Question

A paper mill is in operation near Saguenay river. The mill discharges 3.8 cfs (ft3/s) of wastewater directly into the Saguenay river. The mill is getting half of this water from an intake which is located 0.5 miles upstream of the wastewater outfall of the mill, and the other half from a nearby well field. On the average, the water upstream of paper mill has TSS concentration of 2.5 mg/L. If the Saguenay river has a flow of 12 cfs upstream of paper mill intake, and the Quebec province permits a maximum TSS concentration of 15 mg/L in the Saguenay river, what is the allowable effluent concentration of suspended solids in the wastewater discharge form the paper mill? You may assume TSS is conserved. Well field outfall Intake

Answer 1

procedure - I mass es conserved mill paper mass outlet mass Qout cela = 3.8cf$ a and assuming Iss concentration of open well på nealizable 2,5 TSS & filer=zing/L Quebec province says 15 mg/L Tropria) < 15 mg Qe= 3-8cf 12 Cf § QR - Qe te t Q R XR Tss (mix) = GetQR. 15 = 3.8(XeJ + 12x2.5 (12+3.8) YR = 2.5ing), Xe = 54 mg / of effluent iss

procedure - 2 TSS conserved as said in Question Tss outlet from all Tss inlet to mill Tss inlet tomill = 2.5 mg = 2.5 mg / rss oot let to mull = 2.5mg/l al per conservation check condition Tosomica) = GRYR + geye QR toe 11 12x2.5 + 3.8*2.5 12+3.8 15ing 2.5 s L as per Quebec poovision