Oxygen Transfer In Water

Submitted By NICOLASAINT123
Words: 566
Pages: 3
Open Document
Introduction
Investigation objectives:
Oxygen transfer, the process by which oxygen is transferred from a gaseous to the liquid phase, is vital in a variety of biological and hydrometallurgical processes, in particular wastewater treatment. The aim for this experiment is to evaluate how this oxygen mass transfer varies under a range of different operational conditions (E.g. Stirrer speed and oxygen flow rate), and formulate the optimal parameters for modelling a sewerage plant.

In wastewater treatment plants, diffused air system bubbles are distributed from diffusers at the base of the reactor, where the rising bubbles come in contact with the aqueous layer (BLA). When equilibrium is reached, the liquid is ‘saturated’ into the gas. This can be modelled using equation 1, as proposed by Merchuk et al(1990), where Cl is the gas concentration in the bulk liquid phase (ppm), t is time (sec), Cs is the saturation level of the gas in the liquid phase (ppm) and K is the overall mass transfer rate coefficient (sec-1). This can be further simplified to yield equation (2)

(1)
(2)

Both stirrer speed and oxygen flow rate significantly effect the mass transfer rate ox oxygen in a liquid. Altering these two parameters affects the size and flow of the bubbles which impact the surface area in contact with the liquid and hence the mass transfer. Higher stirrer speeds more efficiently break the air bubbles and consequently increase the superficial area of the bubbles, enhancing the oxygen transfer rate(Karimi et al 2013).
In order to measure the dissolved oxygen within each batch condition, Clark-type electrode probes will be used. These sensors are constructed with a silver anode and a gold cathode, which when submerged in an electrolyte (water) complete the electrolytic cell and serve as a reference electrode. The oxygen molecules present in the aqueous solution diffuse through the membrane resulting in a difference in the oxygen pressures. This produces a perceivable current that is recorded by the instrument.

Reference: http://www.ijehse.com/content/10/1/6 Results qualitative effect of stirrer speed
It was observed that with an increase in the stirrer speed(rpm), the K of the system also increased. This can be attributed to
Show More

Related Documents: Oxygen Transfer In Water

SAORA Newsletter 2 November 2014 Essay example

embraced the job, and is ensuring that SAORA is running very smoothly. Our Networking Breakfast with Lauren Beukes, was a resounding success and thanks go to Sam Peck for her efficient organisation of this event. Unfortunately, owing to work commitments, Sam has resigned from the committee, and I would like to take this opportunity to thank Sam for everything she has done for the committee. We hope she will be back one day. Varsity Orientation and the Welcome to Matrics 2014 was held on 16 July. It…

Words 4253 - Pages 18

Hello I Love Music Essay

Tony dize – Senda Maniatica Wisin y Yandel – Abusadora Actor de telenovela – Rocko & blasty Lil wayne – add up Addicted – prince Royce Addicted to you – shakira Afuego – daddy yankee Agarrala, pegala, azotala –wisin y yandel Agresivo – jowell y randy Agaunile –marc Anthony Ahi controlo yo – pena suoza Ahora es –wisin y yandel Ai Se Eu te Pego - Michel Telo Ain't Thinkin Bout You - ft. Chris Brown Bow Wow Alexis y Fido Mi Musica Ehh Algo Musical - ft Nejo Dalmata Arcangel…

Words 8872 - Pages 36