Solids measurements enable real-time control in wastewater treatment
Opal’s wastewater treatment plant (WWTP) at its Paper & Recycling Botany Mill has significantly improved process visibility, automation and reliability after implementing Valmet’s solids measurements and automation solutions. Located in New South Wales, Australia, Opal’s Botany Mill faced a common challenge in their wastewater treatment operations: a lack of real-time visibility into solids content and manual testing cycles that delayed response and process adjustments.
Transitioning from manual checks to automated clarity
The turning point came in 2019 when Valmet’s solids measurements were introduced to the wastewater treatment plant. Building on the Mill’s existing relationship with Valmet, whose instruments were already proven on the paper machine side, the decision was made to extend Valmet technology into wastewater operations.
Valmet Total Solids Measurements (Valmet TS) determine sludge consistency in clarifier sludge pumps and Valmet Low Solids Measurements (Valmet LS) measure suspended solids in clarifier accepts, mixed liquor suspended solids (MLSS), and final effluent.
“Valmet’s support team was already on-site and their technology was familiar to us, and that, along with the self-cleaning feature of Valmet LS, helped us make the decision,”
Rikesh Roopnarain, On-Site Engineer at Valmet and Allan Bate, Process Expert at Opal with Valmet Low Solids Measurements
Valmet’s solids measurements were integrated into the existing Valmet DNA Distributed Control System, giving operators immediate access to real-time data. This allowed Opal to automate key parts of the process, including:
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Back-up flow activation when effluent solids increase
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MLSS-based control of decanter feed
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Enhanced data validation with DAF system integration
These changes allowed the team to move to a real-time, proactive operating mode. With automated controls, there are fewer decanter issues.
Daily laboratory testing is still conducted, but primarily to validate the accuracy of the online readings. Operators have confidence in the data and can act in real time when parameters deviate. Less time is spent on monitoring.
A step forward in wastewater automation
Looking ahead, Opal plans to continue optimising the performance of its wastewater treatment operations and welcomes the possibility of additional automation features in Valmet’s future offerings.
By implementing Valmet’s solutions, Opal’s wastewater treatment plant has successfully shifted from manual monitoring to intelligent, automated control, achieving not only operational improvements, but also greater reliability and improved environmental performance.
