With a noat figure, explain the four phoses of bacterial dynamias. A completaly mixed activahed studge procens rreats 700m3/hr of weshe Water hating a BOD of 300mg/l. a 90% reduction in B00 is desired in the treatment process. If the maximum seecific substrate utilization rate is 5d-', Yield coefficient. is 0.5 and the ssturation constant is 120m/l, determine the meen cell residonee time in the aeration tant