Adsorption and photocatalytic degradation of metaldehyde in aqueous solution

2015 ◽  
Vol 15 (3) ◽  
pp. 533-540
Author(s):  
Jong Kyu Kim ◽  
Luiza Cintra Campos
Keyword(s):  
Photocatalytic Degradation ◽  
Degradation Rate ◽  
Batch Reactor ◽  
Degradation Process ◽  
Underground Water ◽  
Heterogeneous Photocatalysis ◽  
Ph Values ◽  
Treatment Processes ◽  
Ultraviolet C ◽  
Nanosized Zno

Metaldehyde is best known as the main constituent of slug pellets. This organic compound has been found in relatively high levels in both surface and underground water. While many water treatment processes do not work with metaldehyde degradation, a photocatalytic degradation process has been proved to have a significant effect on metaldehyde stability. Nanosized ZnO/laponite composite (NZLC) was used as a photocatalyst in this investigation of metaldehyde degradation. The reactions were carried out in a ultraviolet C (UVC) lamp fitted batch reactor by considering the following parameters: initial metaldehyde concentration, pH of solution, and light intensity. A comparison of degradation efficiency between photolysis, photocatalysis, and adsorptive ability on NZLC indicated that the latter had the highest efficiency. Furthermore, higher metaldehyde degradation was observed as the initial concentration decreased. However, the fastest metaldehyde degradation rate in heterogeneous photocatalysis was obtained when pH values were greater than 7.0. Consequently, the findings suggest that the removal of metaldehyde by adsorption and photocatalytic degradation using NZLC under UV irradiation was a hybrid reaction process (i.e. photolysis, adsorption, and photocatalysis).

scholarly journals Degradation of Direct Blue 1 through Heterogeneous Photocatalysis with TiO2 Irradiated with E-Beam

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1181
Author(s):  
Elvia Gallegos ◽  
Florinella Muñoz Bisesti ◽  
Katherine Vaca-Escobar ◽  
Cristian Santacruz ◽  
Lenys Fernández ◽  
...  
Keyword(s):  
Rate Constant ◽  
Textile Industry ◽  
Adsorption Process ◽  
Batch Reactor ◽  
Degradation Process ◽  
Heterogeneous Photocatalysis ◽  
Photodegradation Rate ◽  
Direct Blue ◽  
Degradation Rate Constant ◽  
Different Doses

Most dyes used in the textile industry are chemically stable and poorly biodegradable, therefore, they are persistent in the environment and difficult to degrade by conventional methods. An alternative treatment for this kind of substance is heterogeneous photocatalysis using TiO2, so, in this work, it is proposed to degrade Direct Blue 1 (DB1) using microparticulate TiO2 irradiated with e-beam at three different doses: 5, 10 and 20 kGy (J/kg). The DB1 degradation was implemented in a batch reactor (DB1 initial concentration = 50 mg L−1, pH 2.5, TiO2 concentration = 200 mg L−1). We have demonstrated that the photocatalytic power of TiO2, when irradiated with e-beam (5, 10, 20 kGy), varies slightly, with minor effects on photodegradation performance. However, the dose of 10 kGy showed a slightly better result, according to the DB1 photodegradation rate constant. Adsorption process was not affected by irradiation; its isotherm was fitted to Freundlich’s mathematical model. The DB1 photodegradation rate constants, after one hour of treatment, were: 0.0661 and 0.0742 min−1 for irradiated (10 kGy) and nonirradiated TiO2, respectively. The degradation rate constant has an increase of 12.3% for irradiated TiO2. Finally, there was no evidence of mineralization in the degradation process after 60 min of treatment. According to the results, the irradiation of microparticulate TiO2 with e-beam (10 kGy) slightly improves the photodegradation rate constant of DB1.

Photocatalytic removal of taste and odour compounds for drinking water treatment

2009 ◽  
Vol 9 (5) ◽  
pp. 477-483 ◽  
Author(s):  
H. Tran ◽  
G. M. Evans ◽  
Y. Yan ◽  
A. V. Nguyen
Keyword(s):  
Drinking Water ◽  
Sodium Bicarbonate ◽  
Photocatalytic Degradation ◽  
Rate Constants ◽  
Degradation Rate ◽  
Degradation Mechanism ◽  
Drinking Water Treatment ◽  
Degradation Process ◽  
Negative Effects ◽  
Reaction Rate Constants

