Although membrane filtration processes have several advantages, a thorough evaluation of the process

parameters influencing membrane fouling is necessary to optimize permeate flow, and ah the optimal

concentration of the filtered or retained enzyme. The use of sequential separation processes $($e$.$g$.$

microfiltration and ultrafiltration$)$ can reduce the number of downstream steps, thus minimizing production

costs.

In this activity, the aim is to concentrate the lipases produced by Aspergillus niger, through sequential

membrane separation processes, as shown below:

Culture $$ Prefiltration $(20m)$ Microfiltration $(0\mathrm{.}45m)$ Ultrafiltration $($sencentr$-$

ation$)$

Based on previous laboratory pilot tests with a breeding ground of Aspergillus piger, with an approximate

concentration of $20\frac{g}{L},$ it has been determined that the pre$-$filter js capable of remoying about $50\%$ of the

biomass, which drastically reduces the viscosity of the medium to approximately $50cR,$ On the other hand, the

microfiltration membrane $(60cm2)$ retains the rest of the biomass as well as other smells of the micron order

and produces the following experimental data when operated at constant pressure $(14$ psi$)$:

Table $1$: Microfiltration data for A$.$ niger breeding ground

The resulting permeate is processed by tangential flow ultrafiltration jo$\_$order to be concentrated. Based

on the prexieus infermation, it answers as follows:

Make a block diagram of the lipase production and recovery process Mirrofiltration

Plot the change in membrane $(Rm)$ and cake $($Rt$)$ resistances over time. Which of the twe resistances is

more significant? Why?

Based on the operating volume you previously calculated for your problem situation

estimate the filtration area needed to process the culture medium within a maximum of $2$ hours

Ultrofiltration

Make a proposal for the molecular cut$-$off size that the ultrafiltration membrane should have to retain

the lipase. Justify your answer

Whereas the permeate flux of ultrafiltration is $1\mathrm{.}610-2k\frac{g}{m}2s$ and remains relatively constant

throughout the operation, making a proposal of the filtration area and process time to remove $75\%$ of

the fluid. Justifi yeur answer.