Assessing water contamination with Anionic Surfactants in Anzali Lagoon

We assessed amount of surfactants and their seasonal trend in eight stations in Anzali Lagoon and compared them with allowable levels in the years 2001-2002. We obtained 96 water samples and determined their surfactant content using liquid - liquid method applying methylene blue active substance (MBAS).
The concentration of surfactants in Pirbazar varied from 0.176 to 0.422 while that of the Sea station was somewhere between 0.098 to 0.049 mg/l. Seasonal concentration of surfactants varied from 0.049 to 0.422 mg/l averaging on 0.137 mg/l. A significant difference was found for surfactant concentration in different parts of the lagoon (p<0.05) with the eastern zone being the most polluted area with 0.422 g/l of the pollutants compared to 0.066 mg/l in the Sea. The highest amount of the surfactants was seen in winter in contrast to the lowest amount in spring. No statistically significant difference was found between concentrations of the surfactants in different seasons.