Can be used? Yes. Recommended or encouraged? No. It's silica-based sand which in itself is a debate on whether or not you should use it. If you believe it fine's, the problem is where you would collect it. Most public parks, state, county, etc generally have rules against collecting. If you only take a sea shell or two, no one cares. If you're dragging out 5-gal buckets of sand, that might rise a wildlife officer's/park ranger's/etc eyebrow... And because it's a public place, the possibilities of some type of pollutant in the sand is a factor.
The sand itself is rather yellow, although appearing white at the beach. Once in your tank, it gives off more of an appearance of a FW tank rather then SW.