scholarly journals Enhanced Solar Photocatalytic Reduction of Cr(VI) Using a (ZnO/CuO) Nanocomposite Grafted onto a Polyester Membrane for Wastewater Treatment

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4047
Author(s):  
Ambreen Ashar ◽  
Ijaz Ahmad Bhatti ◽  
Asim Jilani ◽  
Muhammad Mohsin ◽  
Sadia Rasul ◽  
...  
Keyword(s):  
Irradiation Time ◽  
Interactive Effect ◽  
Research Work ◽  
Polyester Fabric ◽  
Photocatalytic Reduction ◽  
Solar Irradiation ◽  
Wastewater Sample ◽  
Silar Method ◽  
Solar Photocatalysis ◽  
Natural Sunlight

Among chemical water pollutants, Cr(VI) is a highly toxic heavy metal; solar photocatalysis is a cost-effective method to reduce Cr(VI) to innocuous Cr(III). In this research work, an efficient and economically feasible ZnO/CuO nanocomposite was grafted onto the polyester fabric ZnO/CuO/PF through the SILAR method. Characterization by SEM, EDX, XRD, and DRS confirmed the successful grafting of highly crystalline, solar active nanoflakes of ZnO/CuO nanocomposite onto the polyester fabric. The grafting of the ZnO/CuO nanocomposite was confirmed by FTIR analysis of the ZnO/CuO/PF membrane. A solar photocatalytic reduction reaction of Cr(VI) was carried out by ZnO/CuO/PF under natural sunlight (solar flux 5–6 kW h/m2). The response surface methodology was employed to determine the interactive effect of three reaction variables: initial concentration of Cr(VI), pH, and solar irradiation time. According to UV/Vis spectrophotometry, 97% of chromium was removed from wastewater in acidic conditions after four hours of sunlight irradiation. ZnO/CuO/PF demonstrated reusability for 11 batches of wastewater under natural sunlight. Evaluation of Cr(VI) reduction was also executed by complexation of Cr(VI) and Cr(III) with 1, 5-diphenylcarbazide. The total percentage removal of Cr after solar photocatalysis was carried out by AAS of the wastewater sample. The ZnO/CuO/PF enhanced the reduction of Cr(VI) metal from wastewater remarkably.

scholarly journals Straightforward Synthesis of Mn3O4/ZnO/Eu2O3-Based Ternary Heterostructure Nano-Photocatalyst and Its Application for the Photodegradation of Methyl Orange and Methylene Blue Dyes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4661
Author(s):  
Jayachamarajapura Pranesh Shubha ◽  
Haralahalli Shivappa Savitha ◽  
Syed Farooq Adil ◽  
Mujeeb Khan ◽  
Mohammad Rafe Hatshan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Methyl Orange ◽  
Irradiation Time ◽  
Solar Irradiation ◽  
Anionic Dyes ◽  
One Pot ◽  
Sunlight Irradiation ◽  
Ft Ir ◽  
Degradation Activity ◽  
Ecological Applications

Zinc oxide-ternary heterostructure Mn3O4/ZnO/Eu2O3 nanocomposites were successfully prepared via waste curd as fuel by a facile one-pot combustion procedure. The fabricated heterostructures were characterized utilizing XRD, UV–Visible, FT-IR, FE-SEM, HRTEM and EDX analysis. The photocatalytic degradation efficacy of the synthesized ternary nanocomposite was evaluated utilizing model organic pollutants of methylene blue (MB) and methyl orange (MO) in water as examples of cationic dyes and anionic dyes, respectively, under natural solar irradiation. The effect of various experimental factors, viz. the effect of a light source, catalyst dosage, irradiation time, pH of dye solution and dye concentration on the photodegradation activity, was systematically studied. The ternary Mn3O4/ZnO/Eu2O3 photocatalyst exhibited excellent MB and MO degradation activity of 98% and 96%, respectively, at 150 min under natural sunlight irradiation. Experiments further conclude that the fabricated nanocomposite exhibits pH-dependent photocatalytic efficacy, and for best results, concentrations of dye and catalysts have to be maintained in a specific range. The prepared photocatalysts are exemplary and could be employed for wastewater handling and several ecological applications.

