Portable water filters
I can see that many school children are still not using proper water containers to school. Most of them still sport those plastic disposable mineral water bottles. It may be economical and convenient, but those are not meant to be reused over and over again as those plastic materials may leach poisonous compunds into the drinking water when reused.
It’s way better for them to carry a portable water bottle to school. If you want to buy good quality portable water filters, do get them at purewater2go.com. They have a wide variety for you to choose from.