Equipment and process by which an operator can set (or program) a time sequence of coatings of oxygen with increasing oxidation potential for in-situ treatment (chemical reaction) of organic compounds ranging from superoxidation (catalyzed ozone) to reduction conditions involving hydrogen sulfide gas is described. The equipment makes use of oxygen in a combination of gaseous and liquid forms to produce microbubbles of, e.g., different composition of oxygen forms possessing peroxides, superoxides, and hydroperoxides with increasing oxidative potential. The oxidative potential of the reactive mixture can be set to more cost-effectively degrade byproducts of contaminant decomposition without reformulation and reinjection. A secondary advantage comes with in-situ adjustment of pH or acidity/basicity.