Risk Assessment and Heavy Metal (Cu and Ni) Contamination in Sediments of Shatt Al-Arab Canals, Iraq

Abstract

The present study aims at investigate the relationships between physic-chemical and seasons to determined heavy metals (copper Cu and Nickel Ni) contaminated of sediments of Shat Al-Arab canals. The pH, Electrical Conductivity (EC), Total Organic Carbon (TOC), Oil and grease were measured. The study investigated the effects of season on the sediment characteristics of Shat Al-Arab canals. Data analyses were done using analysis of variance, Tukey's multiple range, Pearson correlation coefficient and descriptive statistics. pH, EC and TOC were significantly higher at dry season (7.44 ± 0.129), (544.212 ± 133.8 μcm/cm2) and (13.94 ± 2.157%) respectively, than at wet season (P<0.05). However, hydrocarbons (Oil and grease) was significantly higher at wet season (4360 ± 1129 mg/l) than at dry season (1920 ± 638.3) (P<0.05). The presence of high levels of organic pollutants indicates organic pollution and stress. Positive and negative Pearson correlation relationship between both heavy metals and physic-chemical parameters were found. Contamination of sediments was assessed on basis of contamination factor (CF), geo-accumulation index (Igeo), pollution load index (PLI) Potential Ecological Risk (Eir) and Potential Ecological Risk Index (RI). Results of geo-accumulation index (Igeo) indicated that sediments were uncontaminated with Cu, uncontaminated to moderately pollution with Ni.