Measurements of flash-induced absorption changes at 325, 436, and 830 nm and of oxygen evolution were performed in order to analyze in detail the inhibition of photosystem II (PS II) by Cu(II) in PS II membrane fragments from spinach. (a) The kinetics of P680+ reduction become markedly slower in the presence of 100 microM CuSO4. (b) The CuSO4-induced kinetics of P680+ reduction are dominated by...

In this work, kinetics and thermodynamics of esterification reaction were studied. This research investigated the esterification reaction between methanol and acidified oil catalyzed by sulfonated cation exchange resin and proposed a new rate equation for consideration of kinetics of this reaction according to the Langmuir-Hinshelwood mechanism. Thermodynamics and kinetics parameters were calcu...

operational variables of a mineral processing circuit are subjected to different variations. steady-statesimulation of processes provides an estimate of their ideal stable performance whereas their dynamicsimulation predicts the effects of the variations on the processes or their subsequent processes. in thispaper, a dynamic simulator containing some of the major equipment of mineral processing...

Background & Aims of the Study: Nitrogenous compounds could directly create many problems for human's health and the environment. Thus, removal of nitrogenous compounds is necessary. Among the most important problems, decreasing dissolved oxygen, toxicity for aquatics, eutrophication, converting aerobic medium into anaerobic one and corrosion could be noted. The aim of this stu...

The present review updates our knowledge about chlorophenols, their chemical reactions and transformations in the natural environment, as well as factors affecting kinetics and mechanisms of these processes. Effects of pH of the environment and structure of molecules (also the number of chlorine atoms and their position in the molecule) on the behaviour of these compounds in the natural environ...

Background: Amongst the methods that remove heavy metals from environment, biosorption approaches have received increased attention because of their environmentally friendly and cost-effective feature, as well as their superior performances. Methods: In the present study, we investigated the ability of a surface-engineered Escherichia coli, carrying the cyanobacterial metallothionein on the cel...

Nickel and cadmium usually enter the environment and water resources through wastewater, released by various industries, and may have adverse effects. The current study employs α–Fe2O3 nanoparticles of 20-40 nm in order to remove nickel and cadmium from the wastewater of Saba Battery Company. Also, it investigates the influence of effective parameters on adsorption process, including pH, contac...

Dyeing wastewaters are one of the most common pollutants that cause many problems for public health and environment due to dermatitis and skin rashes, cancer production, mutagenesis, etc. Thus, treatment of these wastewaters is necessary. The purpose of this study was to investigate the efficiency of montmorillonite nanoparticles as an adsorbent in adsorption process of Reactive Ye...

The kinetics of the flux of a charged macromolecular solution through an environment of changing geometry with wide and constricted regions is investigated analytically. A model device consisting of alternating deep and shallow slits known as an "entropic trap" is used to represent the environment. The flux is supported by the external electrostatic field. The "wormlike chain" model is used for...