Process for Removal of Microcontaminants from Municipal Water

DESCRIPTION (provided by applicant): It has been found that pharmaceuticals and over-the-counter medicines are present in drinking water supplied to at least 41 million Americans. Concern exists over the long-term health effects that will result from ingesting antibiotics, anticonvulsants, mood stabilizers, sex hormones and other drugs. Gender-reversal of fish living in municipal water containing as low as five parts per trillion of estradiol is one of the more shocking examples of documented effects. A study by Thurman et al.,1 revealed that subtle, chronic effects from low- level environmental exposure to select organic wastewater contaminants may be of concern. Other, EPA funded, studies have assessed the impact of pharmaceuticals and antiseptics on drinking water. Although regulatory mandates for removing this newly detected family of pollutants do not yet exist, the impetus for such regulation already exists. Contamination of (municipal) water supplies with low (sub-ppm) levels of these organics (micro- contaminants) presents both monitoring and remediation problems. This proposed Small Business Innovation Research (SBIR Phase I) addresses remediation of water so effected by demonstrating proof of concept of a process technology utilizing adsorption (for pre-concentration of water contaminants) and attack by hydroxyl radicals for removing the aforementioned impurities with concentrations ranging down to the parts-per-billion level. The approach will employ adsorption, electrochemical hydrogen peroxide generation, electrolytic hydroxyl radical generation, and catalytic oxidation unit operations integrated into a compact device. The net effect achieved is the destruction of contaminants using atmospheric oxygen at ambient temperature. Eltron's approach offers energetic and economic advantages over existing advanced oxidation processes, including anodic and oxidation and photocatalytic processes. The low concentrations of microcontaminants pose kinetic hindrances to successful remediation; both because of expected low conversion rate due to low frequency of interaction of reactants and due to competition with the preponderant solvent (and resulting exclusion of contaminant from adsorbent, catalyst, or electrocatalyst surface). Therefore, pre-concentration appears to be essential for any remediation or monitoring approach to succeed. Phase I will primarily investigate application of Eltron's adsorbents for pre-concentration of aqueous solutions of microcontaminants and the ability of the catalytic adsorbents to subsequently destroy molecular species when exposed to hydroxyl radicals generated at the cathode of an electrolytic cell in close proximity to the adsorbent. Phase II will address the design, fabrication, and testing of a prototype system for removal of microcontaminants from drinking water. PUBLIC HEALTH RELEVANCE: The impact on public health caused by contamination of water supplies with low levels of organic contaminants such as hormones, pharmaceuticals, etc. is unknown. Increased consumption of pharmaceutical and personal care products (PPCPs), new technologies for detecting lower levels of them, increasing knowledge about the consequences of ingesting PPCPs (even at trace levels) and the consequences of mixing PPCPs, as well as the need for legislative action to protect the public from them, have provided all the more reason to identify methods for mitigating concentrations of these in drinking water and reducing their consequent effects. The proposed technology has the potential to address a variety of these concerns because it is able to destroy a variety of PPCPs as well as disinfect water from a variety of pathogens. Removing such contaminants offers challenges that must be addressed immediately if a solution is to be proferred. The process, reactor, and system technology developed will find use in the polishing of municipal and other water supplies. The approach will be attractive to municipalities and companies in the water treatment industry.