ILBob is right about the enormous difference in adsorptive ability in regular vs. activated charcoal. We are talking orders of magnitude.

I make a lot of charcoal every year as a soil additive and (for the low grade stuff) outhouse use. I suppose a long column of powdered regular charcoal might be of use in improving odour and flavour, but when it comes to chemical removal its effectiveness would be open to question. Better than nothing, I suppose, but definitely not the first choice if commercial activated charcoal is available.

I need to research whether an off-the-shelf pressure cooker could reach the pressure/temperature required to convert regular charcoal into activated charcoal. Probably not, but it's an interesting idea.