Establishment of electrochemical treatment method to dye wastewater and its application to real samples

2021 ◽  
pp. 1-15
Author(s):  
Nian Cheng ◽  
Jingyi Huang ◽  
Yingru Wang
Keyword(s):  
Free Radicals ◽  
Reaction Kinetics ◽  
Removal Rate ◽  
Electrochemical Treatment ◽  
Order Reaction ◽  
Zero Order ◽  
Electrode Spacing ◽  
Dye Wastewater ◽  
Zero Order Reaction ◽  
Hydroxyl Free Radicals

It is of great significance to study the treatment of organic dye pollution. In this work, a method of electrochemical treatment for reactive blue 19 dye (RB19) wastewater system was established, and it was applied to the actual dye wastewater treatment. The effects of applied voltage, electrolyte concentration, electrode spacing, and initial concentration on the removal effect of RB19 have been studied in detail. The results show that the removal rate of RB19 can reach 82.6% and the chemical oxygen demand (CODcr) removal rate is 54.3% under optimal conditions. The removal of RB19 in the system is mainly the oxidation of hydroxyl free radicals. The possible degradation pathway is inferred by ion chromatography: hydroxyl free radicals attack the chromophoric group of RB19 to make it fall off, and then decompose it into ring-opening. The product is finally oxidized to CO2 and water. The kinetic fitting is in accordance with the zero-order reaction kinetics. At the same time, using the established electrochemical system to treat the actual dye wastewater has also achieved good results. After 3 hours of treatment, the CODcr removal rate of the raw water is 44.8%, and the CODcr removal of the effluent can reach 89.5%. The degradation process conforms to the zero-order reaction kinetics. The result is consistent with the electrochemical treatment of RB19.

scholarly journals Chemical, Microbiological and Sensory Stability of Steam Extracted Jaboticaba (Myrciaria jaboticaba) Juice

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 732
Author(s):  
Ana Beatriz Neves Martins ◽  
Mariana Canto ◽  
Daniel Perrone ◽  
Mariana Monteiro
Keyword(s):  
Phenolic Compounds ◽  
Reaction Kinetics ◽  
Total Phenolics ◽  
Order Reaction ◽  
Zero Order ◽  
Purchase Intent ◽  
First Order ◽  
Color Changes ◽  
Steam Extraction ◽  
Zero Order Reaction

Jaboticaba (Myrciaria jaboticaba) is a Brazilian berry rich in phenolic compounds, much appreciated for its sweet and slightly acid taste, and highly perishable. Thus, we aimed at producing jaboticaba juice by steam extraction and at investigating its microbiological, sensorial and chemical qualities during storage for up to 168 days. Juice was microbiologically safe and even though unsweetened juice was well accepted, sucrose addition further improved flavor (21%), overall impression (11%) and purchase intent (21%) scores. Cyanidin-3-O-glucoside (C3G) was the major phenolic (40%), followed by gallic (28%) and ellagic acids (21%). Total phenolics contents decreased from 27% (50 °C) to 50% (25 °C), mainly driven by C3G degradation. At 60 °C, total phenolics contents did not change after 42 days since C3G degradation was counterbalanced by gallic acid formation (129%), which followed zero-order reaction kinetics. Anthocyanins degradation followed first-order reaction kinetics (C3G half-life at 25 °C = 21.7 days) and was associated with color changes during storage. In conclusion, steam extraction followed by hot-filling technique ensured a juice with at least six months of shelf life.

The Reaction Kinetics of Aluminum and Isopropanol

2012 ◽  
Vol 164 ◽  
pp. 21-25
Author(s):  
Xiu Hui Wang ◽  
Huan Huan Ni ◽  
Ye Cao ◽  
Gang Li ◽  
Hong Gao ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Catalytic Mechanism ◽  
Reaction Order ◽  
Order Reaction ◽  
Zero Order ◽  
Zero Order Reaction ◽  
Kinetics Of

AlCl3was used as catalyst in the reaction. The reaction kinetics of aluminum and isopropanol was investigated in this paper. Metallograph showed that the surface of the aluminum bar had corrosive pitting. The reaction was zero order reaction when aluminum was overdosed. Reaction order was 0.75 when isopropanol was overdosed. Finally, catalytic mechanism of AlCl3was investigated and the reaction of corrosive pitting was the same as that in microbattery.

scholarly journals Retensi Ekstrak Karoten pada Olahan Mie Wortel (Daucus carrota L.)

