•MPAC coupled with UV and US irradiations was applied to efficient decompose of H2O2.•Over 87% of COD removed and the effluent was permissible to discharge environment.•Recalcitrant compounds were ...removed effectively and the biodegradability improved.•MPAC indicated high catalytic activity, reusability and stability in treatment process.
An effective hybrid system was applied as a first report for successful treatment of recalcitrant petrochemical wastewater (PCW). In this regards, magnetic powdered activated carbon (MPAC), as a heterogeneous catalyst, was coupled with ultrasound (US) and UV irradiations for activation of H2O2 (marked as MPAC/US/UV/H2O2). Chemical oxygen demand (COD) removal ratio was evaluated with various influencing operating factors including solution pH, MPAC and H2O2 concentrations, US power and quenchers. A possible mechanism for catalytic degradation and generation of reactive species was proposed. To evaluate the biodegradability of both raw and treated PCWs, the activated sludge inhibition experiments were performed based on Zahn-Wellens test. MPAC indicated high catalytic activity, reusability and stability in the studied system. Over 87% of COD was removed under optimum conditions within 80 min treatment and the residual COD concentration reached 82.9 mg/L, which was permissible to discharge surface water sources based on the environmental standards. Leaching of transition metals from catalyst textural was negligible. Compared to homogeneous system (Fe2+/US/UV/H2O2), heterogeneous system (MPAC/US/UV/H2O2) represented a better performance in COD removal. Identification of intermediates by GC–MS showed that a wide range of recalcitrant compounds was removed and/or degraded into small molecular compounds effectively after treatment. A biodegradability ratio of 64% and the residual COD of 28 mg/L for treated PCW, indicating that the biodegradability was improved and refractory organic matters removed effectively. As conclusion, MPAC/US/UV/H2O2 hybrid system can be introduced as a successful advanced treatment process for efficient remediation of refractory PCWs.
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•Fe-doped TiO2/rGO system showed a good photocatalytic activity in decolorization.•Under optimized conditions, 91 and 66% of dye and COD respectively were removed.•Photocatalytic ...efficiency to complete degradation was observed by adding H2O2.•The raw wastewater biodegradability increased after the photodegradation.
In this work, a simple sol-gel method was used to fabricate a ternary nanocomposite of Fe-doped TiO2 decorated on reduced graphene oxide (Fe-doped TiO2/rGO). XRD, Raman shift, FT-IR, BET, DRS, EIS, TEM, FESEM, EDX and EDS techniques were applied for characterization of the structural, optical, and surface morphological properties of the synthesized catalysts. The DRS results of the photocatalysts showed a narrowing band gap by the introduction of Fe ions to the titania framework. The photocatalytic performance of the prepared samples was determined through the decontamination of rhodamine B under solar illumination. The optimum content of iron and graphene oxide and the effect of operational factors including pH, catalyst dosage and the initial concentration of rhodamine B were studied. The findings revealed that a 0.6 g Fe-doped TiO2/rGO nanocomposite containing 3% Fe and 5% rGO, with an initial pH of 6 and rhodamine B concentration of 20 mg/L could achieve a removal of 91% after 120 min under solar illumination. TOC analyses were conducted to explore the rhodamine B mineralization rate; the data showed complete mineralization after 300 min. The effect of co-existing ions was examined and the results indicated that the degradation efficiency was significantly decreased by the addition of chloride and sulfate anions, although it slightly decreased in the presence of nitrate and phosphate anions. Furthermore, the addition of H2O2 as an enhancer was investigated and the data demonstrated that the addition of 8 mM H2O2 enhanced the photocatalytic efficacy to complete degradation. Finally, in the treatment of real textile wastewater, the concentrations of TOC and COD decreased from 930 mg/L and 1550 mg/L to 310 mg/L and 634 mg/L, respectively, after 390 min under similar operational conditions.
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•WO3/CNT nanocomposites were used for sono-photocatalytic degradation of contaminated waters.•Presence of US irradiation considerably improved the photocatalytic activity of WO3/CNT ...under visible light.•Pharmaceutical wastewater was effectively treated using WO3/CNT heterostructures.•As-prepared samples demonstrated an excellent stability after several cycles.
