Reverse Osmosis Plants

Reverse Osmosis works by using a high pressure pump to increase the pressure on the salt side of the RO and force the water across the semi-permeable RO membrane, leaving almost all (around 95% to 99%) of dissolved salts behind in the reject stream. The amount of pressure required depends on the salt concentration of the feed water. The more concentrated the feed water, the more pressure is required to overcome the osmotic pressure.

The desalinated water that is demineralized or deionized, is called permeate (or product) water. The water stream that carries the concentrated contaminants that did not pass through the RO membrane is called the reject (or concentrate)

One of the common water contaminants addressed by the pre-treatment stage is suspended solids. Fine particles of dirt and other matter floating in suspension within the feed water. These particles are not dissolved into the water and have to be physically removed via filtration.

Reverse Osmosis membranes, the core component of the RO plant are not designed to remove such suspended particles and will foul rapidly if left to do so. As such adequate filtration is required prior to any Reverse Osmosis System in order to achieve proper system operation and avoid premature fouling of the membranes.

Different sources of feed water will typically have different levels of suspended solids. Surface waters such as rivers and dams tend to have the highest levels, as they catch water running across the earth which is typically heavily laden with dirt and other solids. While bore water extracted from deep within the earth has much lower levels as the water has been filtered by the rocks through which it passes prior to collection. As such these two feed waters will typically require different pre-treatment technology. For example, it is considered best practice to operate an Ultrafiltration system prior to an RO plant for surface water, while bore water only requires the use of a media filter.

Skid Mounted RO

One of the first steps in designing a suitable skid mounted reverse osmosis plant therefore is collecting and analysing the proposed feed water. In doing so we will have a much better understanding of water to be purified. The information provided from the analysis can then be directly inputted into our design software, ensuring you get a robust, effective system that works first time with no surprises.

Hub 4 Water RO units are designed and built in Adelaide South Australia, we source the best possible components and control systems to ensure that our RO systems provide the highest levels of reliability.

Hub 4 Water skid mounted RO plant utilise either 2.5”, 4.0” or 8.0” Dow Filmtec or Hydranautics reverse osmosis membranes suitable for the application and we carry a full range of spares and consumables on site to ensure you’re never caught without water when you need it most.

Our RO plant is designed to maximise water efficiency and minimise waste. The recovery rate, that is the ratio of feedwater recovered as product can be as high as 80-85%. However this can drop down depending on the nature of the feed water. Too much salinity or silica amongst other things in the feed water will limit the recovery rate of the unit. Once we have the water analysis of your feed water, we will be able to provide you with an accurate estimation of the final Reverse Osmosis system water recovery.

A typical RO skid will include only the components of the RO unit, whilst both the Pre and Post treatment elements will be separate, floor or wall mounted components that are plumbed together on site. This approach reduces the cost of the actual skid as the frame does not have to be as large. It is also easier for installing systems into pre-existing infrastructure as the individual components are easier to get through door ways

Post Treatment

Following the RO plant there are a number of options for tailoring the product water to different applications. Sterilisation, Remineralisation and pH correction and Resin polishing are all examples of post RO plant processes that can be employed to make sure the system product water meets your specification.

It is quite common, but not necessary for the RO water to go through one of more post treatment processes prior to use and further information is available on this site. Sterilisation is one of the most commonly used types of post treatment.

5-35kl/day – 50-500/klDay Reverse Osmosis Plant

Skid mounted and containerised options available

Remote monitoring 

Spares and consumables 

• RO membranes
• Antiscalants
• CIP Cleaners
• Disinfectants
• Membrane analysis
• Pumps
• Chemical dosing equipment
• Servicing and maintenance
• Controls and Instrumentation
• Valves and piping/fittings