Adsorption and photocatalytic removal of Ibuprofen by activated carbon impregnated with TiO2 by UV-Vis monitoring

MIL-53(Al)@HC nanohybrid for bicomponent adsorption of ibuprofen and metsulfuron-methyl: Application of macro- and microscopic models and competition between contaminants

In this work, a hybrid was synthesized by hydrothermal treatment, metal-organic framework functionalized with hydrochar (MIL-53(Al)@HC) for the adsorption of two organic molecules Ibuprofen sodium salt and Metsulfuron-methyl, in binary system. The hybrid is composed of 71 wt% biomass and 29 wt% MOF. TGA, BET, FTIR, XRD and XPS characterization techniques were used to verify the hybridization of MIL-53(Al)@HC. The MIL-53(Al)@HC hybrid showed in situ MIL-53(Al) crystal growth capability. Batch adsorption experiments were carried out to study the effect of pH, adsorbent dosage, adsorbate concentration, contact time and temperature effect. The results obtained under extreme conditions demonstrate that MIL-53(Al)@HC is an adsorbent capable of removing >98% of IBU and MTM in mixture at a concentration of 0.3 mM (68 ppm IBU and 115 ppm MTM). The pseudo-second order model adequately described the adsorption kinetics and equilibrium using the Sips and Freundlich models. The physico-statistical microscopic model (2-layer) corroborated the hypothesis of a multilayer adsorption proposed by the macroscopic Freundlich model. In the competition study between IBU and MTM, both antagonistic and synergistic effects were observed. In the thermodynamic study, positive values of (ΔH°) indicate that adsorption is endothermic in nature and that the dominant mechanism is physisorption. A mechanism of adsorption by hydrogen bridging and non-covalent π*-π adsorbate-adsorbate and adsorbate-adsorbate-adsorbate interactions was proposed. The desorption study shows that in 5 washing cycles MIL-53(Al)@HC is a recoverable material.

Ultraviolet light spectroscopic characterization of ibuprofen acid aggregation in deionized water

This work provides a description of the aggregation equilibria of ibuprofen acid in deionized water at temperatures between 20 and 40 °C in the 0.1-20.1 ppm concentration range. For this goal, we have made use of UV-Visible spectroscopy. A calculation algorithm was developed to obtain the aggregate orders and thermodynamic parameters from the experimental absorbance values. Monomeric ibuprofen acid was found to be absent in water solutions. In addition to the dimer, two aggregates formed by 32 and 128 monomeric units were found to co-exist in solution at the highest concentration tested. A critical micelle concentration of 7.8 ppm was estimated for this system. The appearance of the first aggregate occurs when the pH drops below the pKa value, which was determined to be 4.62. At higher ibuprofen concentrations, a sudden jump in the electrical conductivity coincides with the onset of formation of the second aggregate. A varied menu of alternatives is offered with respect to the calibration curve of ibuprofen in water, though the linear calibration of ibuprofen concentration with absorbance might be reasonably performed at 224 nm. Finally, the dissolution rate of the commercial ibuprofen used in this work was found to obey the Noyes-Whitney first order equation.

Fabrication of new composite NCuTiO2/CQD for photocatalytic degradation of ciprofloxacin and pharmaceutical wastewater treatment: degradation pathway, toxicity assessment

In this research, the photocatalytic degradation of CIP from aqueous solutions using CQD decorated on N-Cu co-doped titania (NCuTCQD) was made during two synthesis steps by sol-gel and hydrothermal methods. The fabricated catalysts were analyzed using various techniques, including XRD, FT-IR, BET, FESEM, EDX, and DRS. The results showed that N and Cu atoms were doped on TiO2 and CQD was well deposited on NCuT. The investigation of effective operational parameters demonstrated that the complete removal of ciprofloxacin (CIP: 20 mg/L) could be achieved at pH 7.0, NCuTCQD4wt%: 0.8 g/L, and light intensity: 100 mW/cm2 over 60 min reaction time. The O2•- and OH˙ radicals were identified as the primary reactive species during the decontamination process. The synthesized photocatalyst could be recycled after six consecutive cycles of CIP decomposition with an insignificant decrease in performance. Pharmaceutical wastewater was treated through the optimum degradation conditions which showed the photocatalytic degradation eliminated 89% of COD and 75% of TOC within 180 min. In the effluent toxicity evaluation, the EC50 values for treated and untreated pharmaceutical wastewater increased from 62.50% to 140%, indicating that the NCuTCQD4wt%/Vis system can effectively reduce the toxic effects of pharmaceutical wastewater on aquatic environments.