Photodegradation of p-Nitrophenol Catalyzed by ZnO/MWCNTs Composite Catalyst in Water

2012 ◽  
Vol 455-456 ◽  
pp. 1339-1344 ◽  
Author(s):  
Zhe Qi Li ◽  
Jing Yu Liu
Keyword(s):  
Irradiation Time ◽  
Solar Irradiation ◽  
Composite Catalyst ◽  
Catalyst Loading ◽  
Optimal Conditions ◽  
Mass Ratio ◽  
Initial Substrate ◽  
Effects Of Ph ◽  
Potential Use ◽  
Initial Substrate Concentration

Photodegradation ofp-nitrophenol catalyzed by ZnO/MWCNTs composite in water was investigated. The effects of pH, irradiation time, catalyst loading, initial substrate concentration and MWCNTs content on the degradation were investigated. Experiment results revealed that the optimal conditions were ap-nitrophenol concentration of 60.0 mg/L at pH 5.0 with catalyst loading of 10.0 g/L under solar irradiation for the illumination of 180 min. The highest efficiency on photodegradation ofp-nitrophenol can be achieved with an optimal MWCNTs/ZnO mass ratio of 0.16%. Possible decomposing mechanisms were also discussed. The repeatability of photocatalytic activity was tested. The photocatalyst was used ten cycles with degradation efficiency still higher than 95%. The results of the study showed the feasible and potential use of ZnO/MWCNTs composite in degradation of toxic organic pollutants.

scholarly journals Nucleophile sensitivity of Drosophila TRPA1 underlies light-induced feeding deterrence

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Eun Jo Du ◽  
Tae Jung Ahn ◽  
Xianlan Wen ◽  
Dae-Won Seo ◽  
Duk L Na ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Free Radicals ◽  
Tissue Damage ◽  
Transient Receptor Potential ◽  
Uv Light ◽  
Receptor Potential ◽  
Solar Irradiation ◽  
Feeding Deterrence ◽  
Natural Sunlight ◽  
Transient Receptor

Solar irradiation including ultraviolet (UV) light causes tissue damage by generating reactive free radicals that can be electrophilic or nucleophilic due to unpaired electrons. Little is known about how free radicals induced by natural sunlight are rapidly detected and avoided by animals. We discover that Drosophila Transient Receptor Potential Ankyrin 1 (TRPA1), previously known only as an electrophile receptor, sensitively detects photochemically active sunlight through nucleophile sensitivity. Rapid light-dependent feeding deterrence in Drosophila was mediated only by the TRPA1(A) isoform, despite the TRPA1(A) and TRPA1(B) isoforms having similar electrophile sensitivities. Such isoform dependence re-emerges in the detection of structurally varied nucleophilic compounds and nucleophilicity-accompanying hydrogen peroxide (H2O2). Furthermore, these isoform-dependent mechanisms require a common set of TRPA1(A)-specific residues dispensable for electrophile detection. Collectively, TRPA1(A) rapidly responds to natural sunlight intensities through its nucleophile sensitivity as a receptor of photochemically generated radicals, leading to an acute light-induced behavioral shift in Drosophila.

scholarly journals Hydrogen Photo-Production from Glycerol Using Nickel-Doped TiO2 Catalysts: Effect of Catalyst Pre-Treatment

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3351 ◽  
Author(s):  
Jesús Hidalgo-Carrillo ◽  
Juan Martín-Gómez ◽  
Julia Morales ◽  
Juan Carlos Espejo ◽  
Francisco José Urbano ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Uv Light ◽  
Irradiation Time ◽  
Fold Increase ◽  
Synthetic Methods ◽  
Solar Irradiation ◽  
Catalyst Pretreatment ◽  
Metal Support ◽  
Pre Treatment ◽  
Nickel Species

In the present piece of research, hydrogen production via the photo-reforming of glycerol (a byproduct from biodiesel generation) is studied. Catalysts consisted of titania modified by Ni (0.5% by weight) obtained through deposition–precipitation or impregnation synthetic methods (labelled as Ni-0.5-DP and Ni-0.5-IMP, respectively). Reactions were performed both under UV and solar irradiation. Activity significantly improved in the presence of Ni, especially under solar irradiation. Moreover, pre-reduced solids exhibited higher catalytic activities than untreated solids, despite the “in-situ” reduction of nickel species and the elimination of surface chlorides under reaction conditions (as evidenced by XPS). It is possible that the catalyst pretreatment at 400 °C under hydrogen resulted in some strong metal–support interactions. In summary, the highest hydrogen production value (ca. 2600 micromole H2·g−1) was achieved with pre-reduced Ni-0.5-DP solid using UV light for an irradiation time of 6 h. This value represents a 15.7-fold increase as compared to Evonik P25.

