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Aeration for Paper Mill Oxidation Lagoons

Paper Industry Wastewater Aeration

Fluence used a combination of Twister and Tornado aerators to keep solids suspended and prevent sludge accumulation in Pronal's oxidation lagoons.

Fluence designed a hybrid system featuring its TWISTER® and TORNADO® aerators to prevent sludge accumulation

Paper and pulp industry factories are water-intensive and produce wastewater with high levels of pollutants. When the Pronal recycled paper plant in San Luis Potosi, Mexico, needed to update its wastewater treatment, it turned to Fluence to create a hybrid aeration system for its two oxidation lagoons.


Pronal is a recycled paper plant that produces kraft paper. The plant produces an average flow of 14,000 m3/d (3.7 MGPD) of wastewater with high biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS). Pronal struggled for years to find a solution to improve the aeration in its two on-site oxidation lagoons.


At pulp and paper mills without adequate aeration and mixing, basin sludge accumulation is a common, significant problem. Sludge buildup on the basin floor ultimately reduces the depth of the pond, which slows the entire wastewater treatment process. A combined technological solution is required to resuspend settled solids, increase the depth of the pond, improve biological activity, and reduce odors. Pronal's wastewater effluent needed to meet high environmental standards so it could be reused for irrigation and discharged safely into the river.


Fluence worked with Pronal to create a combined technological solution to maximize oxygen transfer and optimize the treatment process in each oxidation lagoon. Combining the mixing action of the low-speed TWISTER® surface aerator with the aerating action of the submerged, blower-assisted TORNADO® provides efficient, controlled wastewater treatment, reducing sludge by keeping solids in suspension. Used in tandem, these two aerators create a hybrid, controlled mixing pattern ideal for pulp and paper industrial wastewater treatment.


Fluence supplied aeration equipment that creates the perfect mixing-aeration ratio to produce the necessary biomass needed to reduce the high loads of organics. The water is successfully treated to levels that meet Mexico's environmental discharge laws. Pronal's deep commitment to the environment was recognized when they earned certification from the Rainforest Alliance and Water Quality by CONAGUA, the National Water Commission in Mexico.

Does treatment of your industrial wastewater require custom solutions? Contact our experts to discuss how Fluence’s efficient, durable aeration equipment can best meet your needs.


Villa de Reyes, San Luis Potosi, Mexico

Productora Nacional de Papel SA de CV

Wastewater Aeration

Four 50 horsepower blower-assisted TORNADO® aerators and eight 50 horsepower TWISTER® float-mounted aerators