Evaluation of heavy metal pollution in the Zayandeh-Rud River as the only permanent river in the central plateau of Iran.

摘要: Zayandeh-Rud River is the only permanent river in central plateau of Iran. This has been subject to an extensive discharge wastewater and effluents from several point nonpoint pollution sources. Accordingly, sediment quality Varzaneh region, were studied. Algae sampled through 3 replications at 6 stations downstream after crossing Isfahan city reaching Gavkhuni international wetland. Chlorophyll content As, Pb, Cd concentrations measured each sample Cladophora sp. Oscillatoria identified using standard identification keys. The mean metals all exceeded background levels. Mean concentration arsenic (162.9 mg/kg) about 31 times more than ISQG (5.9 mg/kg) considerably higher similar studies Iran other regions world. As algae samples most polluted areas Pb (19.69 mg/kg) lower ISQGs (35 mg/kg) studied north such as Chalous, Baboul-Rud, Gorgan-Rud (North), Khiav (North West), Anzali (2.11 mg/kg) significantly (0.6 mg/kg some highly wetlands Anzali. There a significant positive correlation between tissue, negative one chlorophyll b/a. are correlations a, total results Muller index indicate that Cd, occur Unpolluted, Moderate/Heavy, Heavy/Extreme groups, respectively. Degree contamination modified degree show very high area. RI showed ecological risk. bioaccumulation factor for both less one. So, these two species may not be described heavy metal accumulators. study alarm important freshwater source Iranian Plateau.