scholarly journals Study on environmental behaviour of fluopyram in different banana planting soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jia Zhou ◽  
Shuilian Liang ◽  
Yuanyuan Cui ◽  
Yu Rong ◽  
Jia Song ◽  
...  
Keyword(s):  
Sandy Soil ◽  
Alluvial Soil ◽  
Order Kinetic ◽  
Environmental Behaviour ◽  
First Order ◽  
Degradation Rates ◽  
And Migration ◽  
Agricultural Areas ◽  
Banana Leaf ◽  
Order Kinetic Equation

AbstractFluopyram is commonly used to control banana leaf spot, anthracnose, and scab in tropical agricultural areas. To explore its behaviour in tropical agricultural environments, dissipation, adsorption, and leaching behaviours of fluopyram in three typical banana planting soils were studied. Also, its dissipation and migration capabilities in different regions and different soil types were evaluated. The results showed that the dissipation of fluopyram was in accordance with the first-order kinetic equation in the three banana soils, but the degradation rates were quite different. The degradation half-lives in the Hainan latosol, Yunnan sandy soil, and Fujian Plain alluvial soil were 46.21 days, 36.48 days and 57.76 days, respectively. Fluopyram also exhibited high adsorption and low leachability in the three soils. The Fujian Plain alluvial soil had the highest adsorption capacity for fluopyram, while fluopyram had the low leachability in the Yunnan sandy soil.

scholarly journals Effect of inoculum to substrate ratio on biogas production of sheep paunch manure

2016 ◽  
Vol 62 (No. 1) ◽  
pp. 8-14 ◽  
Author(s):  
A.A. Lawal ◽  
A.U. Dzivama ◽  
M.K. Wasinda
Keyword(s):  
Biogas Production ◽  
Coefficient Of Determination ◽  
Order Kinetic ◽  
Production Rates ◽  
Exponential Equation ◽  
First Order ◽  
Gompertz Equation ◽  
Volatile Solids ◽  
Substrate Ratio ◽  
Order Kinetic Equation

Sheep paunch manure was anaerobically digested to study the effect of inoculum to substrate ratio on biogas production rates and accumulation. Inoculum to substrate ratios of 1.37, 2.05 and 4.1 were digested in biodigesters labelled R1, R2 and <br /> R3 respectively. Results showed that inoculum to substrate ratio had a significant effect on biogas production rates and accumulation. Biogas production rates increased to peak in the order of R3 (0.30526 Nm<sup>3</sup>/kg volatile solids (VS) days), R2 (0.15308 Nm<sup>3</sup>/kg VS d) and R1 (0.11009 Nm<sup>3</sup>/kg VS d) on the 5<sup>th</sup> day. The biogas production accumulation increased from 0.57195 to 1.46784 Nm<sup>3</sup>/kg VS as the inoculum to substrate ratio increased. The result of regression showed that coefficient of determination values for the linear equation ranged from 0.707 to 0.797, while the exponential equation had higher values that ranged from 0.7718 to 0.9929 showing better simulation. The modified Gompertz equation showed better simulation of the biogas production accumulation than the first order kinetic equation due to its higher coefficient of determination values.

Degradation of 4-nitrophenol using the Fenton process

2000 ◽  
Vol 42 (3-4) ◽  
pp. 155-160 ◽  
Author(s):  
Y.-S. Ma ◽  
S.-T. Huang ◽  
J.-G. Lin
Keyword(s):  
Kinetic Equation ◽  
Nitrogen Concentration ◽  
Order Kinetic ◽  
Fenton Process ◽  
Nitrogenous Compounds ◽  
First Order ◽  
Degradation Rate Constant ◽  
Before And After ◽  
Pseudo First Order ◽  
Order Kinetic Equation

In this study, The Fenton process was applied as a pretreatment method to treat industrial wastewater containing 4-nitrophenol (4-NP). The effect of oxidant dosages on the decomposition of 4-NP and the reaction kinetics were investigated. More than 99% of 4-NP was readily decomposed when the reaction was carried out at oxidant concentrations of 5 mM H2O2 and 5 mg/L Fe2+ for 2 hours. The total nitrogenous compounds and the nitrogen gas evolved, accounted for 88% of the initial nitrogen concentration. However, the maximum DOC removal efficiency was 30.6%; and only 1/3 of 4-NP was mineralized to carbon dioxide by the Fenton process. 4-NP degradation profiles fitted well into a pseudo first-order kinetic equation; degradation rate constant (min-1) of 4-NP increased from 4.3×10-3 to 66.1×10-3 with increasing dosages of H2O2 and Fe2+. In addition, the t value was calculated for studying the significance of simulation by the t-test. It was found that the t value was greater than the value for 99% confidence. This result suggested that the 4-NP decomposition profile could be described by the pseudo first-order kinetic equation. Biodegradability of 4-NP before and after the reaction was 0.018 and 0.594, respectively.

