Contamination evaluation of Pb, Ni and Zn heavy metals in coast surface sediment of Bushehr county

Due to the toxicity and sustainability in environment, heavy metals are very important. Therefore, in this research, contamination of surface sediments of Bushehr County to Pb, Ni and Zn metals was evaluated. For this purpose, in the end of 2018, surface sediment samples were collected from five stations including Imam Ali Roud, Gaddeh –ye - Saheli, Bandargaah, Del Aram and Ameri Port with 5 replications from depth of 0 to 5 cm. After drying the specimens in oven, the samples were digested with a mixture of nitric acid, perchloric acid and hydrofluoric acid for 8 hours at 200 ° C in PTFE digester. Finally, heavy metals concentrations were analyzed by the GBC Xploraa atomic absorption spectrometer. The Igeo index and contamination factor (CF) were used to assess the contamination of sediment samples to these metals. The results showed that the total average concentrations of Pb, Ni and Zn in the study area were 10.67, 11.77 and 98.41 mg /kg, respectively; indicating Zn concentration is higher than two other metals concentrations. According to the average concentration of Pb in the sediment, the descending trend of Gaddeh –ye - Saheli > Imam Ali Roud > Ameri Port > Bandargaah > Del Aram and according to the Ni average concentration, the descending trend of Imam Ali Roud > Gaddeh –ye - Saheli > Ameri Port > Del Aram > Bandargaah and considering the Zn average concentration in sediment, the decreasing trend of the Gaddeh –ye - Saheli > Del Aram > Ameri Port > Imam Ali Roud > Bandargaah were observed. The results of Igeo index showed the descending trend of Zn > Ni / Pb with average values of -2.86, -1.65 and -1.56, respectively. The contamination factor index showed that sediment samples were moderately contaminated with Pb, Ni and Zn metals