scholarly journals Clays for heterogeneous photocatalytic decolorization of wastewaters contaminated with synthetic dyes: a review

2017 ◽  
Vol 12 (2) ◽  
pp. 432-443 ◽  
Author(s):  
Guolin Jing ◽  
Zhengnan Sun ◽  
Ping Ye ◽  
Shirong Wei ◽  
Yu Liang
Keyword(s):  
Advanced Oxidation Processes ◽  
Organic Content ◽  
Synthetic Dyes ◽  
Reaction Conditions ◽  
Environment Friendly ◽  
Moderate Reaction ◽  
Oxidation Processes ◽  
Photocatalytic Decolorization ◽  
High Organic Content ◽  
Photocatalytic Processes

Photocatalysis is one of the most environment-friendly and technologically viable advanced oxidation processes. Compared to conventional thermal, biological, and physicochemical treatments, photocatalytic processes have more moderate reaction conditions and higher efficiency. They are a promising technology for the treatment of dye wastewaters, particularly those that have toxic and high organic content. Matrix-based photocatalysts have been extensively studied to enhance their efficiency. This paper is a review of recently published literature on matrix-based clay photocatalysts – e.g., bentonite, attapulgite, hydrotalcite, etc. – decolorizing dye wastewaters.

scholarly journals Discoloration and mineralization of a textile azo dye using a hybrid UV/O3/SBR process

2021 ◽  
Vol 11 (10) ◽  
Author(s):  
Hakimeh Mahdizadeh ◽  
Yousef Dadban Shahamat ◽  
Susana Rodríguez-Couto
Keyword(s):  
Textile Industry ◽  
Advanced Oxidation Processes ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Synthetic Dyes ◽  
Oxidation Processes ◽  
Toc Removal ◽  
Reactive Red 198 ◽  
Water And Wastewater ◽  
Ozonation Process

AbstractMost synthetic dyes are toxic and hardly biodegradable compounds that enter the environment mainly through the discharged of non-treated textile industry effluents. The present study investigated the removal of the textile monoazo dye Reactive Red 198 (RR-198) from aqueous solutions using the ultraviolet light and ozonation alone and in combination (i.e., UV/O3) followed by a Sequencing Batch Reactor (SBR). The pH (5 ≤ pH ≤ 9) and dye initial concentration (50–300 mg/L) parameters were optimized in the ozonation process at reaction time of 0–60 min. Then, TOC removal and dye discoloration percentage was compared with the O3, UV and O3/UV processes. In order to compare the performance of the SBR in dye discoloration of RR-198 and TOC removal, four types of effluent, including Raw dye, O3-pretreated dye, UV-treated dye and UV/O3-pretreated dye were separately treated in the SBR system. In the ozonation process, by increasing the pH and reducing the initial dye concentration increased the discoloration percentage. The highest dye discoloration percentage and TOC removal obtained in the hybrid UV/O3/SBR process. Combining biological systems and Advanced Oxidation Processes is an appropriate option for the decomposition of resistant pollutants and increasing the biodegradability of these compounds and is applicable in the water and wastewater industry.

Deactivation of Highly Resistant Microorganisms in Water Using Solar Driven Photocatalytic Processes

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Erick R. Bandala ◽  
Benito Corona-Vasquez ◽  
Raúl Guisar ◽  
Melesio Uscanga
Keyword(s):  
Experimental Data ◽  
Titanium Dioxide ◽  
Bacillus Subtilis ◽  
Radiation Dose ◽  
Advanced Oxidation Processes ◽  
Primary Treatment ◽  
Free Chlorine ◽  
Oxidation Processes ◽  
Sequential Processes ◽  
Photocatalytic Processes

Inactivation of Bacillus subtilis spores was carried out using solar-driven Advanced Oxidation Processes (AOPs) alone and coupled with free chlorine in sequential processes. Experimental results showed that Fenton-like processes are more efficient under the tested conditions than heterogeneous photocatalytic processes using suspended titanium dioxide. Experimental data were fitted using modified Chick-Watson kinetics and the accumulated energy as the radiation dose needed for spore deactivation. It was demonstrated that the deactivation of B. subtilis spores using chlorine can be enhanced by primary treatment with photocatalysis. This study also suggests that AOPs could be an effective alternative to control the occurrence of highly resistant waterborne pathogens.

scholarly journals Advances in Treatment of Brominated Hydrocarbons by Heterogeneous Catalytic Ozonation and Bromate Minimization

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3450
Author(s):  
Asogan N. Gounden ◽  
Sreekantha B. Jonnalagadda
Keyword(s):  
Advanced Oxidation Processes ◽  
Aqueous Media ◽  
Catalytic Ozonation ◽  
Future Research ◽  
Environment Friendly ◽  
Oxidation Processes ◽  
Heterogeneous Catalytic ◽  
Negative Effect ◽  
Bromate Reduction ◽  
Degradation Of Pollutants

The formation of carcinogenic bromate ions is a constraint when ozone is used for the remediation of water containing brominated organic materials. With its strong oxidizing ability, ozone rapidly transforms bromide in aqueous media to bromate, through a series of reactions involving hydroxyl radicals. Several strategies, such as limiting the ozone concentration, maintaining pH < 6, or the use of ammonia or hydrogen peroxide were explored to minimize bromate generation. However, most of the above strategies had a negative effect on the ozonation efficiency. The advanced oxidation processes, using catalysts together with ozone, have proven to be a promising technology for the degradation of pollutants in wastewater, but very few studies have been conducted to find ways to minimize bromate formation during this approach. The proposed article, therefore, presents a comprehensive review on recent advances in bromate reduction in water by catalytic ozonation and proposes reaction mechanisms associated with the catalytic process. The main aim is to highlight any gaps in the reported studies, thus creating a platform for future research and a quest to find environment friendly and efficacious catalysts for minimizing bromate formation in aqueous media during ozonation of brominated organic compounds.

Photocatalytic Degradation of C.I. Reactive Red 2 by Using TiO2-Coated PET Plastic under Solar Irradiation

2013 ◽  
Vol 789 ◽  
pp. 180-188 ◽  
Author(s):  
Tuty Emilia Agustina ◽  
Fitri Suryani Arsyad ◽  
Abdullah Mikrajuddin
Keyword(s):  
Advanced Oxidation Processes ◽  
Organic Pollutant ◽  
Reactive Dye ◽  
Organic Content ◽  
Cod Removal ◽  
Solar Irradiation ◽  
Synthetic Dyes ◽  
Color Degradation ◽  
Colored Wastewater ◽  
Reactive Red 2

The synthetic dyes are a refractory and poisonous material. Most of industrial textile today used the synthetic dyes that can be dangerous to the environment because of the colored wastewater produced from their processes. This study concentrates on the application of Advanced Oxidation Processes (AOPs) for synthetic dyes wastewater treatment. Photocatalysis process as one of AOPs was applied for the degradation of organic content of synthetic dyes wastewater. The reactive dye, C.I. Reactive Red 2 (RR 2) was used as the organic pollutant model at the concentration of 100 mg/l. The TiO2 concentration of 0.05-0.4 g/ml was used as the photocatalyst. The bulk and nanosize of TiO2 were coating on the PET plastic and the degradation of organic content was examined in the term of color and COD within 0-12 hrs under solar irradiation. By using 0.4 g/ml of bulk TiO2, the color degradation of 88% and COD removal of 46% was achieved. Furthermore, by using 0.4 g/ml of nanosize TiO2, the enhancement of color degradation and COD removal was observed, that is 98% and 56%, respectively.

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