chapter  23
6 Pages

Primary Treatment Calculations

As with many other wastewater treatment plant unit processes, several process control calculations may be helpful in evaluating the performance of the primary treatment process. Process control calculations are used in the sedimentation process to determine:

• Percent removal • Hydraulic detention time • Surface loading rate (surface settling rate) • Weir overflow rate (weir loading rate) • Biosolids pumping • Percent total solids (% TS) • BOD and SS removed (lb/day)

In the following sections, we take a closer look at a few of these process control calculations and example problems.