Performance evaluation of anoxic and facultative wastewater stabilization ponds

1996 ◽  
Vol 33 (7) ◽  
pp. 141-145 ◽  
Author(s):  
Muwaffaq M. Saqqar ◽  
M. B. Pescod
Keyword(s):  
Performance Evaluation ◽  
Kinetic Equation ◽  
Simple Model ◽  
Operating Time ◽  
Order Kinetic ◽  
Sediment Depth ◽  
First Order ◽  
Maximum Value ◽  
Wastewater Stabilization Ponds ◽  
Order Kinetic Equation

The performance of anoxic and facultative ponds in Jordan was investigated for 12 months. Calculated values of the first order kinetic equation rate for CBOD removal (KCBOD) has resulted in different KCBOD's for different ponds in the same month, at the same temperature. It is evident that factors other than temperature must influence values of KCBOD. The KCBOD values determined were generally lower than those reported in the literature. The maximum value found was only 0.16 (/day). A pond was emptied after 18 months of operation and sediment was found randomly distributed over the pond area, with a depth ranging from 2 to 6 cm (averaging ≈ 4 cm). A simple model has been established to estimate sediment depth (Hs in cm) in terms of the operating time in months (t).

UV Protectants for the Biopesticide Based on Photostabilization of Ecdysone

2011 ◽  
Vol 183-185 ◽  
pp. 401-405 ◽  
Author(s):  
Hua Nan Guan ◽  
De Fu Chi ◽  
Jia Yu
Keyword(s):  
Ultraviolet Light ◽  
Larvicidal Activity ◽  
Half Life ◽  
Moderate Degree ◽  
Order Kinetic ◽  
Synthetic Compounds ◽  
First Order ◽  
Glass Slides ◽  
Life Values ◽  
Order Kinetic Equation

The ultraviolet protectant (UV protectant) properties of different natural and synthetic compounds were investigated for a biopesticide based on ecdysone. This study examined the photostabilization of ecdysone when exposed to ultraviolet light in the presence of some ultraviolet protectants. Ecdysone solutions with and without UV protectants in methanol were applied onto the surface of glass slides. At particular intervals, the remaining concentration of ecdysone was analyzed by HPLC. Using first-order kinetic equation, the dissipation half-life values (DT50) for the degradation of ecdysone under ultraviolet radiation were obtained. The larvicidal activity was evaluated against the larvae of Martianus dermestoides Chevrolat. It indicated that the addition of congo red, yeast, starch and arabia gum provided moderate degree of photostabilization of ecdysone and that addition of lignin provided the best photostabilization of ecdysone, among these UV protectants studied. Toxicity of the ecdysone with UV protectants was higher to the larvae of M. dermestoides Chevrolat compared to the ecdysone alone as indicated by the lower EC50 value. The dissipation half-life values of ecdysone after irradiation under ultraviolet light and the larvicidal activity suggested that the addition of lignin (in 1:l mol ratio) can provide better photostabilization of ecdysone molecule.

scholarly journals Differential Thermal Analysis of Tobacco as a Function of Heating Rate

1977 ◽  
Vol 9 (1) ◽  
Author(s):  
C. O. Tiller ◽  
E. M. Gentry
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Heating Rate ◽  
Characteristic Temperature ◽  
Inert Atmosphere ◽  
Order Kinetic ◽  
First Order ◽  
Reconstituted Tobacco Sheet ◽  
Decomposition Processes ◽  
Order Kinetic Equation

AbstractThe differential thermal analysis of reconstituted tobacco sheet heated at rates of 0.1°C/s to 500°C/s in an inert atmosphere is reported. As the heating rate is increased, the characteristic temperature of each global process observed is increased. Using a non-isothermal first-order kinetic equation, the activation energies and frequency factors are obtained for these bulk decomposition processes

A field-study of leaching and degradation of nine pesticides in a sandy soil

Soil Research ◽  
1995 ◽  
Vol 33 (6) ◽  
pp. 1019 ◽  
Author(s):  
RS Kookana ◽  
HJ Di ◽  
LAG Aylmore
Keyword(s):  
Field Study ◽  
Sandy Soil ◽  
Water Contamination ◽  
High Performance ◽  
Dilute Solution ◽  
Ground Water Contamination ◽  
First Order ◽  
Degradation Rates ◽  
Residue Concentration ◽  
Different Depths

A field study was conducted on a coastal sandy soil (Karrakata sand) of Western Australia from July to December 1990, to measure the leaching and degradation rates of chlorpyriphos, chlorthal dimethyl, fenamiphos, linuron, metalaxyl, metribuzin, prometryne, propyzamide and simazine. Commercial grade products were sprayed in dilute solution form at recommended rates to the surface of held plots. Irrigation was applied daily which together with rainfall gave effective rainfall equivalent to at least 120% of potential evaporation. Pesticide residue concentrations in soil samples taken at 5 cm increments down to 50 cm, at different days after application, were determined by high performance liquid chromatography (HPLC). Mean leaching depths (MLDs) were calculated by weighting the percentage residues remaining at different depths in the soil profile. The MLDs for the 5 month period followed the order: chlorpyriphos and chlorthal dimethyl (<5 cm) < linuron and simazine (6) < propyzamide (8) and prometryne (9) < metribuzin (12) < metalaxyl (18) < fenamiphos and metabolites (28). This generally corresponded inversely with the sorption coefficients (K-oc). The degradation rates (i.e. decreases with time of total residue concentration in the sampled profile) could mostly be described by first-order regressions (R(2) = 0.59-0.95). Calculated half-lives showed the order: metribuzin (27 days), simazine (28) < fenamiphos (43), chlorthal dimethyl (45) < prometryne (58), propyzamide (59) < metalaxyl (70) < chlorpyriphos (81) < fenamiphos plus metabolites (98) < linuron (219). The potential for causing ground water contamination, as indicated by the ratio of half-life to Koc followed the order: chlorthal dimethyl, chlorpyriphos < metribuzin, prometryne < simazine, propyzamide < linuron < metalaxyl < fenamiphos and metabolites.

