Metcalf & Eddy Wastewater Engineering (5th Ed.) / CPHEEO Manual on Water Supply and Treatment

Physicochemical Treatment (Coagulation, Flocculation & Clarifier)

Chemical dosing rates (Alum/Polymer), rapid flash mix & flocculation tank sizing, velocity gradient G-values, mixer power (kW) & primary clarifier hydraulics

Physicochemical Treatment (Coagulation, Flocculation & Clarifier) Calculator Process & Field Engineering Reference
Engineering Process Reference: Physicochemical Treatment (Coagulation, Flocculation & Clarifier) Calculator governing plant layout conforming to Metcalf & Eddy Wastewater Engineering (5th Ed.) / CPHEEO Manual on Water Supply and Treatment.

1. Engineering Principles & Mathematical Formulation

Comprehensive design model for industrial Effluent Treatment Plant (ETP) primary physicochemical unit operations. Calculates dry chemical consumption (kg/day), dosing pump liquid delivery rates (L/h), rapid flash mix & slow flocculation tank volumes and mixer power (kW) using velocity gradient G-values, and primary clarifier surface area, diameter, detention time, and solids loading rate (SLR).

This calculation engine executes rigorous mass-balance and hydraulic equations. Every parameter is cross-checked to ensure zero rounding drift across bidirectional US Imperial and SI Metric unit systems.

2. Governing Standards & Authoritative Citations

"Design calculations for municipal and industrial water infrastructure must strictly adhere to recognized empirical standards to ensure hydraulic stability, structural integrity, and environmental compliance."
— Metcalf & Eddy Wastewater Engineering (5th Ed.) / CPHEEO Manual on Water Supply and Treatment, American Water Works Association (AWWA) & U.S. Environmental Protection Agency (EPA Manual 832-B-99-002)

Primary benchmark citations include Crane Technical Paper No. 410, ASME Section VIII, and Metcalf & Eddy Wastewater Engineering.

3. Required Input Parameters & Variables

Symbol: Q_feed

Design Feed Flow Rate

Default: 50 (GPM)
Symbol: T_op

Operating Hours per Day

Default: 20 (hr/day)
Symbol: C_coag

Coagulant Optimum Dosage

Default: 150 (ppm)
Symbol: C_poly

Flocculant / Polymer Dosage

Default: 2 (ppm)
Symbol: S_coag

Coagulant Stock Solution Conc.

Default: 10 (% w/v)
Symbol: S_poly

Polymer Stock Solution Conc.

Default: 0.1 (% w/v)
Symbol: t_flash

Rapid Flash Mix HRT

Default: 60 (sec)
Symbol: G_flash

Rapid Mix Velocity Gradient

Default: 750 (s⁻¹)
Symbol: t_floc

Slow Flocculation HRT

Default: 20 (min)
Symbol: G_floc

Flocculation Velocity Gradient

Default: 40 (s⁻¹)
Symbol: SOR

Clarifier Surface Overflow Rate

Default: 1.2 (GPD/ft²)
Symbol: SWD

Clarifier Side Water Depth

Default: 3 (ft)
Symbol: TSS_in

Influent Suspended Solids (TSS)

Default: 400 (mg/L)
Symbol: T

Process Water Temperature

Default: 25 (°F)

4. Professional Engineer (PE) Submittal Workflow

WaterCalcStudio Pro generates timestamped PDF calculation reports complete with formula proofs, intermediate variable breakdowns, and signature review blocks suitable for regulatory submittals.