Diffusion Dialysis Waste Water Treatment Plant: design example

Assignment $7$

DD stack for the recovery of $HN{O}_3$ and $HF$ from spent pickling solutions from steel industry from a waste solution containing

these acids in a mixture with $Fe-$ions. Plant waste treatment capacity: $1\frac{m^3}{h}$ and with $1000m2$ of membrane area.

By using the information provide in the process flow$-$sheet diagram determine the following parameters:

i$)$ HNO$3,$ HF and $Fe(III)$ recovery ratio $(\%),$

ii$)$ Mass transfer coefficients $(\frac{m}{s})$ for HNO$3,$ HF and $Fe($III$)$

iii$)$ Water flux from the dialysate stream to the acid pickling feed stream

iv$)$ If the flow$-$rate of the acid recovery stream is increased a $20\%$ what would be the HNO$3,$ HF and Fe$($III$)$ recovery ratio $(\%)$