For over 200 years, there has been little innovation in traditional filtration methods. Most water treatment plants operate with technology invented over two centuries ago: sand and anthracite filters. How to achieve a Positive Water Footprint with zeolite filter media
However, the challenges and needs that companies and governments face today in desalination and purification have made it urgent to implement new filtration technologies that make water treatment processes more efficient and sustainable, especially in such a critical stage as filtrations stage. This is particularly crucial for companies aiming to improve their water footprint and achieve certification as “Water Positive Companies.“
Consequently, zeolite filtration has become increasingly popular in many countries and sectors.
How can Zeolite improve filtration and reduce the water footprint of water treatment plants?
The secret lies in its micro-macroporous structure; Zeolites are crystalline materials with a surface area ten times greater than sand and anthracite (1-3 m²/gram vs. 20-35 m²/gram), which allows them to have a higher electrostatic charge that retains smaller particles.
Additionally, they can fix metals such as iron and manganese and exchange ions of ammonia and ammonium. At the same time, due to their porosity, they present up to 80% less pressure drop than sand and anthracite filters. They also have a higher solids loading capacity while being 60% lighter than sand.
Designing filtration systems with a double flow
These valuable properties allow for designing filtration systems with a double flow rate typically used with sand and anthracite, reducing the filtration area by up to 50% and, therefore, the CAPEX of any project. This can represent more than 10% savings in the total cost of a desalination plant or dramatically increase the filtration capacity of an existing one.
Furthermore, having a higher loading capacity and being lighter allows longer filtration runs. It requires up to 40% less flow for backwashing, making blowers unnecessary for expansion and reducing annual water and energy expenses by up to 60%.
A ten times greater surface area allows retaining particles within 3 to 1 microns versus the 10-15 microns retained by sand and anthracite, reducing wear and tear on cartridges and membranes in reverse osmosis plants, increasing their lifespan, and reducing maintenance costs. Moreover, retaining iron, manganese ions, and ammonium helps reduce the scaling and fouling problems caused by these contaminants and their economic impact on operations.
Zeolite filters provide better filtration quality as tertiary treatment in wastewater treatment plants, helping to ensure and surpass compliance with the most stringent discharge standards. They also serve as the ideal pretreatment for water reuse in feeding reverse osmosis systems.
If accompanied by proper chemical pretreatment (coagulation and inline disinfection), the costly ultrafiltration systems often used for this purpose can be rendered unnecessary, significantly reducing both CAPEX and OPEX for these plants and projects.
What can we do from our end to help you achieve a Positive Water Footprint with zeolite filter media
In summary, using zeolites as a filter media can be an important ally in companies’ and governments’ efforts to become more efficient and positive in their water footprint, and their implementation is quite practical. However, caution is needed, as not all zeolites available on the market meet the necessary quality for this purpose.
Therefore, when selecting this filter media, it is recommended that it be certified by standards such as NSF 61, ANSI/AWWA B100-89, and UNE 16070, among others.
