Metso Introduces Solution for Increasing Capacity in Wastewater Treatment Plants

Metso has developed an online measurement technology with which municipal and industrial wastewater plants are able to improve their performance and reduce the amount of chemicals used in sludge drying process by even up to one third.

The new Metso Low Solids Measurement is the first online measurement technology for municipal and industrial wastewater treatment plants that enables measurement of a media with very low solids contents in difficult applications like centrifuge centrate. The technology also offers significant savings per centrifuge in polymer and centrifuge usage.

"The new technology developed by Metso offers the world's water treatment plants an opportunity to improve their performance and thus gain major cost savings. A large North American wastewater treatment plant has calculated that it saves even up to 30% in its annual USD 2.5 million chemical costs. In addition, a municipal plant in Finland using Metso LS estimates that they will achieve annually EUR 15,000 savings in polymer and centrifuge usage only by keeping reject water total suspended solids lower that 1000mg/l", says Timo Rantala, Product Manager, Metso's Automation business line.

The Metso Low Solids Measurement system is based on LED and laser technology. It dearates, filters, and measures the process solids along with possessing self-cleaning capabilities to keep the measurement optics clean for continued accurate measurement. It complements Metso's measurement product portfolio to the wastewater processes. Earlier Metso has launched Metso TS, total solid measurement to the waste water treatment processes. Metso TS is based on microwave technology.

The Metso LS device can be connected online to the process and is able to measure continuous sample flow through the system by utilizing an integrated centrifugal pump. The device has two light sources, LED and laser, that measure absorption, scattering and depolarization of these sources as they pass through the flowing media. The measurement cell has an extremely strong sapphire glass with high optical properties. The cell and sample lines are automatically cleaned at given intervals. Metso LS continuously measures the suspended solids content within the range of zero to 5000 mg/l and also the entrained air index, which indicates overdosing of polymer. The Metso LS measurement system dearates, filters and measures the process solids along with possessing self-cleaning capabilities to keep the measurement optics clean.