Grit Characterization Studies

Pacific Wastewater Optimization provides grit sampling and characterization studies. Grit characterization is useful to evaluate the performance of existing grit removal equipment and to inform the design of new or expanded grit processes.

Pacific Wastewater Optimization offers two analysis approaches. The first includes wet sieving the grit and directly measuring the settling velocity of each size category. The second method involved placing a grit sample in a settling column with a range of known upflow velocities (Gerges et al., 2017). The fraction of grit settling at each velocity is measured. Clients can choose one or both methodologies for a given study.

Grit Characterization Services

Pacific Wastewater Optimization provides on-site grit evaluations for wastewater plants and existing grit equipment:

Customized sampling for your unique plant site and constraints
Influent Grit Characterizations
Grit Chamber/Grit Equipment Performance evaluations

Custom Set-up – Sampling systems are constructed for the unique influent and grit removal configurations.

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Sieve analysis with direct settling velocity measurement

Grit samples are collected and sieved. Each sieve fraction is settled in a column and velocity measurements are directly observed.

After sampling, the collected grit is sieved and analyzed for settling velocity. A report is provided documenting:

Size Distribution (% and cumulative)
Sand Equivalent Size (SES)/Design Overflow Rates
Grit concentrations (lb/MG)
Grit System Performance Measurements (Capture Efficiency, %)
Sampling System and Site Photos

Upflow column velocity testing

Grit is poured into a column with a range of fixed upflow velocities (1, 2, 3, 4, 5, and 6 ft/min) and the fraction of grit settling at each velocity is measured.