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Photocatalytic degradation of organic pollutants from wastewater using aluminium doped titanium dioxide
摘要： The objective of this research was to study the performance of batch and continuous recirculating reactor to photo-degrade dye and synthetic wastewater. Here, Aluminium (Al) was used as the doped metal. The commercially available TiO2 P-25 and Al (NO3)3 was used as a Ti-precursor and doping agent, respectively, via the impregnation method. Various parameters such as the concentration of the doping agent, and calcination temperature were studied. The TiO2 nanocrystal doped with Al was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analyzer (TGA). The photocatalytic performance of Al-doped nanoparticle was quantified by the degradation of methylene blue (MB) solution under a visible light irradiation condition. Its performance was compared against undoped-nano-TiO2. The results showed that Al (NO3)3 solution with a concentration of 0.25% and volume of 100 cm/ml, and calcined at 300 C for 4 h, was the optimum condition of Al-doped nano-TiO2. Furthermore, the highest pseudo-first-order kinetic rate was 0.096 where the doped Al(NO3)3 of 0.75 w/v was used in the batch reactor. The Al-doped nano-TiO2 that was obtained has the potential for use as a photocatalyst for degradation organics pollutant from wastewater under the visible light irradiation. The highest removal of organic pollutants from synthetic wastewater was 75% using TiO2 P-25 alone at 2 g/L dosage. In addition, the removal of organic pollutant by TiO2/doped with Al was 80% at a dosage of 0.5 g/L and was 85% at a dosage of 1 g/L.
关键词： Batch reactor,Photo-catalyst,Titanium dioxide,Advanced oxidation process
更新于2025-09-23 15:23:52
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TiO2/Schwertmannite nanocomposites as superior co-catalysts in heterogeneous photo-Fenton process
摘要： The heterogeneous photo-Fenton reaction is an effective technique in combating organic contaminants for both soil and water remediation, and extensive studies have focused on enhancing its efficiency and reducing its costs. In this work, we developed novel photo-Fenton catalysts by simply milling commercially available TiO2 (P25) with Schwertmannite (Sh), a natural iron-oxyhydroxysulfate nanomineral. We expect that the photo-generated electrons from TiO2 could continuously migrate to Sh, which then could enhance the separation of electron-hole pairs on TiO2 and accelerate the reduction of Fe(III) to Fe(II) on Sh, leading to high degradation efficiency of the target organic contaminants. SEM and TEM results showed the distribution of TiO2 on Sh surface for the nanocomposites (TiO2/Sh). Under simulated sunlight irradiation, the much higher content of Fe(II) was determined on TiO2/Sh than on Sh via a common method in the iron ore, and the consumption of H2O2 and the production of ?OH were more significant in the TiO2/Sh system than those in the TiO2 and Sh systems. These results well support our hypothesis that the photo-generated electrons could migrate from TiO2 to Sh on the composites, and can also explain the much higher degradation efficiency of Rhodamine B (RhB) in the TiO2/Sh system. Besides, TiO2/Sh had lower Fe dissolution as compared with Sh, and retained high catalytic stability after four repeated cycles. Above merits of the TiO2/Sh composites, in combining with their simple synthesis method and low-cost property, indicated that they should have promising applications as heterogeneous photo-Fenton catalysts.
关键词： Advanced oxidation,Photo-Fenton reaction,Semiconductor,Schwertmannite
更新于2025-09-23 15:23:52
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Photocatalytic removal of phenanthrene and algae by a novel Ca-Ag3PO4 composite under visible light: Reactivity and coexisting effect
摘要： In this study, the feasibility of a novel Ca-Ag3PO4 composite with visible light irradiation for the phenanthrene (PHE) degradation and algae inactivation in artificial seawater was firstly investigated. The experimental findings revealed that Ag3PO4 phase was sucessfully formed on the Ca-based material, and the presence of Ca-based material could effectively keep Ag3PO4 particles stable. An excellent performance on PHE degradation or algae inactivation was observed from Ca-Ag3PO4 composite under visible light irradiation. The degradation of PHE or inactivation of algae not only could be efficiently achieved in the single mode, but also could be successfully achieved in the coexisting mode. Above 96 % of PHE and algae were simultaneously removed within 12 h in the Ca-Ag3PO4/visible light system. It was further observed that the degradation of PHE and/or inactivation of algae increased with the increase of Ca-Ag3PO4 dosage. HO? was the primary radical responsible for PHE degradation, whereas HO? and Ag+ released from Ca-Ag3PO4 mainly contributed to the algae inactivation. A possible mechanism involving the catalytic removal of PHE and algae by Ca-Ag3PO4 under visible light irradiation was proposed. This study provides helpful guide for the simultaneous removal of various pollutants in real seawater.