Remediation of environmental toxicants using carbonaceous materials: opportunity and challenges

Adsorption and photocatalytic properties of carbonaceous materials, viz., carbon nanotubes (CNTs), fullerene, graphene, graphene oxide, carbon nanofiber nanospheres, and activated carbon, are the legitimate weapons for the remediation of emerging and persistent inorganic/organic contaminants, heavy metals, and radionucleotides from the environment. High surface area, low or non-toxic nature, ease of synthesis, regeneration, and chemical modification of carbonaceous material make them ideal for the removal of toxicants. The research techniques investigated during the last decade for the elimination of environmental toxicants using carbonaceous materials are reviewed to offer comprehensive insight into the mechanism, efficiency, applications, advantages, and shortcomings. Opportunities and challenges associated with carbon materials have been discussed to suggest future perspectives in the remediation of environmental toxicants.

Experimental investigation for treating ibuprofen and triclosan by biosurfactant from domestic wastewater

The presence of emerging pollutants of pharmaceutical products and personal care products (PPCPs) in the aquatic environment overspreads the threat on living beings. Bioremediation is a promising option for treating wastewater. In the present study, an experimental investigation was carried out to produce a biosurfactant by Pseudomonas aeruginosa (MTCC 1688) for the removal of Ibuprofen (IBU) and Triclosan (TCS) from domestic wastewater. It was performed in three stages. Firstly, the production and optimization of biosurfactant was carried out to arrive at the best combination of crude sunflower oil, sucrose and ammonium bicarbonate (10%: 5.5 g/L: 1 g/L) to yield effective biosurfactant production (crude biosurfactant) and further extended to achieve critical micelle concentration (CMC) formation by dilution (biosurfactant at 10.5%). The stability of the biosurfactant was also confirmed. Biosurfactant showed a reduction in the surface tension to 41 mN/m with a yield concentration of 11.2 g/L. Secondly, its effectiveness was evaluated for the removal of IBU and TCS from the domestic wastewater collected during the dry and rainy seasons. Complete removal of IBU was achieved at 36 h & 6 h and TCS at 6 h & 1 h by crude biosurfactant and biosurfactant at CMC formation for the dry season sample. IBU removal was achieved in 2 h by both crude and biosurfactant at CMC and no TCS was detected in the rainy season sample. Thirdly, biotransformation intermediates of IBU and TCS formed during the application of the biosurfactant and degradation pathways are proposed based on the Liquid Chromatography-Mass Spectrometry (LC-MS) and it indicates that there is no formation of toxic by-products. Based on the results, it is evident that biosurfactant at CMC has performed better for the removal of IBU and TCS than crude biosurfactants without any formation of toxic intermediates. Hence, this study proved to be an eco-friendly, cost-effective and sustainable treatment option for domestic wastewater treatment.

Integrated electro-Fenton system based on embedded U-tube GDE for efficient degradation of ibuprofen

Ibuprofen (IBP) is a carcinogenic non-steroidal anti-inflammatory drug (NSAID). It is of certain hazard to aquatic animals and may cause potential harm to human health. As traditional methods cannot effectively remove such a pollutant, many advanced oxidation processes (AOPs) have been developed for its degradation. The electro-Fenton process has the advantages of strong oxidative ability, a synergistic effect of various degradation processes, and a wide application range. This study developed a high-performance gas diffusion electrode (GDE) for electrochemical hydrogen peroxide (H2O2) production. The optimum system performance was found at the current density of 10 mA cm-2, pH of 7.0, and air flow rate at 0.6 L min-1, where the accumulation of H2O2 could reach as high as 769.82 mg L-1. The computational fluid dynamics (CFD) simulation results revealed a fast mass-transfer property in this electro-Fenton system with U-tube GDEs, which resulted in a deep-level degradation (∼100%) of the pollutant (IBP) and a low-concentration degradation of 10 mg L-1 within a 120-min reaction period. The high-performance liquid chromatography-mass spectrometry (LC-MS) studies demonstrated that the hydroxyl radicals were the primary active species in the electro-Fenton system and that the degradation intermediates of IBP were mainly 1-(4-isobutylphenyl) ethanol and 2-hydroxy-2-(4-isobutyl phenyl) propanoic acid through four probable electro-Fenton degradation pathways. This report provides a facile and efficient way to construct a high-performance electro-Fenton reactor, which could be effectively used in advanced oxidation processes (AOPs) to remove emerging contaminants in wastewater and natural water.

Functionalization of graphene nanostructures with inorganic nanoparticles and their use for the removal of pharmaceutical pollutants in water

Emerging pollutants such as pharmaceuticals are of special concern because despite their low environmental concentration, their biological activity can be intense, and they should be prevented to reach uncontrolledly to the environment. A graphene-based hybrid material decorated with Fe3O4 and TiO2 nanoparticles (NPs) has been prepared to effectively remove emerging pollutants as nonsteroidal anti-inflammatory drugs (NSAIDs) Ibuprofen and Diclofenac present in water at low environmental concentrations by a one-step functionalization process following a novel gentle and scalable surfactant depletion approach. Following this methodology, nanoparticles are progressively deprived of their original surfactant in the presence of graphene, leading to the formation of hybrid nanostructures composed of two different types of nanoparticles well dispersed over the graphene nanosheets. Ibuprofen and Diclofenac adsorption kinetics on the composites was investigated via UV-Vis spectroscopy. The as prepared hybrid material possesses high adsorption capacity, superparamagnetic properties, photocatalytic behavior, and good water dispersibility. Thanks to incorporating TiO2 nanoparticles as in situ catalysts, the adsorption performance of composites is restored after use, which could be a promising recycling pathway for the adsorbents in wastewater treatments.

