scholarly journals Improving the Imazapyr Degradation by Photocatalytic Ozonation: A Comparative Study with Different Oxidative Chemical Processes

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1446
Author(s):  
Salma Bougarrani ◽  
Zakarya Baicha ◽  
Lahbib Latrach ◽  
Mohammed El Mahi ◽  
Francisco José Hernandez Fernandez
Keyword(s):  
Removal Efficiency ◽  
Ozone Concentration ◽  
Organic Contaminants ◽  
Synergistic Effects ◽  
Heterogeneous Photocatalysis ◽  
Operational Conditions ◽  
Oxidation Processes ◽  
First Order ◽  
Photocatalytic Ozonation ◽  
Constant Rate

The degradation of imazapyr (C13H15N3O3), an active element in the aqueous solution of commercial herbicide, was investigated. This study was the first to evaluate in a comprehensive manner the efficiency of advanced oxidation processes for imazapyr degradation. Results showed that Imazapyr degradation is significantly affected by operational conditions such as TiO2 concentration, ozone concentration, initial concentration of imazapyr and pH. The kinetics of Imazapyr consumption was the first order with respect to Imazapyr concentration and zero order with respect to ozone concentration with a constant rate of 0.247 min−1 and 0.128 min−1 for photocatalytic ozonation and heterogeneous photocatalysis, while it was the first order with respect to Imazapyr and the first order with respect to ozone concentrations when only ozone was used with a constant rate of 0.053 mol L−1 min−1 at pH 7. The results revealed that more than 90 percent of the removal efficiency representing the elimination of imazapyr was held up to 7 μM. Further increase in the concentration of imazapyr leads to a drop in the removal efficiency, however the total imazapyr degradation was reached in 20 min utilizing photocatalytic ozonation for 5 μM of Imazapyr in the presence of 100 mg L−1 of TiO2, 10 mg L−1 of ozone at pH 7. Photocatalytic ozonation and heterogeneous photocatalysis utilizing TiO2 as a semiconductor process appeared possible and well suited for the treatment of organic contaminants such as imazapyr herbicides, although at certain dosages of pH and common time for wastewater treatment, imazapyr was not degraded with ozonation on its own. The association of two oxidation processes, ozonation and photocatalysis, has improved oxidation efficiencies for water treatment under optimal conditions, leading to the development of non-selective hydroxyl and more reactive radicals in the oxidation medium, as well as the resulting synergistic effects between photocatalysis and ozonation that react more rapidly with imazapyr herbicide.

Photocatalysis (TiO2/Solar) in Water and Wastewater Treatment

2019 ◽  
pp. 171-199
Author(s):  
Nurul Aiin Ab Aziz ◽  
Puganeshwary Palaniandy
Keyword(s):  
Wastewater Treatment ◽  
Water Treatment ◽  
Organic Contaminants ◽  
Advanced Oxidation ◽  
Heterogeneous Photocatalysis ◽  
Complete Oxidation ◽  
Water And Wastewater Treatment ◽  
Oxidation Processes ◽  
Process Characteristics ◽  
Water And Wastewater

Advanced oxidation processes (AOPs) have gained growing importance for the removal of organic pollutants from water. Heterogeneous photocatalysis has been rapidly expanding for water treatment. This approach has economic and sustainability advantages compared with other processes. The main advantage of this process is its capability to gain complete oxidation or mineralization of organic contaminants at conditions of near ambient temperature and pressure. This chapter aims to review the mechanism involved in this process, characteristics of semiconductor photocatalyst, difference between suspended and immobilized photocatalyst system, comparison between the use of natural sunlight and commercial lamp, also the reactor involved. Potential advantages and limitations, as well as the application of photocatalysis in water and wastewater are also discussed.

scholarly journals Evaluation of combined radiation for the treatment of lamivudine and zidovudine via AOP

2021 ◽  
pp. 29-29
Author(s):  
Alex Leandro Lucena ◽  
Rayany Magali da Rocha Santana ◽  
Marcos André Oliveira ◽  
Luciano Costa Almeida ◽  
Marta Maria Bezerra Duarte Duarte ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Environmental Problem ◽  
Aqueous Media ◽  
Kinetic Studies ◽  
Toxicity Tests ◽  
Operational Conditions ◽  
Oxidation Processes ◽  
First Order ◽  
Uv C ◽  
By Products

