What is oxygen mass transfer coefficient?

What is oxygen mass transfer coefficient?

The volumetric oxygen mass transfer coefficient (kLa)1) is the most important parameter in all the aerobic bioprocesses [9], which is influenced by a number of factors, among which are the agitation intensity, aeration, bioreactor features, media composition, biomass concentration, and microbial species [10–14].

What is Standard oxygen transfer rate?

The Standard Oxygen Transfer Rate (SOTR) is the rate at which the SOR is transferred in tap water at 20°C and zero DO. The Actual Oxygen Transfer Rate (AOTR or OTRf) is the rate at which AOR is transferred under field conditions.

How do you calculate kLa?

So, kLa=OUR/(C*-CL) and OUR is generally calculated as OUR=qO2*Cx. Therefore, kLa=qO2*Cx/(C*-CL), where qO2 is the specific oxygen uptake rate of oxygen and Cx is the biomass concentration.

What does a high kLa mean?

The result is an easily reproducible environment and therefore a more comparable growth and production rate etc. If a bioreactor shows a high kLa, then it shows that the equipment is cleverly designed so that a high oxygen transfer rate can be reached.

What is oxygen transfer?

), or oxygen transfer occurs from the surrounding air to the bulk liquid via a liquid/air interface (as for a TF or a rotating biological contactor (RBC)).

What does oxygen transfer mean?

Oxygen transfer, the process by which oxygen is transferred from the gaseous to the liquid phase, is a vital part of a number of wastewater treatment processes. The functioning of aerobic processes, such as activated sludge, depends on the availability of sufficient quantities of oxygen.

What is AOR in wastewater treatment?

Oxygen must be provided in biological treatment systems to satisfy several types of demands. These are referred to as actual oxygen requirements or AOR.

How do you calculate the rate of oxygen uptake?

At steady state, the volumetric rate of oxygen uptake by the cells is equal to the volumetric rate of gas–liquid oxygen transfer, NA (Section 10.5. 2). Once NA is determined using Eq. (10.53), qO is found by dividing NA by the cell concentration x.

What is KLa oxygen?

The kLa (Volumetric Mass Transfer Coefficient) and the OTR (Oxygen Transfer Rate) detail how efficient oxygen is transferred from the gas bubbles into the bioreactor medium, i.e. how much oxygen is available for the cultivated biomass.

What does KLa measure?

volumetric mass transfer coefficient of oxygen
A dynamic method of measuring the volumetric mass transfer coefficient of oxygen, kLa, in gas-liquid reactors is presented which consists in monitoring simultaneously the pressure and oxygen concentration changes. The concentration change due to pressure change is invoked by temporarily closing the gas outlet.

Why is KLa important?

Measurements of kLa provide important information about a bioprocess or bioreactor. These determinations ensure that processing conditions are such that an adequate supply of oxygen is available for proliferation of cells. The kLa value can also be used to optimize control variables over the lifecycle of a bioprocess.

What determines the oxygen transfer rate in liquid medium?

Several factors influence the OTR; the temperature, pressure, and salt concentration influence , while mixing power input, gas flow rate, and liquid viscosity influence k1a. The concentration of oxygen in solution is critical in order to ensure that the biocatalyst is not limited by oxygen.

What are oxygen transfer rates how are they measured in a fermentation process?

The oxygen transfer rate describes the rate of oxygen delivery from gas into liquid such as an agitated suspension culture in a bioprocess vessel. The typical unit for OTR is mmol O2/(L×h), i.e., the amount of oxygen transferred into 1 liter of culture per hour.

What is FM ratio wastewater?

The F/M ratio is a process control number that helps you to determine the proper number of microorganisms for your system. To do this calculation, you will need the following information: Influent Flow into your activated sludge system (Flow MGD) Influent CBOD (mg/l) concentration into your aeration tank.

How is o2 uptake max calculated?

Define the simple VO2 max formula. The simplest formula to calculate VO2 max is VO2 max = 15 x (HRmax/HRrest). This method is considered to compare well with other common formulas. The units for VO2 max are milliliters of oxygen per kilogram of body weight per minute (mL/kg/min).

What is mass transfer coefficient KLa?

The volumetric mass transfer coefficient (kLa) is a parameter that determines the rate at which a gaseous compound (e.g. O2 or CO2) can transfer between the gas phase and the liquid phase.

What is the KLa requirement is pure O2 is used in the gas and the DO is maintained at 50% air saturation?

Here, the theoretical KLa required is 4.67 h-1. This value is given for DO set-point at 50% with a gas flow of 30 mL/min Air and 200 mL/min O2. To get this KLa in the bioreactor, use the relationship between the KLa and the liquid flow rate through the fixed-bed (Figure 3).