title: The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.
abstract: The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01).
authors: Faculty of Science, Department of Biology, Istanbul University, Istanbul, Turkey.
authors: Bihter
authors: B
authors: Minnoş
authors: Esra
authors: E
authors: Ilhan-Sungur
authors: Ayşın
authors: A
authors: Çotuk
authors: Nihal Doğruöz
authors: ND
authors: Güngör
authors: Nurhan
authors: N
authors: Cansever
mesh_terms: D001419:Bacteria / Q000187:drug effects; D058491:Bacterial Load; D018441:Biofilms / Q000187:drug effects*; D003080:Cold Temperature; D003343:Corrosion; D004202:Disinfectants / Q000737:chemistry* / Q000494:pharmacology; D007501:Iron / Q000737:chemistry; D010933:Plankton / Q000187:drug effects / Q000502:physiology; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D013232:Steel / Q000737:chemistry*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis; D014961:X-Ray Diffraction / Q000379:methods; D015032:Zinc / Q000737:chemistry
chemical_list: D004202:Disinfectants; D011135:Polysaccharides, Bacterial; D013232:Steel; D007501:Iron; D015032:Zinc