Preparation of Ca2Al1–mFem(OH)6Cl·2H2O-Doped Hydrocalumites and Application of Their Derived Mixed Oxides in the Photodegradation of Ibuprofen

Aluminum from saline slags generated during the recycling of this metal, extracted under reflux conditions with aqueous NaOH, was used in the synthesis of hydrocalumite-type solids with the formula Ca2Al1–mFem(OH)6Cl·2H2O. The characterization of the obtained solids was carried out by powder X-ray diffraction, infrared spectroscopy, thermal analysis, element chemical analysis, N2 adsorption-desorption at −196 °C and electron microscopy. The results showed the formation of Layered Double Hydroxide-type compounds whose characteristics varied as the amount of incorporated Fe3+ increased. These solids were calcined at 400 °C and evaluated for the catalytic photodegradation of ibuprofen, showing promising results in the elimination of this drug by advanced oxidation processes. The CaAl photocatalyst (without Fe) showed the best performance under UV light for the photodegradation of ibuprofen.

Synthesis of new hybrid composite based on TiO2 for photo-catalytic degradation of sulfamethoxazole and pharmaceutical wastewater, optimization, performance, and reaction mechanism studies

In this study photo-catalytic degradation of sulfamethoxazole (SMX) from aqueous solutions using carbon quantum dot (CQD)-decorated Cu-TiO₂ was investigated. The as-prepared photo-catalyst samples were characterized by various FTIR, XRD, FE-SEM, TEM, EDX, BET, and DRS techniques. The investigation of effective photo-catalytic operational parameters confirmed that the complete removal of SMX (20 mg/L) can be accomplished at pH: 6.0 and light intensity: 75 mW/cm² over a 30-min reaction time. DRS analysis demonstrated adding CQD to the Cu-TiO₂ reduced its bandgap energy from 2.97 to 2.90 eV. The photo-catalytic degradation kinetics of SMX fit well with the pseudo-first-order model. The radical trapping experiment indicates that HO^• and O₂^•- active species were more effective species for SMX degradation, and the higher inhibition effect on the SMX degradation efficiency was assigned to O₂^•- ions. The water matrix species-inhibited effect in SMX removal was as follows: SO₄^2- > Cl^- > NO₃^- > CO₃^- > no ions. The synthesized photo-catalyst could be recycled after six consecutive cycles of SMX degradation with an insignificant decrease in performance. The total organic carbon (TOC) analysis suggested the mineralization of SMZ by composite photo-catalysts. The minimum inhibitory concentration (MIC) for Escherichia coli remained at 12.5 mg L^-1 SMX. A possible mechanism and pathway of SMX degradation in the photo-catalytic system was presented.

Ecofriendly and sustainable Sargassum spp.-based system for the removal of highly used drugs during the COVID-19 pandemic

Analgesic consumption increased significantly during the COVID-19 pandemic. A high concentration of this kind of drug is discarded in the urine, reaching the effluents of rivers, lakes, and seas. These medicines have brought serious problems for the flora and, especially, the ecosystems’ fauna. This paper presents the results of removing diclofenac, ibuprofen, and paracetamol in an aqueous solution, using Sargassum spp. from the Caribbean coast. The study consisted of mixing each drug in an aqueous solution with functionalized Sargassum spp in a container under constant agitation. Therefore, this work represents an alternative to solve two of the biggest problems in recent years; first, the reduction of the overpopulation of sargassum through its use for the remediation of the environment. Second is the removal of drug waste used excessively during the COVID-19 pandemic. Liquid samples of the solution were taken at intervals of 10 min and analyzed by fluorescence to determine the concentration of the drug.

The sorption capacity for diclofenac, ibuprofen, and paracetamol was 2.46, 2.08, and 1.41 μg/g, corresponding to 98 %, 84 %, and 54 % of removal, respectively. The removal of the three drugs was notably favored by increasing the temperature to 30 and 40 °C, reaching efficiencies close to 100 %. Moreover, the system maintains its effectiveness at various pH values. In addition, the Sargassum used can be reused for up to three cycles without reducing its removal capacity. The wide diversity of organic compounds favors the biosorption of drugs, removing them through various kinetic mechanisms. On the other hand, the Sargassum used in the drugs removal was analyzed by X-ray diffraction, FTIR spectroscopy, TGA analysis, and scanning electron microscopy before and after removal. The results showed an evident modification in the structure and morphology of the algae and demonstrated the presence of the biosorbed drugs. Therefore, this system is sustainable, simple, economical, environmentally friendly, highly efficient, and scalable at a domestic and industrial level that can be used for aquatic remediation environments.

