Fouling / Scaling („Low-Fouling“-Membran")
By selecting suitable membrane materials and applying appropriate manufacturing processes during membrane production, it is possible to provide optimized membranes for a wide range of processes, thereby minimizing process-related fouling. This can also be supported by process engineering measures, such as increasing the cross-flow rate.
Scaling can be controlled through the targeted use of antiscalants in the feed stream of an RO system or in combination with water-softening processes.
The use of RO membranes has increased rapidly since their introduction on an industrial scale in the mid-1960s. The development and market introduction of Thin-Film Composite membranes in 1977 marked a significant advancement in reverse osmosis technology. Today, a wide variety of Thin-Film Composite (polyamide) membranes are available on the market.
There are a number of different configurations, ranging from plate-and-frame systems and tubular systems to the most common configuration, the spiral-wound module. These configurations also have different application-specific advantages.
A wide range of applications has been developed, replacing many “traditional” processes. By far the most common applications fall under the general category of water treatment. These include processes such as the softening and desalination of groundwater, well water, surface water, and boiler feedwater. RO membranes are also used today to remove TOC, pesticides, herbicides, and other environmental contaminants from drinking water.
In addition, reverse osmosis has become an established standard technology in other industrial sectors. The process has already proven highly effective for process-stream concentration in the automotive industry and for wastewater treatment with water recirculation.
A shift in the way this technology is evaluated—from the technical perspective of “what is possible?” to the commercial perspective of “what does it cost?”—has created new requirements for membrane development.
The economic efficiency of an LG Chem membrane (and therefore, in many cases, the feasibility of a new application) is based on the following criteria:
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Energy consumption
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Labor, maintenance, and supervision requirements
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Membrane replacement costs
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Chemical consumption for cleaning and production
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Investment costs
Further considerations include extending the service life of membranes and reducing the amount of chemicals required for membrane cleaning. The chemical industry has developed specialized cleaning agents that are less aggressive toward the membrane while providing significantly improved cleaning performance. The use of these substances also considerably reduces the labor and maintenance costs associated with membrane operation.
Through chemical modification, dedicated “anti-fouling” (AFR) membranes are produced. Some manufacturers promote this behavior as a special product feature. LG AFR elements have offered this advantageous property since their market introduction and are available as HR.