Water treatment with a fixed bed catalytic ozonation process

1997 ◽  
Vol 35 (4) ◽  
pp. 353-360 ◽  
Author(s):  
F. P. Logemann ◽  
J. H. J. Annee
Keyword(s):  
Reaction Mechanism ◽  
Fixed Bed ◽  
Catalytic Ozonation ◽  
Solid Catalyst ◽  
Oh Radicals ◽  
Radical Scavengers ◽  
Industrial Plants ◽  
Alkaline Conditions ◽  
Acidic Conditions ◽  
Ozonation Process

Progress in developing the fixed bed, catalytic ozonation process “ECOCLEAR” continues. Experimental evidence supports a reaction mechanism that predominantly takes place at the surface of the solid catalyst. This sets “ECOCLEAR” apart from all other advanced oxidation techniques which depend on the presence of ·OH radicals in the aqueous phase. The catalytic ozonation process requires less ozone, is substantially less affected by dissolved radical scavengers such as (bi)carbonates and is equally effective under both highly acidic conditions – when ·OH radicals are not formed – as well as under highly alkaline conditions. Results of industrial plants in operation are given.

Effectiveness of Ozonation Process on Treating Tofu Industrial Liquid Waste: Effect of pH Conditions

2020 ◽  
Vol 981 ◽  
pp. 336-341 ◽  
Author(s):  
Ria Wulansarie ◽  
Achmad Chafidz ◽  
Pratikno Hidayat ◽  
Wara Dyah Pita Rengga ◽  
Febrian Jefri Afrizal ◽  
...  
Keyword(s):  
Liquid Waste ◽  
Maximum Level ◽  
Alternative Methods ◽  
Oh Radicals ◽  
Water Stream ◽  
Effect Of Ph ◽  
Indonesian Government ◽  
Alkaline Conditions ◽  
Ph Conditions ◽  
Ozonation Process

The tofu industries in Indonesia produce a considerable amount of liquid waste. Most of these tofu industries do not treat waste properly. Liquid waste is channeled directly to the nearest water stream, and thus the values of COD, BOD and TSS are considerably high, which can damage the aquatic ecosystems. According to the Indonesian government rule (Permen LH no.5/2014), the maximum levels of COD, BOD and TSS are 300 mg/L, 150 mg/L, and 200 mg/L. One of alternative methods to reduce these three parameters is the ozonation method. Ozone is able to break down organic components well because of its strong oxidative properties (2.07 mV) and it can decompose into OH radicals which have stronger oxidative properties (2.80 mV). The objectives of this study are to reduce the levels of COD, BOD and TSS of tofu liquid waste into below of the maximum level set by the Indonesian government rule and to study the effect of pH conditions on the effectiveness of ozonation process. Ozonation is carried out under conditions at acidic pH, alkaline pH, and neutral pH, and with a waste concentration of 10%. Ozonation is done by flowing ozone directly into the waste for 120 minutes with an interval of 30 minutes. The levels of BOD, COD, and TSS before ozonation were 1,200 mg/L, 880 mg/L and 600 mg/L. After ozonation, it was found that the levels of COD, BOD and TSS of the waste without any pre-treatment (or acidic condition) was able to be reduced by 46.6%, 44.5% and 41.6%, respectively. Whereas, in neutral conditions the decreases of COD, BOD, and TSS were about 64.3%, 67.0%, and 62.4%, respectively. Optimum ozonation was found in alkaline conditions with the decreases in COD, BOD, and TSS values were about 85.4%, 84%, and 100%, respectively.

Degradation of p-Toluenesulfonic Acid by Ozonation: Performance Optimization and Mechanism

2010 ◽  
Vol 113-116 ◽  
pp. 1551-1554 ◽  
Author(s):  
Qi Zhou Dai ◽  
Shao Qing Cai ◽  
Ming Hua ◽  
Jia De Wang ◽  
Jian Meng Chen
Keyword(s):  
Performance Optimization ◽  
Alkaline Condition ◽  
Direct Oxidation ◽  
Pharmaceutical Wastewater ◽  
Acid Condition ◽  
Sharp Difference ◽  
Toluenesulfonic Acid ◽  
Alkaline Conditions ◽  
Acidic Conditions ◽  
Ozonation Process

This paper explored ozonation for the treatment of pharmaceutical wastewater and p-toluenesulfonic acid (PTSA) was selected as the model pharmaceutical intermediate. The results showed that the ozonation process is efficient for the degradation of PTSA both in concentration and COD removal. The mono factor results showed that 60L/h was a suitable ozone flow rate. There were sharp difference between acid condition and alkaline condition, under acidic conditions, the direct oxidation with molecular ozone is of primary importance, and under alkaline conditions the hydroxyl oxidation starts to dominate, and pH=12 was a suitable value. Further, intermediates of PTSA degradation were analyzed and the reaction mechanism was discussed.

CO2 valorization into synthetic natural gas (SNG) using a Co–Ni bimetallic Y2O3 based catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Radwa A. El-Salamony ◽  
Sara A. El-Sharaky ◽  
Seham A. Al-Temtamy ◽  
Ahmed M. Al-Sabagh ◽  
Hamada M. Killa
Keyword(s):  
Reaction Mechanism ◽  
Natural Gas ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Synthetic Natural Gas ◽  
Methanation Reaction ◽  
Co2 Valorization

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.

Reaction Mechanism for CCl2F2 Catalytic Decomposition over MoO3/ZrO2

2013 ◽  
Vol 295-298 ◽  
pp. 326-330 ◽  
Author(s):  
Tian Cheng Liu ◽  
Yu Jiao Guo ◽  
Ping Ning ◽  
Ming Long Yuan
Keyword(s):  
Reaction Mechanism ◽  
Main Product ◽  
Solid Acid ◽  
Fixed Bed ◽  
Catalytic Decomposition ◽  
Strong Acid ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
Surface Intermediate ◽  
Strong Acid Sites

Catalytic hydrolysis decomposition of dichlorodifluoromethane (CCl2F2) in the presence of water vapor and oxygen was studied over a series of solid acids using a fixed-bed reactor. Solid acid MoO3/ZrO2 displayed the highest activity, over which the conversion of CCl2F2 reached 100 % at 250 °C. CO2 was the main-product and the selectivity to CClF3 remained lower than 28.0 %. CO was not detected as by-product. The decomposition activity depended on the calcination temperature and the ZrO2 content. The activity of solid acid MoO3/ZrO2 correlates well with its specific surface area and the amount of medium-strong acid sites on the surface. To explain the reaction mechanism for CCl2F2 catalytic decomposition over MoO3/ZrO2, a surface intermediate, Osurface-CF2-Osurface is proposed.

scholarly journals Effects of ferric ions on the catalytic ozonation process on sanitary landfill leachates

2013 ◽  
Vol 8 (1) ◽  
Author(s):  
Andre Luiz de Souza ◽  
Helcio Jose Izario Filho ◽  
Andre Luiz de Castro Peixoto ◽  
Oswaldo Luiz Cobra Guimaraes ◽  
Carla Cristina Almeida Loures ◽  
...  
Keyword(s):  
Catalytic Ozonation ◽  
Sanitary Landfill ◽  
Ferric Ions ◽  
Landfill Leachates ◽  
Ozonation Process
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