The presence of pharmaceutical contaminants in nature is an environmental problem generating increasing concerns. Due to this, it is necessary to evaluate treatments that are capable of degrading these contaminants, such as the advanced oxidation processes (AOP). In this work, the photoperoxidation and photo-Fenton AOP were applied to degrade a mixture of the drugs lamivudine and zidovudine, in aqueous medium and synthetic effluent (SE). To this end, a bench reactor (UV-C; UV-A and sunlight irradiations) was built. The AOP treatments efficiency was evaluated by ultraviolet/visible spectrophotometry. The tests involved the application of the irradiations individually and combined. The best operational conditions were [H2O2] of 600 mg.L-1 and [Fe] of 0.5 mg.L-1, for both matrices, with degradations of 90.53% and 89.32% for the photoperoxidation and photo-Fenton processes in aqueous media and 88.69% and 85.79% in SE. Kinetic studies showed a good fit for two pseudo-first order models with R2 > 0.93. Toxicity tests involving the application of lettuce, carrot, and tomato seeds showed an inhibition for the three seeds when submitted to solutions after treatment, for both matrices, this fact is corroborated by the HPLC analysis, in which the formation of small peaks was verified, suggestive of the formation of by-products. Thus, it can be affirmed that both photo-Fenton and photoperoxidation processes are efficient to degrade the drug mixture when applying UV-C radiation.

Nanotechnology: a clean and sustainable technology for the degradation of pharmaceuticals present in water and wastewater

2016 ◽  
Vol 31 (1) ◽  
Author(s):  
Rengaraj Selvaraj ◽  
Tharaya Al Fahdi ◽  
Bushra Al-Wahaibi ◽  
Salma M.Z. Al-Kindy ◽  
Kholood Al-Nofli ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Advanced Oxidation Processes ◽  
Wastewater Treatment Plants ◽  
Environmental Pollutants ◽  
Heterogeneous Photocatalysis ◽  
Aquatic Environments ◽  
Oxidation Processes ◽  
Residential Communities ◽  
Solar Light Irradiation ◽  
Water And Wastewater

AbstractPharmaceuticals, newly recognized classes of environmental pollutants, are becoming increasingly problematic contaminants of either surface water or ground water around industrial and residential communities. Pharmaceuticals are constantly released into aquatic environments, mainly due to their widespread consumption and complicated removal in wastewater treatment plants. Heterogeneous photocatalysis appear to be one of the most destructive advanced oxidation processes (AOPs) for organic contaminants and are possible to obtain complete mineralization of organic pollutants into eco-friendly end products under visible and solar light irradiation. In this study, flower-like In

scholarly journals Removal of Contaminants of Emerging Concern (CECs) Using a Membrane Bioreactor (MBR): a short review

2019 ◽  
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Membrane Bioreactor ◽  
Emerging Contaminants ◽  
Synergistic Effects ◽  
Aquatic Organisms ◽  
Endocrine Disrupting Compounds ◽  
Short Review ◽  
Contaminants Of Emerging Concern ◽  
Operational Conditions

<p>Contaminants of emerging concern (CECs), such as pharmaceuticals and personal care products (PPCPs) and as endocrine disrupting compounds, have recently recognized as the next set of pollutants due to their toxic effects on human health and aquatic organisms at very low concentrations. One of effective methods to remove these emerging contaminants present in the aquatic environment is a membrane bioreactor (MBR). In this review, 27 CECs belonged to diverse categories of PPCPs were surveyed from the point of view of the removal efficiency by several types of MBR modules with various operational conditions, such as a type of MBR, hydraulic retention time and sludge retention time. As a result, this review provided the overall ranges in the removal efficiency of 27 CECs by different MBR filtrations and modules. Certain categories of PPCPs such as analgesics/anti-inflammatory drugs (acetaminophen and ibuprofen), steroids/hormones (estriol and testosterone) and stimulant (caffeine) have relatively higher removal rates, while antimicrobial agent (TCEP) is rarely removed in the different MBRs. For further implementation of CEC removal by a MBR system, physical characteristics/biological fate of a wide variety of CECs, individual/synergistic effects which may occur during MBR operation, and application of advanced MBR technologies should be studied.</p>

Submerged upflow biotower operation and computer simulation

1994 ◽  
Vol 30 (11) ◽  
pp. 143-146
Author(s):  
Ronald D. Neufeld ◽  
Christopher A. Badali ◽  
Dennis Powers ◽  
Christopher Carson
Keyword(s):  
Computer Simulation ◽  
Benzoic Acid ◽  
Computer Model ◽  
Rate Constants ◽  
Batch Mode ◽  
Operational Conditions ◽  
First Order ◽  
Low Concentrations ◽  
Biological Transformation ◽  
Kinetics Of

