scholarly journals Ozonation of Yarn dyed Wastewater in a Continous Stirred Tank Reactor : Kinetic Study and Performance Optimisation

2018 ◽  
Vol 156 ◽  
pp. 03019
Author(s):  
Lieke Riadi ◽  
Andrian Sugiharto ◽  
Hana Gondokusumo
Keyword(s):  
Flow Rate ◽  
Ozone Concentration ◽  
Volumetric Flow Rate ◽  
Stirred Tank ◽  
Order Kinetic ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
First Order ◽  
Pseudo First Order ◽  
Ozonation Process

This paper describes the ozonation process in yarn dyed wastewater using continuous stirred tank reactor with the objective to study the kinetic of COD degradation at various volumetric flow rate (30, 50, 70 ml/min) and ozone concentration (2.70 %, 4.25%, 5.86 % mol/mol). The wastewater which was collected from a yarn dying process located in Surabaya area was pretreated by electrocoagulation prior to ozonation process. The electrocoagulation process was carried out to reduce the color intensity and total suspended solid. The pretreated wastewater was then processed using ozonation for 2.5 hours. The result showed that at various concentration of ozone, maximum COD removal was 90.78% which was achieved at 5.86 %mol/mol of Ozon and volumetric flow rate 50 ml/min. It was found that the degradation process followed the pseudo-first order kinetic model. The obtained pseudo-first order rate constants for volumetric rate of 50 mil/min were 0.0307 min-1, 0.0419 min-1 and 0.053 min-1 for ozon concentration of 2.70 %, 4.25%, 5.86 % mol/mol respectively. The residence time were 41 minutes, 31 minutes and 23 minutes for ozone concentration of 2.70 %, 4.25%, 5.86 % mol/mol respectively. These findings offers an alternative treatment for wastewater containing dyes.

scholarly journals Conceptual Study of Transesterification of Vegetable Oils in the Continuous-Stirred-Tank Reactor at Unsteady-State and Isothermal Conditions

2021 ◽  
Vol 17 (2) ◽  
pp. 181-194
Author(s):  
Fadzil Noor Gonawan ◽  
Azlina Harun Kamaruddin
Keyword(s):  
Flow Rate ◽  
Enzymatic Reaction ◽  
Volumetric Flow Rate ◽  
Packed Bed ◽  
Stirred Tank ◽  
Continuous Stirred Tank Reactor ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Isothermal Conditions ◽  
Continuous Stirred Tank

The continuous-stirred-tank reactor (CSTR) is favorable for bi-phasic enzymatic reaction due to ease of operation, cost-effective and low downtime. Lack of study on the enzymatic reaction in the CSTR has disfavor this type of reactor compared to batch and packed bed. Presently, a simulation was carried out to simulate the behavior of the lipase-catalyzed production of biodiesel by using CSTR at isothermal conditions. The mathematical model incorporated the effect of the kinetic, thermal, and operating parameters. The parameters such as Michaelis constant (Km), inhibition constant (Ki), Gibbs inactivation energy (DelG) and mol flow rate are among determining factors of the course of the reaction. It is suggested that the enzyme with lower , higher , and higher  should be chosen for the reaction. In continuous operation in the CSTR, the volumetric flow rate of the substrates and the initial concentration of the feed could be used to control reaction performance as these parameters will determine the total mol or ratio of the substrates in the reactor. Most, importantly, the longer residence time is preferred to achieve higher conversion, however, the volumetric flow rate must not be too low to prevent underperformance of reaction.

Dynamics of a stirred tank reactor with first-order reaction

1998 ◽  
Vol 53 (21) ◽  
pp. 3719-3728 ◽  
Author(s):  
V.S. Sheplev ◽  
S.A. Treskov ◽  
E.P. Volokitin
Keyword(s):  
Order Reaction ◽  
Stirred Tank ◽  
First Order Reaction ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
First Order

scholarly journals Kinetics of diatrizoate degradation by ozone and the formation of disinfection by-products in the sequential chlorination

2021 ◽  
Author(s):  
Chen-Yan Hu ◽  
Si-Cheng Ren ◽  
Yi-Li Lin ◽  
Ji-Chen Zhang ◽  
Ye-Ye Zhu ◽  
...  
Keyword(s):  
Ozone Concentration ◽  
Ph Value ◽  
Degradation Kinetics ◽  
Order Rate Constant ◽  
Order Kinetic ◽  
Solution Ph ◽  
First Order ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
By Products

Abstract In this study, we studied the degradation kinetics of a common iodine contrast agent, diatrizoate, by ozone and the formation of disinfection by-products (DBPs) in the sequential chlorination. Effects of ozone concentration, solution pH, and bromide concentration on diatrizoate degradation were evaluated. The results indicate that diatrizoate can be effectively degraded (over 80% within 1 h) by ozone, and the degradation kinetics can be well described using the pseudo-first-order kinetic model. The pseudo-first-order rate constant (kobs) of diatrizoate degradation significantly increased with increasing ozone concentration and decreasing bromide concentration. The kobs kept increasing with the increase of pH value and reached a maximum of 6.5 (±0.05) × 10−2 min−1 at pH 9. As the ozone concentration gradually increased from 0.342 to 1.316 mg/L, the corresponding kobs of diatrizoate degradation increased from 1.76 (±0.20) × 10−3 to 4.22 (±0.3) × 10−2 min−1. The bromide concentration exhibited a strong inhibitory effect on diatrizoate degradation because of the competition for ozone with diatrizoate. Trichloromethane was the only detected DBP in the subsequent chlorination in the absence of bromide. However, in the presence of bromide, six other DBPs were detected, and bromochloroiodomethane and tribromomethane became the major products with concentrations 1–2 orders higher than those of the other DBPs. In order to provide safe drinking water to the public, water should be maintained at circumneutral pH values and low bromine concentrations (<5 μM) before reaching the chlorine disinfection process to effectively control the formation of DBPs.

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