Demonstration of Mass Transfer Using Aeration of Water
نویسندگان
چکیده
An experiment was developed using aeration of water for demonstrating the phenomenon of mass transfer. The demonstration was designed to provide both conceptual and practical insight of the mass transfer process. A bubble column fitted with a sieve tray was used to carry out the experiment. The air flow rate and hole size of the sieve tray were varied. Mass transfer coefficient was obtained from the initial and final oxygen concentrations of the aerated water. A dimensionless correlation for mass transfer coefficient in terms of the experimental variables was developed by dimensional analysis and regression of the experimental data. The demonstration is suitable for chemical and other engineering students and can be fit in one laboratory session of three hours. The experimental setup is simple and inexpensive, and can be developed in-house. In addition to the laboratory demonstration, the experiment can also be used for optimizing design parameters of industrial aeration tanks.
منابع مشابه
Aeration and air–water mass transfer on stepped chutes with embankment dam slopes
Stepped spillwayflows are characterised by significant free-surface aeration downstream of the inception point of air entrainment. The stepped design is advantageous for applications which require large energy dissipation and strong flow aeration. While the energy dissipation rate for embankment stepped spillways was studied previously, the optimum design for aeration and air–water mass transfe...
متن کاملEnhancement of oxygen transfer efficiency in diffused aeration systems using liquid-film-forming apparatus.
Surface transfer and bubble transfer both contribute significantly to oxygen transfer in a diffused aeration system. In the present study, liquid-film-forming apparatus is successfully developed on a laboratory scale to improve considerably the surface transfer via the unique liquid film transfer technique. The experimental results show that the volumetric mass transfer coefficient for liquid-f...
متن کاملSurfactant effects on alpha factors in full-scale wastewater aeration systems.
Aeration is an essential process in the majority of wastewater treatment processes, and accounts for the largest fraction of plant energy costs. Aeration systems can achieve wastewater oxygenation by shearing the surface (surface aerators) or releasing bubbles at the bottom of the tank (coarse- or fine-bubble aerators). Surfactants accumulate on gas-liquid interfaces and reduce mass transfer ra...
متن کاملEffects of nanobubble aeration in oxygen transfer efficiency and sludge production in wastewater biological treatment
Low efficiency of conventional aeration techniques and the excessive production and disposal of sludge are great concerns in biological wastewater treatment systems. The present study aimed to evaluate the active sludge method using batch reactors under continuous operation to determine the efficiency of aeration and sludge production through microbubble and nanobubble aeration. The results ind...
متن کاملDevelopment of a model to determine mass transfer coefficient and oxygen solubility in bioreactors
The objective of this paper is to present an experimentally validated mechanistic model to predict the oxygen transfer rate coefficient (Kla) in aeration tanks for different water temperatures. Using experimental data created by Hunter and Vogelaar, the formula precisely reproduces experimental results for the standardized Kla at 20 °C, comparatively better than the current model used by ASCE 2...
متن کامل