New regulations designed to reduce phosphorus levels in the Great Lakes Region watershed can seem daunting if you operate an industrial or a municipal wastewater treatment plant. The strict regulatory standards have been implemented over the past six years as part of a nationwide effort to prevent potentially toxic algae from fouling our water supplies: lakes, rivers, ponds, and reservoirs.
Depending on where you discharge, the limits can be very low. It is not uncommon for industrial facilities that discharge to a Publicly Owned Treatment Works (POTW) to pay surcharges of $50/lb. phosphorus when local limits are not met.
The most effective way to limit phosphorus in wastewater is to take a holistic water management approach that incorporates inputs, chemistries, equipment, and process.
When evaluating the phosphorus levels in your facility, the first line of defense for reduction is source control; that is, try to lower the input of phosphorus so you don’t have to remove it. Start by measuring phosphorus point sources and determine what you can control. You may need to review safety data sheets (SDS) to find phosphorus-containing chemicals used in your production process. In some cases, it might be necessary to talk with your chemical suppliers specifically to uncover potential sources.
The next line of defense in fighting phosphorus is chemical precipitation. This can be achieved with inorganic metal salts such as calcium, aluminum, and iron-based chemistries, as well as Watertech of America’s PHOS-OUT 1718. This unique blend of rare earth metal is capable of forming strong crystalline bonds with phosphorus forming an insoluble precipitate that is hard to separate. PHOS-OUT 1718 has shown the capability to remove phosphorus to less than 0.10 mg/l.
Remember that as the discharge limits decrease, chemistries will need to be evaluated and treatment programs refined to best suit your water quality goals. If additional removal is necessary, specialized ion exchange resin can be used to remove soluble phosphorus if sedimentation, biological treatment, and filtration aren’t adequate.
Taking a 360-degree look at wastewater treatment in a facility also requires a review of the quality and performance of existing equipment, as well as an analysis of what investments may be necessary for system optimization. Solutions can range from large capital expenditures for enhanced biological phosphorus removal, separation and filtration, to monitoring and analysis, and automated chemical feed and control.
It is important to work with your water management partner to determine the most appropriate equipment technology. Ideally you would want a program that enables you to meet your regulatory requirements and provide a quick ROI.
It is important to analyze how water is cycled through your facility’s system and determine methods and practices that can contribute to lower levels of phosphorus. For example, food plants have been able to capture phosphorus-containing wastes before they enter the wastewater system. Metal finishers have gone to low phosphorous or nanotechnology-based solutions to enhance paint adhesion. There is a trend in the water treatment industry to reduce and even eliminate phosphorus from boiler and cooling water systems.
There are many treatment methods available for removing phosphorus from your waste stream. Again, your water management partner can work with you to look at your operation as a whole and create a smooth-running operation that will allow you to meet discharge limits and keep you in regulatory compliance.