scholarly journals The removal of neonicotinoid insecticide imidacloprid in an annular photoreactor

2020 ◽  
Vol 7 (2) ◽  
pp. 63-69
Author(s):  
Kristina Babić ◽  
Vesna Tomašić ◽  
Ivana Grčić ◽  
Marina Duplančić ◽  
Zoran Gomzi
Keyword(s):  
High Performance ◽  
Catalyst Concentration ◽  
Heterogeneous Photocatalysis ◽  
Commercial Titanium ◽  
Photolytic Degradation ◽  
Bet Analysis ◽  
Neonicotinoid Insecticide ◽  
Watch List ◽  
Sun Light ◽  
Degree Of Degradation

Heterogeneous photocatalysis has recently attracted an increasing interest of scientists and experts who deal with the waste water and air treatment. An important area of application is removal of persistent organic pollutants, which can not be easily destroyed by conventional methods. Among these pollutants are neonicotinoid insecticides, which are widely used all over the world and currently are included in the watch list of substances of the European Commission within the Water Framework Directive. Therefore, there is a need to study their influence on the environment and to develop appropriate technologies for their removal. In this work, the photolytic and photocatalytic degradation of neonicotinoid insecticide imidacloprid in an annular photoreactor with recirculation under different working conditions (irradiation source, pH, type and concentration of the catalyst) was studied. The photolytic degradation was examined using lamps that emit UVA, UVC and simulated sun light. The photocatalytic experiments in the suspension involved the use of commercial titanium dioxide (TiO2 P25, Degussa/Evonik), commercial TiO2 P25 pre-treated with UVC irradiation prior to use in the catalytic system and nitrogen-doped TiO2 (CCR 200 N produced by Cinkarna Celje). The catalysts were characterized using XRD, UV/Vis-DRS and BET analysis. The most efficient photocatalyst was then immobilized on the glass woving fibre, using peroxotitanic acid (produced by Cinkarna Celje) as a binder. The degree of degradation of imidacloprid was determined using high performance liquid chromatography (HPLC). According to the obtained results, UVC-treated TiO2 showed the best efficiency among the examined catalysts in the slurry reactor while using lamp that simulates the sun irradiation. The imidacloprid degradation rate increases with the increase in the catalyst concentration. The immobilized UVC-treated catalyst gave satisfying results in terms of stability, activity and reuse.

scholarly journals Bioactive Glass as a Nanoporous Drug Delivery System for Teicoplanin

2020 ◽  
Vol 10 (7) ◽  
pp. 2595 ◽  
Author(s):  
Chih-Ling Huang ◽  
Wei Fang ◽  
Bo-Rui Huang ◽  
Yan-Hsiung Wang ◽  
Guo-Chung Dong ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Bioactive Glass ◽  
Drug Delivery System ◽  
Delivery System ◽  
Inductively Coupled Plasma ◽  
High Performance ◽  
Ph Value ◽  
Sol Gel ◽  
Phase Identification ◽  
Bet Analysis

Bioactive glass (BG) was made by the sol–gel method and doped with boron (B) to increase its bioactivity. Microstructures of BG and B-doped BG were observed by scanning electron microscopy, and phase identification was performed using an X-ray diffraction diffractometer. The ion concentrations released after soaking in simulated body fluid (SBF) for 1, 4, and 7 days were measured by inductively coupled plasma mass spectrometry, and the pH value of the SBF was measured after soaking samples to determine the variation in the environment. Brunauer–Emmett–Teller (BET) analysis was performed to further verify the characteristics of mesoporous structures. High performance liquid chromatography was used to evaluate the drug delivery ability of teicoplanin. Results demonstrated that B-doped BG performed significantly better than BG in parameters assessed by the BET analysis. B-doped BG has nanopores and more rough structures, which is advantageous for drug delivery as there are more porous structures available for drug adsorption. Moreover, B-doped BG was shown to be effective for keeping pH values stable and releasing B ions during soaking in SBF. The cumulative release of teicoplanin from BG and B-doped BG reached 20.09% and 3.17% on the first day, respectively. The drug release gradually slowed, reaching 29.43% and 4.83% after 7 days, respectively. The results demonstrate that the proposed bioactive glass has potential as a drug delivery system.

scholarly journals Removal of Organic Micropollutants from a Municipal Wastewater Secondary Effluent by UVA-LED Photocatalytic Ozonation