Band edge tuned ZnxCd1−xS solid solution nanopowders for efficient solar photocatalysis

2017 ◽  
Vol 19 (44) ◽  
pp. 29998-30009 ◽  
Author(s):  
Shrabani Ghosh ◽  
Samrat Sarkar ◽  
Bikram Kumar Das ◽  
Dipayan Sen ◽  
Madhupriya Samanta ◽  
...  
Keyword(s):  
Solid Solution ◽  
Catalytic Activity ◽  
Band Edge ◽  
Solar Photocatalysis ◽  
Natural Sunlight ◽  
Zinc Blende

Natural sunlight assisted catalytic activity of hydrothermally synthesized zinc blende ZnxCd1−xS solid solution with theoretical insights.

scholarly journals Recent Overview of Solar Photocatalysis and Solar Photo-Fenton Processes for Wastewater Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-27 ◽  
Author(s):  
A. G. Gutierrez-Mata ◽  
S. Velazquez-Martínez ◽  
Alberto Álvarez-Gallegos ◽  
M. Ahmadi ◽  
José Alfredo Hernández-Pérez ◽  
...  
Keyword(s):  
Energy Source ◽  
Free Energy ◽  
Low Cost ◽  
Organic Pollutant ◽  
Catalyst Preparation ◽  
Solar Irradiation ◽  
Applied Potential ◽  
Solar Photocatalysis ◽  
Literature Research ◽  
Commercial Applications

This literature research, although not exhaustive, gives perspective to solar-driven photocatalysis, such as solar photo-Fenton and TiO2 solar photocatalysis, reported in the literature for the degradation of aqueous organic pollutants. Parameters that influence the degradation and mineralization of organics like catalyst preparation, type and load of catalyst, catalyst phase, pH, applied potential, and type of organic pollutant are addressed. Such parameters may also affect the photoactivity of the catalysts used in the studied solar processes. Solar irradiation is a renewable, abundant, and pollution-free energy source for low-cost commercial applications. Therefore, these solar processes represent an environmentally friendly alternative mainly because the use of electricity can be decreased/avoided.

scholarly journals Ferrioxalate-induced solar photo-Fenton treatment of natural rubber latex wastewaters

2015 ◽  
Vol 50 (4) ◽  
pp. 349-358
Author(s):  
Lekshmi Ashok ◽  
S. Adishkumar ◽  
J. Rajesh Banu ◽  
Ick Tae Yeom
Keyword(s):  
Oxalic Acid ◽  
Natural Rubber ◽  
Irradiation Time ◽  
Plug Flow ◽  
Natural Rubber Latex ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Solar Irradiation ◽  
Fenton Process ◽  
Rubber Latex

This study evaluated a ferrioxalate-induced solar photo-Fenton process for natural rubber latex wastewater treatment. The reaction was carried out in a laboratory-scale solar photo-Fenton plug flow baffle reactor. An optimization study was performed using a central composite experimental design including the following variables: pH, initial concentrations of H2O2, Fe2+, and oxalic acid. The photocatalytic degradation efficiency was determined by the analysis of chemical oxygen demand (COD) removal. Under the optimum conditions of pH = 4, Fe2+ = 1.3 g/L, oxalic acid = 2.25 g/L, H2O2 = 82.5 g/L, and solar irradiation time of 6 hours, the COD removal efficiency was 99%. Treatment of latex wastewater by ferrioxalate-induced solar photo-Fenton process increased biodegradability ratio from 0.36 to 0.7 in 2 hours. The overall cost of ferrioxalate-induced solar photo-Fenton oxidation for the treatment of 5 m3 of latex wastewater per day was estimated to be US$85/m3.

scholarly journals Location and optimal sizing of photovoltaic sources in an isolated mini-grid

TecnoLógicas ◽  
2019 ◽  
Vol 22 (44) ◽  
pp. 61-80 ◽  
Author(s):  
Juliana Jiménez ◽  
John E. Cardona ◽  
Sandra X. Carvajal
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
Programming Model ◽  
Irradiation Time ◽  
Optimal Solution ◽  
Solar Irradiation ◽  
Mixed Integer ◽  
Voltage Profile ◽  
Power Losses ◽  
Photovoltaic Generators

