The Dubai Investments Park (DIP) wastewater treatment plant (WWTP) is located about 20 miles south of the Burj Khalifa – the world’s tallest building. The oxidation ditch activated sludge plant recently found itself strained by filamentous sludge bulking likely caused by high organic loads, high summer temperatures and inevitable low dissolved oxygen. The problem was easily solved by replacing ineffective supplemental surface aerators with the proven Aire-O2 Triton® Process Aerator/Mixer.
The DIP WWTP is operated by METITO Limited under a 30-year BOOT contract. The oxidation ditch is currently treating an average 2.6 MGD (10,000 m3/day) composed of 70% municipal and 30% industrial waste streams. The wastewater treatment experts of METITO have been successfully treating the influent BOD of 500 mg/l down to MGD (31,000 m3/day) with plans to expand to 21 MGD (80,000 m3/day) in the future thanks to its modular design. The completed project will serve a population of up to 350,000. Features of the system installed at the Park include water conservation by reuse of water for irrigation purposes, an environmentally friendly atmosphere and fully automated systems.
Normal, day-to-day operations of any treatment plant is never void of interesting challenges. Similarly, the DIP WWTP found itself dealing with filamentous bulking and poor sludge settleability evident in the secondary clarifier. Many factors can contribute to this challenge. For example, a temperature of 95°F (35°C) is normally associated with filamentous bulking. This effect can be remedied by cooling the influent or cooling the mixed liquor. In this particular case it was determined that more effective supplemental surface aeration would be beneficial for improving MLSS temperature, floating sludge, low DO and mixing.
Water Matrix Technologies fZE of Dubai, manufacturer representative of Aeration Industries, was able to provide a solution by suggesting the use of two, 30Hp (22kW) Aire-O2 Triton® Process Aerators/Mixers to upgrade the existing supplemental high-speed surface aspirator aerators. Once the Tritons were installed the results were quickly evident as the powerful mixing and excellent oxygen transfer eliminated the majority of the filamentous bulking. The effects of the Triton are attributed to the proprietary low-RPM, dual-propeller technology coupled with the use of an on-board, high-CFM regenerative blower. The plant also has two existing 177Hp (132kW) slow-speed, vertically-mounted aerators in operation. The use of the Tritons with the existing aerators results in a powerful combination. The vertical aerators provide a high concentration of oxygen in their immediate surrounding areas while the Tritons effectively harness the saturated oxygen cap and channel the aeration plume with downward and horizontal vectors. The result is a high suspension of solids, temperature destratification and greatly increased dissolved oxygen.
Whether it is a case of filamentous bulking, a shortage of oxygen, or a lack of complete mix, Tritons are quickly becoming the gold standard, go-to aeration technology for treatment plants around the world in need of an upgrade or rehabilitation. The Tritons can be mounted onto float systems, under bridges or along basin walls allowing for maximum installation flexibility. In this day and age of restricted economies and aging wastewater treatment infrastructures, the Tritons provide an affordable and easy solution for extending the life of a plant.