Photocatalytic degradation of geosmin and 2-methylisoborneol (MIB), which are two taste and odour compounds commonly found in drinking water supply sources, was investigated using an immobilised TiO2 photoreactor. It was found that the degradation of geosmin and MIB followed similar pseudo-first-order kinetics with reaction rate constants being approximately 0.025 min−1 for typical geosmin and MIB concentrations of 250 and 500 ng/L. The normalised formal quantum efficiency was calculated to be in the range of 162–182 L/mol. Influence of additives (i.e. sodium bicarbonate and alcohols) on the degradation process was also investigated. It was found that there was a small reduction in the degradation rate constants of geosmin and MIB with increasing sodium bicarbonate concentration. At 50 mg/L sodium bicarbonate the degradation rate constants decreased by approximately 5%. Similarly, for methanol and ethanol concentrations up to 35 and 50 mg/L, respectively, these constants were found to also decrease. While addition of sodium bicarbonate and alcohols was seen to have relatively small negative effects on the photocatalytic degradation performance, the magnitude of their influence was consistent with the hypothesis that the degradation mechanism of geosmin and MIB was predominately that of attack involving HO∙ radicals.

scholarly journals Photocatalytic Degradation of Acid Yellow 36 Using Zinc Oxide Photocatalyst in Aqueous Media

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sajjad Khezrianjoo ◽  
Hosakere Doddarevanna Revanasiddappa
Keyword(s):  
Photocatalytic Degradation ◽  
Catalyst Concentration ◽  
Heterogeneous Medium ◽  
Batch Reactor ◽  
Aqueous Media ◽  
Electrical Energy ◽  
Degradation Process ◽  
Active Species ◽  
Catalyst Loading ◽  
Order Of Magnitude

A detailed investigation of photocatalytic degradation of Acid Yellow 36 (AY36) has been carried out in aqueous heterogeneous medium containing ZnO as photocatalyst in a batch reactor. The effects of some parameters such as pH, catalyst loading, and ethanol concentration were examined. Solutions with initial concentration of 50 mg L−1 of dye, within the range of typical concentration in textile wastewaters, were treated at natural pH of 6.93 and catalyst concentration of 1 g L−1 after 180 min irradiation. Investigations on the active species indicated that hydroxyl radicals play the major role in the process. Experiments showed that the most efficient pH on the removal of the dye with photocatalytic degradation process was 8; however, acidic pH was favored for the dark surface adsorption. Electrical energy consumption per order of magnitude for photocatalytic degradation of AY36 has been also determined.

The Effect of Different Ions on Photodegradation Rhodamine B in TiO2 Suspension Liquid

2013 ◽  
Vol 807-809 ◽  
pp. 2739-2742
Author(s):  
Peng Wei Huo ◽  
Mao Bin Wei ◽  
Xin Lin Liu ◽  
Dan Dan Wang ◽  
Zi Yang Lu ◽  
...  
Keyword(s):  
Waste Water ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Degradation Rate ◽  
Ph Value ◽  
Degradation Process ◽  
Photocatalytic Process ◽  
Negative Effect ◽  
Anions And Cations

The photocatalytic degradation process of waste water was usually influenced by many factors, such as different ions, addition reagent and pH value. In order to investigate the effect of ions strength in the photocatalytic process, the anions and cations were systematically investigated with P25 TiO2 photocatalyst with Rhodamine B (RB) as waste water in this work. The results showed that the cations of low valence showed minimum negative effect on degradation rate and the most anions showed enhance the degradation rate of RB. The ions strength showed random in the photocatalytic process.

scholarly journals Photocatalytic degradation of Bisphenol A: Kinetic studies and determination of the reaction pathway

2018 ◽  
Vol 16 (5) ◽  
Author(s):  
Luis F. Garay Rodríguez ◽  
Brenda Zermeño ◽  
Karla Alejandra López De la O ◽  
Elisa Leyva ◽  
Edgar Moctezuma
Keyword(s):  
Aqueous Solutions ◽  
Photocatalytic Degradation ◽  
Reaction Rate ◽  
Reaction Pathway ◽  
Batch Reactor ◽  
Analytical Techniques ◽  
Kinetic Studies ◽  
Degradation Process ◽  
Reaction Products ◽  
Uv Lamps

