please help solve all parts PLEASE

This is for my evironmental engineering class

I started and solved part A but could not figure out b and c.

This is my work for when i started it

help solve parts b and c please

3. (a) A batch test is used to determine the first order decay rate of a pollutant. In the test, 60% removal of the pollutant is achieved after 1.5 hours. What is the first-order decay rate constant for the pollutant (in hr 1 )? (b) A separate CSTR is then used to actually treat this pollutant. If the water flow into and out of the CSTR containing the pollutant is 100m3/min, what must be the CSTR volume (in m3 ) to achieve 99% removal of the pollutant? What is the residence time (in hours) in this CSTR? Assume the CSTR is at steady state, and the decay rate constant in the CSTR is the same as in the batch reactor determined in part (a). (c) If the treatment reactor is designed to be a plug flow reactor rather than a CSTR, what would be the reactor volume (in m3 ) needed to achieve 99% removal? What is the residence time (in hours) in PFR? All other conditions and assumptions for the PFR remain the same as in part (b). ln(Cn1Ca)=kt=01k=1.51ln(10.4)=1.50.4k=0.61h1)C0c0=1.010.61ln(0.61=1.55hourshoremouc99% 3. (a) A batch test is used to determine the first order decay rate of a pollutant. In the test, 60% removal of the pollutant is achieved after 1.5 hours. What is the first-order decay rate constant for the pollutant (in hr 1 )? (b) A separate CSTR is then used to actually treat this pollutant. If the water flow into and out of the CSTR containing the pollutant is 100m3/min, what must be the CSTR volume (in m3 ) to achieve 99% removal of the pollutant? What is the residence time (in hours) in this CSTR? Assume the CSTR is at steady state, and the decay rate constant in the CSTR is the same as in the batch reactor determined in part (a). (c) If the treatment reactor is designed to be a plug flow reactor rather than a CSTR, what would be the reactor volume (in m3 ) needed to achieve 99% removal? What is the residence time (in hours) in PFR? All other conditions and assumptions for the PFR remain the same as in part (b). ln(Cn1Ca)=kt=01k=1.51ln(10.4)=1.50.4k=0.61h1)C0c0=1.010.61ln(0.61=1.55hourshoremouc99%