Envirogen is a world leader in perchlorate treatment, having treated to date over 6,000 tons of perchlorate from groundwater sources. Numerous anoxic FBR systems continue to operate destroying perchlorate, rather than removing it through a phase transfer, permanently purging the contaminant from the environment. Ion exchange is an alternative and proven treatment method for perchlorate contamination in drinking water. Envirogen offers Ion Exchange treatment paired with our high-efficiency design to maximize the use of the exchange resin and lower costs.
The Perchlorate Dilemma
Perchlorate is a highly soluble salt anion that is used in the manufacture of solid rocket fuel, fireworks, road flares, explosives and other products. It is currently regulated in the State of California (6 µg/L) and the Commonwealth of Massachusetts (2 µg/L) and guidelines and advisories exist in 12 other states. In early 2011, the U.S. Environmental Protection Agency announced its intention to set a federal drinking water standard for the chemical but has not yet established a maximum contaminant level goal for perchlorate. Industry experts expect that perchlorate regulations throughout the country will become more stringent.
California regulators – who have the greatest experience with this contaminant – have identified two Best Available Control Technologies for perchlorate treatment: ion exchange and biological treatment, specifically the fluidized bed bioreactor.
Envirogen Solutions for Perchlorate
Envirogen offers two ‘best available technology’ solutions that can be designed to work in a broad range of perchlorate water treatment programs, including groundwater remediation and drinking water treatment. For lower influent concentrations of perchlorate, our high-efficiency ion exchange systems offer high levels of perchlorate removal and sound economics. For moderate to higher concentrations of influent perchlorate, our biological fluidized bed reactor (FBR) technology offers state-of-the-art performance and excellent economics. Envirogen’s perchlorate solutions offer you the flexibility to meet regulatory requirements
High-efficiency ion exchange
ideal for lower concentrations
Ion exchange is an ideal technology for addressing perchlorate in low influent concentrations where minimal variations in influent composition are expected and where additional anions are also at low concentrations. Envirogen has developed designs to meet the conditions found at municipal water well sites and for groundwater remediation applications. Design considerations include varying water treatment volume, start-up/shut-down type operations, protection from the elements, security, quiet operation, and safe delivery and handling of materials in and out of the site.
Envirogen’s proprietary multi-bed system configurations offer faster kinetics and long media life while meeting a wide range of volume requirements. We employ remote monitoring and communication capability to enable our customers and field service technicians to ensure proper performance and attend the unit as needed.
Envirogen can back our high efficiency ion exchange installations with pay-for-performance guarantees over the lifetime of the installation, offering a low lifecycle cost.
Fluidized Bed Reactors
Green performance for high volume, high concentration clean-up
Biological treatment of perchlorate-laden groundwater is an effective option for treating moderate to very high flow rates and perchlorate concentrations – from 50 µg/L up to thousands of mg/L. The ability to achieve complete destruction of perchlorate and other contaminants in a single process step makes biological treatment the most cost-effective alternative at higher concentrations, and bio-treatment is a “green” technology due to reduced energy and chemical requirements. The technology has the capability of treating perchlorate to non-detect levels if required, which makes it an ideal choice for a changing regulatory environment.
Envirogen FBR systems are fixed-film plug flow reactors in which microbes attach to a media such as granular activated carbon (GAC) that is suspended, or fluidized, within the reactor vessel by the upward flow of water through the system. The suspended media provide a large surface area for microbial growth and allow a biomass density several times greater than that of other bioreactor designs under similar loading conditions. Under anoxic conditions, microorganisms in the reactor consume all of the influent dissolved oxygen, nitrate and perchlorate. An electron donor and nutrients are fed into the bioreactor as needed. Treatment byproducts are innocuous and include nitrogen gas, chloride, carbon dioxide, heat generation and additional biomass.
Groundbreaking FBR for drinking water
To adapt this proven groundwater remediation technology to the production of drinking water, Envirogen recently added a multimedia filter to remove suspended solids. In a one-year pilot demonstration of the design, the system proved robust in its ability to reduce influent perchlorate to target levels and operate cost effectively through a number of challenging operational scenarios including system shutdowns, feed pump failures and perchlorate spikes ranging from 100 to 4,000 ppb. The system consistently produced high-quality potable water. After the successful trial, Envirogen began fabrication of a 2,000-gpm system that has been fully on-line and permitted since 2016.
Envirogen is the industry leader in the use of FBR technology for perchlorate remediation, with over 30 systems installed in the United States.
Further reading on Envirogen FBR technology for perchlorate treatment