please solve all

a) Starting from initial mass balance relationship, for a continuous wastewater treatment unit process reactor under steady state, drive the equation for determining the detention time for a second order reaction b) For a k2=0.007 L/mg-hr; initial concentration of organic compound =150 mg/L, plot the decay curve using the relationship drive in (a) above and c) If the flowrate is 0.380 m3/min, determine the required (i) detention time (ii) final effluent concentration and (iii) reactor volume to attain 90% conversion