Abstract
The use of algae to accumulate organic pollutants from polluted aquatic ecosystems is regarded as a modern trend in environmental studies. The trend is an important environmentally friendly bioremediation technique for decontaminating polluted sites. The possibility of using algae as a bio-accumulator for persistent organic pollutants (POPs) from polluted coastal areas was investigated in this study. The ability of eight algae species in Abu Qir Bay, east of Alexandria, to accumulate polycyclic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and pesticides was investigated. The total concentration of sigma 16PAHs in the examined algae species ranged from 158.70 to 128.03 ng/g (average: 136 ng/g). High levels of total carcinogenic PAHs (sigma cPAHs) were recorded in the studied algae, with an average of 59.25% from the total PAHs. The observed ratio of benzo[a]pyrene to the total PAHs was extremely high (7.89%) (average: 10.78 ng/g). The diagnostic ratios of PAHs pointed to various pyrogenic sources. The concentrations of sigma 7PCBs in the studied algae ranged from 9.71 to 8.46 ng/g (average: 9.05 ng/g). Medium penta-CBs (PCB101, PCB118) and hexa-CBs (PCB138, PCB153) were the dominant homologs. Total pesticides concentrations varied between 21.07 and 16.67 ng/g (average: 18.52 ng/g). Due to their relative high solubility in seawater, gamma-HCH and heptachlor presented the highest average concentration in the studied algae species. PAHs represented 85% of the total detected POPs in the studied algae, and Pterocladia capillacea showed the highest accumulation level. The studied algae demonstrated a high capacity for bio-extraction of carcinogenic POPs, confirming its use as a bio-accumulator.