Answer:
First: 1- Heavy Metals
Second: 2- Filtration
Explanation:
In the case of polluted water treatment, the removal of heavy metals can be done by various processes, one of which is chemical precipitation. Precipitation is a process in which a solid forms during the chemical reaction, this solid formed is called a precipitate. Interestingly, the method by which the precipitate is removed, is the filtration process that answers the second item of the question.
