solve the question following the steps below.

I already do steps 1,2,3,4 and 5

so just do steps 6,7 and 8.

A river system with 2 wastewater discharge points (drain B and C ) are shown in the Figure below. The distance between X and Y are 5.82km. Calculate critical DO concentration and the distance at which it would occur. The average river water temperature is 25.8C. The relevant data is given below: Reaeration rate constant at 25.8C=0.06/ day Water flow velocity in the river =0.24m/s Deoxygenation rate constant at 25.8C=0.14/ day Saturation concentration of DO at 25.8C=9.8mg/L D=DOsDOD=krkdkdLa(ekdtek,t)+Da(ekrt)tc=krkd1ln[kdkr[1DakdLaKrkd)] Steps to Solve Streeter-Phelps DO Model 1. Calculate the Total Flow, BODmix and DOmix concentrations at Point X. 2. Calculate the Initial Deficit of DO(Da) by using Eqn 1. 3. Calculate the travel time, t (day) of river water to flow from Point X to Point Y (for 5.82km ). 4. Apply Eqn 2 to calculate DO deficit (D) just a little upstream of Point Y. 5. Now calculate the DO at the upstream of Point Y using Eqn 1. 6. Also calculate the BODt in the river just before Point Y after t days (after Point X ), using Eqn 4 and assuming BODmix mix at Point X is the same as Lo at that point. 7. Then calculate the BODmix and DOmix for Point Y after Drain C joins the river (same as done in Step 1 for Point X). 8. Now apply Eqn 3,2 and 1 respectively to calculate the tc,Dc and DOc after Point Y in the river. Total flow =0.19+0.049=0.239m/s BODmix=Totalflow(flowABODA+flowBBODB)=0.239(0.196+0.04842)=10.03mg/L Step 2 Da=DOsDmix=9.86.15=3.65mg/L step 3 t=VelocityDistance Step 4 D=Daekk1t=3.65e0.060.281=2.61Mg/L Step 5 Doup=DOsD