The 3D companion shows the same four-stage train as a walkthrough pipe; this 2D view flattens it into a schematic flow diagram plus a live strip chart, so you can watch the numbers evolve over time rather than only reading a snapshot. The underlying process model is identical first-order contact-time kinetics used aboard the ISS Water Processor Assembly:
C_out = C_in · (1 − η_stage)
η_MF = 1 − exp(−k_MF · τ_MF) (contact-time removal)
τ = V_stage / flow rate (residence time)
k_CR(T) = A · exp(−Ea / (R·T)) (Arrhenius rate constant)
η_CR = 1 − exp(−k_CR(T) · τ_CR)
The multifiltration beds and catalytic reactor both follow first-order contact-time kinetics: more flow means less residence time τ and a lower removal fraction η, so pushing more water through faster trades throughput for water quality. The catalytic reactor's oxidation rate additionally obeys the Arrhenius law — raising the temperature slider exponentially speeds up the rate constant, even though its absolute contribution stays small next to the ion-exchange stage.
The ion-exchange bed adsorbs the last of the total organic carbon (TOC) and deionises the stream, but its resin has a finite capacity: as contaminant mass keeps flowing through, the bed saturates along a breakthrough curve and its efficiency decays toward zero, exactly like a real resin bed needing regeneration. The Regenerate button resets saturation to 0%.
Fixed vs. the 3D source: the original model capped the ion-exchange bed at η_IX,max = 0.55. Solving the full chain numerically shows that even at the best possible settings — minimum load, minimum flow (maximum residence time), maximum reactor temperature, and a freshly regenerated resin — the combined removal fraction tops out at 1−(1−0.134)(1−0.026)(0.55) ≈ 53.6%, giving a best-case final TOC of ≈3.80 mg/L. That is above the 3 mg/L pass threshold, so the "PASS" state was mathematically unreachable no matter how the sliders were set. This 2D model raises the ceiling to η_IX,max = 0.68 (best case ≈2.70 mg/L), which keeps the gate hard — default settings still fail — while making it genuinely reachable by tuning load, flow and temperature together.
A mineral injector then adds back calcium and magnesium (ion exchange strips minerals along with contaminants), targeting a conductivity band that makes the water behave like drinking water rather than distilled water. The gate passes only when both final TOC ≤ 3 mg/L and conductivity lands inside the target band — a resin bed near saturation can pass TOC but drift conductivity out of range.
- Contaminant load — feed-water TOC in mg/L; a dirtier feed needs proportionally more removal from every downstream stage.
- Flow rate — higher throughput shortens residence time in every stage, cutting each stage's removal fraction.
- Reactor temperature — raises the Arrhenius rate constant of the catalytic stage exponentially, though its absolute effect stays modest.
- Regenerate resin — resets ion-exchange saturation to 0%, temporarily restoring its full removal fraction.
Drag inside the schematic to pan it left/right, or use your mouse wheel to zoom — useful once the particle stream and stage badges no longer fit the default view.