Electrochemical Corrosion Investigations on Anaerobic Treated Distillery Effluent

Present study is focused on the corrosivity of anaerobic treated distillery effluent and corrosion performance of mild steel and stainless steels. Accordingly, electrochemical polarization tests were performed in both treated distillery and synthetic effluents. Polarization tests were also performed in synthetic solutions and it was observed that Cl- and K+ increase whereas SO4 (-), PO4 (-), NO3 (-), and NO2 (-) decrease the corrosivity of effluent at alkaline pH. Further, comparison in corrosivity of distillery and synthetic effluents shows the former to be less corrosive and this is assigned due to the presence of amino acids and melanoidins. Mild steel experienced to have the highest corrosion rate followed by stainless steels-304L and 316L and lowest in case of SAF 2205. Relative corrosion resistance of stainless steels is observed to depend upon Cr, Mo, and N content.