for preventing groundwater and soil from heavy metal contamination and/or to decrease contamination, and to clean up the former disposal sites from these metals, one must be beforehand able to predict the movement of these pollutants in soils. in this research in order to describe cadmium [cd (ii)] transport in soils, we incorporated an equilibrium-kinetic two-site model into the convection-dis...

nickel is one of the toxin heavy metals in surface waters. developing new approaches aimed at removing heavy metals from aqueous solutions that are simultaneously economical and environmentally friendly is of great importance. the purpose of this study will be using nano-lignocellulose adsorbent as a natural material to remove nickel heavy metal. in this study, several important environmental p...

water for agriculture is one of the most important factors in arid and semi-arid areas and municipal wastewater treatment is an important resource for this purpose. therefore, potential of transfer contaminations is a serious problem regarding use of treated wastewater for agriculture. due to the risk of transfer contaminations through the use of wastewater, the study of transfer microbes in so...

plug-flow digesters with periodic loading mechanism are more enthusiastic than fully mechanized digestion plants for the majority of small or medium scale farms according to the costs and operational complexities. a dual-compartment plug-flow reactor equipped with a passive heating system was designed and experimentally operated by purpose of demonstrating a simple and low cost technology for h...

In this study, nano-TiO2 was employed for the adsorption of chloroform from aqueous solution in batch equilibrium experiments to investigate its adsorption properties. The effects of pH, initial chloroform concentration and nano-TiO2 dosage were also investigated. Optimal conditions for chloroform removal by nano-TiO2 have been then identified. Results of equilibrium experiments showed that the...

In this study simulation and optimization of an industrial acetylene hydrogenation reactor was studied. Three well known kinetic models were used for a nearly similar catalyst to predict the industrial data. Due to the complexity of the reactions, none of the offered kinetic models could be considered as an exact kinetic model and it is necessary to determine the kinetic parameters. One of the ...

A kinetic model of a fixed bed tubular reactor incorporating catalyst deactivation was developed for the ISOMAX unit of Arak refinery. The kinetic parameters for the hydrocracking reactions over the commercial catalyst were determined using initial activity plant data i.e. when the catalyst is fresh. Catalyst deactivation was then taken into account by means of deactivation function based on pl...

In this study, nano-TiO2 was employed for the adsorption of chloroform from aqueous solution in batch equilibrium experiments to investigate its adsorption properties. The effects of pH, initial chloroform concentration and nano-TiO2 dosage were also investigated. Optimal conditions for chloroform removal by nano-TiO2 have been then identified. Results of equilibrium experiments showed that the...

A mathematical model for commercial naphtha catalytic reformer of Tehran refinery was developed. This model includes three sequencing fixed beds of Pt/Al2O3 catalyst at the steady state condition using detailed kinetic scheme involving 26 pseudo-components connected by a network of 47 reactions, in the range of C6 to C9 hydrocarbons. The reaction network consisted dehy...