Why monitoring Reverse Osmosis membrane 24/7 matters

vegaabrahamsberg6
Jul 25
3 min read

Updated: Jul 28

Keywords found in the article:

Reverse osmosis

Real-time monitoring of RO process

Conductivity measurement

Temperature measurement

RO Membrane fouling

Pretreatment technologies

permeate conductivity

CIP (cleaning-in-place)

Knowing the unknown: A pilot test comparison between manual operator logs and SWICSSY's data.

Desalination is a delicate balance of chemistry, pressure, precision and energy consumption. Reverse osmosis (RO) systems operate under extreme conditions and are highly sensitive to changes in feedwater quality, membrane fouling, and cleaning effectiveness.

Yet in many plants today, membrane condition data is collected only once or twice a day at best, typically from the entire pressure vessel rather than individual membranes.

That’s why we developed SWICSSY, a solution designed to continuously monitor the performance - conductivity and temperature of membranes inside pressure vessels, capturing the details traditional methods might miss.

Supporting Operators, Not Replacing Them

It is important to underline that SWICSSY does not work against plant operators. Plant operators are highly skilled professionals, trained to detect anomalies, adjust parameters, and respond to system behavior. Manual data logging has always been a cornerstone of this expertise.

SWICSSY doesn’t replace that experience but rather works together with it. By delivering up-to-date membrane data, operators gain a clearer, uninterrupted view of system behavior, helping them make faster, more informed decisions. It’s a tool designed to work alongside operators, giving them the kind of insight that was previously invisible.

Manual vs. Automatic data: A Real-World Comparison

During a recent pilot test at a desalination plant, we were able to directly compare data collected manually by operators with data from SWICSSY over the same period.

And what did we learn?

Manual measurements only told part of the story. Peaks, drops, and fluctuations in conductivity and temperature were entirely invisible between the morning, midday, and evening logs.
Key events were missed or misinterpreted. Cleaning cycles showed minimal impact on membrane performance in manual logs. SWICSSY data revealed the exact moment of impact and showed whether membrane recovery actually occurred and when the cycle was completed.
Undetected performance drifts were captured by SWICSSY, highlighting early membrane fouling that would otherwise go unnoticed until it caused a drop in output or spike in energy use.

A six-month comparative analysis of high-resolution sensor data and periodic manual conductivity measurements within the pressure vessel (PV) of the RO membrane highlights the operational blind spots inherent in low-frequency sampling. While manual readings (orange dots), logged once or twice per day, suggest a stable conductivity profile, the sensor (blue dots), operating at 3-minute intervals, reveals transient excursions exceeding 6000 µS/cm. These short-duration events, which are not visible from the manual dataset, likely correspond to an anomality like the start of membrane fouling, CIP-induced disturbances, or hydraulic instabilities.

From the graph, it can also be noted that plant operators performed cleanings according to a fixed schedule, rather than observing actual membrane conditions.

With continuous conductivity monitoring, it becomes possible to identify the need for cleaning based on conductivity and temperature levels. This allows operators to transition from time-based to need-based cleaning, reducing unnecessary interventions, saving chemicals used, extending membrane life, and improving system efficiency.

And why this matters?

Real-time monitoring isn’t just about collecting more data; it’s about better decisions and having faster reactions.

With SWICSSY, operators gain:

Situational awareness: Know what’s happening on a much granular scale
Event validation: Confirm when a cleaning worked (or didn’t)
Historical traceability: Easily correlate process changes with performance shifts
Fewer surprises: Detect trends before they turn into bigger problems

How SWICSSY works?

SWICSSY is an advanced submerged wireless conductivity sensor system designed to revolutionize reverse osmosis (RO) membrane preventive maintenance. It consists of three seamlessly integrated components: