- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Reduced Graphene Oxide/TiO2 Nanocomposite: From Synthesis to Characterization for Efficient Visible Light Photocatalytic Applications
摘要： In this study, a green and facile thermal reduction of graphene oxide using an eco-friendly system of D-(+)-glucose and NH4OH for the preparation of reduced graphene oxide was described. The obtained reduced graphene oxide dispersion was characterized by SEM, Dynamic Light Scattering, Raman and X-Ray Photoelectron Spectroscopy. TiO2 nanoparticles and reduced graphene oxide nanocomposites were successively prepared and used in the preparation of heterogeneous photocatalysts that were characterized by Atomic Force Microscopy and Photoluminescence Spectroscopy and subsequently tested as visible light photocatalysts for the photodegradation of Alizarin Red S in water as target pollutant. Obtained results of photocatalytic tests regarding the visible light photocatalytic degradation of Alizarin Red S demonstrated that the use of reduced graphene oxide in combination with TiO2 led to a significant improvement for both adsorption of Alizarin Red S on the catalyst surface and photodegradation efficiencies when compared to those obtained with not doped TiO2.
关键词： visible light photocatalysis,wastewater treatment,reduced graphene oxide,TiO2,glucose-NH4OH
更新于2025-09-19 17:15:36
-
TiO2 coated on PVDF membrane for dye wastewater treatment by a photocatalytic membrane
摘要： This work investigated the membrane modi?cation to increase hydrophilicity aiming for application in a photocatalytic membrane. The modi?ed poly(vinylidene ?uoride) (PVDF) ?at sheet membrane was coated with titanium dioxide (TiO2). The chemical and physical changes of membranes were characterized by contact angle, SEM and porosity. The results found that TiO2 successfully modi?ed the PVDF membrane by decreasing the contact angle from 127.1° to 114.3° on increasing the TiO2 concentration from 0.1 to 1.0 g/L. The contact angles were decreased with the increase of coating time. The water permeation after PVDF membrane modi?cation decreased compared with the original membrane, whereas water ?uxes increased with the increase of TiO2 concentration. TiO2 particles were observed on the membrane surface while the porosity of the membrane coated with TiO2 decreased. The optimum condition of membrane coating was obtained at 1.0 g/L of TiO2 and 60 min of coating time. The decolorization of RB 19 by photolysis and photolysis followed by ?ltration was less than 10%; in contrast, the decolorization of RB 19 by photocatalytic oxidation was as well as a photocatalytic membrane for 60 min. The TiO2 photocatalytic membrane is a feasible technology for RB 19 decolorization in wastewater.
关键词： dye,wastewater treatment,PVDF,membrane modi?cation,photocatalytic membrane
更新于2025-09-19 17:15:36
-
3D Printed Floating Photocatalysts for Wastewater Treatment
摘要： Organic contaminants, specifically contaminants of emerging concern (CECs), have a great environmental impact, since the removal of these pollutants is of great difficulty by conventional treatments and the presence of these pollutants in the aquatic medium, even at low concentrations, is extremely hazardous to human health. Advanced oxidation processes and, specifically, TiO2-photocatalytic process is considered an option with positive results for an efficient treatment. However, the photocatalyst must be accessible to the UV radiation, for the activation of the TiO2. For this reason, it is recommendable to use a floating photocatalyst (with lower density than water) if the UV light comes from the solar radiation, because it will be on the water surface. In addition, this characteristic of the catalyst can entail an increase of the process efficiency if the pollutant is mainly located on the surface of water. In this context, the goal of this work is the preparation of floating photocatalysts for the removal of CECs from wastewater. TiO2 is deposited in low-density-polyethylene (LDPE), support with lower density than water and high stability and resistance to degradation. LDPE-TiO2 mixtures were prepared by different methods: mixing TiO2 and LDPE in a hot-cylinder-mixer or using o-xylene or an anionic surfactant as dispersing agent, in order to increase the dispersion of TiO2 before extrusion. Filaments obtained were printed as meshes in a Fused-Deposition-Modelling 3D-printer. The printed photocatalysts improved the activity in comparison with the plate obtained in the cylinder, used as benchmark. Thus, this study opens the doors to the in-situ treatment of CECs, using floating photocatalysts and solar radiation as the sole reagent, a very economical, efficient, easily implantable and environmentally compatible process.
关键词： photocatalysis,polyethylene mesh,wastewater treatment,3D printing.,Fused Deposition Modelling
更新于2025-09-19 17:15:36
-
Development of Cd3(PO4)2/rGO Coupled Semiconductor System for Effective Mineralization of Basic Violet 10 (BV 10) under UV-A Light
摘要： Initially, novel Cd3(PO4)2 was prepared via precipitation method. It was loaded with different concentration of rGO to form rGO/CdP composites. The prepared rGO/CdP were used to degrade Basic Violet 10 (BV 10) dye under UV-A light irradiation. The optimized rGO/CdP composite was characterized along with pristine CdP and rGO by XRD, FT-IR, FT-Raman, BET, HR-SEM with EDX, HR-TEM, and UV-DRS analysis. The effect of initial dye pH in the degradation was studied. The coupled semiconductor system enhanced the photocatalytic activity and used for multiple runs, due to its remarkable stability.