关键词： Ag3PO4,Algae,Photocatalytic,Advanced oxidation processes (AOPs),Visible light,Phenanthrene (PHE)
更新于2025-09-23 15:23:52
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Experimental data on the degradation of caffeine by photo-electro-fenton using BDD electrodes at pilot plant
摘要： Emerging contaminants (EC) are an imminent risk due to potential toxicity to aquatic ecosystems and human beings. This type of contaminants is found in low concentrations and usually present incomplete or inefficient removal by conventional treatments, which entail its permanence and constant increase. Advanced Oxidation Processes (AOP) are an alternative for the elimination of dangerous and resistant substances in wastewater. So, this research evaluates the caffeine degradation in aqueous solution by AOP, such as: Fenton, Electro-Oxidation (EO) with boron doped diamond (BDD) electrodes, Electro-Fenton (EF) and Photo-Electro-Fenton (PEF). The influences of pH, concentration of the supporting electrolyte and specific electric charge were investigated using a Taguchi's factorial design, which allowed to identify the contribution of each variable in the process. The data obtained in this work can be useful for scaling process and cost analysis because it provide the information at pilot plant scale.
关键词： Chemical engineering,Taguchi design,BDD electrodes,Advanced oxidation process,Caffeine degradation
更新于2025-09-23 15:23:52
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Effect of photochemical advanced oxidation processes on the formation potential of emerging disinfection by-products in groundwater from part of the Pannonian Basin
摘要： This study evaluates the effect of photochemical advanced oxidation processes (AOPs) (O3/UV, H2O2/UV and O3/H2O2/UV) on the formation potential (FP) of emerging disinfection by-products including nitrogenous by-products (N-DBPs) and haloketones (HKs) in groundwater from part of the Pannonian Basin (AP Vojvodina, Republic of Serbia). Among the N-DBPs, the haloacetonitrile (HAN) precursor contents were 9.83 ± 0.59 μg/L while precursors of halonitromethanes, particularly trichloronitromethane (TCNM) were not detected. Similarly, precursors of HKs as carbonaceous DBPs were also not detected in raw water. Ozonation alone and H2O2/UV process with a lower UV dose maximally decomposed HAN precursors (about 70%) while during O3 based AOPs, HANFP varied significantly. Application of UV photolysis and H2O2/UV processes with increasing UV dose doubled the HANFP. Ozone alone, O3/UV and H2O2/UV slightly increased HKs formation potential, particularly 1,1-Dichloro-2-propanone FP (0.93 ± 0.21 to 2.01 ± 0.37 μg/L). None of the investigated treatments influenced the formation of TCNM precursors. The effect of the applied treatments on bromide incorporation was the most evident for HANs.
关键词： emerging disinfection by-products,ozone,bromide incorporation,photochemical advanced oxidation processes
更新于2025-09-23 15:23:52
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Degradation and inactivation of adenovirus in water by photo-electro-oxidation
摘要： The present study analyzed the efficiency of the photo-electro-oxidation process as a method for degradation and inactivation of adenovirus in water. The experimental design employed a solution prepared from sterile water containing 5.107 genomic copies/L (gc/L) of a standard strain of human adenovirus type 5 (HAdV-5) divided into two equal parts, one to serve as control and one treated by photo-electro-oxidation (PEO) for 3 hours and with a 5A current. Samples collected throughout the exposure process were analyzed by real-time polymerase chain reaction (qPCR) for viral genome identification and quantitation. Prior to gene extraction, a parallel DNAse treatment step was carried out to assess the integrity of viral particles. Integrated cell culture (ICC) analyses assessed the viability of infection in a cell culture. The tested process proved effective for viral degradation, with a 7 log10 reduction in viral load after 60 minutes of treatment. The DNAse-treated samples exhibited complete reduction of viral load after a 75 minute exposure to the process, and ICC analyses showed completely non-viable viral particles at 30 minutes of treatment.
