Influence of Chemicals on Biofilm Removal in Cooling Water System

Microbial cells can attach onto the stainless steel surface in cooling water system and form biofilms which are harmful to the industrial equipments. In this study, biofilms formed on stainless steel with mixed bacterial were investigated by scanning electron microscopy (SEM) to discuss the biofilm transformation before and after treatment with chemicals. Oxidizing biocide (Tetrakishydroxymethyl phosphonium sulphate), non-oxidizing biocide (Sodium hypochlorite), and surfactant (sodium dodeccyl benzene sulfonate) were selected for biofilm treatment. SEM photos showed that the low-molecular weight biocide possessed penetration function and the oxidizing-biocide exhibited strong oxidation ability. Anionic surfactant could change the dimensional structure of biofilm and was helpful for further treatment.