Assume a single$-$stage RO system treating a feedwater with the following chemistry $($all as mg$/$l as

CaCO$3$ unless noted otherwise$)$: Ca $300,$ Mg $150,$ Ba $25,$ Na $1650,$ HCO$3200,$ SO$4675,$ Cl

$1200,$ TDS $2800,$ CO$211$ ppm$,$ and Temp $70$oF$.$

a$.$ What is the max yield or recovery of the RO system assuming the max ionic strength $($I$)$ of the

concentrate requiring disposal is limited to $0\mathrm{.}24$ M$?$

b$.$ Will any precipitation occur on the membrane if the RO system is operating at the yield noted

above?

c$.$ What is the max yield that one could operate w$/$o precipitating CaSO$4($s$)$ and still satisfy the

concentrate discharge disposal requirement?