6 research outputs found
Separation of oil-in-water emulsions by flow through fiber beds: A response surface approach
Separation of oil-in-water emulsions using fiber bed coalescer was studied by
response surface methodology. The bed was formed of polyethylene
terephthalate fibers. The aim was to investigate the possibility of using
response surface regression for the analysis and prediction of both the
effluent oil concentration and critical velocity in broad ranges of flow
rates, bed permeabilities, and nature of dispersed oil phase. The developed
response surface equations for a constant bed permeability are a responsive
statistical method with the calculated multiple R higher than 90%. It was
found that dispersed oil density, viscosity, neutralization number, and bed
permeability influence significantly the oil removal efficiency of fiber bed
coalescers. The region of highest critical velocity has been observed for a
high viscosity and a high fiber bed permeability. The developed response
surface models can be used to ensure high separation efficiency and improve
coalescer performance when unexpected simultaneous changes in the bed
permeability, hydrodynamic forces and dispersed oil properties take place.
[Projekat Ministarstva nauke Republike Srbije, br. 172022
Separation of mineral oil droplets using polypropylene fibre bed coalescence
This paper investigates the separation possibilities of model emulsion
oil-in-water using polypropylene fibre bed coalescence. Experiments were
carried out over a wide range of physico-chemical characteristics of mineral
oils, bed permeability and operating fluid velocities. The aim of this study
was to analyse the influence of the dispersed oil phase nature and of the bed
geometry on the separation efficiency. From the obtained results, it can be
concluded that polypropylene fibres in the broadest studied range of bed
permeabilities and fluid velocities, effectively separate oil that is highly
polar. On the contrary, for the other two investigated oils at low values of
bed permeability a region was detected in which the coalescer is incapable to
operate. It has to be emphasized that the polypropylene fibres efficiently
separate all three investigated oils at the highest studied bed permeability.
[Projekat Ministarstva nauke Republike Srbije, br. 172022
Relationships between heavy metal content and magnetic susceptibility in road side loess profiles: A possible way to detect pollution
The vertical and horizontal contamination profile of the loess sediments located in the vicinity of the highway Novi Sad-Belgrade, with the intense frequency of vehicles, has been assessed. The heavy metal content (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) and hydrocarbon content were determined for the samples collected from two loess profiles in broad ranges of depth (0.15-4.50 m at 0.15 m intervals) and horizontally deeper in the sediment (0.01, 0.05 and 0.10 m). For all loess samples the contents of heavy metals were lower than the remediation intervention values. Hydrocarbon content in all analyzed sediment samples was below limit of quantification of 50 mg/kg. Magnetic susceptibility of the samples revealed the occurrence of one weak paleosol in one loess profile as well as the anthropogenic loess like deposits in the upper part of the second profile. The polynomial regression was successfully applied to estimate relationship between magnetic susceptibility of the loess and heavy metal content, total organic carbon and grain-size distribution. The developed second order equations are a responsive method with the calculated multiple R higher than 94%. The proposed statistical approach greatly simplifies the analysis of loess profile as a record of pollution, and it may serve to estimate the extremely high values of magnetic susceptibility influenced by small increase in heavy metal content, total organic carbon and grain size distribution
Liquid-liquid equilibrium constant for acetic acid in an olive oil-epoxidized olive oil-acetic acid-hydrogen peroxide-water system
The liquid-liquid equilibrium constant for acetic acid in a quinary system
olive oil-epoxidized olive oil-acetic acid-hydrogen peroxide-water was
experimentally determined for temperatures and component ratios relevant for
in situ epoxidation of plant oils. The values has the constant range from
1.52 to 2.73. To predict the equilibrium constant for acetic acid, the
experimental data were correlated with UNIQUAC (universal quasi chemical) and
NRTL (non-random two liquid) activity coefficient models. For simplified
calculation of the phase equilibrium the insolubility of olive oil and
epoxidized olive oil in the water, as well as insolubility of water and
hydrogen peroxide in the olive oil and epoxidized olive oil, was assumed. The
root mean square deviation (RMSD) of the experimental and calculated values
of the liquid-liquid equilibrium constant for acetic acid is 0.1910 for the
UNIQUAC model and 0.1815 for the NRTL model. For rigorous flash calculation,
when the partitioning of all components between the phases was assumed, the
RMSD for the NRTL model is 0.1749. [Projekat Ministarstva nauke Republike
Srbije, br. 45022