Reverse Osmosis (RO) and Electrodeionization (EDI) process fundamentals — formulas (recovery, rejection, NDP, osmotic pressure, TCF, NPF/NSP), authoritative standards reference (ASTM/ISO/USP/Ph.Eur./WHO/EN), vendor design windows (DuPont, Hydranautics, Toray, Suez, LANXESS), water chemistry, EDI quick reference, IT/EN glossary. Use when working on RO/EDI plant code, KPI calculations, or normative citations.