Process Mineralogy and Flotation Kinetic of a Copper Oxide Ore during Sulfuration Flotation

2013 ◽  
Vol 634-638 ◽  
pp. 3460-3465 ◽  
Author(s):  
Kun Xiong ◽  
Gui Shan Zheng
Keyword(s):  
Kinetic Equation ◽  
Copper Oxide ◽  
Kinetic Equations ◽  
Order Kinetic ◽  
Copper Ore ◽  
Total Recovery ◽  
Flotation Process ◽  
First Order ◽  
Process Mineralogy ◽  
Order Kinetic Equation

This study aims to investigate the process mineralogy of the Dishui copper ore in Xinjiang and determine the flotation kinetic equations of this copper ore during the sulfuration flotation process. The results indicate cuprite is the main form of oxide copper minerals, which is difficult to be vulcanized and floated. The fitting of flotation date to a flotation kinetic equation shows that the copper oxide ore, cuprite, malachite and chrysocolla in this ore are consistent with a first order kinetic equation. The rate constants for copper oxide, cuprite, malachite and chrysocolla are 0.152, 0.104, 0.248 and 0.210 respectively. Thus, the flotation of cuprite in the ore is very important to improve the total recovery of the copper oxide ore.

scholarly journals Dissipation Behavior of Three Pesticides in Prickly Pear (Opuntia ficus-indica (L.) Mill.) Pads in Morelos, Mexico

2019 ◽  
Vol 16 (16) ◽  
pp. 2922 ◽  
Author(s):  
Irene Iliana Ramírez-Bustos ◽  
Hugo Saldarriaga-Noreña ◽  
Ernesto Fernández-Herrera ◽  
Porfirio Juárez-López ◽  
Iran Alia-Tejacal ◽  
...  
Keyword(s):  
Life Time ◽  
Commercial Production ◽  
Residue Level ◽  
Prickly Pear ◽  
Order Kinetic ◽  
Opuntia Ficus Indica ◽  
First Order ◽  
Maximum Residue Level ◽  
Concentration Levels ◽  
Order Kinetic Equation

The dissipation of three field-applied pesticides (chlorothalonil, chlorpyrifos, and malathion), on cultivated prickly pear (Opuntia ficus-indica (L.) Mill.) pads was studied. The extraction of pesticides was carried out using the European quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction technique and detection was carried out using tandem liquid chromatography with mass spectrometry. At harvest, 15 days after application, pesticide dissipation was below the level of detectability. Dissipation curves for prickly pear pads fit to a first-order kinetic equation. Two initial concentration levels were used for each pesticide. The approximate dissipation time for all pesticides studied was similar (10 days) and the half-life time was around six days. Final concentrations for the three pesticides were below the reference maximum residue level (MRL) (0.01 mg/kg), which suggests that these products can be applied safely in the commercial production of prickly pear pads at the established concentrations.

Influence of multiple substrates on anaerobic protein degradation in a packed-bed bioreactor

2003 ◽  
Vol 48 (6) ◽  
pp. 23-31 ◽  
Author(s):  
G. Tommaso ◽  
R. Ribeiro ◽  
M.B.A. Varesche ◽  
M. Zaiat ◽  
E. Foresti
Keyword(s):  
Kinetic Model ◽  
Protein Degradation ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Order Kinetic ◽  
First Order ◽  
Multiple Substrates ◽  
Degradation Rates ◽  
Order Kinetic Model ◽  
Parallel Reactions

Data on the influence of substrate composition on the anaerobic degradation of bovine serum albumin (BSA) in a bench-scale packed-bed reactor are presented and discussed from the standpoint of substrate consumption kinetics. The experiments were carried out in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor fed with BSA based substrates. BSA was the sole carbon source in the first one, while the others were composed of BSA, carbohydrates and lipids. In all the experiments, the HAIB reactor was operated at the hydraulic detention time of 4 hours. The reactor's performance was evaluated based on physicochemical and chromatographic analyses and also on microscopy techniques. A kinetic model of irreversible first-order series-parallel reactions with two intermediate products was proposed, allowing evaluation of the microbial consortiumÕs affinity with the substrates and the metabolic compounds formed. As the first-order kinetic model adhered quite well to the experimental data, the initial protein degradation rates (k) were estimated. The presence of carbohydrates and lipids led the initial protein degradation rate to be reduced. However, the system fed with protein and carbohydrates showed higher process stability.

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