It is desired to recover water from an effluent in an industry and recycle part of it for irrigation and other uses. The main water contaminant is chromium which is present in a concentration of $3\mathrm{.}5$ ppm$.$ The volume of water produced in the plant is $25$ m$3/$h and according to the membrane manufacturer there could be a $95\%$ rejection of chromium, when the product$/$rejection ratio is $1/2\mathrm{.}5.$

a$)$ Under these conditions, what would be the volume of water in the feed, in the product and in the reject.

b$)$ What would be the concentration of chromium in the product and in the reject.