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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]

Background: The development of micro-organism resistance in humans and the environment has been linked to the inadequacy of conventional treatment methods in completely eliminating antibiotics. The purpose of this research is to look at the potential for eliminating Amoxicillin (AMO) from aqueous environments using Nickel (II) Oxide Nanoparticles (NiO nanoparticles). Materials and Methods: In order to determine how successful NiO nanoparticles are in eliminating AMO, the impact of many important adsorption process factors, such as the initial concentrations of AMO (10-50 mg/L), pH (3-10), adsorbent dose (0.1-1 g/L), mixing rate (50-300 rpm), contact time (10-100 min), and temperature (15-45°C) was examined. Results: The greatest AMO removal efficiency was 99.48% at pH=7, 0.8 g/L of adsorbent, and contact time of 60 min. The endothermic nature of the adsorption process was suggested by the positive value of Ho. The observed physical adsorption was consistent with the Ho evolved during adsorption, which was less than 40 KJ/mol. The negative value of Go demonstrated that AMO absorbed on the NiO nanoparticles was a spontaneous process. Conclusion: Accordingly, NiO nanoparticles could be employed as a successful adsorbent to eliminate AMO from pharmaceutical wastewater. [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]

Haematite (Fe2O3) loaded on graphitic carbon nitride (g-C3N4) was synthesised as a new photocatalyst by hydrothermal method, and its photocatalytic activity was evaluated for the degradation of ciprofloxacin (CIP) from aqueous solutions. Structural properties determined by scanning electron microscope (SEM), X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) showed that Fe2O3 nanoparticles were successfully prepared and a good interaction occurred between g-C3N4 and Fe2O3. The g-C3N4/Fe2O3/UV system showed higher degradation efficiencies than UV and g-C3N4/Fe2O3 alone. The maximum removal of CIP (100%) and TOC (93.86%) was achieved at pH of 7, photocatalytic dosage of 0.3 g/L, radiation intensity of 36 W, and reaction time of 60 min. The rate of degradation of CIP was investigated by first-order kinetic and its constant rate confirmed the influence of factors. Trapping experiments showed that hole (h+), hydroxyl radical (•OH) and superoxide radical (O2•-) were involved in photodegradation of CIP, however, h+ and •OH plays major role in the degradation of the target pollutant. The excellent stability and recyclability of g-C3N4/Fe2O3 was confirmed by five consecutive reaction cycles. The energy consumption of the system for different concentrations of CIP (10–50 mg/L) was in the range of 9–44.02 kWh/m3, which emphasises that the g-C3N4/Fe2O3/UV process is energy-efficient. The BOD5/COD rate showed that the photocatalytic process can degrade CIP into degradable compounds. The presence of NH4+, NO3− and F− anions in the treated effluent indicates that CIP is well mineralised. Toxicity experiments performed by Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) culture suggested the applicability of the g-C3N4/Fe2O3/UV process as a promising and effective technology for treatment of CIP-containing solution. [ABSTRACT FROM AUTHOR]

In this study, the effectiveness of activated carbon prepared from the Azolla filiculoides fern (ACAF) in order to remove ampicillin from aqueous solution was examined. The preparation of the ACAF was performed through chemical and physical activation processes with the presence of ZnCl2 and at a temperature of 450 °C. The ACAF yield was 44.7% of the fresh Azolla filiculoides. The results obtained from the characterization study indicate that the prepared ACAF has excellent surface and internal properties to be used as an adsorbent. The surface area, porosity, and pore volume were estimated to be 716.4 m2/g, 51.2%, and 0.621 cm3/g, respectively. The functional groups in ACAF that were responsible for the adsorption of ampicillin molecules were detected using FTIR analyses. The maximum efficiency (96.84%) and uptake (114.3 mg/g) of ACAF to remove ampicillin were achieved under the following conditions: ACAF dose = 0.8 g/L, pH = 7, concentration of ampicillin = 100 mg/L, contact time = 60 min, and temperature = 45 °C. It was found that the kinetic and isotherm data matched the pseudo-second-order and Langmuir models with high precision values, respectively. Considering the thermodynamics of the adsorption, the endothermic and spontaneous nature of the ampicillin adsorption onto ACAF was approved. The ampicillin adsorption capacity by ACAF was not significantly affected by the presence of different concentrations of NaNO3 competitor ion. The considerably higher adsorption capacity of the ACAF for ampicillin (114.3 mg/g) than other previously used adsorbents with excellent regeneration level (five cycles) depicts the superior performance of ACAF in the adsorption systems. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of ciprofloxacin (CIP) was examined by loading spinel ferrite copper (CuFe2O4) nanoparticles onto montmorillonite (MMT) under irradiation using UV light. The laboratory parameters were optimized using response surface methodology (RSM), and maximum efficiency (83.75%) was achieved at a pH of 3, CIP concentration of 32.5 mg/L, MMT/CuFe2O4 dose of 0.78 g/L, and irradiation time of 47.50 min. During the photocatalysis process, the experiments on radical trapping demonstrated the generation of hydroxyls (•OH), superoxide (•O2-) radical, electrons (e-), and holes (h+). A low rate drop (below 10%) in the CIP degradation during the six consecutive reaction cycles corroborated the remarkable recyclability and stability of the MMT/CuFe2O4. The acute toxicity of the treated solution was determined using Daphnia Magna, by applying photocatalysis, which was indicative of a marked decline in the toxicity. Comparing the findings of the degradation using UV and the degradation process using visible light represented results with close resemblance to each other at the end of the reaction time. Besides, under UV and visible light, the particles in reactor are easily activated when the pollutant mineralization exceeded 80%. [ABSTRACT FROM AUTHOR]

