THE EFFECT OF TEMPERATURE, pH, AND AERATION ON THE PRODUCTION OF NITROUS OXIDE AND GASEOUS NITROGEN—A ZERO-ORDER KINETIC MODEL

Soil Science ◽  
1974 ◽  
Vol 118 (3) ◽  
pp. 173-179 ◽  
Author(s):  
D. D. FOCHT
Keyword(s):  
Nitrous Oxide ◽  
Kinetic Model ◽  
Zero Order ◽  
Effect Of Temperature ◽  
Order Kinetic ◽  
Gaseous Nitrogen ◽  
Order Kinetic Model

scholarly journals CHARACTERISTICS OF ASCORBIC ACID RELEASE FROM TPP-CROSSLINKED CHITOSAN/ALGINATE POLYELECTROLYTE COMPLEX MEMBRANES

2018 ◽  
Vol XXIII ◽  
pp. 76-87 ◽  
Author(s):  
Magdalena Gierszewska ◽  
Jadwiga Ostrowska-Czubenko ◽  
Ewelina Chrzanowska
Keyword(s):  
Ascorbic Acid ◽  
Kinetic Model ◽  
Polyelectrolyte Complex ◽  
Zero Order ◽  
Order Kinetic ◽  
Initial Burst ◽  
First Order ◽  
Order Kinetic Model ◽  
Acid Release ◽  
Release Data

Chitosan/alginate polyelectrolyte complex membranes (Ch/Alg) additionally cross-linked with tripolyphosphate (TPP) and containing ascorbic acid (AA) were prepared. The dynamic swelling behaviour of Ch/Alg/TPP and ascorbic acid release from the membrane were characterised in different buffer solutions. It has been found that the pH of the buffer solution affects the swelling and release behaviour of AA. Ascorbic acid release, observed over a period of 360 min, exhibited a biphasic pattern, characterised by a fast initial burst release, followed by a slow, sustained release. Different mathematical models were used to study the kinetics and transport mechanism of AA from Ch/Alg/TPP hydrogels. Drug release data were fitted to the zero order kinetic model and first order kinetic model. To characterise the drug mechanism, the release data were fitted to the Higuchi and Korsmeyer-Peppas equations. The initial burst AA release followed zero order kinetics and was quasi-Fickian in nature. The second step of AA release followed first order kinetics.

Note. Hydrolysis of Onion and Kinetics of Non-Enzymatic Browning of its Hydrolysate

2004 ◽  
Vol 10 (1) ◽  
pp. 41-44 ◽  
Author(s):  
J. M. Kim ◽  
K. S. Ra ◽  
H. J. Suh
Keyword(s):  
Zero Order ◽  
Total Sugar ◽  
Effect Of Temperature ◽  
Enzymatic Browning ◽  
Order Kinetic ◽  
Arrhenius Model ◽  
Browning Index ◽  
Order Kinetic Model ◽  
Kinetics Of ◽  
Hydrolysis Of

Enzymatic hydrolysis of onion was performed by three different commercial enzyme products (Econase, Rapidase and Viscozyme) for preparation of onion hydrolysates. The hydrolysis yield was determined through the analysis of reducing and total sugar contents in final hydrolysates. Total sugar contents after 2 h-hydrolysis with Econase, Rapidase and Viscozyme were 59.6, 64.1 and 62.2 mg/mL, respectively, and reducing sugar contents of 28.5, 42.7 and 35.9 mg/mL in the same order. According to these results Rapidase was more suitable for the hydrolysis of onion than the other enzymatic products. The effect of temperature on non-enzymatic browning reaction kinetics of the onion hydrolysate was determined. The browning index variation was adequately described by both the first- and the zero-order kinetic. However, the zero-order kinetic model was preferred because its fitting was higher. The values of kinetic constants were 0.081 (60 C), 0.185 (70 C), 0.270 (80 C) and 0.377 (90 C). According to the Arrhenius model, the activation energy for browning index in the range 60–90 C was 21.9 kJ/mol.

scholarly journals Removal of Nickel from Aqueous Solutions by Natural Bentonites from Slovakia

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 282
Author(s):  
Matej Šuránek ◽  
Zuzana Melichová ◽  
Valéria Kureková ◽  
Ljiljana Kljajević ◽  
Snežana Nenadović
Keyword(s):  
Kinetic Model ◽  
Gibbs Energy ◽  
Adsorption Process ◽  
Effect Of Temperature ◽  
Standard Entropy ◽  
Order Kinetic ◽  
Processing Conditions ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, the removal of nickel (Ni(II)) by adsorption from synthetically prepared solutions using natural bentonites (Lieskovec (L), Hliník nad Hronom (S), Jelšový Potok (JP), and Stará Kremnička (SK)) was investigated. All experiments were carried out under batch processing conditions, with the concentration of Ni(II), temperature, and time as the variables. The adsorption process was fast, approaching equilibrium within 30 min. The Langmuir maximum adsorption capacities of the four bentonite samples used were found to be 8.41, 12.24, 21.79, and 21.93 mg g–1, respectively. The results best fitted the pseudo-second-order kinetic model, with constant rates in a range of 0.0948–0.3153 g mg–1 min. The effect of temperature was investigated at temperatures of 20, 30, and 40 °C. Thermodynamic parameters, including standard enthalpy (ΔH0), Gibbs energy (ΔG0), and standard entropy (ΔS0), were calculated. The adsorption of Ni(II) by bentonite samples was an endothermic and spontaneous process. These results indicated that, of the bentonite samples used, the natural bentonites from JP and SK were most suitable for the removal of nickel from synthetically prepared solutions.

