the equilibrium adsorption data, and from the results of the Langmuir model, the maximum adsorption capacity was achieved at 146.2 mg/g when the temperature was 298 K and pH was 5. The pseudo-second-order kinetic model offered the best explanation for the adsorption process. Besides, both the intra-particle diffusion and liquid film diffusion models were found to control the kinetic mechanism of the fluoride adsorption onto the Fe3O4–HSAC. The quantity of adsorption energy provided using the Dubinin–Radushkevich model was 4.59 kJ/mol, indicating that the physical adsorption was predominant. Further, the negative values of Gibbs free energy change (ΔG° = -2.73 to -8.11 kJ/mol at temperature = 288 to 318 K, respectively) and the positive values of enthalpy change (ΔH° = 56.01 kJ/mol) and entropy change (ΔS° = 0.198 kJ/mol. K) suggest that the nature of the adsorption thermodynamics is endothermic, spontaneous, and physical. From this study, the observation of the outstanding performance of the Fe3O4–HSAC helped to conclude that this is a material of promise as a treatment agent in the fluoride elimination from contaminated water and wastewater. [ABSTRACT FROM AUTHOR]

Background: The presence of antibiotic residues in water is a matter of concern for both public health and the environment, owing to the phenomenon of antibiotic resistance. One of the Advanced Oxidation Processes (AOPs) employed for the removal of refractory pollutants in the aqueous matrix is sonication. The sonochemical processes have been found to have a multitude of advantages, including the mitigation or complete elimination of secondary pollutants, energy conservation, enhanced safety, and improved cleanliness. Methodology: Antibiotic degradation mechanisms are thoroughly reviewed in this article, with a particular focus on activating Persulfate (PS) and Peroxymonosulfate (PMS) using sonication from 2000 to 2023. The analysis of articles retrieved from Google Scholar, Web of Science, and Scopus was conducted using the suggested reporting items for systematic review and meta-analysis methodology. A total of 195 published publications were found after the initial search. Following a comprehensive evaluation, a total of 58 publications were chosen for the investigation of the utilization of ultrasound-assisted heterogeneous activation in PS and PMS operations. Results: Our findings were indicative of a discernible increase in publications in recent years, especially between 2017 and 2023. In addition, the elements that contribute to the effective degradation of antibiotics, such as pH, initial antibiotics concentration, PMS and PS dosage, contact time, and Ultrasonic frequency intensity, were analyzed and reviewed in this review study. Conclusion: This method has successfully removed antibiotics from aqueous solutions and hospital wastewater. [ABSTRACT FROM AUTHOR]

The removal of Hexavalent Chromium (Cr (VI)) is a challenging task due to its acute toxicity even at low concentration. In the present study, graphene oxide-Fe3O4 composite (Fe3O4-GO) was prepared and utilised for the removal of Cr(VI) from aqueous solution. Batch experiments were conducted to investigate the influence of operating variables. Transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), vibrating sample magnetometer (VSM), and point zero charge (pHpzc) were used to characterise the Fe3O4-GO. BET surface area of GO was 254.2 m2/g, but for Fe3O4-GO, it was decreased to 194.6 m2/g. From the experimentation, it was found that the best conditions were presented at 45°C, 0.6 g/L, Fe3O4-GO mass, PH = 2, concentration 10 mg/L, and contact time = 60 min with removal efficiencies above 99%. Analyses of Cr(VI) adsorption kinetics exhibited relatively rapid adsorption behaviour and obedience of the data from pseudo-second-order kinetics. The Langmuir model resulted in best fits to the adsorption isotherms for both linear and nonlinear models with maximum adsorption of 140.8 mg/g. The adsorption of Cr(VI) was an endothermic and spontaneous process. The removal efficiencies exhibited a moderate reduction in the maximum values (less than 6%) after six regeneration cycles. The Fe3O4-GO composite could be a promising material for the removal of Cr(VI) from wastewater. [ABSTRACT FROM AUTHOR]

The novel photocatalyst of Fe3O4@SiO2/PAEDTC@MIL-101(Fe) was prepared based on the sol–gel method, and its structure and morphology were determined by SEM mapping, TEM, XRD, FTIR, and N2 adsorption–desorption analyses. The photocatalytic activity of nanocomposite was evaluated in comparison with other particles as well as adsorption and photolysis processes. The effect of operating parameters showed that the complete degradation of penicillin G (PNG) can be provided at a photocatalyst dosage of 0.6 g/L, radiation intensity of 36 W, pH of 5, and time of 60 min. In the optimum condition, 84% TOC removal was attained and the BOD5/COD rate for the treated effluent was above 0.4, which was representative of the high biodegradability of the treated effluent compared to the raw sample. The findings of energy consumption showed that PNG can be easily and effectively treated by the photocatalytic process based on magnetic MIL-101(Fe) with electrical energy per order between 10 and 20.87 kWh/m3. Due to the excellent interaction between the MIL-101(Fe) and Fe3O4@SiO2/PAEDTC, the photocatalyst stability test showed a recyclability of the particles for 5 consecutive reaction cycles with a minimum reduction of 7%. Solution treated with photocatalyst under UV and visible light sources explained that the toxicity of the effluent after treatment is significantly reduced with the growth of Escherichia coli. Scavenging experiments showed that •OH radical and hole (h+) are the main agents in degrading PNG to CO2, H2O, and biodegradable and low-toxicity products. Finally, the findings of the diagnostic analysis and comparative experiments proved that with the interaction of Fe3O4@SiO2, NH2, and MIL-101(Fe), a lower band gap can be prepared for more absorption of photons and pollutant and also more and faster production of active radicals. [ABSTRACT FROM AUTHOR]