This article introduces a new mixed integer linear programming model that guarantees the optimal solution to the location and sizing problem of distributed photovoltaic generators in an isolated mini-grid. The solar radiation curves of each node in the mini-grids were considered, and the main objective was to minimize electric power losses in the operation of the system. The model is non-linear in nature because some restrictions are not linear. However, this article proposes the use of linearization techniques to obtain a linear model with a global optimal solution, which can be achieved through commercial solvers; CPLEX in this case. The proposed model was tested in an isolated 14-bus mini-grid, based on real data of topology, demand and generation adapted to a balanced operation. This model shows, as a result, the optimal location of photovoltaic generators and their optimal capacity produced by the maximum active power delivered at the maximum solar irradiation time of the region. It is also evident that the hybrid operation between small hydroelectric power plants and photovoltaic generation improves the network voltage profile and the electric power losses without the use power storage systems.

scholarly journals Comparison of Pistia Stratiotes and Lemna Minor Plants Potentials in Bioremediation of Domestic Wastewater

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Hauwa Mohammed Mustafa ◽  
Dr Gasim Hayder
Keyword(s):  
Lemna Minor ◽  
Research Work ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Quality Parameters ◽  
Pistia Stratiotes ◽  
Wastewater Sample ◽  
Ammoniacal Nitrogen ◽  
Treated Water ◽  
Reduction Efficiency

Phytoremediation is an eco-friendly and cost-effective biotechnological method of wastewater treatment that involves the use of plants. In this research work, the potentials of Pistia stratiotes and Lemna minor aquatic plants in treatment of wastewater was examined. The two plants were cultivated in the wastewater sample for a period of 10 days. Water quality parameters (turbidity, chemical oxygen demand (COD), phosphate, ammoniacal nitrogen and nitrate) tests was subjected on the untreated (influent) and treated water (effluent) samples at a detention time of 24 hours. The outcome of the analysis demonstrates that P. stratiotes effluent achieved a reduction efficiency of up to 91.9%, 68%, 79.6%, and 71% for turbidity, phosphate, ammoniacal nitrogen and nitrate, respectively. Whereas for L. minor treated water samples, the highest reduction efficiency for turbidity, COD, phosphate, ammoniacal nitrogen and nitrate was found to be 87.2%, 46%, 48.7%, 83% and 56%, respectively. Hence, the overall outcome obtained indicate that P. stratiotes performed better in improving the quality of domestic wastewater compared to L. minor plants.

Effect of Ultrasonic During Preparation on Cu-Based Catalyst Performance for Hydrogenation of C02 to Methanol

2005 ◽  
Vol 5 (2) ◽  
pp. 111 ◽  
Author(s):  
M Nasikin ◽  
A Wahid
Keyword(s):  
High Pressure ◽  
Flow Reactor ◽  
Irradiation Time ◽  
Catalyst Activity ◽  
Research Work ◽  
Catalyst Preparation ◽  
Precipitation Method ◽  
Operation Condition ◽  
Gas Treatment ◽  
Co Precipitation

Indonesia is rich in natural gas resources. These resources contain hydrocarbons and impurities such as C02. C02 creates a difficulty in further gas treatment and also becomes an environmental problem. Therefore, it is needed to develop a concept to recover this kind of gas and to convert it into more useful chemicals. Catalytic hydrogenation to methanol is one of the technologies that can be considered. Conversion of C02 to methanol can be catalyzed by Cu-based catalyst. Reported tobe the best catalyst, this catalyst is selected as a catalyst for a pilot plant that is operated at a high pressure and a high temperature. However, further development is needed to rearrange the synthesis to be operated both at lower pressure and temperature. For this system, it is needed to increase its catalytic activity. One of the alternatives is to apply a catalyst preparation method using ultrasonic effect. In this research work, CuO/ZnO/AJp3 catalyst with Cr as a promoter was prepared by co-precipitation method. The effect of ultrasonic on catalyst performance, which was irradiated to the catalyst during preparation, was investigated. Co-precipitation was conducted by using carbonate salt for respective metal cations added to the catalyst. Ultrasonic wave was irradiated to the catalyst preparation chamber with 40kHZ and time variable. The characteristics of the catalyst were analyzed by BET method for surface area, while SEM and H2 chemical adsorption were conducted to determine active site dispersion. A high-pressure continuous flow reactor was used for catalyst activity and stability test. The test was conducted at an operation condition of 30 bars and 200-30QoC. The effect of ultrasonic on the CuO/ZnO/AJp3 catalyst shows that ultrasonic irradiation enhances the catalyst surface from 23 to 50 m2/g. SEM analysis shows the change of catalyst morphology to be more uniform and the catalyst particle becomes smaller. The activity test shows that the catalyst with 60 min irradiation time has the highest activity in the hydrogenation of C02 to methanol at 30 bars and at 275°C. Keywords: Hydrogenation, dispersion, methanol, and ultrasonic.

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