Objectives: The entry of antibiotics into surface and groundwater will cause problems in the environment. This study aimed to investigate the removal efficiency of ciprofloxacin (CFX) from aqueous solutions using the sonophotocatalytic process of Magnesium Oxide Nanoparticles (MgO). Materials and Methods: This study is an experimental-laboratory study performed in a reactor with a discontinuous system. In this study, the effect of parameters such as solution pH, MgO dose, reaction time in two processes, photocatalyst and sonocatalyst, initial concentration of antibiotic and the power of UV lamps in the photocatalytic reactor at ultrasonic frequencies of 35 and 130 kHz on the reduction of CFX in aqueous solution was investigated. Results: The results showed that the process of photosonocatalysis with MgO can effectively lead to the removal of the antibiotic CFX. In the process of using a photosonocatalyst with a pH of 7 and ultrasonic waves with a frequency of 35 kHz and an optimal time of 30 min, 0.3 g/L of MgO, CFX concentration of 150 mg/l, UV lamp with a power of 30 watts and the optimal irradiation time of 60 min was obtained as the optimal variables in the removal of CFX antibiotic. Conclusion: The results showed that the photosonocatalytic process with the help of MgO is an effective and efficient method to remove the CFX antibiotic from aqueous solutions. [ABSTRACT FROM AUTHOR]

This pilot study synthesized the γ-Fe2O3@SiO2@ZIF8-Ag nanocomposites via the hydrothermal method to study its potential use in amoxicillin degradation as a novel photocatalyst in aqueous solutions under visible light radiation. Various diagnostic methods were used to determine the morphology and functional structure of the photocatalyst, and the results confirmed its proper formation. Complete degradation of AMX was obtained at a pH of 5, catalyst dosage of 0.4 g/L, AMX concentration of 10 mg/L, and reaction time of 60 min. The efficiency of the degradation was diminished when anions were present in the reaction medium, and the order of their effect was SO42− < Cl− < NO3− < HCO3−. Biodegradability (BOD5/COD ratio) increased from 0.20 to 0.68 after 120 min of photocatalytic treatment, with a COD removal of 87.54% and a TOC removal of 74.88%. Through the experimental trapping of electrons, we found the production of reactive species, such as hydroxyl radical (•OH), superoxide (O2•−), and holes (h+), in the photocatalysis reactor and that •OH was the predominant species in AMX photodegradation. Comparative experiments emphasized that the oxidation process occurs with the adsorption of pollutants on the surface of the catalyst, and the photocatalyst has the potential to be activated by various light sources, including visible light, UV light, and sunlight, with an AMX decomposition above 88%. The synthesized particles can be recovered after five consecutive cycles with minimal reduction in the degradation rate (< 4%). γ-Fe2O3@SiO2@ZIF8-Ag can be considered a promising photocatalyst for use in AMX degradation due to its recyclability, easier activation by different light sources, and excellent mineralization. [ABSTRACT FROM AUTHOR]

Here, the magnetic Fe3O4@SiO2/PAEDTC@MIL-101 (Fe) with a new core-shell structure was synthesized, and its sonophotocatalytic properties were evaluated for acid red 14 (AR14) degradation. Particle characterizations were determined by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and vibrating-sample magnetometer (VSM), and the analysis results offered an excellent synthesis of mesoporous particles. Fe3O4@SiO2/PAEDTC@MIL-101 (Fe)/UV/US showed high degradation kinetics rate (0.0327 min−1) compared to sonocatalytic processes (0.0181 min−1), photocatalytic (0218 min−1), sonolysis (0.008 min−1), and photolysis (0.005 min−1). Maximum removal efficiencies of AR14 (100%) and total organic carbon (69.96%) were obtained at pH of 5, catalyst mass of 0.5 g/L, initial AR14 concentration of 50 mg/L, and ultrasound power of 36 W. Evaluation of BOD5/COD ratio during dye treatment confirmed that the sonophotocatalysis process can be useful for converting major contaminant molecules into biodegradable compounds. After recycling eight times, the prepared composite still has sonophotocatalytic degradation stability above 90% for AR14. Scavenging tests confirmed that holes (h+) and hydroxyl (•OH) were the pivotal agents in the decomposition system. Based on the results, the synthesized sample can be suggested as an excellent and promising sonophotocatalyst for the degradation of AR14 dye and its conversion into biodegradable compounds. [ABSTRACT FROM AUTHOR]

