RO & EDI Process Fundamentals Reference for water-treatment expertise: formulas, normative standards, vendor design envelopes, water chemistry, and bilingual terminology. Convention markers used throughout the membrane skills: - — likely bug or incorrect numerical approximation in calling code; highest priority - — enhancement opportunity (new KPI, new model field, refined threshold) --- §1 — RO Process Fundamentals All formulas in SI (LMH, bar, °C) with US field-unit (GFD, psi, °F) variant noted. Variables: feed flow, permeate, concentrate, / / concentrations, membrane area, temperature. 1.1…