Methods of Treating a Water Sample or a Substrate to Remove Organic Compounds

Reference #: 00875

Keywords: Advanced oxidation processes (AOPs), hydroxyl radical, treatment/remediation, sustainable oxidation

The subject invention is a system of equations (a model) that can be used to develop sustained free radical oxidation processes using low energy, environmentally sustainable feedstocks such as Fe salts, atmospheric oxygen, and naturally occurring organic molecules.

The oxidation of aqueous Fe(II) by atmospheric dioxygen is associated with the production of several reactive oxygen species (ROS). These include hydrogen peroxide, hydroxyl radical and superoxide. These ROS all have demonstrated utility in the remediation of trace organic contaminants and pathogens. Dr. Ferry and co-workers have reported an empirical, combinatorial investigation of Fe(II) oxidation that evaluated the variations of Fe(II) oxidation rates and ROS production across the pH, Fe(II), PO43-, Cl-, Br-, CO32- and natural organic matter (NOM) axes. Furthermore, they describe the development and field testing of two combinatorial experimental designs that simultaneously account for the effects of independent and co-varying factors on net Fe(II) oxidation. This was accomplished by application of a novel experimental design that co-varied Fe(II), PO43-, Cl-, Br-, and CO32-along the pH axis. Factors and inter-factor interactions were statistically evaluated to determine their importance to Fe(II) oxidation at the 95% level of confidence. Significant factors were used to construct predictive numerical models of Fe(II) oxidation rates and correlated ROS yield. Models were constructed to represent the conditional end-members of unrestricted Fe cycling and restricted Fe cycling (due to forced precipitation of Fe(III)). The models were challenged to predict Fe(II) oxidation rates across a wide variety of conditions. Both models were capable of predicting Fe(II) oxidation rates to within the 95% confidence interval at all of the tested points.

• Remediation (transformation or mineralization) of trace organic pollutants in solution or on surfaces

• The Purox process, the Peroxone process, associated ozone peroxide or UV based technologies

• These currently used techniques involve the use of high energy or harsh reagents like ozone, chlorine or radiation to achieve the same ends.

• All of the current oxidation technologies used in fruit, vegetable and nut production areas damage the product or cause the perception of damage to the product.

• Removal of trace organics on food surfaces without exposure to oxidants that affect food quality

• Cleaning delicate surfaces from trace organic contaminants and/or pathogens

• Particular Industry Interest: fruit, vegetable and nut production industries.

• This technology relies on building sustainable radical chain reactions without the deliberate addition of strong oxidants.

• Even when the predicted and experimental values were significantly different, the rates differed by less than a factor of 5.

• Additional advantages to this model’s approach for generating reactive oxygen species (ROS) is that it represents an environmentally sustainable technique for generating species that can be used to degrade trace organic contaminants.

• This model, derived from processes that occur naturally in surface waters, is potentially less expensive, could produce less chemical waste and could directly incorporate atmospheric oxygen into the treatment train without requiring any of the aforementioned sources of oxidants.

• None of the species involved in this model are prone to cross hydrophobic membranes, making the technique particularly appropriate for cleaning hydrophobic surfaces without harming the interior.