Copper ferrite nanoparticles loaded on montmorillonite (MMT−CuFe2O4) were prepared by co‐precipitation method and applied as catalyst for activation of peroxymonosulfate (PMS) in degradation of reactive black 5 (RB5). The maximum removal efficiency of RB5 completely depends on the operating parameters and the highest removal percentage was obtained at MMT−CuFe2O4 dosage of 250 mg/L, PMS concentration of 4 mM, initial RB5 concentration of 50 mg/L and time of 15 min. The presence of anions such as Cl−, NO3−, HCO3−, and SO42− showed a significant limitation in the degradation of RB5 in the MMT−CuFe2O4/PMS system. Trapping experiments showed that ⋅OH and SO4⋅− radicals were involved in the catalytic degradation of RB5, however ⋅OH is the major specie in the catalysis system. Consecutive cycles were considered for testing the reusability of MMT−CuFe2O4; its results showed the stability of five consecutive cycles. The toxicity test was evaluated using Daphnia magna and the results illustrated a substantial drop in the toxicity of the solution treated. The significant reduction of TOC during RB5 degradation and the production of SO42−, NH4+ and NO3− confirm the proper progress of pollutant mineralization. The high catalytic performance of the catalyst in a short time compared to other removal systems emphasizes that MMT−CuFe2O4 can be suggested as a promising catalyst for the degradation of RB5 from aqueous solutions. [ABSTRACT FROM AUTHOR]

The adsorption of Acid orange 7 (AO7) by Polypyrrole/nanosilica composite (PPN/SiO2) was studied and various parameters have been investigated, more than 99.4% of the adsorption efficiency was obtained under the optimal conditions (PPN/SiO2 mass = 1 g/L, contact time = 90 min, Initial AO7 concentration = 10 mg/L, shaking speed = 200 rpm and temperature = 328 K and pH = 3).PPN/SiO2specifications were determined using FTIR, XRD, TGA, pHzpc,TEM and SEM analysis. The kinetic data were fitted by the pseudo-second-order kinetic; the rate constant K increased when temperature increased indicating the adsorption was endothermic in nature. The studies related to the adsorption mechanism illuminated that the AO7 adsorption process was complex and obeyed both surface adsorption and particle diffusion. Moreover, based on the results, the adsorption happens through film diffusion at low concentrations while the particle diffusion is the rate-determining step at higher concentration. The isotherm equations showed that the equilibrium data followed more than the Langmuir isotherm with a maximum adsorption capacity of 181.4 mg/g. The thermodynamic parameters were calculated, and their negative value of ΔG° and positive value of ΔS° and ΔH° showed that the adsorption was spontaneous and endothermic. [ABSTRACT FROM AUTHOR]

In the present work, the adsorption mechanism and capacity of MWCNTs/CoFe2O4 nanocomposite as an adsorbent were investigated. Levofloxacin (LFX), a widely used antibiotic, was selected as a hazardous model contaminant in aqueous solutions. The surface and inner characterization of MWCNTs/CoFe2O4 was obtained via SEM/TEM, XRD, BET/BJH, and pHPZC. These analyses indicated that MWCNTs/CoFe2O4 possess excellent surface and pore characteristics, e.g., specific surface area, pore volume, and mean pore diameter, which were 72 m2/g, 0.51 cm3/g, and 65 nm, respectively. The results demonstrate that by supplementing 1 g/L of MWCNTs/CoFe2O4 at experimental conditions of pH value of 5, temperature of 30 °C, initial LFX concentration of 50 mg/L and mixing time of 90 min, a significant outcome of 99.3% removal was achieved. To identify the phenomenon of adsorption, the thermodynamic parameters of ΔH° and ΔS° were calculated, which indicated that the nature of LFX adsorption onto MWCNTs/CoFe2O4 nanocomposite was endothermic and spontaneous. Nine isotherm models, including four two-parameter and five three-parameter models, were investigated. In addition, the regression coefficient as well as five error coefficient models were calculated for nonlinear isotherm models. According to the goodness of fit tests, the equilibrium data were well coordinated with the Freundlich and Sips isotherms. The kinetics study showed that the LFX adsorption data well fitted with pseudo-second-order model, and the adsorption of LFX molecules occurred through several stages from surface to intraparticle diffusion. In conclusion, the present work evinces that LFX wastewater can be efficiently treated via an adsorption process using a MWCNTs/CoFe2O4 nanocomposite. [ABSTRACT FROM AUTHOR]