Well, in order to understand the oxidation process, you have to understand that this reaction cannot be done alone. Indeed, where there is oxidation, there is reduction.
The amalgam between these two reactions is called oxidation-reduction. In a simple way, redox consists of two half-reactions that take place simultaneously. These two half-reactions are those of electron loss (oxidation) and those of electron gain (reduction).
The oxidation process is a chemical reaction consisting of the loss of electrons from any compound. The oxidation reaction is also characterized by the addition of oxygen to an element.
During the oxidation process, it is the reducing agent that loses electrons to the oxidizing agent. For example, when metals oxidize (rust) in contact with water or any other compound, the metals are the reducing agents in this situation.
In contrast to oxidation, reduction consists of the gain of electrons to an oxidizing agent and the reduction of oxygen atoms. During the reduction process, it is the oxidizing agent that acquires the "stolen" electrons from the reducing agent.
In a situation where chlorine is added to the water to effect disinfection, the chlorine is the oxidizing agent while the contaminants targeted for disinfection would be the reducing agents.
To take the oxidation of metals as an example, here is the formula showing the chemical process behind the electron transfer allowing metals to rust.
- 4Fe(s)+3O2(g)4Fe(s)+3O2(g)→ 2Fe2O3(s)2Fe2O3(s).