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ClariPhos rare earth coagulant. Remove more phosphorus, produce less sludge, save money

Achieve ultra-low phosphorus limits, produce less sludge, save money.


ClariPhos™ Rare Earth Coagulant is a game-changing phosphorus removal technology that dramatically outperforms alum- or ferric-based coagulants.

With this advanced coagulant, wastewater treatment plants can achieve ultra-low phosphorus limits—as low as 0.07 mg/L—without the need to install or upgrade costly tertiary filtration systems. ClariPhos also produces far less sludge than alternatives and improves dewaterability, helping treatment plants significantly reduce costs for solids management. 

ClariPhos has been successfully used in numerous wastewater systems including conventional activated sludge, membrane bioreactors, sequencing batch reactors, lagoon systems, rotating biological contactors, trickling filters, and more.

Why does ClariPhos work so well to remove phosphorus?

ClariPhos is made with the rare earth elements lanthanum and cerium, which have a very high affinity for phosphorus. These elements form a tight ionic bond with phosphorus to create rhabdophane, a dense and insoluble precipitate that settles up to two times faster than conventional Al- or Fe- based coagulants. The results are improved clarifier performance and reduced risk of carryover of suspended solids.

ClariPhos forms a dense precipitate that settles up to two times faster than ferric- or alum-based coagulants

Up to 50% less sludge with improved dewaterability

ClariPhos forms a tight preferential bond with phosphorus, which means far less coagulant is needed to achieve regulatory requirements—typically 30 to 70% dose reduction over alternatives. This lower dose rate results in significant reductions in sludge volume; as much as 34% less sludge than alum and 50% less sludge than ferric coagulants. ClariPhos also helps improve sludge dewaterability, enabling up to 40% increase in attained solids.

Reports have estimated some wastewater plants may spend up to 40% of their operating budget on sludge management, so reduced sludge production and improved dewaterability can help significantly reduce sludge management costs.

ClariPhos vs. alum. A comparison of precipitate produced to remove an equivalent amount of phosphorus.

Low acidity – reduced impact on pH

ClariPhos is 100 times less acidic than alum- or ferric-based coagulants and is typically dosed at a much lower rate. That means it is far less likely to lower pH of the wastewater system and require pH adjustment with alkaline chemicals.

Extensive operational and economic benefits

Wastewater treatment plants throughout the US and Canada have switched to ClariPhos or are evaluating its ability to comply with stringent phosphorus discharge limits. In addition to the advantages above, ClariPhos also provides many more operational benefits that include:

  • Low freeze temperature (-40°C); eliminating the need for heated storage and pipe heat tracing
  • Non-hazardous rating; safer to handle than alum- or ferric-based coagulants
  • Inhibits struvite buildup
  • Repeatedly passes whole effluent toxicity testing at 100% effluent concentration
  • Doesn’t stain or discolour structures and equipment
  • Sludge is suitable for land application – rare earth elements have low toxicity and are not bioavailable to plants

Make the switch — ClariPhos easily replaces conventional coagulants

In most cases, plant operators can simply replace conventional alum or ferric coagulants with ClariPhos to easily and cost-effectively improve the chemical precipitation and settling of phosphorus. ClariPhos requires no special chemical feed equipment and will often work with existing feed pumps.

Bishop Water can provide comprehensive services for a trial and full-scale implementation of ClariPhos Rare Earth Coagulant. Our team will assess your plant’s current phosphorus removal equipment and operation to determine the optimal dosing location and dose rate for ClariPhos. Samples will also be obtained at various points in the treatment process to optimize ClariPhos performance through steady conditions as well as variable flows and loads.

Once ClariPhos is fully implemented, Bishop Water can provide ongoing support through routine technical service visits and ongoing sampling, analysis and optimization.

Contact us to learn more about the benefits of ClariPhos rare earth coagulant and to discuss how your plant can make the switch.


Download the ClariPhos brochure.