background & aims of the study: dyes are one of the widespread chemicals which may have many adverse effects on life cycle. thus, this study was conducted to survey the rb19 dye removal efficacy from aqueous solution, using the sio2 nanoparticles. materials and methods: this study was an experimental-lab study. the batch adsorption system were utilized to evaluated the rb19 dye removal efficien...

microbial cells are producers of natural polymers present in plant cells. production of pullulan (an extracellular microbial polysaccharide) by aureobasidium pullularia pullulans (p. pullulans) was studied under fermentation conditions, and kinetic parameters were determined. pullulan formation obeyed a growth and non-growth associated term. phb (polyhydroxybutyrates) an intracellular biopolyme...

abstractthe purpose of this study was to investigate the controllable operating parameters influence, including ph, solid content, collector, co-collector, and depressant dose, and conditioning time, on apatite flotation kinetics. four first order flotation kinetic models are tested on batch flotation time-recovery profiles. the results of batch flotation tests and the fitting of first-order ki...

bioremediation, the process by which microorganisms degrade organic compounds to non-toxic or less toxic substances, has been widely used for cleanup of coastal ecosystems after oil spills. in this study, the hydrocarbon degradation rate and half lives in three bioremediation strategies (natural attenuation, biostimulation, and bioaugmentation) were compared in weathered crude oil (wco) contami...

in this research, adsorption of dibenzothiophene (dbt) as a model of sulfur containing material has been studied by pb exchanged y-zeolite under different experimental conditions. the adsorption was kinetically fast and high adsorption capacity was obtained. the equilibrium adsorption data were analyzed using langmuir and freunlich isotherm models. the corresponding parameters and correlation c...

in the present work, we have investigated the sorption efficiency of the treated activated carbon from walnut shell(acw) towards direct red 81 (dr81) and direct blue 71 (db71) for the removal from aqueous solution. thesorption study of acw at the solid-liquid interface was investigated using kinetic, sorption isotherms, ph effectand amount of adsorbent. experimental data were analyzed by langmu...

this study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (v). the method is based upon the catalytic effect ofvanadium (v) on the oxidation of carminic acid by bromate in sulfuric acid media. the reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...

the present work reports a kinetic spectrophotometric method for the determination of traceamounts of sulphite that is based on inhibitory effect of sulphite on the oxidation of methyleneblue (mb) in acidic media. the reaction is followed spectrophotometrically by monitoring thedecrease in absorbance of mb at 664 nm with a fixed time of 0.5-4.5 minutes. it was found thatsulphite exert a strong ...

this paper deals with a theoretical mathematical analysis of one-dimensional solidification problem, in which kinetic undercooling is incorporated into the this temperature condition at the interface. a model problem with nonlinear kinetic law is considered. we prove a local result intimate for the uniqueness of solution of the corresponding free boundary problem.

Lactic acid production in a batch submerged fermentation process by five Lactobacilli: bulgaricus, casei, lactis, delbrueckii and fermentum in lactose fortified whey culture were investigated. Kinetic behavior of Lactobacilli growth rate and lactose utilization was studied based on the Moser and Gompertz kinetic models. Trendline tool in Excel software was applied for fitness assessment of the ...