Removal of ibuprofen from synthetic wastewater using photocatalytic method in the presence of FeO photocatalyst supported on modified Iranian clinoptilolite

This study investigated the removal of an organic drug called ibuprofen from the wastewater containing this drug. Iron oxide supported on modified Iranian clinoptilolite was used as the photocatalyst in the presence of the light of a solar lamp. XRD, SEM, EDAX, and FT-IR analyses were performed to detect the prepared photocatalyst. The results of photocatalytic identification analyses proved the suitable loading of iron oxide supported on modified Iranian clinoptilolite. This study investigated the effect of initial concentration of ibuprofen (5-25 mg/L), photocatalyst concentration (100-300 mg/L), and process time (10-240 min) on the removal from ibuprofen from wastewater containing this drug. The experiments were performed in a setup in the presence of a solar lamp with a flux of 300 W/m². The results indicated that with the initial ibuprofen concentration of 25 mg/L, photocatalyst concentration of 300 mg/L, and time of 210 min, the highest percentage of ibuprofen removal and ibuprofen adsorbed on the catalyst were 99.80% and 83.17 mg/g, respectively. Kinetic modeling was then performed using the Langmuir-Hinshelwood model, and a quasi-first-order kinetic model showed a good agreement with the results obtained. Finally, the recovery of the photocatalyst was investigated, and the results showed that under optimal conditions about 91% of ibuprofen was removed after five re-uses of the photocatalyst.

Titanium dioxide based nanocomposites - Current trends and emerging strategies for the photocatalytic degradation of ruinous environmental pollutants

Many ruinous pollutants are omnipresent in the environment and among them; pesticides are xenobiotic and pose to be a bio-recalcitrance. Their detrimental ecological and environmental impacts attract attention of environmental excerpts and the surge of stringent regulations have endows the need of a technically feasible treatment. This critical review emphasizes about the occurrence, abundance and fate of structurally distinct pesticides in different environment. The practiced remedial strategies and in particular, the advanced oxidation processes (AOPs) those utilize the photo-catalytic properties of nano-composites for the degradation of pollutants are critically discussed. Photo-catalytic degradation utilizes many composite materials at nano-scale level, wherein synthesis of nano-composites with appropriate precursors and other adjoining functional moieties are of prime importance. Therefore, suitable starter materials along with the reaction conditions are prerequisite for effectively tailoring the nano-composites. The aforementioned aspects and their customized applications are critically discussed. The associated challenges, opportunities and process economics of degradation using photo-catalytic AOP techniques are highlighted and in addition, the review tries to explain how best the photo-degradation can be a stand-alone tool with a societal importance. Conclusively, the future prospects for undertaking new researches in photo-catalytic breakdown of pollutants that can be judiciously sustainable.

Synthesis of new composite based on TiO2 immobilized in glass fibers for photo-catalytic degradation of chlorobenzene in aqueous solutions

In this study photo-catalytic degradation of chlorobenzene from aqueous solutions using CQD decorated Fe-doped TiO₂ immobilized in Glass Fibers (GF) was investigated. Characteristics of the synthesized photo-catalyst were determined by EF-SEM, EDX, BET, XRD, FTIR, and DRS analysis. Additionally, DRS analysis demonstrated adding CQD to the TiO₂-Fe reduced its band gap energy from 2.96 eV to 2.91eV, while that was 3.10 eV for undoped TiO₂. Among that three photo-catalysts, GF/CQD_(4.5 wt%) decorated Fe-TiO₂ composite had performance nearly 100.0%, when pH was 5 and low concentration of chlorobenzene. In addition, GF/CQD_(4.5 wt%) decorated Fe-TiO₂ composite show it could be well applied for five times and with a little reduction on the performance. Also, no detectable Fe found to be released from the composite. Minimum inhibitory concentration (MIC) for E. coli bacteria was 12.2 mg L^-1 of chlorobenzene residual. Our findings show the catalyst was successful for chlorobenzene removal in the wastewater effluent. In conclusion, present hybrid composite could successfully and safely remove chlorobenzene from synthetic aqueous solution.

Enhanced removal of ibuprofen by heterogeneous photo-Fenton-like process over sludge-based Fe3O4-MnO2 catalysts

Heterogeneous photo-Fenton-like catalysts with low cost, little hazard, high effectiveness and facile separation from aqueous solution were highly desirable. In this study, sludge-based catalysts combining nano Fe₃O₄-MnO₂ and sludge activated carbon were successfully synthesized by high-temperature calcination method and then characterized. These synthetic materials were applied to remove ibuprofen in the heterogeneous photo-Fenton process. The preparation conditions of sludge-based catalysts optimized by orthogonal experiments were 2.0 M of ZnCl₂, a temperature of 500 °C, a pyrolysis time of 60 min, and a sludge ratio: Fe₃O₄-MnO₂ of 25:2. In batch experiments, the optimal experimental conditions were determined as catalyst dosage of 0.4 g·L^-1, hydrogen peroxide concentration of 3.0 mL·L^-1, pH value of 3.3, and contact time of 2.5 h. The degradation rate sludge/Fe₃O₄-MnO₂ catalyst to ibuprofen is up to 95%. The removal process of ibuprofen fitted the pseudo-second-order kinetic model, and the photocatalytic degradation process was the main factor controlling the reaction rate. The catalytic mechanism was proposed according to the Fourier transform infrared analysis and mass spectrometry product analysis; it was mainly attributed to the interaction between hydroxyl groups and benzene rings.