scholarly journals Removal of the 2-Mercaptobenotiazole from Model Wastewater by Ozonation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jan Derco ◽  
Angelika Kassai ◽  
Michal Melicher ◽  
Jozef Dudas
Keyword(s):  
Kinetic Model ◽  
Oxygen Demand ◽  
Zero Order ◽  
Order Kinetic ◽  
Total Removal ◽  
Respiration Activity ◽  
Benzothiazole Derivatives ◽  
Ozonation Time ◽  
Order Kinetic Model ◽  
Ozonation Process

The feasibility of ozonation process for 2-mercaptobenzothiazole (2-MBT) removal follows from results of ozonation of the model wastewater. Total removal of 2-MBT was observed after 20 minutes of ozonation. Very good reproducibility of repeated ozonation trials including sampling and analysis was observed. However, the majority of dissolved organic carbon (DOC) and chemical oxygen demand (COD) remained in the reaction mixture. Benzothiazole (BT) and 2-hydroxybenzothiazole (OBT) intermediates were identified during degradation of 2-MBT with ozone. In addition to the above benzothiazole derivatives, the creation of some other organic compounds follows from results of mass balance. The best fits of experimental data were obtained using the first kinetic model for 2-MBT and zero-order kinetic model for COD and DOC. The reaction time of 60 minutes can be considered as effective with regard to controlled oxidation in order to increase a portion of partially oxidized substances. Higher biodegradability and lower toxicity of ozonation products on respiration activity of activated sludge microorganisms was observed at higher ozonation time.

scholarly journals Investigation of Seeds and Peels of Citrullus colocynthis as Efficient Natural Adsorbent for Methylene Blue Dye

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1279
Author(s):  
Wafa Mohammed Alghamdi ◽  
Ines El Mannoubi
Keyword(s):  
Methylene Blue ◽  
Kinetic Model ◽  
Langmuir Isotherm ◽  
Order Kinetic ◽  
Citrullus Colocynthis ◽  
Natural Adsorbent ◽  
Spontaneous Process ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Mb Adsorption

Natural adsorbents as low-cost materials have been proved efficient for water remediation and have significant capacity for the removal of certain chemicals from wastewater. The present investigation aimed to use Citrullus colocynthis seeds (CCSs) and peels (CCPs) as an efficient natural adsorbent for methylene blue (MB) dye in an aqueous solution. The examined biosorbents were characterized using surface area analyzer (BET), scanning electron microscope (SEM), thermogravimetric analyzer (TGA) and Fourier transform infra-red (FT-IR) spectroscopy. Batch adsorption experiments were conducted to optimize the main factors influencing the biosorption process. The equilibrium data for the adsorption of MB by CCSs were best described by the Langmuir isotherm followed by the Freundlich adsorption isotherms, while the equilibrium data for MB adsorption by CCPs were well fitted by the Langmuir isotherm followed by the Temkin isotherm. Under optimum conditions, the maximum biosorption capacity and removal efficiency were 18.832 mg g−1 and 98.00% for MB-CCSs and 4.480 mg g−1 and 91.43% for MB-CCPs. Kinetic studies revealed that MB adsorption onto CCSs obeys pseudo-first order kinetic model (K1 = 0.0274 min−1), while MB adsorption onto CCPs follows the pseudo-second order kinetic model (K2 = 0.0177 g mg−1 min−1). Thermodynamic studies revealed that the MB biosorption by CCSs was endothermic and a spontaneous process in nature associated with a rise in randomness, but the MB adsorption by CCPs was exothermic and a spontaneous process only at room temperature with a decline in disorder. Based on the obtained results, CCSs and CCPSs can be utilized as efficient, natural biosorbents, and CCSs is promising since it showed the highest removal percentage and adsorption capacity of MB dye.

Dyeing mechanism and photodegradation kinetics of gardenia yellow natural colorant

2020 ◽  
pp. 004051752095848
Author(s):  
Huiyu Jiang ◽  
Xiaodong Hu ◽  
Asfandyar Khan ◽  
Jinbo Yao ◽  
Muhammad Tahir Hussain
Keyword(s):  
Kinetic Model ◽  
Cotton Fabric ◽  
Reaction Rate Constant ◽  
Second Order ◽  
Order Kinetic ◽  
Natural Colorant ◽  
Yellow Solution ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Dyeing Rate

In this study, gardenia yellow solution is used to dye 100% cotton fabric. The dyeing rate curve and adsorption isotherms were recorded to explore the thermodynamic model and to calculate the corresponding parameters. A definite concentration of gardenia yellow solution was placed under the xenon arc lamp for irradiation to test its photodegradability. Absorbance of the solution was measured at different degradation times and the corresponding varying curve of the absorbance was drawn to explore the photodegradation reaction order of the natural colorant and consistent parameters were calculated. The experimental results proved that the dyeing of cotton fabric with gardenia yellow colorant followed the pseudo second order kinetic model whereas adsorption isotherm followed the Langmuir model and the photodegradation process followed the second order kinetic model. Values of different parameters were calculated: reaction rate constant k = 2.26 × 10–3 (mg · L−1)1−m h−1, the correlation coefficient R2 = 0.994, and half decay time t1/2 = 5.82 h.

Iron Chelation by Polyamidoamine Dendrimers: A Second-Order Kinetic Model for Metal–Amine Complexation

2011 ◽  
Vol 115 (46) ◽  
pp. 13534-13540 ◽  
Author(s):  
Michael R. Mankbadi ◽  
Mohamed A. Barakat ◽  
Mohamed H. Ramadan ◽  
H. Lee Woodcock ◽  
John N. Kuhn
Keyword(s):  
Kinetic Model ◽  
Iron Chelation ◽  
Second Order ◽  
Order Kinetic ◽  
Polyamidoamine Dendrimers ◽  
Order Kinetic Model ◽  
Metal Amine
Sign in / Sign up

Export Citation Format

Share Document