Use of ATR/FTIR spectrometry to study fouling of microfiltration membranes by natural waters

ddAttenuated total reflection (ATR) Fourier transform infrared (FTIR) spectrometry provided insight into the chemical nature of deposits on polypropylene microfiltration membranes after filtration of two North American surface waters. The spectra of the foulants were easy to distinguish from the spectra of the membrane material. The results did not show strong evidence for the presence of carboxylic acid, carboxylate, phenolic, or hydroxyl functional groups in the foulants, although these functional groups are common in natural waters. ATR/FTIR also indicated the presence of inorganic foulants; the ratio of inorganic to organic foulants varied between the two water sources. The spectra of the foulants were significantly more distinct than spectra of other natural waters, suggesting that relatively few components present in Medina River and Beaver Lake surface waters may adsorb to this membrane material. ATR/FTIR appears to be a valuable tool for studying membrane fouling by natural waters.