Seattle, Washington Zeolite Composites: Smarter Solutions for Sustainable Change™
Current Problem
About 300 million tires are produced annually in the United States. 10-16% of the weight of the tires through vehicle tire wear are deposited on the roads in the form of Tire Particles (TP). These tire particles have been shown to be composed of heavy metals (such as Zn, Pb, Co, Al, Cu, and Ni), chemicals such n6PPD-quinone (N- (1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone) and micro and nano-plastics. TPs are deposited on the roads which then during rainfall become part of the runoff and can enter sources of drinking water or ecologically sensitive streams and rivers where they have detrimental effects to animal and plant life.
6PPD-quinone (6PPDQ) is particularly harmful to Coho salmon (Coho). Research has shown that this chemical is highly toxic to juvenile Coho, causing rapid mortality even at low concentrations. The toxicity of 6PPDQ poses a significant threat to Coho populations, especially in urban areas where runoff from roads carries tire wear particles into water bodies. This pollution can have devastating effects on salmon ecosystems, as Coho are a keystone species important for the ecological balance of their habitats.
Our Solution
An engineered stormwater management system integrating the world’s first Low Carbon Water Permeable Pavers and coarse clinoptilolite zeolite (Zeolite) granules as a filtration media can improve stormwater runoff water quality by removing a wide range of pollutants, including specific contaminants such as rubber tire dust particulates, heavy metals, and 6PPDQ contributing to healthier urban water cycles and ecosystems. This type of integrated system would improve groundwater quality by filtering out contaminants, toxins, and heavy metals that would otherwise pollute urban water bodies. Stormwater can drain through the water permeable pavers and filter through layers of coarse Zeolite granules before cleaner rainwater is discharged into streams and rivers. Another benefit is that water tables are recharged because the rainwater does not simply runoff from impervious surfaces like traditional concrete and asphalt roadways.
Our Partners and Collaborators
PFAS (aka "Forever Chemicals")
PFAS, often referred to as "forever chemicals", do not break down and can accumulate over time in the environment and in human bodies. PFAS are used in various industries worldwide for their water- and grease-resistant properties, being found in non-stick cookware, water-repellent clothing, stain-resistant fabrics and carpets, firefighting foams, and many other products.
Clinoptilolite Zeolite is a naturally occurring form of zeolite, a microporous, aluminosilicate mineral. Due to its high surface area, porosity, and cation-exchange capacity, clinoptilolite has been extensively studied for various environmental applications, including water purification and pollutant removal.
Clinoptilolite zeolite is a natural environmentally friendly mineral, which means that its use in stormwater filtration systems comes with a lower carbon footprint compared to synthetic materials. This aligns with sustainable practices, especially when incorporated into low-carbon water permeable pavers.
By using clinoptilolite zeolite in stormwater filtration systems, it is possible to effectively reduce the concentration of PFAS, thereby minimizing their harmful impact on the environment and public health.
Health and Environmental Concerns:
- Health Risks: PFAS exposure has been linked to various adverse health effects, including cancer, liver damage, decreased fertility, hormone suppression, and increased risk of asthma and thyroid disease.
- Environmental Impact: PFAS contamination is a significant environmental concern, affecting water sources, soil, and living organisms. Their persistence makes them challenging to remediate. PFAS is found in water, air, fish, and soil at locations across the globe. Due to their persistence, they can spread extensively through water systems.
Clinoptilolite zeolites have been extensively researched for their adsorption capacity and effectiveness in removing per- and polyfluoroalkyl substances (PFAS) from various environmental matrices, including landfills, stormwater, and other contaminated sites.
Adsorption Capacity and Mechanism: Clinoptilolite, a natural zeolite, has a porous structure and high cation-exchange capacity, making it an effective adsorbent for various pollutants. Research has shown that clinoptilolite can adsorb PFAS through mechanisms involving both physical adsorption and ion exchange. The large surface area and the presence of exchangeable cations in clinoptilolite facilitate the adsorption of PFAS molecules from water (SpringerLink) (SpringerLink).
Affinity for Organic Contaminants: PFAS molecules are highly resistant to degradation due to their strong carbon-fluorine bonds. The hydrophobic channels within the zeolite can attract and trap these fluorinated compounds, preventing them from remaining in the stormwater. The ability of zeolite to retain these compounds makes it a useful material in filtration systems designed to remove PFAS from stormwater, especially in environments where these contaminants are prevalent.
Effectiveness in Different Environments:
- Landfills: Clinoptilolite has demonstrated effectiveness in capturing PFAS from landfill leachate. Its ability to adsorb heavy metals and other contaminants simultaneously helps in reducing the overall toxicity of landfill leachate. Studies have reported significant reductions in PFAS concentrations in treated landfill leachate, highlighting clinoptilolite's potential for large-scale applications (MDPI).
- Stormwater: The use of clinoptilolite in stormwater treatment systems, such as permeable pavers or filtration media, has shown promising results in reducing PFAS levels. The zeolite's high adsorption capacity ensures that stormwater runoff is effectively treated before it enters natural water bodies, thus preventing environmental contamination (SpringerLink).
- Other Environmental Applications: Clinoptilolite has been utilized in various other environmental contexts, such as industrial wastewater treatment and groundwater remediation. Its versatility and effectiveness in removing not only PFAS but also other organic and inorganic pollutants make it a valuable material for environmental protection efforts (SpringerLink).
Clinoptilolite zeolite is a cost-effective and sustainable option for environmental remediation due to its abundance and low cost compared to synthetic alternatives (MDPI) (SpringerLink). While activated carbon is commonly used for PFAS removal, clinoptilolite zeolite has shown comparable or even superior performance in certain conditions, especially when modified. Its cost-effectiveness and natural abundance make it an attractive alternative to other more expensive adsorbents.
Clinoptilolite zeolite shows significant potential as a filtration media for reducing PFAS contamination in water. Its natural abundance, cost-effectiveness, and adaptability make it a promising solution for mitigating PFAS pollution from stormwater, landfills, and other contaminated sites.
WA Governor Elect Bob Ferguson Learning About Zeolite
As Governor, Bob Ferguson will support environmental initiatives like ours. We look forward to collaborating with Bob's climate team.
Posted with Permission from Bob Ferguson
Patent Pending
