scholarly journals The kinetics of tempeh wastewater treatment using Arthrospira platensis

2021 ◽  
Author(s):  
Lieke Riadi ◽  
Theresia Desy Askitosari ◽  
Ragil Puspita Dutaning Widhi ◽  
Melvina Laurensia ◽  
Yuana Elly Agustin ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Kinetic Model ◽  
Sodium Nitrate ◽  
Kinetic Constant ◽  
Arthrospira Platensis ◽  
Pilot Scale ◽  
Cod Removal ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Kinetics Of

Abstract The microalga Arthrospira platensis (Spirulina) is used for tempeh wastewater treatment. The microalga growth and the kinetics of COD degradation under different light intensities (2,100 and 4,300 lux), tempeh wastewater concentrations (0, 0.5, 1, 1.5% v/v), and sodium nitrate concentrations (0, 0.75, 1, 2, 2.5 g/L) were studied. Improved cell growth in wastewater indicated that mixotrophic growth was preferred. The addition of sodium nitrate up to 2 g/L increased the COD removal. The highest COD removal was 92.2%. It was obtained from the cultivation with 1% v/v tempeh wastewater, 2 g/L sodium nitrate, 2,100 lux, and the specific growth rate of 0.33 ± 0.01 day−1. The COD removal followed a pseudo first – order kinetic model with the kinetic constant of 0.3748 day−1 and the nitrate uptake rate of 0.122 g/L-day. The results can be used to design a pilot – scale tempeh wastewater treatment facility using A. platensis for tertiary treatment. Based on the kinetic model, a 20 m3 reactor can treat tempeh wastewater to reduce the COD from 400 to 100 ppm in 4 days and produces approximately 32.8 kg of dried microalgae.

scholarly journals Kinetic Modeling of a Heterogeneous Fenton Oxidative Treatment of Petroleum Refining Wastewater

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Diya'uddeen Basheer Hasan ◽  
Abdul Aziz Abdul Raman ◽  
Wan Mohd Ashri Wan Daud
Keyword(s):  
Kinetic Model ◽  
Direct Conversion ◽  
Order Kinetic ◽  
Initial Oxidation ◽  
Oxidation Step ◽  
Kinetic Rate Constants ◽  
Order Kinetic Model ◽  
Generalized Kinetic Model ◽  
Petroleum Refinery Effluent ◽  
Kinetics Of

The mineralisation kinetics of petroleum refinery effluent (PRE) by Fenton oxidation were evaluated. Within the ambit of the experimental data generated, first-order kinetic model (FKM), generalised lumped kinetic model (GLKM), and generalized kinetic model (GKM) were tested. The obtained apparent kinetic rate constants for the initial oxidation step (k2′), their final oxidation step (k1′), and the direct conversion to endproducts step (k3′) were 10.12, 3.78, and 0.24 min−1for GKM; 0.98, 0.98, and nil min−1for GLKM; and nil, nil, and >0.005 min−1for FKM. The findings showed that GKM is superior in estimating the mineralization kinetics.

scholarly journals Fractional kinetics of photocatalytic degradation

2018 ◽  
Vol 08 (05) ◽  
pp. 1850034 ◽  
Author(s):  
C. L. Wang
Keyword(s):  
Kinetic Model ◽  
Photocatalytic Degradation ◽  
Degradation Process ◽  
Order Kinetic ◽  
Material Parameters ◽  
First Order ◽  
Fractional Kinetics ◽  
Order Kinetic Model ◽  
Kinetics Of ◽  
Degradation Time

In this paper, photocatalytic degradation processes of different materials are fitted to the first-order kinetic model, second-order kinetic model and fractional first-order kinetic model. Deterministic coefficients are calculated for the evaluation of the validity of these models. The fitting results show clearly that the degradation process can fit the fractional first-order kinetic model in a very good manner. In this way, two material parameters can be well defined. One is the degradation time, which can be used to describe the photocatalytic degradation process quantitatively. Another is the order of the derivative, which could be related to the material’s microstructure.

