On Feb. 20, 2018, Minnesota Attorney General Lori Swanson ...
Product gives real-time feedback for system control
Corrosion in water distribution systems can impact consumers’ health, costs and the aesthetics of finished water. Older systems may include lead-based solders that must be protected to avoid elevated lead concentrations, which is regulated by the U.S. Environmental Protection Agency (EPA) at ≤0.015 mg/L. Corrosion occurs because metals tend to oxidize when they come in contact with oxygenated water, resulting in the formation of stable metal oxides.
Corrosion inhibitors—such as inorganic phosphates in the form of polyphosphates, orthophosphates, glassy phosphates and bimetallic phosphates—are often employed. To ensure proper corrosion control, ensure proper feed and reduce operating cost, proper monitoring is required.
Phosphate is commonly used to minimize corrosion to potable water distribution systems and residential, commercial and industrial potable water piping, and reduce lead corrosion to comply with EPA standards. To achieve passivation of new or previously untreated systems, phosphate is typically dosed at >3.0 mg/L as orthophosphate. The typical maintenance dosage to ensure corrosion control is 0.5 to 1.5 mg/L as orthophosphate.
Reliable monitoring of critical phosphate levels can be achieved using the Swan Analytical AMI phosphate analyzer. Analog/digital outputs give real-time feedback for system control. Built-in surveillance functions generate alarms if measurement is not valid, such as missing flow, empty reagents and valve and photometer functionality.