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 $(concentration)$

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

approximate concentration of $20\frac{g}{L},$ it has been determined that the pre$-$filter is capable. of

removing about $50\%$ of the biomass, which drastically reduces the viscosity of the medium to

approximately $50cP.$ 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 in order to be concentrated.

Based on the previous information, it answers as follows:

Microfiltration

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

resistances is more significant? Why?

Based on the operating volume of $246,430\mathrm{.}7L$ estimate the filtration area needed to process

the culture medium within a maximum of $2$ hours