Recently, Waterhouse was called upon to assist a Wastewater Treatment Plant with the operation of their centrifuge. This particular plant had been dealing with another speciality chemical supplier for years, and had never been able to achieve the performance specifications required for proper plant operation.
Fortunately, the WWTP was able to dewater their sludge solids to an acceptable cake dryness level. However, the centrate going back to their biological secondary plant was reaching levels as high as 7,000 mg/L TSS! This was overloading and disrupting the biological secondly process, compromising its performance and effluent quality. Our competitor had performed a series of jar tests and plant trials, and had been unable to find a solution.
Waterhouse visited the plant site several times to fully understand the operation and limitations, performed several laboratory bench tests, and determined that while a change in polymer selection would be beneficial, the real key to success was to change the operational mode of the centrifuge. Significant adjustments were made to the operating parameters, and within half a day the centrate solids were less than the performance criteria of 1,000 mg/L. The most encouraging aspect was these gains were made with no effect seen on cake solids.
At the end of the second day evaluation period ,with two Waterhouse representatives on-site, we were able to keep their cake dryness constant, while lowering the TSS from 7,000 mg/L down to less than 200 mg/L, or 80% below the design performance specification.
This is a reduction of over 95% when compared to previous steady state operation, and something the plant had never been able to achieve in the past!!