Fe-TiO2/AC and Co-TiO2/AC Composites: Novel Photocatalysts Prepared from Waste Streams for the Efficient Removal and Photocatalytic Degradation of Cibacron Yellow F-4G Dye

Fe-TiO2/AC and Co-TiO2/AC composites were prepared from activated carbon (AC) derived from residues of peanut hulls and TiO2 photocatalyst, electrochemically prepared from titanium scrap, and doped with Fe and Co, respectively. The adsorption capacity and photocatalytic activity of the Fe-TiO2/AC and Co-TiO2/AC composites were studied for removing and degrading Cibacron Yellow F-4G (CYF-4G) from wastewater. Doped ACs were characterized by thermogravimetry (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), a new X-ray absorption technique (XRA), and elemental analysis (EA). Interesting relationships were found between SEM, XRA, and TGA data and the doped amount of catalyst on ACs. Optimal dye adsorption was found at a pH of 2.0. The CYF-4G adsorption kinetics are followed according to the pseudo-second order model. The experimental data revealed that the Langmuir model fits better than the Freundlich and Temkin models. A decrease in adsorption capacity was observed when the catalyst dope percentage increased. A removal and degradation efficiency of the dye close to 100% was achieved around 120 min. A synergistic adsorption and photocatalytic degradation effect of the Fe-TiO2/AC and Co-TiO2/AC composites could be observed when adsorption experiments were conducted under simulated visible radiation.

Sorptive and microbial riddance of micro-pollutant ibuprofen from contaminated water: A state of the art review

Continuous discharge of ibuprofen, a pharmaceutical compound in local water systems is becoming a budding concern as seen from data procured from the past few decades. Increased concentrations of the compound in water reservoirs resulted in adverse effects on the environment. In order to prevent the deleterious impacts of increasing ibuprofen concentration in water bodies, application of cost effective and energy efficient elimination of ibuprofen (IBP) is needed. As a result, various techniques over time have been tested for IBP expulsion from aqueous media. However, adsorption and bioremediation are still the most realistic approaches to remove ibuprofen than conventional methods, like precipitation, reverse osmosis, ion exchange, nano-filtration etc., because of their lower initial cost, reduced electricity consumption, minimized sludge generation, local availability of precursor material etc. Various researchers have reported the applicability of the adsorption and bioremediation process in remediation of ibuprofen from water. Therefore, the present review article confers both the biosorption and bioremediation process towards IBP removal from water bodies and explicates the performances of various adsorbents and microorganisms derived from various sources. The presented review also substantially emphasizes on the effect of different parameters on sorptive uptake of ibuprofen, various isotherms and kinetic models, sorption mechanism and assessment of costs, which could enable future researchers to determine widespread use of reported adsorbents and microbes towards effective elimination of IBP from aqueous media.

Removal of ibuprofen from aqueous media by adsorption: A comprehensive review

Ibuprofen (IBP) is a non-steroidal anti-inflammatory drug released into the environment through hospital and medical effluents, pharmaceutical wastewater and veterinary use. The aim of this paper is to review the empirical findings on the adsorption of IBP from aqueous media. A preliminary ecotoxicological assessment confirmed the environmental risk of IBP in the aqueous environment. Open literature works considered in this review were for the past decade (2010-2020). Carbon-based adsorbents are the best class of adsorbent for the uptake of IBP and the highest reported maximum adsorption capacity (q_max) for IBP is 496.1 mg/g by SWCNTs. The range of adsorption capacities for IBP uptake in this review is between 0.0496 and 496.1 mg/g. The mechanism of uptake is majorly by hydrophobic interactions, π - π stacking, hydrogen bonds, electrostatic interactions and dipole-dipole interaction. IBP uptake was best fit to a wide variety of isotherm models but was well suited to the pseudo-second order kinetics model. The thermodynamics of IBP uptake depends majorly on the nature of the adsorbent and desorption from the solid phase is based on an appropriate choice of the eluent. Knowledge gaps were observed in used adsorbent disposal and process improvement. In the future, interest would increase in scale-up, industrial applications and practical utilisation of the research findings which would help in sustainable water resource management.

