Sludge treatment solution for wastewater treatment plant in BC, Canada

Alumichem optimized the sludge treatment performance and reduced total cost at a major Canadian water treatment plant.


The performance of solids dewatering can vary over time due to changes in solids composition.  This was the case for a wastewater treatment plant in BC, Canada that had frequent after hours callouts for their dissolved air flotation thickener (DAFT) system, which was used to thicken secondary solids ahead of a centrifuge.  

This compositional change caused the polymer to lose efficacy, leading to high chemical cost and poor thickener performance, which had a negative impact on the dewatering performance of their centrifuge as well.

Solution Highlights

Alumichem performed a complete audit of their plant performance, dosages, polymer dilution procedures and feed rates, and determined that the dosages in both the DAF and the centrifuge were above average while the performances were below average. 

As a two-stage solution, we ran trials on-site with new polymers, identified through a proprietary test method developed in-house, which significantly improved both the thickener performance along with a TSS reduction in the effluent.

Similar tests and trials were run on the centrifuge, due to the altered physical properties of the sludge, leading to an enhanced dewatering performance over what had previously been possible.


The DAFT polymer change resulted in a 60-70% reduction in dosage and significantly improved the TSS in the effluent, which has led to zero callouts on the DAFT system in over four years. The centrifuge was also optimized and produced 21-22% cake solids with a 10% polymer reduction, while previous performance was approximately 17-18% cake solids. 

This led to additional savings for sludge transportation and polymer usage, along with less hours of troubleshooting and guesswork by the operators. 


Alumichems solution for sludge treatment has significantly improved performance on the wasterwater plant. Analyzing and testing all aspects of the plant performance and providing all the necessary chemical products, resulted in superior performance and a significantly reduced total cost of operation.

Alumichem continues to work with the client to ensure their process is continually optimized for both performance and efficiency.


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