Citric Acid Liquid (RO Membrane Cleaning Grade)

Citric acid liquid for RO membranes (C6H8O7, CAS 77-92-9) is a ready-to-use low-pH membrane cleaner: a 2–3% buffered citric acid solution at pH 3–4, supplied by Global Chemicals LLC from stock in Muscat in 25 kg and 200 kg drums and 1,000 L IBCs, with a food-grade formulation for beverage, dairy and pharmaceutical water systems. Citric acid is the mild, biodegradable acid chosen for membranes because it chelates iron, manganese and calcium as it dissolves scale, and it does not attack polyamide, seals or stainless steel the way hydrochloric acid can.

What it removes. Calcium and magnesium carbonate scale, calcium sulphate at an early stage, and the iron, manganese and aluminium hydroxide deposits that colour a fouled membrane brown or grey. It does not remove biofilm, organics or silica; those need the alkaline cleaner, and membrane makers recommend the alkaline clean first as the general rule, a permeate flush, then the acid clean; the acid clean goes first only when the foulant is known to be mainly carbonate scale or iron, because acid can set organic and biological foulants. The RO membrane chemicals guide linked on this page covers diagnosis.

How to use it. Fill the CIP tank, warm the solution to 35–40 °C (never above the membrane maker's limit), circulate at low flow for a few minutes to displace feed water, then recirculate for one to four hours, soaking for the second half if the fouling is heavy. Watch the pH: if it rises by more than about half a unit the acid is being consumed by scale, so dose more or replace the solution. Flush with permeate until the pH returns to normal before restarting, and record flux and differential pressure before and after. Clean when normalised flux falls 10% or differential pressure rises 15%, not later; scale that has hardened needs more cycles.

Handling: the solution is mildly acidic, non-flammable and non-toxic in use; wear gloves and goggles, keep it off concrete and mild steel, and store drums closed and shaded. Every delivery carries a certificate of analysis, a technical data sheet with the cleaning procedure and a GHS safety data sheet.

Delivery is same day within Muscat, next day to Sohar, Salalah and Duqm, and by road across the GCC with a certificate of origin. Request a quote with the pack size and the membrane area you clean, and our team will size the CIP volume.