scholarly journals Bulk and Nanocatalysts Applications in Advanced Oxidation Processes

2020 ◽  
Author(s):  
Luma Majeed Ahmed
Keyword(s):  
Renewable Energy ◽  
Hydroxyl Radicals ◽  
Advanced Oxidation Processes ◽  
Uv Light ◽  
Advanced Oxidation ◽  
Oxidation Processes ◽  
Nano Catalyst ◽  
Bulk Catalyst ◽  
Metal Doped ◽  
Green Technique

Advanced oxidation processes (AOPs) are considered to be vital methods for treating the contaminations produced mainly by the human activations. In present-day, UV light or solar light, bulk and nano- photocatalysts are often used to enhance this technology by creating the highly reactive species such as the hydroxyl radicals. Extreme hydroxyl radical is considered as a key to start the photoreaction. Photoreaction is widely used in treatment of Lab and industrial contaminations, preparation of compounds and produced the renewable energy, so it’s classified as green technique. In order to improve the efficiency of this reaction with fabrication the surface of the used photocatalyst such as metal doped, sensitized and produced a composite as bulk catalyst or nano catalyst.

FOTODEGRADATION OF LOW MASS MOLECULE PAHS IN FENTON PROCESS

2017 ◽  
Vol 168 (48) ◽  
pp. 25-34 ◽  
Author(s):  
Jolanta Kozak ◽  
Maria Włodarczyk-Makuła
Keyword(s):  
Hydroxyl Radicals ◽  
Advanced Oxidation Processes ◽  
Uv Light ◽  
Advanced Oxidation ◽  
Alternative Source ◽  
Calcium Peroxide ◽  
Oxidation Processes ◽  
Low Mass ◽  
Alternative Sources ◽  
Oxidation Efficiency

Nowadays, the attention of many researchers and scientists is focused on wastewater treatment technologies which are designed to remove toxic and/or persistant compounds. PAHs belong to this type of compounds. Studies have shown that advanced oxidation processes (AOP-advanced oxidation processes) can be used for PAHs degradation. One of the AOP methods is oxidation using Fenton's reagent (Fe2 + / H2O2). The aim of this modification is a search for alternative sources of hydroxyl radicals than H2O2 and support that processes by UV light.. The aim of the study was to determine the efficiency of photocatalysis of low molecular weight PAHs in pretreated coking wastewater under Fenton reaction conditions. The source of hydroxyl radicals was calcium peroxide and the process was supported by UV radiation. The oxidation efficiency was assessed on the basis of PAH analyzes in the pre-and post-oxidation samples. Qualitative and quantitative identification of PAHs was carried out using gas chromatography in combination with GC-MS mass spectrometry. The decrease in the concentration of the analyzed carbohydrates was in the range of 17 to 96%. Studies have shown that calcium peroxide can be an alternative source of hydroxyl radicals for the PAH degradation present in coke wastwater.

scholarly journals Degradation of Losartan in Fresh Urine by Sonochemical and Photochemical Advanced Oxidation Processes

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3398 ◽  
Author(s):  
John F. Guateque-Londoño ◽  
Efraím A. Serna-Galvis ◽  
Yenny Ávila-Torres ◽  
Ricardo A. Torres-Palma
Keyword(s):  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Advanced Oxidation Processes ◽  
Degradation Products ◽  
Advanced Oxidation ◽  
Fukui Function ◽  
Oxidation Processes ◽  
Theoretical Analyses ◽  
Fresh Urine

In this work, the degradation of the pharmaceutical losartan, in simulated fresh urine (which was considered because urine is the main excretion route for this compound) by sonochemistry and UVC/H2O2 individually, was studied. Initially, special attention was paid to the degrading action of the processes. Then, theoretical analyses on Fukui function indices, to determine electron-rich regions on the pharmaceutical susceptible to attacks by the hydroxyl radical, were performed. Afterward, the ability of the processes to mineralize losartan and remove the phyto-toxicity was tested. It was found that in the sonochemical treatment, hydroxyl radicals played the main degrading role. In turn, in UVC/H2O2, both the light and hydroxyl radical eliminated the target contaminant. The sonochemical system showed the lowest interference for the elimination of losartan in the fresh urine. It was established that atoms in the imidazole of the contaminant were the moieties most prone to primary transformations by radicals. This was coincident with the initial degradation products coming from the processes action. Although both processes exhibited low mineralizing ability toward losartan, the sonochemical treatment converted losartan into nonphytotoxic products. This research presents relevant results on the elimination of a representative pharmaceutical in fresh urine by two advanced oxidation processes.

Experimental and theoretical studies on aqueous-phase reactivity of hydroxyl radicals with multiple carboxylated and hydroxylated benzene compounds

2015 ◽  
Vol 17 (17) ◽  
pp. 11796-11812 ◽  
Author(s):  
Daisuke Minakata ◽  
Weihua Song ◽  
Stephen P. Mezyk ◽  
William J. Cooper
Keyword(s):  
Aqueous Phase ◽  
Hydroxyl Radicals ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Theoretical Studies ◽  
Oxidation Processes ◽  
Experimental And Theoretical Studies ◽  
Benzene Compounds ◽  
Shed Light

In this study, we shed light on the initial addition of hydroxyl radicals (HO˙) to multiple carboxylated and hydroxylated benzene compounds in aqueous-phase advanced oxidation processes (AOPs).

Applications of Advanced Oxidation Processes in Palm Oil Mill Effluent Treatment

2019 ◽  
pp. 123-149
Author(s):  
Azmi Aris ◽  
Muhammad Noor Hazwan Jusoh ◽  
Nurul Shakila Ahmad Abdul Wahab
Keyword(s):  
Hydroxyl Radicals ◽  
Palm Oil ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Effluent Treatment ◽  
Palm Oil Mill Effluent ◽  
High Concentration ◽  
Experimental Conditions ◽  
Oxidation Processes ◽  
Palm Oil Mill

This chapter presents a review on limited studies that have been conducted using advanced oxidation processes (AOPs) in treating biologically treated palm oil mill effluent. Palm oil mill effluent is the byproducts of palm oil production that is normally treated using a series of biological processes. However, despite being treated for a long period of retention time, the effluent still possesses high concentration of organics, nutrients, and highly colored, and will pollute the environment if not treated further. Advanced oxidation processes that utilized hydroxyl radicals as their oxidizing agents have the potential of further treating the biologically treated POME. Fenton oxidation, photocatalysis, and cavitation are the main AOPs that have been studied in polishing the biologically treated POME. Depending on the experimental conditions, the removal of organics, in terms of COD, TOC, and color, could reach up to more than 90%. Nevertheless, each of this process has its own limitations and further studies are needed to overcome these limitations.

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