Question

Discuss the consequences of using HCl, NaCl, or CO2 to break the suspension. Can we re-use or dispose of water after it has been treated with HCl, NaCl, or CO2? If not, what would we have to do to the water before it could be re-used or disposed of?

Answer 1

Both HCl and CO2   will decrease the pH of the solution  

HCl ======> H+     Cl-

CO2   + H2O =======>   H2CO3

H2XO3 + H2O <======> H3O+ + HCO3-

HCl rises the Cl- content also,

similarly CO2 will rise CO3-     

however both of them accepted in a cerain range ( EPA has given some protocol)

NaCl will not affect the pH but will add   Na+   and Cl-    

Carbonate content can be removed by simple heating   (CO2 gas will come out)

Na+   Cl- can be removed by ion exchange method