The photocatalytic degradation of BPA aqueous solutions with commercial TiO2 (Evonik P25) was carried out in a home-made batch reactor illuminated with four UV lamps (λmax= 365 nm) in order to determine the kinetic parameters of the reaction rate equation and to identify and quantify some of the most stable aromatic intermediate reaction products. Low concentration (20 ppm) BPA solutions were completely degraded and mineralized in less than three hours of reaction. Whereas, BPA aqueous solutions with concentration above 50 ppm are transformed in other chemical compounds in 6 hours of reaction and fully mineralized in 15 hours of reaction. Kinetic analysis of the experimental results of BPA concentration as a function of time indicated that this photocatalytic degradation process follows a LH-HW reaction rate law where the reaction order shift from zero order to first order as the reactant concentration is decreased. Analysis of the reaction samples by different analytical techniques indicated that BPA is mineralized via formation of hydroquinone, benzoquinone, benzene-triol, catechol, and phenol by two simultaneous reaction pathways.

scholarly journals Modeling and optimization of the photocatalytic degradation of Tartrazine in aqueous solution

2021 ◽  
pp. 133-145
Author(s):  
Mirvet Assassi ◽  
Farid Madjene ◽  
Sara Harchouche ◽  
Hind Boulfiza
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Heterogeneous Photocatalysis ◽  
Active Species ◽  
Influential Factor ◽  
Solar Irradiation ◽  
Uv Lamp ◽  
Positive Effect

The application of heterogeneous photocatalysis process using ZnO photocatalyst for the degradation of Tartrazine (TRZ) dye in aqueous solution was investigated in a batch reactor. The estimation, the comparison of the parameter?s effects and the optimization of the removal yield of TRZ were realized by using Box-Behnken experimental design (BBD). The results suggested that the most influential factor on the photocatalytic degradation of the dye was the initial TZR concentration with an effect of (-23.24), the second in the order was the amount of the catalyst with an effect of (+18.09), the third was the reaction time with an effect of (+15.38) and the fourth was stirring speed with a positive effect of (+4.41). The model obtained by BBD led to the following optimal conditions for degradation yield of TRZ: initial concentration of TZR equal to 20.035 mg/L, reaction time equal to 88.635 min, 0.6409 mg/L of ZnO amount and 404.9 rpm for the stirring speed, which gave 98.576% of degradation efficiency. The study of irradiation type effect shows that a solar irradiation gave higher yield than photocatalysis by UV lamp. The O2?- radicals were the principal active species responsible of the degradation of TRZ. The BOD5/COD ratio increased from 0.26 to 0.41 after 60 minutes of photocatalysis under solar light, indicating the feasibility of coupling the photocatalysis process to biological treatment for the removal of TRZ.

Photocatalytic degradation of methylene blue from aqueous solutions using nanopillars-TiO2 thin films: Batch reactor studies

2018 ◽  
Vol 18 (3) ◽  
pp. 81-91 ◽  
Author(s):  
C. Lalhriatpuia
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Organic Carbon ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Tio2 Thin Films ◽  
Initial Concentration ◽  
Bet Specific Surface Area ◽  
Interfering Ions

Nanopillars-TiO2 thin films was obtained on a borosilicate glass substrate with (S1) and without (S2) polyethylene glycol as template. The photocatalytic behaviour of S1 and S2 thin films was assessed inthe degradation of methylene blue (MB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the SEM, XRD, FTIR and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data confirmed that the TiO2 particles are in its anatase mineral phase. The SEM and AFM images indicated the catalyst is composed with nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of MB was well studied at wide range of physico-chemical parameters. The effect of solution pH (pH 4.0 to 10.0) and MB initial concentration (1.0 to 10.0 mg/L) was extensively studied and the effect of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of MB was demonstrated. The maximum percent removal of MB was observed at pH 8.0 beyond which it started decreasing and a low initial concentration of the pollutant highly favoured the photocatalytic degradation using thin films and the presence of several interfering ions diminished the photocatalytic activity of thin films to some extent. The overall photocatalytic activity was in the order: S2 > S1 > UV. The photocatalytic degradation of MB was followed the pseudo-first-order rate kinetics. The mineralization of MB was studied with total organic carbon measurement using the TOC (total organic carbon) analysis.

Use of Nanopillars-TiO2 Thin Films in the Photocatalytic Degradation of Bromophenol Blue from Aqueous Solution

2018 ◽  
Vol 6 (1) ◽  
pp. 22-30
Author(s):  
C. Lalhriatpuia ◽  
◽  
Thanhming liana ◽  
K. Vanlaldinpuia
Keyword(s):  
Thin Films ◽  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Bromophenol Blue ◽  
Tio2 Thin Films ◽  
Initial Concentration ◽  
Bet Specific Surface Area ◽  
Interfering Ions

