This simulator walks raw water through a complete teaching treatment train: a rapid-mix vessel where a coagulant is dosed, slow flocculation paddles, inclined settling plates with a sludge hopper, a granular media filter, and a baffled contact chamber. Change plant flow, raw suspended solids, coagulant dose, disinfectant feed and chamber volume, or bypass the filter, and watch solids at each stage and nominal contact time respond.
• A real-time 3D view with numbered, clickable parts: rapid-mix vessel and impeller; flocculation paddles and baffles; inclined settling plates and sludge hopper; granular media and underdrain; baffled contact chamber; raw, treated and residuals flow paths. Scene tools include home view, focus-selected-part, auto-rotate, expand and show/hide labels, and drag-to-orbit with pinch-to-zoom. • Experiment controls: plant flow (20–120 L/s); raw suspended solids (20–300 mg/L); illustrative coagulant dose (0–50 mg/L); bypass granular filter; disinfectant applied (0–3 mg/L); contact chamber volume (50–500 m³), plus a show flow/process markers toggle, pause/resume, single-step buttons (0.1 s and 1 s), a playback-speed selector and a restart trial action. • Live readouts: after settling; after filtration; nominal contact time; outlet residual; integrated concentration × time; solids removed. A model response curve is drawn beside the 3D view and updates as you change controls. • A Curves & measurements tab with two live charts, the model equations as written in the simulator and snapshot readouts; an Experiments tab with 2 guided presets (filter bypass; double flow) plus a model-verification bench, timestamped event log and copyable trial report. • A Learn & assess tab with 3 lessons (the train uses several mechanisms; flow changes residence time; cT is not a treatment certificate), a 2-question knowledge check with reset, and a written model-scope statement.
Each stage of the train does a different job. Rapid mixing distributes the coagulant, flocculation grows particles into settleable flocs, inclined plates capture much of that floc and send it to a sludge outlet, and the granular filter polishes what remains. In this model the settling efficiency follows an explicitly illustrative bell-shaped dose curve centered near 25 mg/L, and the filter removes a fixed 95% of the remaining suspended solids unless you bypass it.
Notice that water and sludge are separate streams: the blue path is treated water and the brown outlet is the residuals stream. Bypassing the filter leaves upstream settling active, so filtered solids simply equal settled solids.
The contact chamber gives nominal contact time as volume divided by flow, so at a fixed volume doubling the plant flow halves the contact time. A first-order disinfectant decay model then yields the outlet residual and an integrated concentration-times-time value that the simulator displays in mg·min/L.
That CT number is a teaching quantity. It is not a regulatory CT target, an organism-specific inactivation prediction or a compliance determination, and suspended solids (TSS) here are not turbidity. The coagulant curve and filter efficiency are illustrative, the model is steady-state, and it does not include pathogen log removal, water chemistry or short-circuiting in the chamber.
Rapid mixing blends the coagulant into the raw water, flocculation grows small particles into larger flocs, inclined settling plates let those flocs drop out into a sludge hopper, the granular filter captures most remaining fine solids, and the baffled chamber provides time for the disinfectant to act.
The filtered-solids value becomes equal to the settled-solids value because the 95% filter capture is skipped. Upstream mixing and settling still operate and the contact chamber still receives flow, so you can isolate exactly how much the filter contributes.
Nominal contact time is chamber volume divided by flow. With the volume held constant, twice the flow leaves the water in the chamber half as long, which also lowers the integrated concentration-times-time value for the same disinfectant feed.
No. The CT shown is a simple first-order teaching calculation and is not a regulatory CT requirement or a pathogen inactivation prediction. Real compliance depends on the target organism, water chemistry, temperature, chamber hydraulics and validation, none of which are modeled here.