Mathematical methods have been developed to evaluate solid-state kinetics. They generally fall into two categories: model-fitting or model-free (isoconversional). Modelfitting methods determine the kinetic triplet (model, frequency factor and activation energy) whereas isoconversional (model-free) methods generate the activation energy as a function of reaction progress without modelistic assum...

the hydrolysis of sodium borohydride as a source of hydrogen gas is studied at different mole ratios of h+ to nabh4. the sulfonated porous carbon (spc) is used as a source of hydrogen ion and catalyst. it is found that the sulfonated porous carbon exhibits high activity for the hydrolysis of nabh4 to generate hydrogen gas at room temperature in comparison to amberlyst-15 and nafion-nr50. the ki...

Steady-state isotopic-transient kinetic analysis (SSITKA) is a very useful technique for the kinetic study of heterogeneous catalytic reactions. Initially developed by Happe1,l Bennett,2 and Biloen? SSITKA has been used in a number of studies to determine in situ kinetic information about the reaction mechanism and the catalyst-surface reaction intermediates. The technique is based upon the det...

UV photolysis is an effective process to remove nitrosamines from contaminated water resources.

the solutions of mathematical models for the estimation of the kinetic, and biokinetic parameters of naphthalene, anthracene and pyrene during degradation in surface and subsurface soils are presented in this work. the models were developed using the twin concepts of rate-determining step and steady-state approximation method. they described the biodegradation of single and a mixture of polycyc...

Determination of the optimum kinetic model is an essential prerequisite for characterizing dynamics and mechanism of a reaction. Here, we propose a simple method, termed as singular value decomposition-aided pseudo principal-component analysis (SAPPA), to facilitate determination of the optimum kinetic model from time-resolved data by bypassing any need to examine candidate kinetic models. We d...

Adsorption-desorption of arsenic is the primary factor that impacts the bioavailability and mobility of arsenic in soils. To examine the characteristics of arsenate [As(V)] adsorption-desorption, kinetic batch experiments were carried out on three soils having different properties, followed by arsenic release using successive dilutions. Adsorption of As(V) was highly nonlinear, with a Freundlic...