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 472 ◽  
Author(s):  
Ana M. Chávez ◽  
Ana R. Ribeiro ◽  
Nuno F. F. Moreira ◽  
Adrián M. T. Silva ◽  
Ana Rey ◽  
...  
Keyword(s):  
High Performance ◽  
Municipal Wastewater ◽  
Solid Phase ◽  
Radical Reaction ◽  
Packed Bed ◽  
Heterogeneous Photocatalysis ◽  
Packed Bed Reactor ◽  
Secondary Effluent ◽  
Organic Micropollutants ◽  
Refractory Compounds

Numerous contaminants of emerging concern (CECs) have been found in different water bodies. Directive 2013/39/EU and Decision 2018/840/EU are consequently being implemented in the field of water policies. Twelve CECs (e.g., isoproturon, ciprofloxacin, and clarithromycin are among those listed) were detected in a municipal wastewater secondary effluent by means of solid phase extraction and ultra-high-performance liquid chromatography with tandem mass spectrometry (SPE-UHPLC-MS/MS). Different advanced oxidation processes (AOPs), based on the combination of ozone, UVA-LED and powdered TiO2, were investigated for their removal in a semi-batch operation. In addition, TiO2-coated glass rings (P25R) were characterized with different techniques (SEM, WDXRF) and used for continuous mode operation in a packed bed reactor (PBR). Among the AOPs studied, ozone-based processes were found to be more efficient than heterogeneous photocatalysis. A kinetic study was performed showing that direct ozonation is the main oxidation pathway for CEC removal. Ozone was successfully decomposed in combination with UVA-LED and P25R, resulting in an apparent rate constant of 3.2 × 10−2 s−1 higher than in the O3/LED system (1.0 × 10−3 s−1) or with ozone alone (8.6 × 10−5 s−1). Hydroxyl radical reaction could prevail over direct ozone reaction for the most refractory compounds (e.g., isoproturon).

scholarly journals Photodegradation of Chloridazon Using Coreshell Magnetic Nanocompsites

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Dina Mamdouh Fouad ◽  
Mona Bakr Mohamed
Keyword(s):  
High Performance ◽  
Magnetic Nanoparticle ◽  
Chemical Methods ◽  
Tem Analysis ◽  
Photodegradation Rate ◽  
Transmission Electron ◽  
Visible Spectra ◽  
Uv Visible ◽  
Particle Size And Shape ◽  
Sun Light

A new synthesized magnetic nanoparticle of Fe3O4and coreshell Fe3O4@Au is prepared chemically. A comparative study between the photocatalytic activity between Fe3O4and core shell Au-Fe3O4nanoparticles has been studied on the effect of UV and sun light on the photodegradation of chloridazon. The particle has been prepared using chemical methods and the particle size and shape have been examined via transmission electron microscopy (TEM). Analysis of the degradation of 20 ppm chloridazon under ultraviolet (UV) and visible light was analyzed with high-performance liquid chromatography (HPLC) and UV-Visible Spectra. Influence of different parameters on the activity photodegradation rate has been studied. The results indicate that the Fe3O4@Au nanoparticles are much more active catalyst in presence of sun light than pure Fe3O4nanomaterials which have maximum absorption at 560 nm.

Removal of the neonicotinoid insecticide acetamiprid from wastewater using heterogeneous photocatalysis

2021 ◽  
pp. 1-20
Author(s):  
Katarina Licht ◽  
Vanja Kosar ◽  
Vesna Tomašić ◽  
Marina Duplančić
Keyword(s):  
Heterogeneous Photocatalysis ◽  
Neonicotinoid Insecticide

DEVELOPMENT AND VALIDATION OF A STABILITY-INDICATING RP-HPLC METHOD FOR ESTIMATION OF AMBRISENTAN AND ITS PROCESS-RELATED IMPURITIES IN BULK AND PHARMACEUTICAL DOSAGE FORMS

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (12) ◽  
pp. 34-41
Author(s):  
S. K Kondila ◽  
◽  
K Sujana ◽  
A Prameela Rani
Keyword(s):  
High Performance ◽  
Reversed Phase ◽  
Dosage Forms ◽  
Hplc Method ◽  
Forced Degradation ◽  
Chromatography Method ◽  
Pharmaceutical Dosage Forms ◽  
Stability Indicating ◽  
Photolytic Degradation ◽  
Acid And Base

