In open channel flows, local surface aeration processes occur mainly at weirs and drop structures and in hydraulic jumps. Air entrainment in the wakes of bluff bodies is observed only in high speed flows. In water pollution abatement, the natural gas exchange at the free surface is sometimes not sufficient to balance the oxygen consumption due to pollutants. In such cases, local aeration is nee...

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 fro...

The removal of linear alkylbenzene sulfonate (LAS) was evaluated in a UASB reactor using shortchain alcohols (ethanol and methanol) and complex co-substrate (yeast extract). Using only methanol and ethanol as co-substrates resulted in removal of LAS between 30 and 41%. At the end, addition of a complex substrate (yeast extract) increased the removal of LAS to 50%. During the assay, water supply...

With intermittently operated municipal waste water plants the aeration switching sequence should be optimized under the constraints that the solved nitrogen concentration in effluent has to be kept within its environmental limits. This is a highly nonlinear control problem because of the nonlinear biological process model ASM1 (Activated Sludge Model 1), the on-off state of the manipulated sequ...

Submerged membrane bioreactors (MBRs) have been gaining in popularity in various types of wastewater treatment. One drawback of submerged MBRs is the difficulty in removing nitrogen because intensive aeration is usually carried out in the tank and the MBRs must therefore be operated under aerobic condition. In this paper, feasibility of a baffled MBR (BMBR), treating municipal wastewater partic...

The relevance of wastewater treatment service has increased in recent years, since it has a significant impact on the natural environment. A treatment plant facilitates energy generation, the recovery of products from waste, and the reuse of wastewater for industrial and irrigation purposes. An indirect environmental effect is the high energy consumption for pumping water and for tank aeration....