Here are some others, mentioned before in other threads.

Sodis- solar water treatment using the sun and a large pop bottle.
effective on bacteria and virus.

Sari cloth filter combined with settling,
good for cholera.

biotic sand filters,
after a couple of weeks, biotic organisms grow that will
eat even metals as well as bacteria and virus. No need for charcoal. Locally they took care of a large diesel spill
by piling up the dirt and inoculating the soil with oil
eating bacteria.