Ibuprofen elimination from water and wastewater using sonication/ultraviolet/hydrogen peroxide/zeolite-titanate photocatalyst system

The present investigation was designed to remove ibuprofen from aqueous solutions and wastewater by activating hydrogen peroxide using ultrasonication (US)/ultraviolet (UV) radiation/zeolite-titanium. The physical-chemical properties of the photocatalyst were determined using BET, FTIR, XRD, FESEM, and EDX-mapping techniques. The titanium oxide crystal size and the catalyst BET were determined to be 4.97 nm and 39.88 m²/g, respectively. Tests were performed in a reactor (with a volume of 316 mL) located in an ultrasonic bath to intensify reactions. The synergistic impact of the components of the UV/US/H₂O₂/Photocatalyst system was explored. The maximum efficiency (99.58%) was obtained at H₂O₂ concentration of 0.05 mM, pH 5, UV power of 6 W, photo-catalyst dose of 1 g/L, and contact time of 100 min. The pH variable was more effective than the other parameters. Ions of NO₃^-, Cl^-, and SO₄^2- had a slightly negative effect on contaminant removal efficiency. The ibuprofen removal (based on COD) from urban water and hospital wastewater was attained 77.82% and 66.24%, respectively. The ibuprofen removal by the developed system followed the first-order kinetic. The results show that the system has high efficiency and reasonable costs (with treatment cost of 6.25 €/m³) for ibuprofen decontamination.

Photo-catalytic degradation of bisphenol-a from aqueous solutions using GF/Fe-TiO2-CQD hybrid composite

In this photocatalytic study, removal of bisphenol-A from aqueous solution was studied using the GF/Fe-TiO2-CQD composite. Due to its health and environmental effects, this compound should be disposed of sources that are mainly industrial wastewater. The phis-chemical properties of the composite were determined by traditional analyzes of EF-SEM, EDX, BET, XRD, FTIR and DRS. In this study, different ratios of CQD in the composite (1.5, 4.5 and 7.5 wt%), pH, and bisphenol-A concentration as variable parameters were investigated. All analyzes, EF-SEM, EDX, BET, XRD, FTIR, show that the GF/Fe-TiO2-CQD composite is well coated on glass fibers (GF) and all the elements in the catalyst are present. On the other hand, DRS analysis showed that CQD reduces the band gap of Fe-TiO2 from 2.96 eV to 2.91 eV, it was 3.10 eV for TiO2. Among different catalysts, GF/Fe-TiO2-CQD4.5wt% has the best performance. The results showed that for GF/Fe-TiO2-CQD4.5wt%, optimum for the process was at pH = 6 in low concentration of bisphenol-A. The first order model for the photocatalytic degradation process were well studied. In addition, GF/Fe-TiO2-CQD4.5wt% showed that it can be used many times with a minimal reduction in performance. As a result, the GF/Fe-TiO2-CQD4.5wt% composite can successfully remove bisphenol-A form in synthetic aqueous solution. However, it is necessary to further studies to applied that for real water source in water and wastewater treatment plants.

Photoactivation and photoregeneration of TiO2/PAC mixture applied in suspension in water treatments: approach to a real application

The process TiO₂/PAC/UV-vis has been under study and compared with the isolated treatments of adsorption and photocatalysis determining possible synergies between adsorption and photocatalysis of target antibiotics: amoxicillin, enrofloxacin, sulfadiazine, and trimethoprim. The characterization of the TiO2/PAC mixture was carried out via FESEM and FTIR. Moreover, a kinetic study has been performed. The effect of UV-vis radiation and the type of matrix was analyzed in TiO₂/PAC/UV-vis process. The performance of this treatment has been monitored during three cycles, evaluating also the regeneration of TiO₂/PAC mixture by UV-vis light. TiO₂/PAC/UV-vis process allowed the removal of the antibiotics in the range 90-100% (an average removal of 93% of the initial concentration) after 60 min of treatment. However, only amoxicillin showed a significant synergy applying TiO₂/PAC/UV-vis process. Regarding matrix effect, no influence of the matrix type (ultrapure water or treated wastewater) was observed. Since PAC tends to be deactivated gradually, the TiO₂/PAC/UV-vis process performance decreases after each cycle in a 15% average. Finally, regeneration via UV-vis light started to be effective after a total of 4 h of regeneration.

Solar photocatalytic degradation of ibuprofen with a magnetic catalyst: Effects of parameters, efficiency in effluent, mechanism and toxicity evolution

