Question

The Audhumla town council has asked that you determine whether the discharge of the town's wastewater into the Einherjar River will reduce the DO below the state standard of 5,00 mg.L-1 at Gotterdämmerung, 5.79 km downstream or at any other point downstream. The pertinent data are as follows: Parameter Wastewater Einherjar River Flow (in m3 5-1) 0.280 0.877 for Ult-BOD at 15°C (mg L-1) 6.44 7.00 DO (in mg L-1) 1.00 6.00 kd at 28°C (in day-1) N/A 0.199 kr at 28'C (in day-1) N/A 0 370 Speed (in m S-1) N/A 0.650 28 28 Temperature in C)

Answer 1

volumehic flow rate a waste wat volumetric flow rate of Einherjar river Ult- Bop of waste water & Einhejor rived respectively Initial BOD Qwt.ELE CO 28 x 654 + 0-873x7). Qwtar (0.28 +0.817) L T= 2soc 7.92 mg/l De DOS- Qw Dow + BE DOE QwtQE Da 7.92 - 3.13 ms 0-28 x 1 + 0.577x 0:18 +0.877 delict in river after exertion of BOD-PL -kat ekst) toa e -kart ka La Krka 6907 sec = D.1930 9 Lex Distance Speed SE40 0-650 mts -0-199 Xoloog -0-37 X0-10305) -0-37 X0-103 +213 e D20 X 6096 0.37 -0.19g 3.149 mg/L DOS - D= 7.92 3.149 = 4.77 is h-17 mall teritical - [ter Hy kyky kala Wroke

0.37 0.1gg 2013 (0:37 -0.19 1032 0.199x6.86 019 Dentical i hala ar ki kat [ + Ra Celest - D.lggx6:86 -0.199xo. 71674 -0.374 0.21634 -0.37 xo Tits 1+ 3.13xe 0-37 -0.19 3.16 Critical oxygen deficis co Dos Daritiah = 7.92 3.16 4.76 ng IL