关键词： advanced oxidation process,water,adenovirus,photo-electro-oxidation
更新于2025-09-23 15:22:29
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Unsubstituted metallophthalocyanine catalysts for the removal of endocrine disrupting compounds using H2O2 as oxidant
摘要： Advanced oxidation processes have become increasingly important to treat non-biodegradable compounds entering environmental waters. In recent decades, water-soluble metallophthalocyanines have been shown to catalyse H2O2-containing oxidation reactions through the production of unique reactive species, nucleophilic metal-peroxo complexes. Few reports in the literature have examined water insoluble metallophthalocyanines (MPc). The oxidative catalytic activity of water insoluble manganese- and iron-phthalocyanine (MnPc, FePc) at pH 7 has been shown through the decolourisation of methylene blue and removal of bisphenol A. These studies expand on this previous study, exploring the catalytic activity of a range of metallophthalocyanines catalysts under both acidic and neutral conditions. FePc, while only active under neutral conditions, was the best performing catalyst. This activity was significantly improved upon by the addition of acetonitrile as a co-solvent, as well as increasing the ratio of H2O2 to catalyst. MnPc was catalytically active at both pH 3 and 7. FePc and MnPc catalysts showed the ability to remove bisphenol A in the presence of dam water. Reaction rates were reduced for bisphenol A removal with FePc as a catalyst but were unchanged in the presence of MnPc. The removal of 17β-estradiol, estrone, and coumestrol was successfully demonstrated, with greater than 96% removal of all tested EDC’s achieved. This is the first reported study showing the removal of the phytoestrogen, coumestrol. Even though considerably lower concentrations of costly catalysts and oxidation reagents were used in our work, the removal extent of EDC’s by the MPc-catalysed oxidation reactions achieved here compares favourably with literature.
关键词： Bisphenol A,Endocrine disrupting compounds,Metallophthalocyanine,Advanced oxidation processes,Coumestrol
更新于2025-09-23 15:22:29
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Characterization and removal of antibiotic residues by NFC-doped photocatalytic oxidation from domestic and industrial secondary treated wastewaters in Meric-Ergene Basin and reuse assessment for irrigation
摘要： Antibiotics are important contaminants that have become an increasingly big problem due to the discharge of the receiving environment. The presence of these organic based pollutants in influent wastewater can inhibit the biological processes and resist to degradation in wastewater treatment plants. Moreover, the consumption of agricultural products, irrigated with water containing antibiotic residues, leads to major harmful effects to the human body through the food chain. In this study; firstly, a conventional characterization was made in terms of COD, TOC, SS, color and of antibiotic residue characterization of untreated raw (influent) and biologically treated (effluent) water from domestic and industrial wastewater treatment plants located in the Meri?-Ergene Basin. After that, photocatalytic activity test was run under visible light for selected antibiotics (Erythromycin, Ciprofloxacin, Sulphametoxasol) which were detected by HPLC MS/MS in excess amount. Finally, for the photocatalytic oxidation, a new generation NFC (Nitrogen-Floride-Carbon)-doped titanium dioxide photocatalyst, which has never been studied in the literature before, was prepared according to the sol-gel method without using thermal processing. Photocatalysts were characterized by UV–vis DRS reflectance and Laser Raman Spectra measurements. All other analyzes were made according to the standard methods. Considering the conventional characterization results; investigated domestic wastewaters exhibited moderate characteristics while industrial wastewater samples had strong characteristics in terms of COD, TOC and SS pollution in accordance with the literature. By the way, contrary to expectations, antibiotic residue results have proved that the effluent wastewater contains more antibiotics than the influent. This can be explained by the fact that, some antibiotics in domestic wastewaters are probably already trapped in feces and cannot be purified by conventional systems since they are released after biological treatment, as mentioned similar studies in the literature. Moreover, by means of 7 h NFC-doped photocatalytic oxidation under visible light, beside approximately % 62 to %79 COD and 62%–86% TOC removal, %99 to %100 removal of antibiotic residue was provided. According to these results, domestic and industrial secondary treated wastewaters in Meric-Ergene Basin can be advance treated, succesfully, with NFC-doped photocatalyst to remove antibiotic residues besides conventional pollutants. This result show that Meri?-Ergene discharge criteria determined by Forest and Water Ministry of Turkey can be provided with this new type photocatalytic process and healthy reuse of this river for irrigation will be possible.
