1. Enhanced Filtration: Diatomaceous earth is composed of microscopic fossilized remains of diatoms, which have a unique porous structure. When added to a sand filter, these tiny particles form a layer on top of the sand bed. This layer acts as a pre-filter, capturing suspended solids, microorganisms, and other impurities that might otherwise pass through the sand.
2. Increased Surface Area: Diatomaceous earth particles have a high surface area-to-volume ratio, providing more adsorption sites for contaminants. As water passes through the DE layer, it comes into contact with these surfaces, enhancing the removal of pollutants through physical adsorption and chemical bonding.
3. Improved Depth Filtration: DE forms a deeper filter bed compared to sand alone. This depth filtration mechanism allows for more efficient trapping of particles as water percolates through the DE layer and the sand filter media. The increased depth also helps prevent premature clogging and extends the filter's lifespan.
4. Reduced Turbidity: DE aids in reducing turbidity, which refers to the cloudiness or haziness of water caused by suspended particles. By capturing these particles, DE improves water clarity and produces clearer, more polished water.
5. Enhanced Microorganism Removal: Diatomaceous earth has a natural ability to trap and immobilize microorganisms, including bacteria, viruses, and protozoa. This makes DE an effective filtration media for removing microbial contaminants from water, improving its microbiological quality.
It's important to note that while DE can enhance the efficiency of a sand filter, it also increases the pressure drop across the filter. Therefore, the filtration system should be designed and operated accordingly to accommodate the increased pressure requirements.
Overall, the addition of diatomaceous earth to a sand filter can significantly improve the filter's performance by removing more contaminants, reducing turbidity, and enhancing microbial water quality.