Centrate / Filtrate monitoring
Monitoring filtrate or centrate ensures dewatering efficiency and allows optimisation of centrifuge/filter performance.
If allows economic savings by reducing energy or PE-usage, is lower the impact of the reject water going back for processing.
The specially designed Olpas sensors have a superior fouling resistance, measure in the most dirty circumstances (even when high loads of TSS and PE are present) and can even compensate for air bubbles present in centrate.
Next to measuring TSS in filtrate, assessing residual polymers -which represent the polymers that haven't been used effectively and remain in the centrate- provides valuable insights into the overall effectiveness of the dewatering process.
Centrate quality as an essential parameter to monitor the dewatering process, and provide feedback control
TSS in centrate gives important insight in the dewatering efficiency, but also provides quality assurance: it ensures that the quality of the separated liquid (centrate, filtrate or reject water) meets the requirements before it is flown back into the WWTP for processing.
An accurate reliable measurement that swiftly follows the trend allows the control system logic to adapt the sludge flow-rate, dewatering-parameters and PE-concentration.
Monitoring reject water for an efficient feedback control
( See these posts about Olpas' vision on the dewatering process, and how to optimise it: Olpas measurement solutions for sludge dewatering optimization )
Key features for an efficient filtrate monitoring
A reliable drift-resistant measurement of TSS and/or residual PE in centrate
Fouling resistance, also in challenging environments; even when high residual polymers lead to additional fouling
Automatic compensation for air-bubbles in filtrate
Advanced end-2-end solution for centrate with many air-bubbles
With a sample grabber (centrate pump) and flow-cell, the sensor provides an end-to-end measurement solution, which supresses the impact of air-bubbles in centrate.
Low maintenance and easy cleaning thanks to the flowcell and the automatic cleaning process
Only once per 3 months maintenance of the pump
Polymers (flocculants and/or coagulants) in the dewatering process
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!
Products for this application
Number of selected Products:
3
OTD-SDPB
TSS in dewatering centrate (with centrate pump and flowcell)
An easy to install end-to-end measurement solution with limited impact of air-bubbles and exceptional fouling resistance thanks to ultrasound measurement technology. For measuring TSS in concentrations from 0 - 2.000 mg/L.
The device consists of a sample grabber (centrate pump) and flow-cell.
OTD-SDPC
Residual Polymers in dewatering centrate (with centrate pump and flowcell)
An easy to install end-to-end measurement solution with limited impact of air-bubbles and exceptional fouling resistance thanks to ultrasound measurement technology. For measuring polymer concentrations.
The device consists of a sample grabber (centrate pump) and flow-cell.
