scholarly journals Partial acidulation of phosphate rock for enhanced phosphorus availability in alluvial soils of Bihar, India

2016 ◽  
Vol 8 (3) ◽  
pp. 1393-1397 ◽  
Author(s):  
Kasturikasen Beura ◽  
Rajeev Padbhushan ◽  
Amit Kumar Pradhan ◽  
Nintu Mandal

The present study was undertaken to fractionate partially acidulated phosphate rock (PAPR) and evaluate its effect on Phosphorus availability in alluvial soils. For this purpose, low grade phosphate rock was collected from Udaipur, Rajasthan and acidulated at different degrees with sulphuric acid (H2SO4) (v/v)Results from an incubation study showed that the available fraction of P [Water soluble (WSP) and Citrate soluble (CSP)] increased with increasing degree of acidulation. The maximum WSP was obtained at 50% H2SO4 (52.30% of total P) and the maximum CSP was obtained at 80% H2SO4 (49.54% of total P). 50 % dissolution of rock phosphate was the best treatment and found to be at par with that of 60% and 80% but was significantly superior to rest of the treatments. The maximum WSP in the soil samples was obtained after acidulation with 50 %H2SO4 and the maximum Olsen’s P by the 14th day of incubation. An increasing trend was found at initial stages of incubation (7-14 days) with a notable decrease in the later stages. WSP demonstrated the maximum correlation at 40% dissolution(r = 96* for first order reaction, r =95* for second order reaction) while for Olsen’s P, the maximum correlation was found in initial rock phosphate sample (r =88* for first order reaction, r =94* for second order reaction). Kinetics analysis of the obtained rock phosphate demonstrated that the PARP has more influence on phosphorus release pattern as compared to the inorganic P (SSP).

2014 ◽  
Vol 25 ◽  
pp. 6-11 ◽  
Author(s):  
R. Aathithya ◽  
J. Rajani Sowparnika ◽  
V. Balakrishnan

Biosorption is an attractive technology which is used for the sorption of substances by a biomaterial. In this present work the heavy metal chromium was subjected to biosorption because of their non-degradability nature and causes water and land pollution. Cherry leaves were used as a biomaterial for the biosorption. Kinetic studies were performed for the biosorption experiment. From the experiment it was found that the reaction follows pseudo first order reaction because of the larger value of regression coefficient R2 and lower value of standard errors (χ2) for pseudo first order reaction than second order reaction.


2014 ◽  
Vol 28 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Lech W. Szajdak ◽  
Jerzy Lipiec ◽  
Anna Siczek ◽  
Artur Nosalewicz ◽  
Urszula Majewska

Abstract The aim of this study was to verify first-order kinetic reaction rate model performance in predicting of leaching of atrazine and inorganic compounds (K+1, Fe+3, Mg+2, Mn+2, NH4 +, NO3 - and PO4 -3) from tilled and orchard silty loam soils. This model provided an excellent fit to the experimental concentration changes of the compounds vs. time data during leaching. Calculated values of the first-order reaction rate constants for the changes of all chemicals were from 3.8 to 19.0 times higher in orchard than in tilled soil. Higher first-order reaction constants for orchard than tilled soil correspond with both higher total porosity and contribution of biological pores in the former. The first order reaction constants for the leaching of chemical compounds enables prediction of the actual compound concentration and the interactions between compound and soil as affected by management system. The study demonstrates the effectiveness of simultaneous chemical and physical analyses as a tool for the understanding of leaching in variously managed soils.


1993 ◽  
Vol 28 (2) ◽  
pp. 135-144 ◽  
Author(s):  
S. Matsui ◽  
R. Ikemoto Yamamoto ◽  
Y. Tsuchiya ◽  
B. Inanc

Using a fluidized bed reactor, experiments on glucose decomposition with and without sulfate reduction were conducted. Glucose in the reactor was mainly decomposed into lactate and ethanol. Lactate was mainly decomposed into propionate and acetate, while ethanol was decomposed into propionate, acetate, and hydrogen. Sulfate reduction was not involved in the decomposition of glucose, lactate, and ethanol, but was related to propionate and acetate decomposition. The stepwise reactions were modeled using either a Monod expression or first order reaction kinetics in respect to the reactions. The coefficients of the kinetic equations were determined experimentally. The modified Monod and first order reaction equations were effective at predicting concentrations of glucose, lactate, ethanol, propionate, acetate, and sulfate along the beight of the reactor. With sulfate reduction, propionate was decomposed into acetate, while without sulfate reduction, accumulation of propionate was observed in the reactor. Sulfate reduction accelerated propionate conversion into acetate by decreasing the hydrogen concentration.


