Bölümümüz öğretim elemanlarından Prof. Dr. Hüseyin Sarıçimen'in '' Huseyin Saricimen, Anwar Ul-Hamid, Abdul Quddus'' "Effect of Phosphorous on Corrosion of Metallic Metarials in Watewater Treatment Plants in Jubail" isimli makalesi Middle Est Corrosion Conference 2016 konferansına kabul edilmiştir. Makalenin özetine aşağıdan bakabilirsiniz. Hocamızı tebrik eder başarılarının devamını dileriz.
Abstract
An investigation of wastewater lift stations and wastewater treatment plants in residential areas of Jubail Industrial City (JIC) in 1985, showed that some of the lift stations and treatmemt plants, particularly at unsubmerged surfaces, severely corroded in less than six years after construction. In order to supplement the findings of the above investigation, corrosion coupons of various metals and alloys commonly used in construction of the wastewater treatment tanks were installed at submerged (anaerobic) and above water or unsubmerged (aerobic) environments in the contact stabilization zone of Wastewater Treatment Plant # 10. The objective of this investigation was to evaluate performance of the materials in the plant environment.
The submerged coupons in the process fluid consisted of (1) carbon steel, (2) galvanized steel, (3) bronze, and (4) stainless steel-316. On the other hand, the coupons exposed to above-water environment consisted of (1) carbon steel, (2) galvanized steel (3) copper and (4) stainless steel-316.
The coupons were retrived after two different exposure periods. First group of coupons were retrived after 54 days of exposure. Whereas the second group of coupons were retrieved after 335 days of exposure.
The coupons were then evaluated by qualitative and quantitative methods. Quanlitative analysis consisted of recording the characteristis of corrosion products on the coupon surface immediately afte retrieval. The extent of corrosion attack and the type of attack was also assessed visually and recorded photographically. Quick site tests and SEM, EDX-ray analysis, line scan and elemental mapping for phsphorous and sulfur were conducted for some of the coupons. For quantitative analysis, weight loss analysis was performed on the coupons and corrosion rate was determined after 54 and 335 days.
The results showed that:
1. Investigation of the metal coupons revealed the presence of subtantial amounts sulfur and phosphorous in the corrosion products, submerged or unsubmerged alike, pointing at the chemical reactions that might have involved these elements during corrosion of the metal coupons.
2. Corrosion rate of carbon steel coupons is higher in unsubmerged environment than under submerged conditions. The corrosion rate varied between 8.59-3.64mpy in unsubmerged environment whereas it varied from 1.40 to 2.25mpy during exposure periods. There was a decrease in corrosion rate of unsubmerged carbon steel coupons with time due most probably to the corrosion resistance of accumulated corrosion products on the coupon surfaces.
3. Corrosion of copper coupons varied between 2.85 - 2.20mpy in unsubmerged environment and 0.70mpy under submerged conditions during the exposure periods.
4. Corrosion of stainless steel-316 varied between 0.07 - 0.045mpy in the unsubmerge conditions and between 0.05 to 0.09mpy under submerged (anaerobic) environment.