关键词： Wastewater treatment,Photocatalysis,Basic Violet (BV 10),rGO,Cd3(PO4)2
更新于2025-09-16 10:30:52
-
A facile heterogeneous system for persulfate activation by CuFe <sub/>2</sub> O <sub/>4</sub> under LED light irradiation
摘要： In this study, the removal performance for rhodamine B (RB) by persulfate (PS) activated by the CuFe2O4 catalyst in a heterogeneous catalytic system under LED light irradiation was investigated. The effect of vital experimental factors, including initial solution pH, CuFe2O4 dosage, PS concentration, co-existing anion and initial RB concentration on the removal of RB was systematically studied. The removal of RB was in accordance with the pseudo first-order reaction kinetics. Over 96% of 20 mg L?1 RB was removed in 60 min using 0.5 g L?1 CuFe2O4 catalyst and 0.2 mM PS at neutral pH. In addition, free radical quenching experiments and electron spin resonance (EPR) experiments were performed, which demonstrated the dominant role of sulfate radical, photogenerated holes and superoxide radical in the CuFe2O4/PS/LED system. The morphology and physicochemical properties of the catalyst were characterized by XRD, SEM-EDS, TEM, N2 adsorption–desorption isotherm, UV-vis DRS, and XPS measurements. Moreover, 18.23% and 38.79% total organic carbon (TOC) removal efficiency was reached in 30 min and 60 min, respectively. The catalyst revealed good performance during the reusability experiments with limited iron and copper leaching. Eventually, the major intermediates in the reaction were detected by GC/MS, and the possible photocatalytic pathway for the degradation of RB in the CuFe2O4/PS/LED system was proposed. The results suggest that the CuFe2O4/PS/LED system has good application for further wastewater treatment.
关键词： LED light,persulfate,wastewater treatment,rhodamine B,CuFe2O4
更新于2025-09-16 10:30:52
-
The synthesis of Co <sub/>x</sub> Ni <sub/>1?x</sub> Fe <sub/>2</sub> O <sub/>4</sub> /multi-walled carbon nanotube nanocomposites and their photocatalytic performance
摘要： A series of CoxNi1?xFe2O4/multi-walled carbon nanotube (CoxNi1?xFe2O4/MWCNTs) nanocomposites as photocatalysts were successfully synthesized, where CoxNi1?xFe2O4 was synthesized via a one-step hydrothermal approach. Simultaneously, methylene blue (MB) was used as the research object to investigate the catalytic effect of the catalyst in the presence of hydrogen peroxide (H2O2). The results showed that all the photocatalysts exhibited enhanced catalytic activity compared to pure ferrite. In addition, compared with the other photocatalysts, the reaction time was greatly shortened a significantly higher removal rate was achieved using 3-CNF/MWCNTs. There was no significant decrease in photodegradation efficiency after three catalytic cycles, suggesting that CoxNi1?xFe2O4/MWCNTs are recyclable photocatalysts for wastewater treatment. Our results indicate that the CoxNi1?xFe2O4/MWCNT composite can be effectively applied for the removal of organic pollutants as a novel photocatalyst.
关键词： methylene blue,photocatalysts,hydrothermal approach,wastewater treatment,multi-walled carbon nanotube,hydrogen peroxide,CoxNi1?xFe2O4
更新于2025-09-16 10:30:52
-
Screening of microalgae and LED grow light spectra for effective removal of dissolved nutrients from cold-water recirculating aquaculture system (RAS) wastewater
摘要： Popularity of recirculating aquaculture systems (RAS) is increasing. Because of the high water recirculation rate, dissolved nutrients originating from fish feed are concentrated enough in RAS wastewater (WW) to enable growth of primary producers, e.g. microalgae. This study evaluated nitrate-nitrogen (NO3-N) and phosphate-phosphorus (PO4-P) removal efficiency of ten temperate zone freshwater microalgae species during their exponential growth phase in unfiltered RAS WW at 17 ± 0.5 °C. Growth and nutrient uptake efficiency of six green and four non-green microalgae strains were compared between WW and reference growth medium in batch monocultures. The effect of three different LED grow light spectra on growth and nutrient uptake efficiency were compared for four green microalgae in WW. The specific growth rate (SGR, 0.5-0.8 d-1) and removal of NO3-N (N%, 57–96%) and PO4-P (P%, 78–94%) of green microalgae in WW in 4 days were comparable to the results obtained in the reference medium (SGR, 0.6-0.9 d-1, N%, 59–99%; P%, 86–99%). In contrast, non-green microalgae had negligible growth (SGR, from -0.1 to 0.2 d-1) and poor nutrient removal (N%, 1–29%; P%, 0–34%) in both growth media after 9 days. The three LED spectra did not differ on their effect on growth and nutrient removal of three green microalgae in WW after 4 days, while the fourth tested species, Haematoccocus pluvialis, had its highest nutrient removal after 8 days under a specific LED spectrum. Current results show that RAS WW supports well green microalgae growth in batch cultures in temperatures common in Nordic RAS and that continuous spectrum LED grow lights can induce high removal of dissolved nutrients. Our findings lend support to the concept of using temperate zone microalgae for nutrient removal and recycling from RAS WW.