In this paper, in-situ fabrication of tungsten oxide (WO3) on carbon nano-tube (CNT) was performed via sol-gel/hydrothermal method to prepare WO3/CNT nanocomposites and then coupled with visible light and ultrasound (US) irradiations for sono-photocatalytic removal of tetracycline (TTC) and pharmaceutical wastewater treatment. The as-prepared catalysts were characterized by FT-IR, XRD, TEM, UV-VIS DRS, FESEM, EDS, TGA, BET, BJH, EIS, and EDX techniques. The characterization tests, indicated successful incorporation of CTNs into the WO3 framework and efficient reduction of charge carries recombination rate after modifying with CNT. The investigation of experimental parameters verified that 60 mg/L TTC could be perfectly degraded at optimum operational parameters (WO3/CNT: 0.7 g/L, pH: 9.0, US power: 250 W/m2, and light intensity: 120 W/m2 over 60 min treatment. Trapping experiments results verified that HO radicals and h+ were the main oxidative species in degradation of TTC. The as-prepared photocatalysts could be reused after six successive cycles with an approximately 8.8 % reduction in removal efficiency. Investigation of the effect of real pharmaceutical wastewater revealed that this system is able to eliminate 83.7 and 90.6 % of TOC and COD, respectively after 220 min of reaction time. Some compounds with lower toxic impact and molecular weight, compared to raw pharmaceutical wastewater, were detected after treatment by sono-photocatalysis process. The biodegradability of real pharmaceutical wastewater was improved significantly after treatment by WO3/CNT sono-photocatalysis.
•NZVI particles anchored on kaolinite was applied in Fenton oxidation process.•NZVI@K possess high adsorption capacity and good ability in H2O2 decomposition.•A tentative mechanism was proposed for ...activate H2O2 and reactive species.•Decreasing decolorization obeys the order of sulfate > nitrate > chloride > bicarbonate.•After four consecutive cycles, decolorization rate by was still remains at 72.5%.
Herein, nano zero-valent iron (NZVI) particles were anchored on kaolinite (K) for preparation of a mesoporous heterogeneous catalyst (marked as NZVI@K) in Fenton-like oxidation of Acid Black 1 (AB1) dye. The properties of morphological, physico-chemical and textural of catalyst were characterized using powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), transmission electron microscope (TEM), field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectrometer (EDS) techniques. Results indicated that NZVI particles with 40–80 nm diameter were incorporated successfully on K surface and iron was predominantly in Feo form. Prior oxidation experiments, adsorption studies were performed to determine the equilibrium point and also modeling (kinetic and isotherm) of the process. Fenton-like oxidation showed a better performance in decolorization of AB1, compared to adsorption process. The excellent reusability and high stability were found for NZVI@K during four consecutive use cycles. Under optimum operational conditions (pH: 2.0, catalyst dose: 0.3 g/L, H2O2 amount: 4.0 Mm), over 98% of dye (30 mg/L) and 76% of TOC were removed within 120 min reaction. A tentative mechanism was proposed for decomposition of H2O2 and production of reactive oxidizing species, based on the results of quenching tests. Decreasing decolorization rate in the presence of anions obeys the order of bicarbonate > chloride > nitrate > sulfate. A significant synergistic effect was detected when NZVI@K were coupled with H2O2. Reducing removal efficiency and the scavenging effect were observed at excessive concentrations of both catalyst and oxidant. Integration of adsorption and oxidation processes using NZVI@K coupled with H2O2 can be introduced as a promising technique for efficient decolorization of wastewaters, due to high adsorption capacity, good catalytic activity and minimal iron leaching.
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•The prepared hybrid composite (AC@Fe3O4) was successfully applied in heterogeneous Fenton-like system.•The composite and adsorption/catalytic properties were evaluated.•Kinetic and ...mechanism of reaction in catalyst was investigated.•TC degradation on AC@Fe3O4/PS was fully described by the first order kinetic model.•AC@Fe3O4 exhibits high activity for TC degradation with good magnetic separation.
Fenton-like catalytic degradation of tetracycline (TC) was studied by using ferro–ferric oxide (Fe3O4) nanoparticles coated on activated carbon (AC@Fe3O4) which acts as a peroxidase mimetic and persulfate (PS) as a green oxidant. Adsorption and degradation experiments were carried out in a batch system as functions of pH, PS, catalyst and TC concentrations. Kinetic and pathway of TC degradation by AC@Fe3O4/PS system was also investigated. Under the optimum conditions, the removal efficiency of TC and total organic carbon (TOC) were 99.8 and 50.6%, respectively. AC@Fe3O4 retained its activity and degradation efficiency remained even after five concessive cycles of use.
