Electropolishing of AISI-304 stainless steel for protection against SRB biofilm

Electropolishing treatment (EP) can be used to remove the biofilm formed on AISI-304 stainless steel surface and protect it against bacterial colonization. High levels of both smoothness and brightness of AISI-304 stainless steel surfaces can be attained by using electropolishing technique, where the sample was fixed as anode and a suitable current was applied into electrolytic cell containing H3PO4. AISI-304 stainless steel was exposed to stabilized mixed culture of sulfate reducing bacteria (SMC-SRB) under different conditions as, temperature, pH, salinity, incubation time and inoculum size. The present study recorded the main indicators of bacterial activity such as S−−, Fe++, most probable number (MPN) of SRB and weight loss (corrosion rate) by milinches per year (mpy). The results revealed that the bacterial counts were obviously decreased under all conditions of bacterial biofilm formation after electropolishing treatment.

► Protection of SS 316 surface is increased by elimination of roughness.
► EP leads to high smoothness, low burrs of SS 316 surface and then no bacteria.
► Under all bacteria culturing conditions, the bacteria was reduced.
► EP can be recommended to improve sterilization of the surface of St 316.