Aeration is the process of bringing water and air into close contact in order to increase dissolved oxygen concentration. The concentration of dissolved oxygen is an important indicator of water quality because aquatic life lives on the dissolved oxygen in the water. The hydraulic structures can be accepted as the key components in increasing dissolved oxygen concentration because of the strong turbulent mixing associated with substantial air bubble entrainment at these structures. Closed conduit is a classic example of a hydraulic structure where aeration occurs. This work focused on determining the effect of conduit length on air-demand ratio and aeration efficiency in free-surface gated circular conduits. Experimental results showed that the Froude number had an important effect on the air-demand ratio and the aeration efficiency. The effect of the conduit length on the air-demand ratio and the aeration efficiency changed depending on the Froude number. It was demonstrated from the results that a free-surface gated circular conduit flow system had high efficiency in transferring oxygen from air bubbles to water. Moreover, a formula for the aeration efficiency was presented relating the aeration efficiency to the conduit length and the Froude number.
- IWA Publishing
- The effect of length of free-surface gated circular conduit on ...
Water mixing in waste lagoons
Man-made lagoons have been used worldwide for the treatment of domestic and industrial wastewater, it seems, forever. All waste lagoons were first designed and thoughtfully planned considering their locations, soil makeup, and waste reduction processes prior to being implemented. The biological process of organic waste reduction is always a consideration of waste lagoon designs. There are three biological concepts considered for waste lagoons - Anaerobic lagoons, commonly at least 10 feet deep, have no dissolved...
The elimination of fecal coliforms and e. coli in lagoons
Many horse racetracks throughout the world are designed to drain water from the track into a lagoon that is located in the infield of the track. Due to the track being predominantly used for horse racing, there is a high amount of fecal coliform, especially of the Escherichia coli species, bacteria in the water that drains from the track. During the racing season, fecal coliform and E. coli counts increase dramatically and the subsequent drainage of these lagoons can become a problem for the receiving waters.In...
Eliminating sludge islands in your wastewater lagoon
Old municipal and industrial wastewater lagoons have the tendency to build islands of sludge at various locations around the lagoon. It is most common for older lagoons to build such islands wherever wastewater enters the lagoons. Of course, this is because the solids entering the lagoon have enough weight to fall out of the water as flow velocity is reduced, so the solids pile up just after entering the lagoon. Sometimes these sludge islands will build very near a surface aerator, because the violence of the...
Collection system aeration and the microbial benefits
In late 2015 Reliant Water Technologies introduced the Wet Well Wizard, an aeration tool for the wet wells in collection systems. During 14 months of field testing the patent pending Wizard System, the primary objectives were to eliminate FOG (fat, oil and grease) caps and to reduce H2S, eliminating it if possible. All trials were proven excellent with very few changes to the product that eventually was introduced to the collection system market.Now, after a number of months with customer owned Wizards in collectio...
Case study - Galway City Compost Facility
Facility Owner: Galway City CouncilContact: Mr Garry O’Lochlainn, Galway City CouncilLocation: Carrowbrowne Compost Facility, Headford Road, GalwayContact: 00-353-21-462-1721Site Area: 2 acresFeed stock: Source separated household and commercial organics (landscape, food, paper, wood)Capacity: 9,000 tpaCommissioned: Due in November, 2007Facility HistoryThe facility was originally developed as an ASP facility in 2001 in Galway City and was relocated to Carrowbrowne in 2004. In response to the ABPR, CCS was...