Treatment of polluted urban river water using filamentous green algae

Filamentous green algae dominated treatment system was set up to remove contaminants from polluted urban river water under lab conditions. Experiments show that TP is decreased up to 50%, associated with 72% removal of TSS. The removal efficiencies of soluble species, PO₄^3- and NH₄⁺-N, are up to 90% and 85% respectively. Under heavily polluted conditions (TP > 3.0 mg·L^-1, TN > 22.0 mg·L^-1), the average removal efficiencies of TP and TN are 89% and 45% respectively, while under light polluted conditions (TP < 0.50 mg·L^-1, TN < 10 mg·L^-1), the average effluent concentration of PO₄^3- and NH₄⁺-N are well below 0.1 mg·L^-1 and 2.0 mg·L^-1 respectively. During the experiments, the biomass of filamentous green algae is increased significantly (38.78%), and at the same time a large number of unicellular Chlorophytes and Cyanophytes species are occurred on the interior wall surface of experimental fertility. The maximum biomass occurs at the highest concentration of DO.