关键词： Advanced oxidation processes,Domestic/industrial wastewater,Solvent-casting method,UV,Antibiotic,Photocatalyst,NFC-doped TiO2
更新于2025-09-23 15:22:29
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From micro to macro-contaminants: The impact of low-energy titanium dioxide photocatalysis followed by filtration on the mitigation of drinking water organics
摘要： This study evaluated strategies targeting macro- and micro-organic contaminant mitigation using low-energy titanium dioxide photocatalysis. Energy inputs of 1, 2, and 5 kWh m-3 resulted in incomplete oxidation of macro-organic natural organic matter, signified by greater reductions of UV254 and specific ultraviolet UV absorbance (SUVA) in comparison to dissolved organic carbon (DOC). The rate of UV254 removal was 3 orders of magnitude greater than the rate of DOC degradation. Incomplete oxidation improved operation of downstream filtration processes. Photocatalysis at 2 kWh m-3 increased the bed life of downstream granular activated carbon (GAC) filter by 340% relative to direct filtration pretreatment. Likewise, photocatalysis operated ahead of microfiltration decreased fouling, resulting in longer filter run times. Using 2 kWh m-3 photocatalysis increased filter run time by 36 times in comparison to direct filtration. Furthermore, levels of DOC and UV254 in the membrane permeate improved (with no change in removal across the membrane) using low-energy photocatalysis pretreatments. While high-energy UV inputs provided high levels of removal of the estrogenic micro-organics estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynlestradiol (EE2), low-energy photocatalysis did not enhance removal of estrogens beyond levels achieved by photolysis alone. In the cases of E1 and E3, the addition of TiO2 as a photocatalyst reduced degradation rates of estrogens compared to UV photolysis. Overall, process electrical energy per order magnitude reductions (EEOs) greatly improved using photocatalysis, versus photolysis, for the macro-organics DOC, UV254, and SUVA; however, energy required for removal of estrogens was similar between photolysis and photocatalysis.
关键词： granular activated carbon (GAC),estrogens,UV photolysis,dissolved organic carbon (DOC),advanced oxidation process (AOP),natural organic matter (NOM)
更新于2025-09-23 15:21:01
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New Insights on the Photodegradation of Caffeine in the Presence of Bio-Based Substances-Magnetic Iron Oxide Hybrid Nanomaterials
摘要： The exploitation of organic waste as a source of bio-based substances to be used in environmental applications is gaining increasing interest. In the present research, compost-derived bio-based substances (BBS-Cs) were used to prepare hybrid magnetic nanoparticles (HMNPs) to be tested as an auxiliary in advanced oxidation processes. Hybrid magnetic nanoparticles can be indeed recovered at the end of the treatment and re-used in further water purification cycles. The research aimed to give new insights on the photodegradation of caffeine, chosen as marker of anthropogenic pollution in natural waters, and representative of the contaminants of emerging concern (CECs). Hybrid magnetic nanoparticles were synthetized starting from Fe(II) and Fe(III) salts and BBS-C aqueous solution, in alkali medium, via co-precipitation. Hybrid magnetic nanoparticles were characterized via X-ray diffraction (XRD), thermo-gravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The effect of pH, added hydrogen peroxide, and dissolved oxygen on caffeine photodegradation in the presence of HMNPs was assessed. The results allow for the hypothesis that caffeine abatement can be obtained in the presence of HMNPs and hydrogen peroxide through a heterogeneous photo-Fenton mechanism. The role of hydroxyl radicals in the process was assessed examining the effect of a selective hydroxyl radical scavenger on the caffeine degradation kinetic.
关键词： hybrid nanomaterials,photo Fenton,caffeine,advanced oxidation processes,magnetic materials,bio-based substances
更新于2025-09-19 17:15:36