The environmental-friendly photocatalytic process with a magnetic catalyst CoFe₂O₄/TiO₂ mediated by solar light for ibuprofen (IBP) degradation in pure water, wastewater effluent and artificial seawater was investigated systematically. The study aims to reveal the efficiency, the mechanism and toxicity evolution during IBP degradation. Hydroxyl radicals and photo-hole (h⁺) were found to contribute to the IBP decay. The presence of SO₄^2- showed no significant effect, while NO₃^- accelerated the photodegradation, and other anions including HCO₃^-, Cl^-, F^-, and Br^- showed significant inhibition. The removal efficiency was significantly elevated with the addition of peroxymonosulfate (PMS) or persulfate (PS) ([Oxidant]₀:[IBP]₀ = 0.4-4), with reaction rate of 5.3-13.1 and 1.3-2.9 times as high as the control group, respectively. However, the reaction was slowed down with the introduction of H₂O₂. A mathematic model was employed to describe the effect of ferrate, high concentration or stepwise addition of ferrate was suggested to play a positive role in IBP photodegradation. Thirteen transformation products were identified and five of them were newly reported. The degradation pathways including hydroxylation, the benzene ring opening and the oxidation of carbon were proposed. IBP can be efficiently removed when spiked in wastewater and seawater despite the decreased degradation rate by 41% and 56%, respectively. Compared to the IBP removal, mineralization was relatively lower. The adverse effect of the parent compound IBP to the green algae Chlorella vulgaris was gradually eliminated with the decomposition of IBP. The transformation product C178a which possibly posed toxicity to rotifers Brachionus calyciflorus can also be efficiently removed, indicating that the photocatalysis process is effective in IBP removal, mineralization and toxicity elimination.

RETRACTED: Visible-light-induced photocatalytic mitigation of ibuprofen using magnetic black TiO2-x/CaFe2O4 decorated on diatomaceous earth

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editors-in-Chief. Jun Wang and Youtao Song are listed as authors on the manuscript but have informed the journal that this occurred without their consent or knowledge of the submission and the email addresses provided were fake. Jun Wang and Youtao Song do not support the scientific conclusions of the article. Qiong Wu and Yan Chen furthermore note significant scientific errors with the article (including the wrong deconvolution method used for analysis of the XPS data, misuse of some characterization images and inability to reproduce some of the photodegradation data). One of the conditions of submission of a paper for publication is that all authors must be aware of and agree with its submission. As such this article represents a misuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Photocatalytic activity of G-TiO2@Fe3O4 with persulfate for degradation of alizarin red S under visible light

A composite photocatalyst combined with TiO₂, graphite (G) and Fe₃O₄ was prepared by co-precipitation method. Then the G-TiO₂@Fe₃O₄ was employed with persulfate (PS) to degrade alizarin red S (ARS) under visible light. The removal rate of ARS reached 100% after 60 min irradiation. The degradation rate constant of G-TiO₂@Fe₃O₄/PS exhibited 20.8, 9.0 and 3.1 times than that of TiO₂, G-TiO₂ and G-TiO₂@Fe₃O₄, respectively. The effects of photocatalyst dosage, mass ratios of graphite and Fe₃O₄ to TiO₂, PS dosage, initial pH and ARS concentration on the degradation efficiency were investigated. The optimal removal efficiency of ARS was obtained when G-TiO₂@Fe₃O₄ dosage was 0.25 g/L, G: TiO₂ = 0.005, Fe₃O₄: TiO₂ = 0.8, PS concentration was 6 mmol/L, initial pH = 3, and initial concentration of ARS was 100 mg/L. The SO₄·^- was demonstrated more important than O₂^- and·OH in the degradation of ARS. The intermediates and possible degradation pathways of ARS were discussed. Reuse and stability of G-TiO₂@Fe₃O₄ were also tested, and 88.3% photocatalytic activity was maintained after five cycles. Therefore, the proposed G-TiO₂@Fe₃O₄/PS not only had excellent photocatalytic activity, but also showed superior stability and reusability.

Ibuprofen degradation using a Co-doped carbon matrix derived from peat as a peroxymonosulphate activator

The wider presence of pharmaceuticals and personal care products in nature is a major cause for concern in society. Among pharmaceuticals, the anti-inflammatory drug ibuprofen has commonly been found in aquatic and soil environments. We produced a Co-doped carbon matrix (Co-P 850) through the carbonization of Co²⁺ saturated peat and used it as a peroxymonosulphate activator to aid ibuprofen degradation. The properties of Co-P 850 were analysed using field emission scanning electron microscopy, energy filtered transmission electron microscopy and X-ray photoelectron spectroscopy. The characterization results showed that Co/Fe oxides were generated and tightly embedded into the carbon matrix after carbonization. The degradation results indicated that high temperature and slightly acidic to neutral conditions (pH = 5 to 7.5) promoted ibuprofen degradation efficiency in the Co-P 850/peroxymonosulphate system. Analysis showed that approx. 52% and 75% of the dissolved organic carbon was removed after 2 h and 5 h of reaction time, respectively. Furthermore, the existence of chloride and bicarbonate had adverse effects on the degradation of ibuprofen. Quenching experiments and electron paramagnetic resonance analysis confirmed that SO₄^·-, ·OH and O₂^·- radicals together contributed to the high ibuprofen degradation efficiency. In addition, we identified 13 degradation intermediate compounds and an ibuprofen degradation pathway by mass spectrometry analysis and quantum computing. Based on the results and methods presented in this study, we propose a novel way for the synthesis of a Co-doped catalyst from spent NaOH-treated peat and the efficient catalytic degradation of ibuprofen from contaminated water.

