BioSpikes 4000 significantly improved sludge reduction at a municipal lagoon

Dredging with BioSpikes 4000 at a municipality increased the plant’s lagoon capacity through effective sludge reduction and postponed a $600,000 project.


  • A 28% improvement in sludge reduction levels in the treated area
  • An increase in lagoon treatment capacity from 9% to 35% in the treated area
  • Defers a $600,000 dredging project without associated negative impacts on effluent quality


A municipality was concerned about potential problems from years of poor sludge reduction, resulting in sludge buildup in its wastewater treatment lagoon. The 2.5 hectare (6-acre) lagoon is 3.4 m (11 ft.) deep, and sludge levels ranged from 2.4 to 3.0 m (8 to 10 ft.) throughout the lagoon, severely limiting treatment capacity. Looking for alternatives to a $600,000 dredging quote, the municipality teamed up with Novozymes Biologicals to evaluate BioSpikes 4000.


The lagoon is aerated by two floating mixers in the front end. BioSpikes were added to an area of the lagoon with significant sludge buildup, and lacking sludge reduction. Sludge measurements were performed monthly for 6 months and compared to the untreated control area.


After 60 days the sludge levels were reduced in the treated area by 28% – 0.87 m (2.8 ft.), while the sludge levels in the untreated areas increased by 19% – 0.47 m (1.5 ft.). The drop in sludge levels led to an improvement in operating capacity from 9% before the trial to 35% after the trial – a 289% increase.

Fig. 1. The application of Novozymes BioSpikes resulted in a 28% improvement in sludge reduction in the treatment area over 60 days.




The addition of BioSpikes 4000 to the municipal lagoon system successfully deferred dredging and increased treatment capacity by improving sludge reduction. The municipality is planning to scale up the application and treat a much larger area.