In this work, the TiO2 decorated magnetic reduced graphene oxide was fabricated by the hydrothermal method. The characterization of prepared composite was studied by XRD, FT-IR, SEM, EDX, BET, and ...TGA techniques. Both the magnetization of TiO2 by Fe3O4 nanoparticles and then its decorating on rGO surface were confirmed using characterization tests. The photocatalytic efficacy of the provided samples was defined via the degradation of metronidazole (MNZ) under visible light irradiation. The operational parameters' effect, including pH, catalyst dosage, initial MNZ concentration, rGO, and TiO2, was evaluated. The results indicated that the maximum degradation rate of MNZ (0.0092 min−1) was obtained for 0.75 g composite containing 4% rGO and 5% TiO2 at pH = 5 and MNZ concentration of 20 mg/L. MNZ and TOC were eliminated completely at optimum operational conditions within 120 and 250 min reaction times, respectively. The quenching test revealed that O2•- acted as dominant radical in the degradation process.
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•TiO2 nanoparticles are decorated on magnetic reduced graphene oxide.•rGO improved the photocatalytic efficiency of TiO2 by hindering the electron/hole recombination.•O2•- acted as dominant radical in the degradation process.•4% rGO and 5% TiO2 content provide maximum MNZ degradation.
In this work, ZnO was supported on ferroferric oxide for preparation of a magnetic nanocomposite (ZnO@Fe3O4) and its catalytic activities were examined in the presence of ultrasound (US) irradiation ...to sonocatalytic degradation of amoxicillin (AMX) during ZnO@Fe3O4/US system. FESEM, EDX, XRD and FTIR techniques were employed for characterization of the as-synthesized catalyst properties. Different experimental variables influencing on the removal of AMX such as solution pH, catalyst loading, initial AMX concentrations and US power were investigated and then optimized. Under optimum experimental conditions, the effect of scavengers, water matrix components and some enhancers on the process performance was examined. A plausible oxidation mechanism was also proposed. In all experiments, AMX removal rates by sonocatalysis process were significantly higher than that of US alone, confirming a synergistic effect between ZnO@Fe3O4 and US irradiation. Under optimized conditions, over 90% of AMX was removed during 120 min reaction. The degradation rate of AMX was enhanced in the presence of enhancers in order of IO4− > S2O82− > H2O2, while it dropped significantly in the presence of anions as Cl− > CO32– > SO42−. Fe leaching from catalyst surface was very minimal (0.3 mg/L) in the studied pH range. The quenching tests confirmed that OH radicals were the dominant species and responsible in AMX degradation. Cycling tests certificated that the degradation efficiency dropped only by 5% after five successive runs. To conclude, coupling of US and ZnO@Fe3O4 can be satisfactory utilized as an efficient and effective approach to degrade organic matters to remediate the antibiotics-polluted aqueous media.
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•Nano-ZnO on ferroferric oxide (ZnO@FeIIFe2IIIO4) was applied as a sonocatalyst.•Catalytic activity enhanced substantially when it was coupled with US irradiations.•Synthesized catalyst showed an excellent reusability and high durability.•Degradation rate dropped significantly at the presence of anions as Cl− > CO32– > SO42−.•Increasing the degradation efficiency of AMX was in order of IO4− > S2O82− > H2O2.
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•UVC/persulfate activation was enhanced by coupling with SCF@GCN composite.•Complete elimination of BPA was achieved in 15 min with kobs = 0.32 min−1.•Both radical and non-radical ...mechanisms were involved during the degradation process.•Transfer pathway of photo-induced e-/h+ followed the direct S-scheme mechanism.•An excellent synergistic effect was obtained for SCF@GCN/PS/UVC hybrid system.
