Views: 14 Author: Site Editor Publish Time: 2022-09-26 Origin: Site
Thin-film composite membrane - A thin film composite or TFC is a reverse osmosis membrane composed of and manufactured as three layers bonded together.
Thin film composite (TFC) reverse osmosis membranes are the leading product on the market for controlling fresh water supplies. However, TFC RO membranes are very sensitive to oxidising agents (e.g. chlorine). This type of membrane may undergo direct aromatic substitution (irreversible) or N-chlorination reactions (reversible) upon exposure to chlorine. Such reactions can deteriorate the structural integrity of the membrane, leading to loss of performance and therefore requiring frequent replacement.
The feed water for reverse osmosis systems, mainly tap water, groundwater, surface water, seawater, waste water, etc. These bodies of water have different characteristics and different impurities contained in the water due to the different environments in which they are located, and these impurities can affect the performance of the RO membrane.
Firstly, the particles in the water can easily scratch the surface of the RO membrane, leading to blockage or perforation;
Secondly, the calcium and magnesium ions in the water can easily scale on the surface of the RO membrane, requiring frequent cleaning;
Thirdly, oxidants can easily cause the R0 membrane to be oxidised and perforated.
Therefore, before the raw water enters the RO membrane, different pretreatment technologies are required for different water qualities to meet the feed water quality requirements of the RO membrane element, which is also the basic condition for the subsequent RO system to be able to maintain stable operation.
Finding an RO membrane with higher chlorine resistance and similar desalination performance to existing TFC RO membranes has long been a goal of the industry, as it would greatly improve the reliability and sustainability of RO technology and reduce the cost of desalination and wastewater recovery. However, for the time being, TFC RO membranes are undoubtedly the most suitable product.