Answer:
oxygen deficit = 3.851 mg/L
Explanation:
given data
flow rate of the river= 165 × [tex]10^{6}[/tex] gal/d
saturation value of dissolved oxygen = 9.17 mg/L
to find out
oxygen deficit he two flows
solution
we will apply here formula for dissolved oxygen content after dilution is
Do mix = [tex]\frac{Qw*(Do)w +Qr*(Do)r}{Qw+Qr}[/tex] ..........................1
here Qw is rate of flow of waste water i.e 26 ×[tex]10^{6}[/tex] gal/d
(Do)w is Do of waste waster i.e 1 mg/L
Qr is aret of flow of river i.e 165 ×[tex]10^{6}[/tex] gal/d
(Do)r is do of river water i.e 6 mg/L
so put all value in equation 1 we get
Do mix = [tex]\frac{26*10^6*1 +165*10^6*6}{(26+165)10^6}[/tex]
solve we get
Do mix = 5.319 mg/L
so
oxygen deficit = saturation oxygen - (Do) mix ..............2
oxygen deficit = 9.17 - 5.319
oxygen deficit = 3.851 mg/L