KOVALEN ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 99-105
Author(s):  
Putri Wahyuni ◽  
Ni Ketut Sumarni ◽  
Prismawiryanti ◽  
Jaya Hardi
Keyword(s):  
Shelf Life ◽  
Reaction Kinetics ◽  
Room Temperature ◽  
Storage Period ◽  
Order Reaction ◽  
Zero Order ◽  
Carotene Content ◽  
Zero Order Reaction ◽  
Kinetics Of

Carotene extract from carrots (Daucus carrota L.) can improve the quality of processed noodles. Determining of carotene retention in processed carrot noodles during the storage period that has been done aims to know the reaction kinetics and shelf life of the noodles. Carrot noodles were stored for 8 weeks at room temperature and analyzed its carotene content by using a UV-Vis spectrophotometer every 7 days. The result showed that the retention of carrot noodles during storage of 0, 1, 2, 3, 4, 5, 6, 7, and 8 weeks was 53.64%, 53.19%, 52.49%, 51.68%, 51.07%, 46.30%, 45.96, 45.88, and 44.93%, respectively. The retention kinetics of carrot noodles during storage followed a zero-order reaction and had a shelf life of up to 30 weeks, 4 days, 4 hours. Keywords: carrot noodles, retention, self life

Intensification of cooling in a batch reactor with an exothermic reaction by nonisothermal control in stable pseudostationary states

1984 ◽  
Vol 49 (11) ◽  
pp. 2566-2578 ◽  
Author(s):  
Josef Horák ◽  
Petr Beránek ◽  
Dagmar Maršálková
Keyword(s):  
Batch Reactor ◽  
Exothermic Reaction ◽  
Reaction Model ◽  
Order Reaction ◽  
Zero Order ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Adaptive Parameter ◽  
Zero Order Reaction ◽  
Set Up

An algorithm is set up and tested for the temperature control of a batch reactor consisting in jump changes in the inlet temperature of entering coolant. This temperature is so chosen that its difference from the temperature of the reaction mixture is near the highest difference at which the stable pseudostationary state of the system still exists. For the prediction of the new coolant inlet temperature, a zero-order reaction model is used with an adaptive parameter estimated from the experimentally established value of the maximum of the reaction mixture overheating at the previous coolant temperature.

The Characteristics and Kinetics of 4-CP with Pb2+ Biodegradation by Fusarium sp.

2013 ◽  
Vol 726-731 ◽  
pp. 2506-2509
Author(s):  
Xiao Xiao Wang ◽  
Xiao Qin Yu ◽  
Jun Ya Pan ◽  
Ji Wu Li
Keyword(s):  
Carbon Source ◽  
Kinetic Equations ◽  
Order Reaction ◽  
Zero Order ◽  
Biodegradation Rate ◽  
Reaction Equation ◽  
Zero Order Reaction ◽  
Kinetics Of ◽  
Additional Carbon Source

The effects of Pb2+concentration, pH and additional carbon source on biodegradation of 4-chlorophenol (4-CP) byFusariumsp. were investigated, and the characteristic and kinetic of 4-CP biodegradation were analyzed. It was concluded that 4-CP biodegradation rate byFusariumsp. decreased a little at concentration of Pb2+0.20 mg/L and 4-CP 50 mg/L. The suitable biodegradation pH was range from 6 to 7. Additional carbon source (phenol) might increase the rate of 4-CP biodegradation. The kinetic equations of 4-CP biodegradation were well accord with the zero order reaction equation at different concentration of Pb2+.

scholarly journals Akinetic model for the consumption of stabilizer in single base gun propellants

2002 ◽  
Vol 67 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Ljiljana Jelisavac ◽  
Milos Filipovic
Keyword(s):  
Life Time ◽  
Order Reaction ◽  
Zero Order ◽  
Final Phase ◽  
Single Base ◽  
First Order ◽  
Low Concentrations ◽  
Zero Order Reaction ◽  
High Concentrations ◽  
Gun Propellants

A suitable kinetic model for the consumption of stabilizer (diphenylamine) in single base gun propellants was investigated and successfully verified. The model assumes that a reaction of shifting order can be applied for the consumption of diphenylamine in single base gun propellants. It was found that the experimental data were well evaluated by a first-order reaction at high concentrations of diphenylamine in the propellant, but by a zero-order reaction at low concentrations during the final phase of the propellant life time. The mechanism of diphenylamine depletion was discussed with relation to the model and the ageing behavior of the propellants. The kinetic parameters of this model, which permit the calculation of the time up to complete consumption of the diphenylamine, were determined. The results were compared with the kinetic data obtained by a widely accepted model, which combines formally reactions of first and zero order, designated as an "exponential and linear" model. All comparisons gave satisfactory agreement.

