Protech Announces Availability of New Automated Control System for Stormwater Treatment

ProTech General Contracting Services, Inc., a full service environmental compliance company, announced the availability of a new control system for stormwater treatment using polymer coagulants for suspended sediment removal. The control system, based on Streaming Current Detector (SCD) technology, provides real-time automated polymer monitoring and dosage control, with the capability to respond to changes in flow, turbidity, or water chemistry within minutes.

“Precise and accurate coagulant dose is critical for polymer coagulant systems because it eliminates the possibility of overdosing and minimizes coagulant consumption,” states Chris Ott, chief technology officer of ProTech. “SCD control has been used for many years for industrial process control—ProTech has simply adapted the technology to meet the requirements of our stormwater treatment systems. We demonstrated SCD control on several projects last season and it greatly increased reliability, as well as client and regulator confidence, in our systems.”

Polymers coagulants and flocculants offer significant improvements in clarification efficiency and effluent water quality for many projects. However, they require precise and accurate dosage control for optimum efficiency, to minimize polymer consumption, and to eliminate potential toxicity due to excess polymer in the effluent. To date, most polymer treatment systems have used simple proportional metering control systems. While these control systems are effective, they do have potential limitations—the most important being that the system operator must monitor and account for variation in suspended sediment levels.

The SCD measures an electric current, which is the net surface charge, direct measurement of the efficiency of particle coagulation, of a water sample. The SCD, in conjunction with a controller processor, metering pump, and flow and turbidity meters, constitutes a feedback system assuring continuous, accurate polymer dosage. As flow and suspended material load varies, the system continuously recalculates dose to maintain the optimum, varying polymer feed accordingly. The optimum polymer dose is reestablished within minutes of changes in flow or suspended material.

”SCD control is the best available method for maximizing the efficiency of a polymer coagulation system,” says Ott. “This technology automatically responds almost immediately to changes, and allows the system to be fine tuned for minimum polymer consumption and best efficiency.”

The SCD system contains comprehensive data storage and reporting capabilities, including the ability to automatically send data reports by cell phone or email. The polymer feed and SCD control unit itself is compact, requires little electrical power, and can be operated with a small generator, solar array, or Pelton wheel.

Source: ProTech General Contracting Services, Inc.