Effect of pH, flow rate and concentration on the sorption of Pb and Cd on montmorillonite: II. Modelling

Altin, O
Ozbelge, OH
Doğu, Timur
A mathematical model is proposed and compared with experimental data for the migration of heavy metal ions (Pb and Cd) during the flow of aqueous solutions through calcium-saturated montmorillonite packing. The main system parameters are pH, flow rate and concentration. It is assumed that the Liquid phase in the porous montmorillonite can be divided into two regions, mobile and immobile; that adsorption and ion exchange on the clay surface are instantaneous, and that adsorption isotherms are Linear throughout the modelling considered. The Ranges of experimental parameters are: pH 2.5-7.3, solution flow rate of 0.1-1 cm(3) min(-1) and heavy metal concentrations of 5-10 ppm. Breakthrough curves (BTCs) obtained experimentally are affected by changes in pH and flow rates. Between pH 2.5 and 4, the model equations describe the process quite well but from 4 to 7 a large deviation between the model and experimental data is observed due to precipitation of metals. (C) 1999 Society of Chemical Industry.


OZEN, S; OZILGEN, M (Wiley, 1992-01-01)
The kinetics of growth and lactic acid production by mixed cultures of Lactobacillus bulgaricus and Streptococcus thermophilus were modeled with a set of modified logistic and Luedeking-Piret equations. The specific growth rates and the inhibitory effect of each individual species on the mixed culture growth were found to be determined by the media composition. The kinetic analysis clearly showed that the contribution of each microbial species to the mixed culture growth process changed drastically when the...
Effect of pH, flow rate and concentration on the sorption of Pb and Cd on montmorillonite: I. Experimental
Altin, O; Ozbelge, OH; Doğu, Timur (Wiley, 1999-12-01)
Continuous column adsorption of lead (Pb) and cadmium (Cd) was studied using pH adjustment and calcium-saturated montmorillonite in a short stainless steel column. Changing either pH or flow rate, while keeping inlet concentration of the ions constant, led to considerable changes in effluent concentrations and breakthrough curves (BTCs). At low pH values (2-4), H+ ions competed strongly with lead and cadmium ions; at intermediate pH (4-6), ionic size played the major role in adsorption and ion exchange and ...
Effect of gramicidin S on the dipalmitoylphosphatidyl-glycerol thermotropic phase transition in DPPG/GS systems: A mathematical approach
Stan, Cristina; Cristescu, C. P.; Severcan, Feride; Dorohoi, Dana (Informa UK Limited, 2006-01-01)
We present a mathematical approach to the experimental data recorded via Fourier transform-infrared spectroscopy regarding the influence of the concentration of the antimicrobial peptide gramicidin S (GS) on the thermotropic phase transition of the dipalmitoylphosphatidyl-glycerol (DPPG) lipid bilayer membrane in DPPG/GS systems. The model is based on the influence of the GS concentration on the parameters of a nonlinear damped oscillator, which models the CH2 symmetric stretching band.
Effect of biogenic substrate concentration on chlorophenol degradation kinetics
ŞAHİNKAYA, Erkan; Dilek, Filiz Bengü (Wiley, 2006-09-01)
The effects of biogenic substrate (peptone) concentration on reactor performance, yield coefficient (Y) and degradation kinetics were evaluated in an instantaneously fed sequencing batch reactor (SBR) receiving a mixture of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP). High chemical oxygen demand (COD) removal efficiencies (90-95%) and complete removal of chlorophenols were observed even in the absence of peptone (i.e. chlorophenols served as sole carbon and energy sources). During the degradation...
Effect of heating rate on thermal properties and kinetics of raw and cleaned coal samples
Özbas, Kazim Esber; Hicyilmaz, Cahit; Kök, Mustafa Verşan (Informa UK Limited, 2003-01-01)
In this article, thermogravimetry (TG/DTG) was used to determine the effect of heating rate on the thermal properties and kinetics of raw and cleaned coal samples from Soma, Tuncbilek, and Afsin Elbistan regions. TG/DTG experiments were carried out at 4 different heating rates (5, 10, 15, and 20degreesC/min). Generally, for all of the samples higher peak and burnout temperatures were measured with an increasing heating rate. Kinetic parameters of the samples were determined using an Arrhenius-type kinetic m...
Citation Formats
O. Altin, O. Ozbelge, and T. Doğu, “Effect of pH, flow rate and concentration on the sorption of Pb and Cd on montmorillonite: II. Modelling,” JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY, pp. 1139–1144, 1999, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/62806.