The photocatalytic activity of Nanopillars-TiO2 thin films was assessed in the degradation of Bromophenol blue (BPB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the XRD, SEM and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data showed anatase phase of TiO2 particles with average particle size of 25.4 and 21.9 nm, for S1 and S2 catalysts respectively. The SEM and AFM images indicated the catalyst composed with Nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The average height of the pillars was found to be 180 and 40 nm respectively for the S1 and S2 catalyst. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of BPB using the UV light was studied at wide range of physico-chemical parametric studies to determine the mechanism of degradation as well as the practical applicability of the technique. The batch reactor operations were conducted at varied pH (pH 4.0 to 10.0), BPB initial concentration (1.0 to 20.0 mg/L) and presence of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of BPB. The maximum percent removal of BPB was observed at pH 6.0 and a low initial concentration of the pollutant highly favours the photocatalytic degradation using thin films. The presence of several interfering ions suppressed the photocatalytic activity of thin films to some extent. The time dependence photocatalytic degradation of BPB was demonstrated with the pseudo-first-order rate kinetics. Study was further extended with total organic carbon measurement using the TOC (Total Organic Carbon) analysis. This demonstrated an apparent mineralization of BPB from aqueous solutions.

scholarly journals Photocatalytic Treatment of Wastewater Containing Simultaneous Organic and Inorganic Pollution: Competition and Operating Parameters Effects

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 855
Author(s):  
Ahmed Amine Azzaz ◽  
Salah Jellali ◽  
Nasser Ben Harharah Hamed ◽  
Atef El Jery ◽  
Lotfi Khezami ◽  
...  
Keyword(s):  
Ultra Violet ◽  
Degradation Process ◽  
Molar Ratio ◽  
Experimental Conditions ◽  
Retention Capacity ◽  
Isotherm Study ◽  
Related Data ◽  
Ph Values ◽  
Pseudo Second Order ◽  
Maximum Retention

In the present study, methylene blue (MB) removal from aqueous solutions via the photocatalytic process using TiO2 as a catalyst in the presence of external ultra-violet light (UV) was investigated. The results of adsorption in the absence of UV radiation showed that adsorption reached an equilibrium state at 60 min. The experimental kinetic data were found to be well fitted by the pseudo-second-order model. Furthermore, the isotherm study suggested that dye uptake by TiO2 is a chemisorption process with a maximum retention capacity of 34.0 mg/g. The photodegradation of MB was then assessed under various experimental conditions. The related data showed that dye mineralization decreased when dye concentrations were increased and was favored at high pH values and low salt concentrations. The simultaneous presence of organic and inorganic pollution (Zinc) was also evaluated. The effect of the molar ratio Zn2+/MB+ in the solution at different pH values and NaCl concentrations was also monitored. The corresponding experimental results showed that at low values of Zn2+ in the solution (30 mg/L), the kinetic of the MB removal became faster until reaching an optimum at Zn2+/MB+ concentrations of 60/60 mg/L; it then slowed down for higher concentrations. The solutions’ carbon contents were measured during the degradation process and showed total mineralization after about 5 h for the optimal Zn2+/MB+ condition.

scholarly journals Preparation of Ti-Nb-Fe-O Nanotubes on Ti10NbxFe Alloy and the Application for Photocatalytic Degradation under Solar Irradiation

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 327
Author(s):  
Yujie Zhao ◽  
Qiquan Li ◽  
Yan Li
Keyword(s):  
Photocatalytic Degradation ◽  
Mixed Oxide ◽  
Tio2 Nanotubes ◽  
Degradation Rate ◽  
Solar Irradiation ◽  
Methylene Blue Degradation ◽  
Co Doping ◽  
Secondary Pollution ◽  
The Rich ◽  
Thick Layers

Highly oriented and self-ordered titanium-niobium-iron mixed oxide nanotubes were synthesized by anodizing Ti10NbxFe alloys in ethylene glycol electrolytes containing NH4F and water at 20 °C. The nanostructure morphologies were found to depend closely on the nature of the alloy substrates. The results demonstrate the possibility of growing mixed oxide nanotubes possessing several-micrometer-thick layers by a simple and straightforward electrochemical route. The methylene blue degradation rate of fabricated Ti-Nb-Fe-O nanotubes increased by 33% compared to TiO2 nanotubes and TiO2 nanoparticle films under solar irradiation. The combination of the gully-like morphology and the rich defects introduced by Nb and Fe co-doping in Ti-Nb-Fe-O mixed nanotube oxides was demonstrated to be beneficial for enhanced photocatalytic degradation performance. Ti-Nb-Fe-O nanotubes can achieve effective photodegradation without secondary pollution with more reusability than powder photocatalysts.

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