The aim of the present work was to develop and validate an accurate, precise, simple, and efficient stability indicating Reversed phase High Performance Liquid Chromatography method for determination of an abrisentan and its process impurities in bulk and pharmaceutical dosage forms. The drug substance was subjected to stress conditions such as hydrolysis (acid and base), oxidation, photolysis and thermal degradation as per International Conference on Harmonization guidelines to study the stability-indicating profile of drug. Significant degradation was observed during acid hydrolysis and peroxide degradation. The chromatographic conditions were optimized using an impurity-spiked solution and samples generated from forced degradation studies. The method was developed using Agilent XDB-C18 (150×4.5mm, 5μ) column and 10mM NH4OAc (pH-5.2 adjusted with acetic acid): ACN as the mobile phase with gradient programme at a flow rate of 1 mL/min. effluents were monitored at 289 nm. The retention times were found as 25.945 min for IMP-1, 24.685 min for IMP-2, 23.83 min for IMP-3, 10.53 min for AMB, 5011 min for IMP-4 and 3.48 min for IMP-5. The mean recovery values were found to be 98.52-100.44% for AMD and its impurities. The degradation rate of AMB in acid, base, peroxide (oxidative) thermal and photolytic degradation processes was found in range 7-22%. The developed analytical method has been validated for specificity, linearity, precision, accuracy, and robustness which were within the acceptance limit according to ICH guidelines. The developed method was successfully employed for routine quality control and stability analysis of AMB in pharmaceutical dosage forms.

scholarly journals Determination of Ketorolac in the Effluent from a Hospital Treating Plant and Kinetics Study of Its Photolytic Degradation

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Hector Hugo Ortega Soto ◽  
Jorge Javier Ramírez García ◽  
Paula Gamboa Suárez ◽  
Angie Michelle Dávila Estrada
Keyword(s):  
High Performance ◽  
Solid Phase ◽  
Degradation Kinetics ◽  
Treatment Plant ◽  
Order Model ◽  
Dark Chamber ◽  
First Order ◽  
Photolytic Degradation ◽  
Wastewater Samples

In this work, two specific, sensitive, and rapid analytical methods were developed. One of them was for the determination of ketorolac in a hospital wastewater treatment plant where there is no interference with other organic substances; the other one was for the determination of the degradation kinetics in aqueous medium. Ketorolac was extracted from wastewater samples through solid-phase extraction (SPE) cartridges, then it was identified and quantified by high-performance liquid chromatography (HPLC). Ketorolac was detected in concentrations between 0.1376 and 0.2667 μg/L. Photolytic degradation was performed on aqueous solutions of ketorolac tromethamine reference substance, at a concentration of 50 μg/mL. Samples were in direct contact with ultraviolet light in a dark chamber, equipped with two mercury lamps (254 nm) at a radiation source of 15 W. The results of the photolytic degradation were adjusted to a first-order model, obtaining a half-life of 4.8 hrs.

SYNTHESIS AND CHARACTERIZATION OF Si3N4@Al(OH)3–Y(OH)3 CORE-SHELL COMPOSITE PARTIC3LES

2008 ◽  
Vol 15 (05) ◽  
pp. 581-585 ◽  
Author(s):  
JIE-GUANG SONG ◽  
GANG-CHANG JI ◽  
SHI-BIN LI ◽  
LIAN-MENG ZHANG
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Ceramic Materials ◽  
Composite Particles ◽  
Core Shell ◽  
High Temperature Strength ◽  
Bet Analysis ◽  
Co Precipitation ◽  
Shell Composite

Silicon nitride ( Si 3 N 4) has attracted substantial interest because of its extreme chemical and physical properties, but the sintering densification of Si 3 N 4 is difficult, and it is easily oxidized in the high-temperature air to impact high-temperature strength, which restricts its applied range. In order to decrease the oxidization and improve the strength of Si 3 N 4 at high temperature, the surface of Si 3 N 4 is coated with Al ( OH )3 and Y ( OH )3 to synthesis Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite particles. Through TEM, XRD, and BET analysis, when pH is about 9, Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite particles are successfully synthesized by co-precipitation methods. Coating layer is about 200 nm, which is compaction and conformability. Dispersion of coated Si 3 N 4 with Al ( OH )3 and Y ( OH )3 particles are very good. Synthesis of Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite powder will lay the foundation for preparing high-performance YAG/Si 3 N 4 multiphase ceramic materials.

