Oil & gas, manufacturing, and many other industries face increasing pressure from water-quality regulators to clean up dissolved metals, nitrate and other contaminants found in wastewater.
Even trace amounts of certain compounds attract attention from government agencies and the public as well. As a result, environmental and water resource managers are looking for better, more cost-effective alternatives to conventional water treatment processes.
One method in use since the 1950s is reverse osmosis (commonly referred to as RO), which is a separation process that uses pressure to force water (solvent) through a semi-permeable membrane that retains contaminants (referred to as "concentrate") on one side while allowing cleaner water (known as "permeate") to pass through to the other side. Here's how it works:
How Reverse Osmosis Works
The membrane, composed of substances such as polyamide thin film composites (TFC), cellulose acetate (CA) and cellulose triacetate (CTA), is an essential component of any RO water treatment system.
It is wound into a spiral shape and enclosed in a high-pressure plastic tube that is fitted with valves, which allow passage of concentrate permeate their respective locations.
In many, if not most cases, permeate is recycled through secondary and tertiary systems to extract as much clean water as possible.
Though as much as 80 percent of water can be recycled for reuse, the remainder contains so much concentrate that further recycling makes little economic sense. The reject is disposed of using a variety of methods that include surface water or sewage discharge, evaporation or deep well injection.
Reverse Osmosis Uses
By far, desalination - the separation of pure water from brackish water and seawater - is the largest application of reverse osmosis. It also plays a crucial role in reclaiming municipal wastewater to augment water sources and even create potable water.
Industrial uses include metals removal and finishing, boiler feed water treatment, cleaning effluent water, processing food and beverage products, and even producing maple syrup!
Need for RO Chemical Treatment
Over time, membranes can become fouled or plugged by the accumulation of particulate matter and require cleaning to perform at optimum efficiency, and to extend the range of their useful life. Absent such cleaning, membranes are less able to produce clean water from the feed water being forced through it.
That's where Plymouth Technology comes in.
Our propriety cleaning products, designed by one of the worlds most respected chemists, are responsible for process improvements of >60 percent and operational cost reductions of >40 percent.
Due to the cost benefits and variety of uses, environmental and water resource managers will likely rely on reverse osmosis as a method to produce clean water for years to come.Contact us
to learn how we can keep your RO system running at its peak capacity.
YouTube video demonstrating how reverse osmosis works.