Influence of salinity on the heterogeneous catalytic ozonation process: Implications to treatment of high salinity wastewater

2021 ◽  
pp. 127255
Author(s):  
Yuting Yuan ◽  
Shikha Garg ◽  
Yuan Wang ◽  
Wenbo Li ◽  
Guifeng Chen ◽  
...  
2015 ◽  
Vol 5 (2) ◽  
pp. 1143-1152 ◽  
Author(s):  
L. Ciccotti ◽  
L. A. S. do Vale ◽  
T. L. R. Hewer ◽  
R. S. Freire

Systematic evaluation of experimental variables in magnetic nanoparticle preparation and hybrid catalyst application in the heterogeneous catalytic ozonation process.


2011 ◽  
Vol 368-373 ◽  
pp. 3793-3796
Author(s):  
Li Ping Wang ◽  
Yong Jing Mao ◽  
Yu Chuan Guo ◽  
Er Deng Du

It is of great practical significance to develop integrated processes with high efficiency, adaptability and stability to treat the dyeing wastewater with the feature of high organic matter, high-color and large ranges in water quality and quantity. In this paper, a novel catalyst MnOx+FexOy/AC was prepared by the impregnation method. The catalyst was used in the heterogeneous catalytic ozonation process to treat the dyeing wastewater. The results showed that the optimal Fe:Mn ratio of catalyst is 1:2. Under the optimized conditions of pH 5, ozone aeration rate 0.2L/min, catalyst dosage 20g and the reaction time 60min, the removal rate of COD, NH3-N, TP, Chromaticity were 81.7%, 90.2%, 93.4%, 99.1%, respectively. The heterogeneous catalytic ozonation is a promising process for the treatment of dyeing wastewater.


2020 ◽  
Vol 2 (1) ◽  
pp. 26
Author(s):  
Savvina Psaltou ◽  
Efthimia Kaprara ◽  
Manassis Mitrakas ◽  
Anastasios Zouboulis

Catalytic ozonation is an Advanced Oxidation Process (AOPs) based on the production of hydroxyl radicals, which are very reactive oxidative species. The aim of this study is to evaluate the catalytic activity of calcite on the ozonation of four different typical micropollutants (atrazine, benzotriazole, carbamazepine, and p-CBA) at pH 7 and for low initial concentrations (4 μΜ) by performing batch mode experiments. These compounds have different physico-chemical characteristics, as well as different rate constants, when reacting with ozone and hydroxyl radicals (•OH), being in the range of <0.15 − 3 × 105 M−1s−1 and 2.4 − 8.8 × 109 M−1s−1, respectively. It was found that most of these micropollutants can be sufficiently removed by the application of heterogeneous catalytic ozonation, using calcite as the catalyst, except for the case of atrazine, which was the compound that was most difficult to degrade, when compared to the application of single ozonation. Carbamazepine with kO3 = 3 × 105 M−1s−1 can be easily removed even by single ozonation after the first minute of the reaction time, and the addition of the catalyst eliminated the oxidation/reaction time. The application of catalytic ozonation resulted in 50% and 68.2% higher removals of benzotriazole and p-CBA, respectively, in comparison with single ozonation, even during the first 3 min of the reaction/oxidation time, due to the higher production of hydroxyl radicals, caused by the catalytic ozonation. For the case of atrazine, the addition of calcite did not enhance the micropollutant degradation, and its removal reached 83% after a 30 min application of catalytic ozonation, whereas during the single ozonation, the removal under the same reaction time was 90%.


2020 ◽  
Vol 7 (2) ◽  
pp. 79-88
Author(s):  
Mina Ghahrchi ◽  
Edris Bazrafshan ◽  
Behruz Adamiyat Badan ◽  
Yousef Dadban Shahamat ◽  
Fariba Gohari

Background: The discharge of untreated wastewater containing toxic and resistant compounds into the environment is a serious threat for ecosystems. Therefore, this study was conducted to evaluate the treatment of poison production factory wastewater using heterogeneous catalytic ozonation process (COP). Methods: Magnetic carbon nanocomposite was used as a catalyst at concentrations of 1, 2, and 4 g/L. Its effect on improving the treatment process was evaluated at reaction time of 30, 60, 90, and 120 minutes. At the end of each experiment, parameters including total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD5 ), pH, electrical conductivity (EC), and turbidity were measured. Results: It was revealed that in single ozonation process (SOP), the maximum removal efficiencies of TOC, COD, and BOD5 were achieved at reaction time of 120 minutes as 56%, 40%, and 11.7%, respectively. By adding the catalyst to the wastewater, the treatment process was improved, so that the maximum removal efficiencies of COD (91%), TOC (73%), and BOD5 (74%) were obtained at catalyst concentration of 4 g/L. Under this condition, BOD5 /COD ratio increased from 0.22 to 0.64. Also, the results of analysis of ozone consumption per each mg of reduced COD showed that its amount sharply decreased from 2.1 mgO3 / mg COD removal in the SOP, to 0.34 mgO3 /mg COD removal in the COP. The results of kinetic reaction analysis also revealed that the rate constant increased from 0.007 to 0.02 min-1. Conclusion: According to the results, it can be concluded that the COP at a catalyst concentration of 4 g/L, by decomposing resistant compounds and increasing the biodegradability, can be used as a suitable pretreatment method for biological processes.


2018 ◽  
Vol 26 (5) ◽  
pp. 4488-4497 ◽  
Author(s):  
Jenny Castro ◽  
Santiago Paz ◽  
Natali Mena ◽  
Julián Urresta ◽  
Fiderman Machuca-Martinez

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