of Raman chemical imaging for quantifying and qualifying membrane fouling$\backslash $fs20

h $-abstract- $\backslash $\textbf{pard}Operating Membranes in verity of industries such as pharmaceutical, food processing and water purification and desalination. During the membrane process, the pores are covered with foulants which affects flux rate, membrane lifetime and operation time. It is valuable to understand the effect of foulants causing pore blockage in the membranes. In this research Raman Chemical Imaging introduced an effective method to characterize foulants caused by three different salts namely CaSO$_{\mathrm{4}}$, BaSO$_{\mathrm{4}}$ and CaCO$_{\mathrm{3}}$ on the surface of a Polytetrafluoroethylene (PTFE) membrane. Membrane distillation was operated in presence of the mentioned salts and fundamental information about location and distribution of the salts have been achieved. Raman chemical imaging has been introduced an effective method to identify and locate the foulants. It was observed that CaSO$_{\mathrm{4\thinspace }}$tended to agglomerate and settle on the certain areas while BaSO$_{\mathrm{4\thinspace }}$and CaCO$_{\mathrm{3}}$ were distributed over the whole membrane. Information such as this can be used to study the mechanism of fouling.$\backslash $pard/abstract-\tex