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Sediment Removal

Comprehensive removal of suspended sediment — from coarse grit and sand to fine silt and colloidal clay — across the full particle-size spectrum, engineered to protect downstream plant and meet discharge consent.

Why Sediment Removal Matters

Suspended sediment drives abrasion, siltation, turbidity and regulatory non-compliance

Abrasion & Wear

Sand and grit erode pumps, valves and pipework, shortening equipment life and raising maintenance requirement if not removed early.

Siltation & Capacity Loss

Settling solids accumulate in tanks, channels and reservoirs, eroding hydraulic capacity and treatment performance over time.

Turbidity & Compliance

Suspended solids raise turbidity above discharge limits, shield pathogens from disinfection and foul membranes downstream.

The Sediment Particle-Size Spectrum

Removal technology is selected by particle size and settling behaviour

Grit & Sand (>200 micron)

Coarse, dense inorganic particles with high settling velocity, removed by grit chambers and hydrocyclones.

Silt (2–60 micron)

Intermediate particles that settle slowly under gravity, captured by sedimentation and lamella clarification.

Clay & Colloids (<2 micron)

Charge-stabilised particles that will not settle unaided and require coagulation before clarification or filtration.

Stokes' Law — the Governing Settling Relationship

For discrete particles in the laminar regime, settling velocity follows Stokes' law: vs = g(ρp − ρw)d² / 18&mu. Velocity scales with the square of particle diameter and with the density difference, which is why coarse grit drops out in seconds while colloidal clay (d < 2 µm) is effectively non-settling and must first be aggregated by coagulation.

The Sediment Removal Train

Complementary stages, each tuned to a band of the particle-size spectrum

Screening & Grit Removal

Bar screens and grit chambers remove debris and abrasive grit as a protective first stage.

Sedimentation & Lamella

Gravity clarifiers and inclined-plate (lamella) units settle silt and coagulated floc at high rate.

DAF & Filtration

Dissolved air flotation and media or membrane filtration polish fine and low-density solids the settlers leave behind.

Sediment Removal Engineering Guides

In-depth scientific guides to the challenges, methods and compliance of sediment removal

Grit & Sand Removal

Settling-velocity-based design of grit chambers, aerated and vortex units and hydrocyclones to capture abrasive inorganic particles.

View Guide

Sedimentation & Clarification

Type I to IV settling, surface overflow rate, Hazen theory and lamella high-rate clarification for suspended-solids removal.

View Guide

Sediment Discharge Compliance

TSS and turbidity limits, SDI for membrane feed, monitoring methods and construction sediment-control regulation.

View Guide

Meeting Discharge & Process Limits

Sediment removal is verified against numeric consent and downstream feed specifications

TSS & Turbidity Limits

Consents cap total suspended solids and turbidity; the train is sized to the limit, its averaging basis and a margin for variability.

Membrane Feed Quality

Silt Density Index and turbidity targets protect downstream RO and UF membranes from particulate fouling.

Monitoring & Evidence

Online turbidity and proportional sampling provide continuous, auditable evidence of compliant discharge.

Need a sediment removal solution?

Reynolds & Bauhm engineers sediment-removal trains from grit chambers to colloidal polishing, matched to your particle-size distribution and discharge consent.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.