How to determine the products of a redox reaction
I did some research on this topic (water treatment for TCE) and I come out three answer which is by using peroxide, ozone and permanganate. Since you asked for ozone first, so I will give that first.

What are you missing in the reaction is that water is the reactant of this reaction instead as a product. Here's the equation:

$$\ce{C_2HCl_3 + O_3 + H_2O -&gt; 2CO_2 + 3HCl}$$

For the reaction involved ozone, The reaction will be more effective in an acidic medium and it must perform in a enclosed delivery pipes.

Second, The reaction involving peroxide. Hydrogen peroxide react with TCE will also produce carbon dioxide and hydrogen chloride but water is a product here. Here is the equation:

$$\ce{C_2HCl_3 + 3H_2O_2 -&gt; 2CO_2 + 2H_2O + 3HCl}$$

Same as the ozone reaction, this reaction is more effective in an acidic medium.

Last one is the reaction involving permanganate. We will be using potassium permanganate but you can use sodium permanganate, calcium permanganate or magnesium permanganate. It will react with TCE to produce carbon dioxide, manganese (IV) oxide, metal chloride and hydrogen chloride. Here is the reaction:

$$\ce{C_2HCl_3 + 2KMnO_4 -&gt; 2CO_2 + 2MnO_2 + 2KCl + HCl}$$

This reaction is a bit different compared with the other two. It could be effective in acidic or basic medium between the PH range of 3.5 to 12.

Hope this helps you.