PSR™: Phosphorus Discharge and Sulfur Emissions Compliance
A Sustainable, Iron-Rich Alternative to Conventional Phosphorus Removal Chemicals
Municipal and industrial wastewater treatment plants are under increasing pressure to meet stringent phosphorus limits stated in their NPDES (National Pollutant Discharge Elimination System) permits. With growing scrutiny on nutrient pollution and its role in harmful algal blooms and aquatic ecosystem degradation, compliance is more challenging and critical than ever. Green Steel PSR™ is an upcycled cleantech product engineered to help wastewater treatment plant operators meet even ultra-low-level phosphorus discharge limits cost-effectively and sustainably.
Why Phosphorus Control Matters for the Environment
Phosphorus is a key nutrient that contributes to eutrophication in surface waters, often leading to oxygen-depleted “dead zones” and significant ecological harm. The EPA and many state agencies are now enforcing total phosphorus (TP) limits as low as 0.1 mg/L in NPDES permits, requiring plants to optimize their phosphorus removal strategies.
Challenges with Conventional Phosphorus Removal Methods
Operators traditionally rely on chemical precipitation using ferric chloride, ferric sulfate, or aluminum sulfate.
While effective, these chemicals come with drawbacks. . .
Rising costs
due to inflationary pressure and volatile global supply chains
Increased chloride & sulfate loading
which can trigger secondary discharge concerns
Operational risks
including corrosion, workplace safety hazards, and complex handling requirements
Aluminum accumulation
which may raise downstream environmental compliance issues
Advantages of Green Steel PSR™
Key Benefits . . .
Green Steel PSR™ offers a compelling alternative by leveraging the inherent reactivity of an iron-rich byproduct of steel manufacturing to remove phosphorus through sequestration and chemical precipitation, without introducing chlorides or sulfates into the effluent.
High phosphorus-binding capacity
No added chlorides, sulfates, or aluminum
Sustainable and upcycled—diverts industrial byproducts from landfills
Non-hazardous material with safer handling profile
Can reduce or replace reliance on conventional treatment chemicals
How Green Steel PSR™ Achieves Ultra-Low Phosphorus Discharge and Sulfur Emissions Limits
Green Steel PSR™ interacts with soluble phosphorus in wastewater, forming stable iron-phosphate compounds that are entrained in the biosolids at wastewater treatment plants. Its porous structure enhances contact efficiency, while its alkaline composition provides buffering benefits in low-pH environments.
Proven Performance. Real NPDES Compliance Gains.
Pilot studies and field applications have demonstrated that Green Steel PSR™ reduces phosphorus levels comparable to or better than conventional treatment chemicals such as ferric chloride, ferric sulfate, and aluminum sulfate. One of the key advantages Green Steel PSR™ has over these chemicals is that it does not introduce chlorides or sulfates into the effluent. As such, it can help wastewater treatment plant operators remain compliant with their NPDES permits, even when allowable phosphorus levels are considered ultra-low.