Kinetics of Reductive Dechlorination of DDT in Soil with Zero-Valent Iron

2011 ◽  
Vol 295-297 ◽  
pp. 1236-1239
Author(s):  
Yin Hai Lang ◽  
Min Jie Wang ◽  
Nan Nan Wang
Keyword(s):  
Kinetic Model ◽  
Reductive Dechlorination ◽  
Reaction Rate ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
First Order ◽  
Reaction Rate Constants ◽  
Order Kinetic Model ◽  
Pseudo First Order ◽  
Kinetics Of

In this study, reductive dechlorination of DDT compounds by zero-valent iron in Jiangxi red soil was investigated. DDT compounds were effectively dechlorinated by zero-valent iron. The pseudo-first-order kinetic model for 2,4¢-DDT and 4,4¢-DDT reduction with zero-valent iron was proposed. The reaction rate constants for 2,4¢-DDT and 4,4¢-DDT were 1.19´10-2(min-1) and 1.44´10-2(min-1), respectively. The dechlorination of 2,4¢-DDT and 4,4¢-DDT were mainly affected by the specific surface area of iron. The data from the variable-pH experiments (between 3.6 and 8.8) suggested that pH does not play a role in the rate-determination step.

Rehydration Capacity and Kinetics of Solar-Dried Carrot (Daucus carota) Slices as Affected by Blanching and Osmotic Pretreatments

2016 ◽  
Vol 12 (2) ◽  
pp. 203-210
Author(s):  
F. Teferra Tadesse ◽  
Solomon Abera ◽  
W. K. Solomon
Keyword(s):  
Kinetic Model ◽  
Hot Water ◽  
Soluble Solids ◽  
Order Kinetic ◽  
Salt Solutions ◽  
First Order ◽  
Treatment Conditions ◽  
Order Kinetic Model ◽  
Soluble Solid ◽  
Kinetics Of

Abstract This study investigated effects of pretreatments on rehydration characteristics of solar-dried carrot slices. Blanching at 55, 65 and 75°C for 45 minutes and osmotic dewatering in 5%, 10% and 15% salt solutions for 5 h were used as pretreatments. Rehydration capacity of the dried carrots was determined by soaking 20 g sample in hot water at 95°C for 10 min and rehydration kinetics was carried out by soaking 5 g samples at 75, 85 and 95°C. All the treatment conditions separately and in combination influenced the rehydration characteristics of the carrot slices. High values of rehydration capacity and low lixiviated soluble solids, which indicates better quality, were obtained for samples treated at the lower blanching temperature. Similarly the lower salt concentration resulted in higher rehydration capacity and lower lixiviated soluble solids. The interaction of the lower level of both pretreatments produced higher rehydration capacity and lower soluble solid losses. A first-order kinetic model was used to describe the rehydration kinetics. A better rehydration performance was observed for the samples subjected to the lower levels of pretreatments and rehydration conditions.

Color Change Kinetics of Tea Leaves During Microwave Drying

2015 ◽  
Vol 11 (2) ◽  
pp. 255-263
Author(s):  
Elçin Demirhan ◽  
Belma Özbek
Keyword(s):  
Kinetic Model ◽  
Color Change ◽  
Microwave Drying ◽  
Order Kinetic ◽  
Tea Leaves ◽  
Total Color Change ◽  
Order Kinetic Model ◽  
Hue Angle ◽  
Sample Amount ◽  
Kinetics Of

Abstract In the present study, the effect of microwave power and sample amount on color change kinetics of tea leaves was investigated during microwave drying. Hunter L, a and b system was used for the color change of the materials; and the total color change (ΔE), chroma, hue angle and browning index (BI) were calculated by using these values. The color of the tea leaves was shifted towards the darker region after the microwave drying process. The mathematical modeling study of color change kinetic showed that a, b, chroma and BI fitted to a first-order kinetic model, while L, total color change (ΔE) and hue angle followed a zero-order kinetic model. For calculation of the activation energy for color change kinetic parameters, the exponential expression based on Arrhenius equation was used.

Oxidation Decoloration Kinetics of C.I. Direct Blue 108 in Activated Oxygen Bleach Systems

2011 ◽  
Vol 332-334 ◽  
pp. 391-394 ◽  
Author(s):  
Yang Zhu ◽  
Ren Cheng Tang
Keyword(s):  
Kinetic Model ◽  
Order Kinetic ◽  
Activated Oxygen ◽  
Direct Blue ◽  
Two Systems ◽  
Order Kinetic Model ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Decoloration Rate ◽  
Decoloration Kinetics

The decoloration behaviors of C.I. Direct Blue 108 in two activated oxygen bleach systems (PB/TAED and PC/TAED) were investigated. It was found that the decoloration kinetics of the dye in the two systems followed the first-order kinetic model and the rate constants calculated by linear regression increased significantly with increasing temperature. The activation energies for the decoloration in PB/TAED and PC/TAED systems were 63.34 and 58.10 kJ/mol, respectively. Moreover, the highest decoloration rate constant was obtained at pH 9 in the two systems. The kinetic model had not changed with temperature and pH in the two systems.

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