污染杂志

Heavy Metals Bioaccumulation by the Green Alga Cladophora herpestica in Lake Mariut, Alexandria, Egypt

Abstract

Dahlia M El Maghraby and Ibrahim A Hassan

The present study was carried out to evaluate the concentrations of some trace metals in the water of Lake Mariut and their accumulation in tissues of the green alga (Cladophora herpestica). Sampling of water and algae were carried out at four different sites throughout the period from July to Sept 2017. The water of the collected samples was mostly alkaline (7.91-8.51) and showed a wide range of variation in Biological Oxygen Demand "BOD" (5.11-18.92 mg L-1), Chemical Oxygen Demand "COD" (21.36 - 81.36 mg L-1) and Electric conductance "EC" (918 -1827 μS Cm-1) Concentrations of heavy metals in algae were higher compared to their levels in water samples. The concentrations of the selected trace metals were ranged between 11.19 μg L-1 for Pb in water samples collected from site 1 to 271.36 mg Kg-1 for Cd in algae collected from site 3. The concentrations of trace metals exceeded the Egyptian Standards limits. The results showed that the water quality is unacceptable and should be improved for human consumption. Moreover, the study indicated that the high concentrations of trace metals in algal tissues demonstrated the utility of using Cladophora herpestica as a biomonitor of heavy metal contamination and bioavailability. The study included some recommendations aiming at improving both water quality and ecosystem of the lake.