"Is there any type of treatment to replace moisture or to sand these sections of floor board without making them worse?"

Generally no.

It sounds like the wood is flat sawn and may not have been intended as a 'show' surface.

You can try a less aggressive sander like a 6 inch random orbit and some finer paper, or a vibratory sander (the least aggressive, but also slowest).

Glue down the splintery areas with a medium-viscosity superglue before sanding any further.
Casey

Here is a link that might be useful: super t glue