Analysis on Operation & Maintenance Points of RO Membrane Process for High‑Salinity Inlet Water

High‑salinity inlet water is one of the toughest working conditions for reverse osmosis systems. High total dissolved solids, scaling ions, colloids and organic pollutants easily trigger membrane fouling, scaling and performance attenuation. Poor operation and maintenance will cause rising differential pressure, dropping desalination rate, frequent membrane replacement and increased overall project cost. Mastering targeted O&M points is essential to guarantee continuous and reliable system operation.

Pretreatment management is the foundation for high‑salinity RO process. Feed water SDI, turbidity and heavy metal indexes must be strictly controlled. Security filtration such as large‑flow filter cartridges intercepts residual particulate impurities. Rational addition of scale inhibitor restrains precipitation of calcium sulfate, barium sulfate and carbonate scales. Oil and organic substances shall be eliminated in advance, otherwise irreversible adsorption fouling will occur on the membrane surface. Untreated fluctuating influent quality will directly damage membrane elements.

Reasonable setting of operating parameters cannot be ignored. Water recovery rate shall not pursue excessive value blindly. Too high recovery leads to salt supersaturation on the concentrate side and accelerates scaling. Feed pressure, cross‑flow velocity and concentrate flow need to match real‑time salinity. Real‑time monitoring of inlet‑outlet pressure difference, permeate flux and conductivity helps staff spot abnormal fouling or scaling at an early stage. Timely adjustment avoids overloading membrane modules under fluctuating high‑salinity influent.

Scientific chemical cleaning strategy slows down membrane performance degradation. When pressure difference rises obviously or flux declines, differentiate fouling types first. Acid cleaning targets inorganic salt scale; alkaline cleaning removes organic and microbial contaminants. Cleaning agent concentration, temperature, flow rate and soaking time should comply with onsite pollution status. Over‑cleaning or improper chemical formula will damage membrane surface layers and shorten service life.

Daily routine maintenance covers standby protection and regular inspection. For long‑time shutdown, implement membrane preservation measures to prevent drying and microbial breeding. Periodically calibrate online monitoring instruments to ensure data authenticity. Record running data to form operation log, summarize fouling rules under high‑salinity conditions. Select anti‑fouling RO membrane elements as an auxiliary measure. Coordinating pretreatment, parameter control and standardized maintenance can effectively reduce failure rate and lower operating expenditure for high‑salinity water treatment projects.