This study was designed to enhance wastewater treatment by the UVC/persulfate process via its coupling with spinel cobalt ferrite (SCF) nanoparticles anchoring graphitic carbon nitride (g-C3N4, GCN). The performance of SCF@GCN was assessed against bisphenol A (BPA) degradation as a model recalcitrant contaminant. Characterization tests confirmed the successful preparation of SCF@GCN with high photocatalytic activity and excellent capability in PS activation compared to plain SCF or pristine GCN. The results strongly pointed out that SCF@GCN combined with UVC and PS is capable to rapidly degrade BPA with a remarkable synergistic effect. Under optimum conditions (pH: 9.0, SCF@GCN: 0.3 g/L and PS: 4.0 mM), complete elimination of BPA (40 mg/L) was achieved in 15 min with excellent degradation kinetics (0.32 min−1). Scavenging experiments ascertained the generation of h+, 1O2 , O2•− , SO4•−, HO• species in SCF@GCN/PS/UVC system, indicating that both radical and non-radical mechanisms were involved during the degradation process. Furthermore, the developed process displayed a satisfactory performance for effective treating BPA-contaminated wastewater samples. Over 95% BPA was removed by the system after five catalyst reuse cycles, suggesting a cost-effectiveness potential in the reusability of SCF@GCN. A comprehensive mechanistic pathway for BPA degradation was proposed based on the reactive species and intermediates identified: A S-scheme heterojunction mechanism of photo-generated electron/hole pairs transfer in the SCF@GCN catalyst was found. Overall, our results present a promising technique with synergistic character for intensification of wastewater treatment.
It has been demonstrated that human exposure to environmental chemicals may have sperm genotoxic potentiality. Among the different classes, Polycyclic Aromatic Hydrocarbons (PAHs) have been receiving ...attention in recent years due to reports of sperm geno-toxicity, a series of reproductive defects and male infertility. This review aims to substantiate the effects of PAHs exposure on male infertility, with focus on the sperm characteristics (count, concentration, volume, motility, DNA damage, and morphology). To this end, international databases such as Cochrane Library, PubMed, Web of Science, Embase Ovid, Scopus, and Google Scholar were used to conduct a systematic search for papers on the subject, based on PRISMA guidelines, published up to 24 March 2022. The Newcastle-Ottawa Scale was subsequently used to assess the quality of the studies. The results showed that there is a significant negative relationship between PAHs metabolites and sperm volume, concentration, motility, morphology, as well as an observed DNA degeneration. Also, the CYP1A1 genotype polymorphisms were considered as a representative of PAHs exposure to infertility; the review highlights that polymorphisms of this genotype were more common in the infertile people. In overall, this work provides a solid summary of the existing works correlating PAHs exposure and male infertility, which could impulse further protective measures and informative campaigns on users, workers, and general population.
•Human exposure to environmental chemicals may have sperm genotoxic potentials.•Polycyclic Aromatic Hydrocarbons (PAHs) have been receiving attention in recent years due to reports of sperm geno-toxicity, a series of reproductive defects and male infertility.•There is a significant negative relationship between PAH metabolites and sperm volume, concentration, motility, morphology, and DNA degeneration.•CYP1A1 genotype polymorphisms were considered as a representative of PAH exposure to infertility; the review highlights that polymorphisms of this genotype were more common in the infertile people.•This work provides a solid summary of the existing works correlating PAH exposure and male infertility, which could impulse further protective measures and informative campaigns on users, workers, and general population.
Furfural is as one of the major environmental pollutants in different industrial effluents such as refinery and petrochemical, paper, cardboard and oil refining. This toxic chemical is irritant and ...causes allergy for skin, eyes and mucous membranes. This study was developed to investigate the efficiency of a three-dimensional electrochemical process in the presence of granular activated carbon magnetized with Fe3O4 (Fe3O4@GAC) particle electrodes for removal of furfural from aqueous solution. The particle electrodes structural and morphological featured were determined via BET, VSM, XRD, FE-SEM and FTIR techniques. The experiments were performed based on central composite design (CCD) and the role of influencing factors including reaction time, pH, voltage and initial furfural concentrations at five levels were evaluated. The Quadratic model with high correlation coefficient = 0.9872 (R2 and (R2Adj = 0.9724)) was suggested for experimental data analysis. The performance of electrochemical oxidation towards furfural degradation was enhanced substantially after adding Fe3O4@GAC. The highest furfural removal efficiency (98.2%) was achieved under optimal conditions (furfural: 201 mg/L, electrolysis time: 69 min, voltage: 19 V, and pH: 5.0). Besides, over 78 and 74 % of COD and TOC were removed by Fe3O4@GAC-based three-dimensional process, respectively. Based on the COD/TOC ratio and average oxidation state (AOS) index, a significant increase was observed in the biodegradability of intermediates of furfural after treatment. Results showed that three-dimensional electrochemical process with particle electrodes is a promising technology for efficient removal of furfural, even at high concentrations. Results of Liquid chromatography–mass spectrometry (LC-MS) analysis and degradation pathway showed that furfural could be oxidized to compounds with smaller molecular masses, which eventually converted to carbon dioxide and water.
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