Enzymatic assay of magnesium through glucokinase activation.

1989 ◽  
Vol 35 (11) ◽  
pp. 2212-2216 ◽  
Author(s):  
P Fossati ◽  
M Sirtoli ◽  
G Tarenghi ◽  
M Giachetti ◽  
G Berti
Keyword(s):  
Atomic Absorption Spectrophotometry ◽  
Order Reaction ◽  
Zero Order ◽  
Good Sensitivity ◽  
Test Results ◽  
Enzymatic Method ◽  
Absorption Spectrophotometry ◽  
Routine Work ◽  
Zero Order Reaction ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract We describe an improved enzymatic method for assaying magnesium in serum, plasma, or urine. Magnesium participates as an Mg.ATP complex in a reaction catalyzed by glucokinase (EC 2.7.1.2) coupled to an NADP+-dependent glucose-6-phosphate dehydrogenase (EC 1.1.1.49) reaction. The increase of absorbance at 340 nm, due to the NADPH produced, is proportional to the amount of the activated glucokinase, which in turn is related to the concentration of magnesium in the sample. The method is characterized by a zero-order reaction kinetics, affording a simple and rapid assay with good sensitivity and linearity (up to 2.06 mmol/L) and by working solutions that are stable (refrigerated) for one month. The method is reliable, produces test results that compare closely with those of the atomic absorption spectrophotometry (r greater than or equal to 0.99), is suitable for routine work, and lends itself to automation.

Interactions of hypochlorite ion and humic acid: photolytic and photocatalytic pathways

2001 ◽  
Vol 44 (5) ◽  
pp. 205-210 ◽  
Author(s):  
D. Gonenç ◽  
M. Bekbolet
Keyword(s):  
Humic Acid ◽  
Reaction Kinetics ◽  
Removal Efficiency ◽  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Order Reaction ◽  
First Order Reaction ◽  
Acid Oxidation ◽  
First Order ◽  
Toc Removal

Photolytic and photocatalytic interactions of hypochlorite ion and humic acid are investigated under various conditions. Humic acid oxidation by aqueous chlorine under dark conditions are expressed in terms of first order reaction kinetics. Upon irradiation (300 nm < λ < 400 nm), photolysis of aqueous chlorine affect the removal efficiency of humic acid via oxidation. TiO2 sensitised photocatalytic oxidation conditions reveal an increase in the TOC removal rate of humic acid in the presence of aqueous chlorine. Under the specified conditions, increasing the photocatalyst loading up to 1.0 mg/mL markedly increase the TOC removal rate.

Pseudo-Homogenous Kinetics Model for the Synthesis of Dimethyl Carbonate from Urea and Methanol with Heterogeneous Catalyst

2011 ◽  
Vol 233-235 ◽  
pp. 481-486
Author(s):  
Wen Bo Zhao ◽  
Ning Zhao ◽  
Fu Kui Xiao ◽  
Wei Wei
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Dimethyl Carbonate ◽  
Side Reaction ◽  
Order Reaction ◽  
Zero Order ◽  
Kinetics Model ◽  
First Order ◽  
Zero Order Reaction ◽  
Kinetics Of

The synthesis of dimethyl carbonate (DMC) from urea and methanol includes two main reactions: one amino of urea is substituted by methoxy to produce the intermediate methyl carbamate (MC) which further converts to DMC via reaction with methanol again. In a stainless steel autoclave, the kinetics of these reactions was separately investigated without catalyst and with Zn-containing catalyst. Without catalyst, for the first reaction, the reaction kinetics can be described as first order with respect to the concentrations of methanol and methyl carbamate (MC), respectively. For the second reaction, the results exhibit characteristics of zero-order reaction. Over Zn-containing catalyst, the first reaction is neglected in the kinetics model since its rate is much faster than second reaction. After the optimization of reaction condition, the macro-kinetic parameters of the second reaction are obtained by fitting the experimental data to a pseudo-homogenous model, in which a side reaction of DMC synthesis is incorporated since it decreases the yield of DMC drastically at high temperature. The activation energy of the reaction from MC to DMC is 104 KJ/mol while that of the side reaction of DMC is 135 KJ/mol.

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