Water & Wastewater › Water Systems
Membrane Treatment
RO and NF skids, their instrumentation, and their control sequences.
Written guides in this section
Full references, procedures, and diagnostic guides published under Membrane Treatment.
Reverse Osmosis
Reverse osmosis from the controls side: what the skid contains, the instruments that matter, the numbers an operator watches, recovery, rejection, normalized permeate flow, and the trends that say when the membranes need cleaning or replacement.
10 min readUpdated Sep 5, 2026
Nanofiltration
Nanofiltration from the controls side: how it differs from reverse osmosis in pressure, recovery, and what it removes, the softening and color removal applications where it dominates, and trends that are shared with reverse osmosis and the ones that differ.
8 min readUpdated Sep 5, 2026
Membrane Control
The control system of a membrane skid: the loops for permeate flow, recovery, and dosing, the permissives and trips, the start, run, flush, and shutdown sequences, and the data the operators and the membrane supplier need from the historian.
9 min readUpdated Sep 5, 2026
Clean-in-Place
Cleaning membranes in place: the triggers from the normalized trends, the low pH clean for scale and the high pH clean for organics and biofouling, the sequence of flush, heat, recirculate, soak, and rinse, and how automation makes cleaning repeatable.
9 min readUpdated Sep 5, 2026
Membrane Feed Pumps
The high-pressure feed pumps of a membrane plant: multistage centrifugal pumps on drives, the pressure ramp that protects the elements, suction protection and the cartridge filters ahead of them, and the maintenance that the trends point to.
8 min readUpdated Sep 5, 2026
Concentrate Systems
Handling the concentrate a membrane plant produces: the concentrate valve and the recovery it sets, flow and quality monitoring for the permit, the disposal routes, surface discharge, sewer, and the alarms and records a concentrate permit expects.
8 min readUpdated Sep 5, 2026
Topics in this area
Reverse Osmosis
Reverse Osmosis — practical reference notes for controls engineers, integrators, and technicians working with membrane treatment.
Nanofiltration
Nanofiltration — practical reference notes for controls engineers, integrators, and technicians working with membrane treatment.
Membrane Control
Membrane Control — practical reference notes for controls engineers, integrators, and technicians working with membrane treatment.
CIP
CIP — practical reference notes for controls engineers, integrators, and technicians working with membrane treatment.
Feed Pumps
Feed Pumps — practical reference notes for controls engineers, integrators, and technicians working with membrane treatment.
Concentrate Systems
Concentrate Systems — practical reference notes for controls engineers, integrators, and technicians working with membrane treatment.
Direct contact
Have a controls question?
Reach Eric Sullivan directly about anything on this site, a controls or automation topic, or one of his personal projects.
References to manufacturers, products, model numbers, software platforms, technical specifications, companies, standards organizations, or other organizations are provided for informational purposes and do not imply sponsorship, endorsement, authorization, or affiliation unless expressly stated. Manufacturer specifications must be independently verified against current manufacturer documentation.