Ballast water is a major vector for transporting aquatic alien species and The International Marine Organization (IMO) has implemented new international regulations to treat ship’s ballast water (BW) before discharge. One potential treatment is electrolysis; however electrolysis can corrode the interior of ballast tanks. Dr. Guangzhou Lui et al from Zhejiang University, Chemistry Department, China are analyzing the effects of electrolysis on Q235 steel.
Using four different concentrations of total residual chlorine (TRC) (0,5,10,20 mg/L) on Q235 steel, the group analyzed TRC’s effect on Q235 to determine which concentration will remain effective at treating ballast water without corroding the metal. The TRC was analyzed using electrochemical impedance spectroscopy. Concentration levels of 5 and 10 mg/L enhanced the corrosion of steel while 20mg/L TRC inhibited the corrosion
Dr Lui et al concluded that electrolysis which result in TRC levels greater than 10 mg/L is more efficient on alien species and these TRC levels are not detrimental to the ship’s structural integrity.
Source: Acta Metall Sin 2010, 46(09) 1093-1097 DOI: 10.3724/SP.J.1037.2010.00239