关键词： Wastewater treatment,Nitrate-nitrogen,Bioremediation,Nutrient uptake,Fish farming,Phosphate-phosphorus,Continuous light spectra,Coregonus lavaretus
更新于2025-09-12 10:27:22
-
Photocatalytic filtration reactors equipped with bi-plasmonic nanocomposite/poly acrylic acid-modified polyamide membranes for industrial wastewater treatment
摘要： In this study, two new composite membranes with antifouling and anti-biofouling properties were prepared through the modification of commercial polyamide (PA) discs using combination of in-situ polymerization of polyacrylic acid (PAA) and grafting of two synthesized bi-plasmonic Au-Ag and Ag-Au photocatalysts. The synthesis and characterization of the photocatalysts in batch mode were discussed in details as primary studies. Two intense 405-nm and 532-nm lasers for Ag-Au and Au-Ag photocatalysts, respectively and a solar-simulated xenon lamp for both photocatalysts were applied for photodegradation studies and the results were compared. In addition, the effect of other parameters such as type and amount of photocatalysts, and initial concentration of pollutants on the degradation efficiency of ofloxacin (OFX) and methylene blue (MB) as the model pollutant drug and dye were comprehensively investigated and the Langmuir-Hinshelwood adsorption model was used for evaluation of kinetics, degradation rate and half-life time of the reactions. After selection of xenon lamp as the optimum light source, the photodegradation of OFX and MB was evaluated in a dead-end membrane reactor (MR) and flux performance, antifouling property and pollutant removal of the membranes were evaluated using pharmaceutical and textile wastewater samples. In addition, the antibacterial activity of the prepared membranes was evaluated using Gram-negative E. coli bacteria as the model microorganism using thin film assay and Kirby-Bauer disk diffusion methods to examine the anti-biofouling potential of the constructed reactors. It was demonstrated that the prepared MR is able to produce cleaner water with more stable ?ux performance and good membrane fouling/biofouling properties in energy saving manner with respect to the unmodified ones.
关键词： Membrane ?ltration,Wastewater treatment,Permeate ?ux,Bi-plasmonic nanoparticles,Photodegradation,Antifouling/anti-biofouling properties
更新于2025-09-11 14:15:04
-
Application of ZnO-Ag-Nd nanocomposite as a new synthesized nanophotocatalyst for degradation of the organic compounds: Kinetic, thermodynamic, and economic study
摘要： In the present research, a zinc oxide (ZnO)–silver (Ag)–neodymium (Nd) nanocomposite was synthesized via the combustion method for the degradation of dyes as organic pollutants. The synthesized nanophotocatalyst was characterized using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques. The process of organic pollutant (Acid Red 18) removal was carried out in a semi-batch photoreactor equipped with an ultraviolet lamp. Also, the influence of key operational parameters such as pH, temperature, initial concentration of solution, and nanophotocatalyst dosage was investigated to evaluate kinetic and thermodynamic properties. Under optimum process conditions (pH ? 6.21, dosage of nanophotocatalyst ? 0.08 g/l, and low initial concentration of the solution), degradation of pollutant was monitored by measuring the total organic carbon of the solution. Finally, an economic study showed that the photocatalytic advanced oxidation process is an viable treatment method for low concentrations of organic pollutants.
关键词： wastewater treatment,degradation,organic pollutant,Nanophotocatalyst
更新于2025-09-10 09:29:36
-
Influence of Cr doping on the oxygen evolution potential of SnO2/Ti and Sb-SnO2/Ti electrodes
摘要： Oxygen evolution potential is the determining factor affecting the anode efficiency of the wastewater treatment process. In this study, we focus on increasing oxygen evolution potential of Cr-SnO2/Ti and Cr-Sb-SnO2/Ti electrodes with the pyrolytic method. XRD, SEM and XPS techniques had been applied to characterize the microstructures and chemical compositions of the samples. Electrochemical measurements had been performed to evaluate the oxygen evolution potential as a criterion of the wastewater treatment efficiency. The results show that co-doping of Sb and Cr improved the crystallinity and grain size of SnO2 coating, and Cr existed in the form of Cr(Ⅲ) valence states. The Cr doping treatment improved the electronic conductivity and the electrocatalytic activity of the electrodes. DFT calculation of the band-structure indicates Cr doped SnO2 had a superior electrical conductivity, where Cr atom acts as an acceptor providing vacancies for electron transportation. The DOS diagrams reveal the Cr doped SnO2 showing a p-type conductivity which would subsequently influence the built-in potential on metal-semiconductor interface. We proposed the mechanism of the increase of oxygen evolution potential is the doping of Cr expands the built-in potential.
关键词： Cr doping,oxygen evolution potential,DFT,wastewater treatment
更新于2025-09-10 09:29:36