As soils age in the presence of moisture, the particles become smaller and smaller. Water retention is directly related to particle size, so what you have left is probably forever inappropriate for use in a container ..... unless you used it as a VERY small fraction of a new soil that had a very high % of large particles. A soil like you describe could easily support a 6" PWT. That is to say that after the soil is fully saturated, the bottom 6" or more of the soil might remain completely saturated and airless. This means that if the soil supported 6" of perched water, if you used it in a pot 6" deep or shallower, 100% of the soil would be saturated after a thorough watering. Hopefully, that's not acceptable to you, because it surely isn't to your plants. ;-) That condition severely inhibits/smothers root function and very often causes rot issues, so you'd need to weigh the risks of using it in container media.

You might spread it on the lawn or 'donate' it to someone with a compost pile.

Al

If you are looking for environmental purpose. I do not know if your area garbage collectors have a day to pick up just this type of trash. My borough sells the compost every year. Maybe your apartment trash has a separate bin for something like mulch/compost.

If you have a balcony you could get a small decorative trash bin and start your own compost using the soil and kitchen craps and grow a pot of cherry tomatoes this summer.

You could spread it under a tree in your common area or at work.