Dairy Wastewater Presents A Difficult Phosphorus Removal Problem

It is no secret that dairy wastewater is high in phosphorus, which must be removed to safely discharge either into a receiving stream or as part of a pretreatment program to keep from compromising a domestic wastewater system.

One Midwestern Dairy Turns To Neo Water Treatment For Assistance

Faced with a 15 mg/L pretreatment total phosphorus limit, one midwestern dairy struggled to meet the P removal required to discharge to their municipal treatment system. Frequently, despite treating adding ferric chloride to their activated sludge tank, their effluent showed P concentrations of 20 to 25 mg/L. To add to the treatment complexity, they were constrained by alkalinity, which the ferric chloride consumed quickly. This alkalinity concern limited the dosage of ferric they could use.

Phosphorus In Dairy Is More Difficult To Remove

For reasons that are not fully understood, the phosphorus in dairy wastewater is more difficult to remove, requiring double the coagulant dose required in typical domestic wastewater for comparable removal. Keep in mind that the dosage for traditional coagulants, like ferric chloride, increases almost exponentially as the effluent limit decreases. This high dosage also increases the pH adjustment chemical cost, and severely increases the amount of chemical sludge produced.

Dosage for Neo WaterFX also is higher for dairy wastewater.

If you have been following WaterFX for a while, you know that in typical wastewater, the dosage for WaterFX does NOT increase as the limit gets lower, remaining approximately 1:1 on a molar basis. For dairy wastewater, it is a bit different. The molar ratio of WaterFX to P does increase, but not exponentially.

The dairy found that a molar ratio of 1.5:1 WaterFX to P was needed to remove the phosphorus from the dairy wastewater. This is substantially lower than the dosage required by other coagulants. With the lower dosage comes lower chemical sludge production and reduced sludge disposal.

Reliable compliance while maintaining alkalinity.

What the dairy found was that switching to WaterFX helped them maintain the alkalinity in their system and also reduced the chemical sludge produced. But best of all, they were able to achieve reliable compliance with their effluent limit. And isn’t that the most important factor?

Do you have dairy wastewater? Or some other difficult phosphorus removal issue?

Our engineers are phosphorus removal experts. Contact us for a free consultation. We will help evaluate your treatment process and requirements and determine if WaterFX is a good fit. From there, we can assist in pilot testing so you know exactly what you can expect. See what WaterFX can do for your treatment.