Study on the characteristics of metal corrosion and sterilizing effect of chlorine dioxide

The sterilizing effect of heterotrophic bacteria, sulfur bacteria and iron bacteria treated with chlorine dioxide is examined experimentally in this paper.The weight loss method was used to simultaneously study the comparative corrosion behavior of four different metals under treatments of chlorine dioxide, liquid chlorine and their mixture.The experimental results indicated that chlorine dioxide had a good sterilization effect against heterotrophic, sulfur and iron bacteria at different dosages, pH, temperatures and reaction conditions.Chlorine dioxide is used as a high-efficiency circulating water oxidizing sterilizer; its sterilizing effect on heterotrophic, sulfur and iron bacteria exceeds 90% at 0.6 mg/L dosage, pH 7, 20°C and 15 min reaction.Considering its strong oxidizing effect and chemical corrosion of metal pipes, the corrosion behavior of ClO 2 , liquid chlorine and their mixture to carbon steel, aluminum, red copper and stainless steel were investigated.It was concluded that ClO 2 , liquid chlorine and their mixture could all cause metal corrosion: liquid chlorine caused the greatest metal corrosion and ClO 2 gave the weakest metal corrosion; moreover, corrosion inhibition was observed under low concentrations of ClO 2 .Therefore, the corrosion behavior of ClO 2 needs to be considered when it used as a sterilant for circulating cooling water.