21. An activated sludge aeration basin with secondary clarifier is used for BOD reduction before discharge to the Mississippi River. 22. The result is a system which offers significant cost reduction compared to activated sludge and granular carbon treatment options. 23. An upgrade to the Activated Sludge plant began in 2014, and is expected to be completed in 2018. 24. Wasted Activated Sludge ( WAS ) is sent from the aeration basin to sludge lagoons, then to drying beds. 25. The amount of sewage sludge produced from the activated sludge process is directly proportional to the amount of wastewater treated. 26. The mixing modelling and design techniques applied to MBRs are very similar to those used for conventional activated sludge systems. 27. The activated sludge and partially treated sewage pass on to the final settlement tanks, where the sludge settles out. 28. In 1914, he began the first large-scale investigations of the new sewage treatment process called activated sludge . 29. Imhoff stated that the treatment efficiency of 60-80 percent could be achieved in highly loaded activated sludge basins. 30. Upgrading of the first Activated Sludge plant to use the'Simplex'system took place between 1970 and 1973.
