RO membrane glossary — terms & acronyms
39 reverse-osmosis and water-treatment terms explained in plain English — from process shorthand (CIP, ZLD) to membrane chemistry (TFC, TDS) and element-variant suffixes (HR, LE, FR). Tap a term for its full definition and the Hi-Tech elements it relates to.
API — Active Pharmaceutical IngredientThe molecule in a drug that delivers the therapeutic effect. API-manufacturing water has the strictest purity requirements in pharma.BOD — Biological Oxygen DemandThe amount of oxygen microbes need to break down the organics in a water sample. High in food-processing effluent.BWRO — Brackish Water Reverse OsmosisRO designed for feed waters with TDS roughly 500–10,000 ppm — typical of tap water, wells, and many industrial streams.CE — Conformité EuropéenneThe mark that certifies a product meets EU health, safety and environmental requirements for sale in the European Economic Area.CIP — Clean-In-PlaceAn automated cleaning cycle that flushes a piping system or RO train with hot water and detergents without dismantling it. Standard practice in food, beverage, dairy and pharma to keep surfaces sanitary between batches.CIP-cycleA single Clean-In-Place run — typically a sequence of caustic flush, acid flush, then rinse — used to remove biofilm, mineral scale and organic foulants from a system between production batches.COD — Chemical Oxygen DemandA measure of the total chemicals (organic and oxidizable inorganic) in wastewater, in mg/L. High in textile dye-house effluent.CTA — Cellulose TriacetateAn older membrane chemistry that tolerates free chlorine — useful for chlorinated municipal feed or systems that sanitize between batches. Lower rejection than TFC.EHEDG — European Hygienic Engineering & Design GroupA European industry consortium that publishes hygienic design guidelines for food-contact equipment. The reference for sanitary RO trains in EU food plants.ETP — Effluent Treatment PlantAn industrial facility that treats process wastewater (textile, chemical, food, etc.) to meet discharge norms before release or reuse.FDA — U.S. Food and Drug AdministrationThe U.S. regulator that sets food-contact and drug-water purity standards. Hi-Tech residential and food-grade elements use FDA-listed materials.FGD — Flue Gas DesulfurizationA process that scrubs sulfur dioxide from coal-fired power plant exhaust. The make-up and blow-down water for FGD scrubbers is one of the toughest streams in heavy industry.FR — Fouling ResistantMembrane variant with a more open feed-spacer and tweaked surface chemistry to handle high-fouling streams (textile, food, ETP) before scaling forces a clean.GPD — Gallons Per DayThe daily permeate flow rate of an RO element under standard test conditions. The number after the dash in residential model names (e.g. RE-1812-75 produces 75 GPD).HalalA certification confirming the product meets Islamic dietary law — required by some food, beverage and pharma customers in Muslim-majority markets.HR — High RejectionMembrane variant tuned for higher salt-rejection (typically 99.5% or better), at a small cost in permeate flow.HRFR — High Rejection Fouling ResistantA combined variant — high rejection plus the foulant-tolerant feed spacer of an FR element. Common pick for high-TDS, high-foul seawater intakes.HRLE — High Rejection Low EnergyA combined variant — the rejection of an HR element with the lower operating pressure of an LE element. Useful where both targets matter.ISO 14001International environmental-management standard. Hi-Tech's facilities are certified to ISO 14001 covering waste, energy and emissions.ISO 9001:2015International quality-management standard. Hi-Tech's manufacturing facilities are certified to ISO 9001:2015 across both Thailand and India operations.LE — Low EnergyMembrane variant tuned for lower operating pressure (typically ~100 psi vs. 150 psi standard) to cut energy cost on long-running systems.MLD — Minimum Liquid DischargeA near-ZLD scheme that recovers most of the feed water but allows a very small reject stream — typically used where ZLD is not economically viable.NSF — National Sanitation FoundationA U.S. testing body that certifies water-treatment products. NSF/ANSI 58 covers residential RO performance; 61 covers material safety for drinking-water contact.OEM — Original Equipment ManufacturerA company that builds finished water-purification systems (and resells them under its own brand) using component-grade RO elements supplied by Hi-Tech.OPEX — Operating ExpenseThe recurring cost of running a system — energy, chemicals, membrane replacement, labor. Low-energy elements cut OPEX without redesigning the train.Ph. Eur — European PharmacopoeiaThe European counterpart of USP — defines water purity grades for pharmaceutical manufacturing in the EU and EEA.POE — Point Of EntryA whole-house or whole-building RO unit installed where water enters the property — treats every tap downstream.POU — Point Of UseA compact RO unit installed at the kitchen tap or under-counter — purifies the water at the exact point it is consumed. Typical residential or small-office system.ppb — parts per billionConcentration unit equal to 1 microgram per liter. Used for ultrapure water targets in semiconductor and pharma applications.RoHS — Restriction of Hazardous SubstancesEU directive limiting the use of lead, mercury, cadmium and other hazardous materials in manufactured goods. Hi-Tech components are RoHS-compliant.SDI — Silt Density IndexA 15-minute filter test that quantifies how much suspended fine matter is in the feed. RO membranes need SDI < 5 to avoid premature fouling.STP — Sewage Treatment PlantA municipal facility that treats domestic and city wastewater so it can be discharged or reused.SWRO — Seawater Reverse OsmosisRO designed for seawater feed (~35,000 ppm TDS), running at high pressure (~800 psi) with very high salt rejection (>99.7%).TDS — Total Dissolved SolidsThe total mass of all dissolved minerals and salts in a water sample, in mg/L or ppm. The single most important number for sizing an RO system.TFC — Thin Film CompositeHi-Tech's standard membrane chemistry — an ultrathin polyamide barrier on a polysulfone support, on a polyester web. High rejection, high flux, intolerant of free chlorine.TOC — Total Organic CarbonA measure of all organic compounds dissolved in water. Critical for semiconductor ultrapure-water and pharma systems where organics must stay below ppb levels.USP — United States PharmacopeiaThe compendium that defines pharmaceutical-grade water specifications (Purified Water, Water for Injection). RO is a primary stage in any USP-water plant.XLE — Extra Low EnergyEven lower operating-pressure variant than LE — used in cooling-tower make-up and other large-volume duty where every kWh matters.ZLD — Zero Liquid DischargeA water-treatment design that recovers virtually all incoming water as permeate so the plant releases no liquid effluent to the environment. Required by regulation in many Indian and Chinese textile / mining operations.