scholarly journals Function ofTiO2Lattice Defects toward Photocatalytic Processes: View of Electronic Driven Force

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Huanan Cui ◽  
Hong Liu ◽  
Jianying Shi ◽  
Chuan Wang
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Great Influence ◽  
Heterogeneous Photocatalysis ◽  
Charge Carriers ◽  
Energy Structure ◽  
Practical Applications ◽  
Short Range Force ◽  
Surface Active ◽  
Photocatalytic Reactions

Oxygen vacancies and Ti-related defects (OTDs) are the main lattice defects ofTiO2, which have great influence on its photocatalytic activity. To understand the relationship between the defects and photocatalytic activities, detailed discussions based on the electronic driven force provided by these defects are carried out during the three commonly accepted processes in photocatalytic reactions. It is found that these defects inevitably (i) influence the energy structure of the pristineTiO2as the isolate acceptor/donor level or hybrid with the original orbital, (ii) provide a disordered short-range force that confuses the charge carriers transferring to surface active sites, (iii) act not only as the surface active sites for trapping the charge carriers but also as the main chemisorption sites forO2,H2O, and organic species. These effects of the defects make them one of the key factors that determine the efficiency of heterogeneous photocatalysis. Clarifying the role of the defects will further facilitate the exploration and the construction of high-performance photocatalysts for practical applications.

scholarly journals Photocatalytic degradation of an organophosphorus pesticide from agricultural waste by immobilized TiO2 under solar radiation

2016 ◽  
Vol 11 (4) ◽  
pp. 778
Author(s):  
Marcia Regina Assalin ◽  
Vera Lucia Ferracini ◽  
Sonia Claudia Nascimento Queiroz ◽  
Cláudio Martin Jonsson ◽  
Zaira Clemente ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
High Performance ◽  
Methyl Parathion ◽  
Agricultural Waste ◽  
Organophosphorus Pesticide ◽  
Artemia Salina ◽  
Heterogeneous Photocatalysis ◽  
Photocatalytic Process ◽  
Toc Removal ◽  
Immobilized Tio2

This paper describes solar heterogeneous photocatalysis using immobilized TiO2 applied in the treatment of agricultural waste resulting from the application of commercial formulations of methyl parathion. The disappearance of the insecticide, as well as the formation of its metabolite, was monitored by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), while mineralization efficiency was monitored by measurements of total organic carbon (TOC). Toxicity studies were performed using the microcrustacean Artemia salina. The TOC removal efficiency by photocatalytic process was 48.5%. After 45 minutes of treatment, the removal efficiency of methyl parathion was 90%, being completely mineralized at the end of treatment. The formation and removal of the metabolite methyl paraoxon was observed during the photocatalytic process. The photocatalytic treatment resulted in increased microcrustacean mobility, indicating a reduction of acute toxicity.

VALIDATED STABILITY INDICATING HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHIC METHOD FOR REPAGLINIDE API

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (09) ◽  
pp. 48-54
Author(s):  
P. P. Thakkar ◽  
◽  
N. R Patel ◽  
C. S Kothari ◽  
R Patel ◽  
...  
Keyword(s):  
Thin Layer ◽  
High Performance ◽  
Chromatographic Method ◽  
Degradation Products ◽  
Linear Regression Analysis ◽  
Tablet Formulation ◽  
Content Uniformity ◽  
Calibration Data ◽  
Stability Indicating ◽  
Photolytic Degradation

A simple, precise and accurate stability-indicating high performance thin layer chromatographic method for estimation of repaglinide in bulk drug and in tablet formulation has been developed and validated. The stationary phase used was HPTLC plates precoated with silica gel 60F254 using the mobile phase of chloroform: methanol: ammonia (4.5:1.0:0.05 V/V/V). Densitometric analysis was performed in absorbance mode at 242 nm. The method showed compact bands of drug at RF value of 0.31 ± 0.02. Linear Regression analysis of calibration data showed good linear relationship with r2= 0.9981 in concentration range of 500 - 3000 ng/band. Drug was subjected to ICH-prescribed stress conditions such as acid, base, peroxide, thermal and photolytic degradation and method was found able to separate the peaks for all degradation products from analyte peak. Validation of the developed method was carried out for its specificity, linearity, range, precision, accuracy and robustness. The method was further applied for repaglinide estimation in pharmaceutical tablet formulation and it was found to be reliable. The method was also used successfully to carry out content uniformity test of repaglinide in tablet dosage form.

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