Assertion: fluoride's use | /r/Desires | treatment
Facets:
value: to lower the ph
type: PURPOSE
value: afterwards
type: TEMPORAL
Source sentences:
text: This is largely because the chemical reactions associated with the ion exchange are self-regulating in regards to pH, automatically moving the pH of the solution to its optimal point of 10.5-11.Thus the use of magnesia in defluoridation requires additionally treatment afterwards to lower the pH to an acceptable drinking level.