Assertion: whelk's shell | /r/CapableOf | remove lead
Facets:
value: from contaminated waters
type: LOCATION
value: by swapping the calcium
type: MANNER
Source sentences:
text: It has been found that, as long as the water is maintained at an alkaline pH, crushed shells will remove cadmium, lead and other heavy metals from contaminated waters by swapping the calcium in their constituent aragonite for the heavy metal, and retaining these pollutants in a solid form.