Oxidation ditch process is used to treat the municipal and domestic sewage. The untreated sewage generates fouling smell, harmful bacteria, etc. which is hazardous for public health and degrades the environment by librating noxious gases. This paper examines the use of curved blade aerator for oxidation ditch process. The rotor, which controls the aeration, is the main component of the aeration...

Background When scaling up a monoclonal antibody (mAb) production process in stirred tank bioreactor, oxygen transfer is probably one of the most challenging parameters to consider. Approaches such as keeping constant specific power input or tip speed across the scales are widely described in the literature and are often based on the assumption that mammalian cells are sensitive to shear stress...

the hybrid molten/solid in2o3 - 30-48 wt.% bi2o3 oxide materials were studied with respect to their transport properties. the conductivities, oxygen ion transport numbers and oxygen permeation fluxes have been measured by using the four-probe dc, volumetric measurements of the faradaic efficiency and gas flow techniques, respectively. we show that the oxygen permeability of the hybrid molten/so...

The modified rotating simplex method has been successfully used to determine the best combination of agitation rate and aeration rate for maximum production of extracellular proteases by Staphylococcus aureus mutant RC128, in a stirred tank bioreactor operated in a discontinuous way. This mutant has shown altered exoprotein production, specially enhanced protease production. Maximum production ...

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 coeffici...

An upflow microbial fuel cell (UMFC) system with a U-shaped cathode inside the anode chamber was developed and produced a maximum volumetric power of 29.2 W/m3 at a volumetric loading rate of 3.40 kg COD/(m3 day) and an operating temperature of 35 degrees C while feeding sucrose continuously. The Coulombic efficiency decreased from 51.0% to 10.6% with the increase in the volumetric loading rate...

This study aims at improving the knowledge on effects of gas injection, bubbles sizes and contaminants oxygen transfer in microbubble clouds. First injection are studied linked to several parameters that change together with changes flow rate, namely bubble rise velocities. Oxygen is then presence shown affect size distribution, modify dynamics interfacial mass transfer. efficiencies also measu...

Shell and Tube heat exchangers are the heat exchangers that are most widely used in industries and for other commercial purposes. There are many techniques that have been utilized to enhance the heat transfer performance of the shell and tube heat exchangers. Air bubble injection is one of the promising and inexpensive techniques that can create turbulence in the fluids resulting in to enhancem...

A new semiempirical approach is presented for predicting air-to-water oxygen transfer rates in mixed tanks and gravity sewers, using methods adopted from mixing theory. First, a flocculation unit was used to impart selected mean velocity gradients (G) into a completely mixed tank, from which oxygen was first removed, and dissolved oxygen concentrations were measured with time. Regression analys...