A two step operation is proposed for the biodegradation of low concentrations (&lt; 10 mg/L) of BETX substances in an up flow submerged biotower configuration. Step 1 involves growth of a lush biofilm using benzoic acid in a batch mode. Step 2 involves a longer term biological transformation of BETX. Kinetics of biotransformations are modeled using first order assumptions, with rate constants being a function of benzoic acid dosages used in Step 1. A calibrated computer model is developed and presented to predict the degree of transformation and biomass level throughout the tower under a variety of inlet and design operational conditions.

scholarly journals Degradation of the pharmaceuticals lamivudine and zidovudine using advanced oxidation processes

2020 ◽  
Vol 42 ◽  
pp. e9
Author(s):  
Alex Leandro Andrade de Lucena ◽  
Daniella Carla Napoleão ◽  
Hélder Vinícius Carneiro da Silva ◽  
Rayany Magali da Rocha Santana ◽  
Beatriz Galdino Ribeiro ◽  
...  
Keyword(s):  
Lactuca Sativa ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Kinetic Studies ◽  
Degradation Process ◽  
Oxidation Processes ◽  
First Order ◽  
Input Variables ◽  
Pharmaceutical Degradation ◽  
Uv C

The existence of pharmaceuticals in nature is a growing environmental problem, turning necessary the use of efficient treatments for the degradation of these substances, as the advanced oxidation processes (AOPs). In this work the AOPs UV/H2O2 and photo-Fenton were applied to degrade the pharmaceuticals lamivudine and zidovudine in an aqueous solution using a bench reactor, composed of three UV-C lamps. It was verified that the UV/H2O2 process presented a degradation of 97.33 ± 0.14% for lamivudine and 93.90 ± 0.33% for zidovudine, after 180 min of treatment and for an initial concentratin of each pharmaceutical of  5 mg.L-1 and [H2O2] of 600 mg.L-1.  A methodology by artificial neural networks (ANNs) was used to model the photocatalytic process, with the MLP 7-23-2 ANN representing it well, and determining the relative importance (%) of each of the input variables for the pharmaceutical’s degradation process. Kinetic studies for the pharmaceutical degradation and the conversion of organic matter showed good adjustments to the pseudo first-order models with R2 raging from 0.9705 to 0.9980. Toxicity assays for the before treatment solution indicated that the seeds Lactuca sativa and Portulaca grandiflora showed growth inhibition whereas the post-treatment solution inhibited only the growth of Lactuca sativa.

scholarly journals Evaluation of the degradation potential of different advanced oxidation processes for a textile dye mixture: a kinetic study with mathematical modeling and toxicological tests

2020 ◽  
Vol 42 ◽  
pp. e7
Author(s):  
Joanna Cysneiros Silva ◽  
Rayany Magali da Rocha Santana ◽  
Graziele Elisandra do Nascimento ◽  
Alex Leandro Andrade de Lucena ◽  
Ana Maria Ribeiro Bastos da Silva ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Treatment Process ◽  
Wastewater Treatment Plants ◽  
Advanced Oxidation ◽  
Textile Dye ◽  
Rapid Decay ◽  
Oxidation Processes ◽  
First Order ◽  
Heterogeneous Processes ◽  
Brazilian Northeast

Studies and research have been developed around the world on environmental pollution. Among the most diverse types of pollutants, textile dyes have attracted attention in the Brazilian Northeast. These compounds, besides being persistent, resist to the conventional treatments applied in the wastewater treatment plants. Thus, the present study evaluated the degradation of the mixture of direct red 23, direct red 227 and direct orange 26 dyes by advanced oxidation processes (AOPs). It was observed that the homogeneous AOPs were more efficient, being able to degrade 100% of the chromophoric groups after the optimization of the variables [H2O2], [Fe] and pH. The reaction kinetics for the photo-Fenton process followed a pseudo-first order non-linear model, with rapid decay of the concentrations in the first 60 min. Aiming to have a methodology capable of predicting the degradation efficiency for the studied processes, it was verified that the artificial neural networks MLP 4-9-3 and MLP 5-6-3 well represent the data from the homogeneous and heterogeneous processes, respectively. A toxicity study was carried out using seeds, bacteria and microcrustaceans and it was found that the intermediate compounds formed during the treatment process act differently for each of them.

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