Mobile system and method for pfas effluent treatment

Description (excerpt)

STATEMENT OF GOVERNMENT INTEREST Under paragraph 1(a) of Executive Order 10096, the conditions under which this invention was made entitle the Government of the United States, as represented by the Secretary of the Army, to an undivided interest therein on any patent granted thereon by the United States. This and related patents are available for licensing to qualified licensees. BACKGROUND Field of the Invention The present invention relates to PFAS (Per-Poly-fluorinated alkyl substances) effluent treatment, and, more particularly but not exclusively, to mobile system and method for PFAS effluent treatment. Description of the Related Art This section introduces aspects that may help facilitate a better understanding of the invention. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is prior art or what is not prior art. PFAS have been used in aqueous film-forming foams for about 50 years because they are very effective at suppressing fuel fires. Consequently, these contaminants are frequently found on military installations that have firefighting training and maintenance areas, including in the firefighting areas, in washout areas, and in collected groundwater. PFAS are also found in many other commercial products, such as non-stick surfaces and water repellent fabrics. As such, PFAS contaminated water is also widely found resulting from non-military activities. According to the Environmental Protection Agency (EPA), PFAS are persistent, bioaccumulate in organisms, and are toxic at very low levels. PFAS-contaminated sites require remediation and cleanup to protect human health and the environment. The EPA has established a Lifetime Health Advisory of 70-ppt for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), both part of the PFAS family of chemicals. The agency also has published a roadmap for PFAS, indicating that maximum contaminant levels for these compounds will soon be established. For example, the EPA drinking water health advisory is 0.070 ug/L. There are at least 401 active or closed Department of Defense installations or bases that have potential PFOS or PFOA release, with 36 sites having been identified to date where drinking water levels of PFOS and PFOA exceed the lifetime health advisory levels as defined by the EPA. Effluent creates logistical issues when it comes to storage, transportation, and eventual treatment; additional, it is a liability until the final treatment or disposal. There is a great need for a technology that will safely decommission water-based PFAS contamination while reducing logistical issues and liabilities. SUMMARY The present invention was developed to address the need for a robust, versatile, and adaptable approach to treat PFAS effluent. Research and development has led to novel deployable PFAS effluent treatment system and method. The system can be trailer-mounted and have its own generator so that it can operate virtually anywhere as a mobile unit. A cartridge filter is used to remove sediment followed by a granular activated carbon (GAC) treatment for removal of oils, greases, and natural organic carbon. These precede one, two, or more canisters/columns of ion exchange material (it is general practice to have 2 or more to insure complete treatment, but one vessel is possible), which is an ion exchange resin (e.g., Purofine produced by Purolite or similar product) that has been shown to have a very high exchange affinity for PFAS constituents. The system is used to treat PFAS-contaminated water to the lifetime health advisory levels established by the EPA. The present invention advances the science of PFAS remediation and water/wastewater treatment. Embodiments of the present invention encompass systems and methods for (1) pumping water into the system and through the system, (2) treatment of constituents that may interfere with PFAS removal, (3) PFAS removal, (4) monitoring the system operation, such as pressure and flow (instantaneous and cumulative), and (5) control systems for easy operation and monitoring, including allowing remote and/or unmonitored operation. Certain challenges are involved when (1) treating sites with high sediment concentration, (2) sites with very high organic content, or (3) sites with very high salt concentration. These challenges are overcome by employing a pretreatment process to remove sediment (e.g., using a sediment filter) to prevent sediment clogging in the apparatus and using the granular activated carbon (GAC) column to remove organic compounds including greases and oils that may interfere with effective PFAS treatment. Higher salinities can be managed us