The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor

Minnos B., Ilhan-Sungur E., Cotuk A., Gungor N., CANSEVER N.

BIOFOULING, cilt.29, sa.3, ss.223-235, 2013 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 29 Sayı: 3
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1080/08927014.2012.763117
  • Dergi Adı: BIOFOULING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.223-235
  • Anahtar Kelimeler: galvanized steel, cooling tower water, microbiologically influenced corrosion (MIC), sulphate reducing bacteria (SRB), biocide, corrosion inhibitor, MICROBIALLY INFLUENCED CORROSION, SULFATE-REDUCING BACTERIA, DRINKING-WATER, ORGANIC-MATTER, BIOFILM, ZINC, COPPER, GROWTH, IRON, ORTHOPHOSPHATE
  • İstanbul Üniversitesi Adresli: Evet

Özet

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).