Antimony in Water
Antimony (Sb) is naturally occurring in small quantities in water, but elevated levels can become a concern in industrial environments. To maintain safe drinking water standards for toxic elements, regulatory agencies restrict antimony to 6 parts per billion (ppb). According to the EPA, that microscopic limit is roughly equivalent to finding six grains of sand across an entire playground—highlighting just how low acceptable concentrations must be.
Higher concentrations of antimony are typically associated with coal combustion, petroleum refining, and manufacturing processes such as fire retardants, ceramics, and electronics. As a result, antimony is often identified in contaminated groundwater and industrial process water, making it an important target for effective industrial water treatment and groundwater remediation.
Challenges in Treatment
Antimony removal can be difficult due to its varying chemical forms in water. Conventional treatment methods, such as coagulation with ferric chloride followed by filtration, can achieve partial removal but often require careful optimization and may not deliver consistent results. Technologies like reverse osmosis can be effective, but they add cost and can introduce operational challenges if upstream treatment is insufficient.
Treatment Evaluation
Hydrosil recently worked with a client managing elevated antimony levels in contaminated water. Two approaches were evaluated:
- Ferric chloride coagulation
- A pump-and-treat system using HS-250-AC filtration media
While ferric chloride provided some reduction, performance varied. HS-250-AC, on the other hand, delivered more consistent results in removing contaminants like antimony and other heavy metalsSee results below to understand how well HS-250-AC works when treating antimony.
| Raw Water | 5 ppm Ferric Chloride | 10 ppm Ferric Chloride | 20 ppm Ferric Chloride | HS-250-AC | |
| Antimony, Total (mg/L) | 0.155 | 0.145 | 0.142 | 0.139 | 0.02 |
HS-250-AC Performance
HS-250-AC is designed for advanced water filtration and pollutant removal in demanding applications. In this case, it effectively reduced antimony concentrations without complex chemical dosing. When used in a pump-and-treat system, it offered a more streamlined and reliable solution, while also supporting overall water treatment system performance.
