Wind-driven surficial oxygen transfer into stationary water bodies has become increasingly important because the fate of many pollutants in these water bodies is strongly influenced by oxygen mass transfer. There are many existing correlations that can be used for predicting wind-driven surficial oxygen transfer; however, the actual prediction has been difficult because there are large variatio...

Pseudomonas aeruginosa PAO1 was recently found to exhibit two remarkable physiological responses to oxidative stress: (1) a strong reduction in the efficiency of oxygen transfer from the gas phase into the liquid phase, thus causing oxygen limitation in the culture and (2) formation of a clear polysaccharide capsule on the cell surface. In this work, it has been shown that the iron concentratio...

An empirical correlation, based on conventional forms, has been developed to represent the oxygen mass transfer coefficient as a function of operating conditions and organic fraction in two-phase, aqueous-organic dispersions. Such dispersions are characteristic of two-phase partitioning bioreactors, which have found increasing application for the biodegradation of toxic substrates. In this work...

helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. in this kind of heat exchangers, flowand heat transfer are complicated. this paper reports a numerical investigation of theinfluence of different parameters such as coil...

This paper reports the results of experimentally removing ammonia from synthetically prepared ammonia solution using a micro scale mixing loop air stripper. Effects of various operational parameters (such as: pH, air flow rate, wastewater flow rate and initial ammonia concentration) were evaluated. By increasing the pH from 10 to 12.25 the amount of KLa increased from 0.26 to 0.73 hr-1. A consi...

The interfacial area a was measured by the sulfite oxidation method in a three-phase external loop airlift bubble column suspending completely the different concentrations of ion exchange resin particles in aqueous carboxymethyl cellulose (CMC) solutions with a wide range of viscosity. The column had been previously studied for the circulating liquid velocity UL, gas holdup G and volumetric gas...

The mass transfer performance of a pulsed disc and doughnut column for extraction of samarium and gadolinium from aqueous nitrate solution with D2EHPA was investigated. The effects of operating parameters such as pulsation intensity, continuous and dispersed phase velocities on column performance were investigated. The axial dispersion model was used to obtain the overall mass transfer coef...

Problem Statement: Mixing filamentous fungi entails delicate balance between promoting high volumetric oxygen transfer coefficient (kLa) while keeping low hydrodynamic stresses in the microenvironment of cultures. This study examined the oxygen transfer capability of a prototype low shear helical impeller as a potential replacement for the standard Rushton turbine. Approach: The dependence of k...

The rate of oxygen transfer from the gas phase to liquid is a critical process parameter for biocatalytic oxidations due poor water solubility molecular and low affinity many relevant enzymes, such as oxidases. In gas–liquid systems, mechanical mixing can be used increase interfacial area available mass thereby volumetric coefficient (kLa). As such, operation these reactions in continuous stirr...