Fabrication of black TiO2-x /NiFe2O4 supported on diatomaceous earth with enhanced sonocatalytic activity for ibuprofen mitigation

This study reports a facile fabrication of black TiO_2-x /NiFe₂O₄ (Ti³⁺ self-doped titania coupled with nickel ferrite), an efficient sonocatalyst for ibuprofen (IBP) mitigation. Compared with TiO_2-x or NiFe₂O₄, TiO_2-x /NiFe₂O₄ heterojunction displayed higher sonocatalytic activity, and their immobilization onto diatomaceous earth further enhanced mitigation efficiency due to the synergy between adsorption and sonocatalysis. About 96.7% of 10 mg l^-1 IBP was removed in 100 min using 0.7 g l^-1 catalyst at pH = 6, with the ultrasonic power of 144 W and frequency of 60 KHz. Quenching experiment results demonstrated the roles of reactive species. The intermediates during IBP sono-oxidation were determined by HPLC-MS method, and the acute toxicity was evaluated. Furthermore, the reaction mechanism was proposed. The sonocatalyst revealed excellent reusability, suggesting itself promising for wastewater treatment.

Photodecomposition of ibuprofen over g-C3N4/Bi2WO6/rGO heterostructured composites under visible/solar light

A microwave-assisted hydrothermal preparation of heterostructured graphitic carbon nitride/bismuth tungsten oxide/reduced graphene oxide nanocomposites (denoted as GBR-T, T = microwave irradiation time) is performed. The prepared GBR-T photocatalysts are identified by employing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), time-resolved photoluminescence (TRPL) and nitrogen adsorption-desorption isotherms. The photocatalytic performance of these GBR-T is evaluated by the photocatalytic degradation of ibuprofen (IBP) under the visible light (λ > 420 nm) and solar light irradiation. Among all prepared photocatalysts, ca. 93% of IBP photodegradation can be achieved with a degradation rate constant (k) of 0.011 min^-1 under visible-light irradiation upon the optimal microwave-assisted reaction time of 60 min. The improvement is primarily attributable to the higher crystallization degree, specific surface area and increased charge transfer efficiency as verified by XRD, nitrogen adsorption-desorption isotherms and TRPL, respectively. The photocatalytic performance of this catalyst is further enhanced in the photodecomposition of IBP (ca. 98.6%) under sun light irradiation. The electron spin resonance (ESR) and liquid chromatography-mass/mass spectrometry (LC-MS/MS) studies show that the superoxide radicals and hydroxyl radicals are the dominant active species in the photocomposition of IBP and degradation intermediates are formed through three probable photodegradation pathways. This investigation provides a simple way to prepare triple 2D heterojuction photocatalysts which could be effectively used in the advanced oxidation process for removal of emerging contaminants in wastewater by using renewable energy.

Fabrication of black TiO2−x/CuFe2O4 decorated on diatomaceous earth with enhanced sonocatalytic activity for ibuprofen mitigation

This study reports facile fabrication of black TiO_2−x/CuFe₂O₄ (Ti³⁺ self-doped titania coupled with copper ferrite), an efficient sonocatalyst for ibuprofen (IBP) mitigation.

Photocatalytic degradation of ibuprofen using modified titanium oxide supported on CMK-3: effect of Ti content on the TiO2 and carbon interaction

TiO₂ nanoparticles dispersed in ordered mesoporous CMK-3 carbon with different Ti contents were successfully synthesized and their activity in the photocatalytic degradation of ibuprofen was presented.

Cross-Linked Magnetic Chitosan/Activated Biochar for Removal of Emerging Micropollutants from Water: Optimization by the Artificial Neural Network

One of the most important types of emerging micropollutants is the pharmaceutical micropollutant. Pharmaceutical micropollutants are usually identified in several environmental compartments, so the removal of pharmaceutical micropollutants is a global concern. This study aimed to remove diclofenac (DCF), ibuprofen (IBP), and naproxen (NPX) from the aqueous solution via cross-linked magnetic chitosan/activated biochar (CMCAB). Two independent factors—pH (4–8) and a concentration of emerging micropollutants (0.5–3 mg/L)—were monitored in this study. Adsorbent dosage (g/L) and adsorption time (h) were fixed at 1.6 and 1.5, respectively, based on the results of preliminary experiments. At a pH of 6.0 and an initial micropollutant (MP) concentration of 2.5 mg/L, 2.41 mg/L (96.4%) of DCF, 2.47 mg/L (98.8%) of IBP, and 2.38 mg/L (95.2%) of NPX were removed. Optimization was done by an artificial neural network (ANN), which proved to be reasonable at optimizing emerging micropollutant elimination by CMCAB as indicated by the high R2 values and reasonable mean square errors (MSE). Adsorption isotherm studies indicated that both Langmuir and Freundlich isotherms were able to explain micropollutant adsorption by CMCAB. Finally, desorption tests proved that cross-linked magnetic chitosan/activated biochar might be employed for at least eight adsorption-desorption cycles.