Hermine Ramzy Zaki Tadros
Marine Chemistry Lab., Marine Environment Division, National Institute of Oceanography and Fisheries, Alexandria, Egypt
Key words: Physicochemical parameters, Weight loss technique, Corrosion of steel, Western Harbor.
This study focuses on the physicochemical parameters of the Western Harbor of Alexandria and the corrosion rate of steel in seawater by using weight loss technique. Triplicate surface water samples were collected seasonally from fixed 10 stations from winter to autumn 2012. The results indicated that the temperature fluctuated between 16.2oC to 27.6oC, with annual average of 22.62oC. Salinity differed between 22.7 and 37.9, with annual average 34.34. The pH ranged from 7.93 to 8.92. Total alkalinity varied between 1.209 and 4.2meq/l, with an annual average of 3.13meq/l. Dissolved oxygen ranged from 1.136 to 15.445 mg/l, the annual average was 8.324 mg/l. Biochemical oxygen demand fluctuated between 0.12 and 10.45 mg/l; the annual average was 3.62 mg/l. Oxidizable Organic Matter ranged between 0.19 and 7.2mgO2/l, with annual average 1.551mgO2/l. While nutrient salts (μmol) displayed wide ranges and annual averages; 0.075- 9.75μmol/l; 2.451μmol/l, 0.476-51.23μmol/l; 13.148μmol/l, 0.005-32.35μmol/l 9.311μmol/l, 0.547-35μmol/l; 9.941μmol/l, 0.702-16.15μmol/l; 3.59μmol/l for phosphate, silicate, nitrite, nitrate, ammonia respectively. N/P ratio showed that phosphorus was the limiting factor. Sulfate fluctuated between 1.015 and 3.25 g/l with annual average of 1.829 g/l. The weight loss was calculated from the differences between the steel panels immersion date in seawater and after 24hrs of immersion in seawater on laboratory scale and the corrosion rate of steel was calculated. The corrosion rates of steel differed between 0.2321 and 0.8998mpy. The annual average was 0.5099mpy. The Water quality index showed that stations 6, 1 and 2 suffered from pollution during summer accompanied by highest silicate, oxidizable organic matter, nitrate and sulfate.
Get the original articles in Source: Volume 6, Number 6, June 2015 – JBES