Activated carbon is produced at high temperatures in controlled atmospheres. I don't think sewerage sludge is a good choice for feed stock.

You can use pyrolysis at inert atmosphere (nitrogen, argon) at high temperature (i.e. 400-900 °C). Actication before pyrolysis by KOH leads to good result (high porosity and surface area).

https://www.sciencedirect.com/science/article/pii/S0011916411003973

dear colleague??????

you can prepare your activated carbon ????????? 1-mix your virgin material with a strong acid for example H2SO4 (10 to 10 M) (it becomes black) let this mixture rest for 2 hours then put it all in the oven under (2000 to 3000 ° C).

thank you