4e3eafac_ell_Water_Treatment_Strategies__What_it_does
[Treatment process] Oxidation [Contaminants Removed/Altered] Does not technically remove anything; alters water chemistry. [What it does] 
By introducing oxidizers such as chlorine, ozone, oxygen, or ozone (there are others too), ions' electrical charges change (get more positive). This is often done to prepare for filtration. Sometimes oxidation alone is sufficient to manage hydrogen sulfide (a gas which has a rotten egg smell).
Well Water Treatment Strategies
What it does