Part 1 - Development and Application of a Limit Dryness Test Methodology to Assess the Optimum Polymer Dose for the Dewatering of Anaerobically Digested Biosolids.

Examining changes in the dewaterability of anaerobically digested biosolids has become an increasingly important metric as facilities move to implement enhanced biological phosphorus removal processes. The Limit Dryness Test, a bench-scale dewaterability measurement procedure, can provide insight into changing wastewater treatment process impacts on dewaterability, and an estimation of polymer demand in biosolids dewatering. This paper details the development of the Limit Dryness Test at Metro Wastewater Reclamation District in Denver, Colorado, and provides a detailed procedure for the replication of the test. The results of the Test’s ability to determine the Optimal Polymer Dose over a 12-week period are presented in graphical and numerical formats. Additionally, the impact of changing wastewater treatment processes on polymer demand is tracked using the Limit Dryness Test as well as the ability of the procedure to predict full-scale dewatering polymer demand.