31. These ponds use gravity to chemical precipitation, biological treatment ( such as an activated sludge process ), and evaporation. 32. Construction costs of this new technology could even be less expensive than the activated sludge systems that are currently in use. 33. Suspension mixed lagoons flow through activated sludge systems where the effluent has the same composition as the mixed liquor in the lagoon. 34. Therefore the installation can be built very compact, needing only 20 % of the surface area of conventional activated sludge systems. 35. "Nocardia " species are often responsible for the accumulation of foam that occurs in activated sludge during sewage treatment. 36. A ?00 million upgrade to the second Activated Sludge Plant began in 2014, and is expected to be completed in 2018. 37. The MBBR system is often installed as a retrofit of existing activated sludge tanks to increase the capacity of the existing system. 38. BOD values are determined by incubating samples for 5 days with proper source of microbes, usually activated sludge collected from wastewater plants. 39. The Jones Island Plant was among the first sewage treatment plants in the United States to succeed in using the activated sludge treatment process. 40. Acinetobacter " which was isolated from activated sludge . " Acinetobacter bouvetii " is named after the French microbiologist Philippe Bouvet.
