PCM - Polymer Concentration Measurement (PE concentration)

Challenges caused by polymers

Even though polymers play a crucial role in enhancing the efficiency of wastewater treatment processes, usage in treatment-processes also introduces challenges and issues:

• Overdosing, which can result in the formation of larger, denser flocs that are difficult to settle or filter effectively

• Foaming, which can interfere with clarifiers and filters

• Economic reasons, caused by the high cost of polymers

• Concerns for downstream processes, where the polymers have a negative impact on the process

• Environmental concerns when polymers are released into nature

Monitoring polymers to mitigate issues

To mitigate potential problems, it's crucial to carefully monitor and control the dosage of polymers for the specific wastewater characteristics, and optimize the treatment process to minimize any adverse effects.

Regular testing, process optimization, and adherence to environmental regulations can help in managing these challenges.

Olpas has sensors available to monitor the watertreatment process, and sensors for monitoring residual polymers during different stages of the dewatering process, both in high concentration or low concentrations.

Many wastewater treatment plants (WWTPs) incorporate some sort of flocculants and/or coagulants in their processes, especially in the sludge dewatering phase where dewatering polymers are often used, often a combination of flocculant and coagulant.

Typically the final stage of the dewatering process involves the addition of dewatering polymers to the sludge before introducing it to the decanter, centrifuge or press.

The dosage of polymers is determined based on the mass flow of solids and often falls within the range of 10-20 kg of polymer per tonnen of dry solids, depending on specific circumstances.

Less polymer in centrate for a more economic measurement

Typically, the concentration of polymers in centrate or filtrate is in the range of 0-2.000 µg/L(*), while the dewatering processes operate most economically at 200-400 µg/L(*) of polymers in the centrate or filtrate.

The Olpas Polymer Concentration Measurement (PCM) system will be pre-calibrated with the correct parameters for this range. Offset and scaling are user-defined to match polymervariations or supplier diversity.

(*) Theses concentrations greatly vary per installation, type of sludge, type of polymers and process parameters. That's why an online measurement is do important!