1981 ◽  
Vol 46 (2) ◽  
pp. 452-456
Author(s):  
Milan Šolc

The successive time derivatives of relative entropy and entropy production for a system with a reversible first-order reaction alternate in sign. It is proved that the relative entropy for reactions with an equilibrium constant smaller than or equal to one is completely monotonic in the whole definition interval, and for reactions with an equilibrium constant larger than one this function is completely monotonic at the beginning of the reaction and near to equilibrium.


1992 ◽  
Vol 57 (7) ◽  
pp. 1451-1458 ◽  
Author(s):  
Refat M. Hassan

The kinetics of oxidation of arsenic(III) by hexachloroiridate(IV) at lower acid concentrations and at constant ionic strength of 1.0 mol dm-3 have been investigated spectrophotometrically. A first-order reaction in [IrCl62-] and fractional order with respect to arsenic(III) have been observed. A kinetic evidence for the formation of an intermediate complex between the hydrolyzed arsenic(III) species and the oxidant was presented. The results showed that decreasing the [H+] is accompanied by an appreciable acceleration of the rate of oxidation. The activation parameters have been evaluated and a mechanism consistent with the kinetic results was suggested.


2019 ◽  
Vol 292 ◽  
pp. 01063
Author(s):  
Lubomír Macků

An alternative method of determining exothermic reactor model parameters which include first order reaction rate constant is described in this paper. The method is based on known in reactor temperature development and is suitable for processes with changing quality of input substances. This method allows us to evaluate the reaction substances composition change and is also capable of the reaction rate constant (parameters of the Arrhenius equation) determination. Method can be used in exothermic batch or semi- batch reactors running processes based on the first order reaction. An example of such process is given here and the problem is shown on its mathematical model with the help of simulations.


1975 ◽  
Vol 28 (4) ◽  
pp. 759 ◽  
Author(s):  
NS Ham ◽  
JR Hall ◽  
GA Swile

A quantitative analysis of the variable-temperature 1H N.M.R. spectra of acetylacetonatotrimethyl-platinum(IV) has been made. In CDCl3 solution the exchange of acetylacetonate ligands is a first-order reaction and proceeds predominantly by dissociation of the dimer into two separated five-coordinate activated complexes. The activation energy is 61.5 � 0.8 kJ mol-1.


2015 ◽  
Vol 10 (2) ◽  
Author(s):  
Iwan Sumarlan

Abstrak: Dispersi TiO2 ke dalam montmorilonit terpilar aluminium (PILM) telah sukses dilakukan. Fotokatalis dibuat dengan menginterkalasikan Al13 ke dalam montmorilonit alam kemudian dikalsinasi pada temperatur 500oC. Dispersi TiO2 ke dalam montmorilonit terpilar aluminium (PILM) dilakukan dengan menggunakan metode impregnasi dengan konsentrasi teoritis 0,4%, 0,8% 1% dan 3%. Fotodegradasi metil oranye optimum diperoleh pada Ti/PILM 1%, pH 10, konsentrasi metil oranye 1,5 M dan konsentrasi katalis 1 gram/liter dengan laju konstanta orde satu sebesar 21,77x10-3 per menit.Kata kunci : Metil Oranye, Montmorilonit,Optimasi, Fotokatalis, TiO2Abstract: Dispersion of TiO2 on montmorillonite pillared aluminium has been done successfully. The photocatalyst were prepared by intercalation of Al13 onto natural montmorillonite and then calcined at 500oC. Titania dispersion onto aluminium pillared montmorillonite was carried out by impregnation method at the theoritic concentration of 0.4%, 0.8%, 1% and 3% titania. Photodegradation optimum of methyl orange was found to be at Ti/PILM 1%, pH 10, methyl orange concentration 1.5 M and concentration of photocatalyst 1 gram/litre. The photodegradation follows first order reaction with constan rate of 21.77x10-3 per minutes.Key Word: Methyl Orange, Montmorillonite, Optimation, Photocatalyst, TiO2


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