Reverse Osmosis System

The water intensity of industries is in sharp contrast to the dwindling fresh water reserves, which necessitates the utilization of saline water—seawater or groundwater through Reverse Osmosis installations. Reverse Osmosis (RO) is a process that is widespread for purifying water across industries for divergent manufacturing and production purposes.

Nadis has an extensive range of chemical solutions for industries that rely on Reverse Osmosis (RO) systems to meet their water-intensive needs. Our chemical formulations address different issues concerning the type and quality of water that depend on its source of extraction; underground water, surface water or sea water. The application of the chemicals in the calculated dosage and its frequency depends on the combining factors of pretreatment, feed water quality, product recovery, production besides other factors.

We have the knowledge, expertise, and experience behind our chemical solutions to analyze and treat all kinds of water chemistries yielding maximum output of water, by increasing the efficiency of the RO membranes and prolonging the life of the installations, cutting back on capital costs in the long run. Our family of RO chemical formulations is specifically designed to counteract the unwanted production decrease, variation in equipment operation and product quality. Nadis uses its broad arsenal of chemicals to give you precise solutions to solve your water issues and to get the best performance out of your RO installations.

Pre-treatment of Feed Water

Raw water contains different suspended and dissolved solids making it essential for the pretreatment of water prior to passing it from the RO plants and has to meet a stringent set of criteria for the RO operation to run efficiently without developing any problems halfway through the system, causing unforeseen shutdowns resulting in extensive costs.

Different pre-treatment operations can be performed to remove the suspended solids and organic matter which may involve screening of solid matter in the initial stages by sedimentation and passing through different filtration units. Filter aids are added to the raw water or to the filters to enhance the filtration process by increasing the permeability of the filtration system.

To remove colloids that are less than 10 µm, coagulant aids and flocculants are added that bridge and bind the particulates and help to increase the rate of coagulation and flocculation, making it possible to treat water to a large degree.

Chemical dosing is another critical step necessary to kill a variety of bacteria; the use of chlorine is widely acceptable for this purpose. At a later stage, dechlorinators are added to remove chlorine from the water.

The alkalinity or hardness of water is determined by the presence of high concentrations of calcium carbonate ions or other such compounds, softeners are generally used to solve this issue during pretreatment.

Effect of Pretreatment on RO Membranes

The pretreatment of water has weightage because it can have a serious impact on the RO membranes and affect its performance, requiring additional dosing and frequent chemical cleaning resulting in undue cost increase and reduced production pace downstream.

Our engineering department analyzes and runs tests on the pre-treated feed water to make sure its quality is compatible with the Reverse Osmosis System because if it’s not, it can jeopardize the system efficiency and result in major system failures amounting to huge costs.

Nadis Reverse Osmosis Chemical Treatments

The RO system is bound to slow down at regular intervals if the accurate and calculated dosage of special chemical formulations is not injected into the system during Reverse Osmosis.

The severe impact is a massive cost increase that is directly linked to the malfunctioning of RO membranes and reduced water production. Nadis has a concise range of chemical treatments specially designed and formulated for Reverse Osmosis Membranes for low, medium and high concentration fluid movements that prevent fouling and scaling of the membranes and improve their shelf life.


During Reverse Osmosis, hydraulic pressure is applied on the feed water which separates and traps dissolved contaminants. The scaling occurs due to the deposition of ions on the membrane layers which affects the volume and quality of water permeate at the other end.

Nadis chemical treatments are formulated to prevent scaling and fouling in the Reverse Osmosis (RO), Nano Filtration (NF), Ultrafiltration (UF), Cellulose Acetate (CA) and thin-film composite membranes (TFC or TFM). Our engineers recommend antiscalant dosage based on the analysis of the feedwater as optimum performance from the RO system can only be achieved with balanced chemistries.


Nadis has broad spectrum non-oxidizing microbiocides to control microbiological growth and to sanitize the RO membranes from bacteria, fungi, and algae that if left unchecked, breed and multiply rapidly in the dark and wet layers of the RO membranes, leading to fouling and degrading of the membrane surfaces. Our fast-acting microbiocides are highly-effective in dispersing biofilms and slime from the RO systems without causing physical or chemical changes in the structure of the membranes resulting in extended operating time and improved water permeate quality. The efficacy of the RO system maximizes water production and supply down the line and ensures stability in the industrial operations.


Nadis chemical treatments are formulated to disperse and remove the agglomeration/aggregation resulting in scaling and fouling that disrupt the flux rate and cause a reduction in concentrate/reject stream by deteriorating the membranes and affecting the efficiency and output of the RO System. Our Clean-in-Place (CIP) chemical compounds regulate the RO system operations by thoroughly cleaning the membrane pores and reducing the frequency of cleaning operations if administered appropriate to the magnitude of feed water passing through the membranes, its pH value and other determining factors.