1.The effluent from a factory has a dissolved oxygen concentration of 1.5mg/L, a flowrate of 0.5 m3/s, temperature of 26C and BOD5( at 20C)48mg/L. The effluent is discharged to a river of a flowrate at 2.2m3/s at a saturated dissolved oxygen concentration, a temperature of 12C, and BOD5 (at 20C ) of 13mg/L. A decay rate constant for mixture k1 is found to be 0.21/ day at 20 C. Calculate BODu, dissolved oxygen, oxygen deficit, flowrate, decay rate and deoxigination rate in the river immediately after the discharge point. (4 marks) Note: Dissolved oxygen saturation in water between 12C and 15C can be assumed as 11mg/L