Investigation of adsorbent effect of Chlorella vulgaris and Scenedesmus sp. (Chlorophyta) for the removal of some heavy metals and nutrients

The aim of PhD. thesis study is to evaluate the efficiency of two microalgae strains (Chlorella vulgaris and Scenedesmus sp.) removal of some inorganic nutrients and heavy metals. For this aim the green microalgae (Chlorophyta), grown in controlled laboratory conditions, were used as biosorbent for the removal of six different concentrations of Antimony (Sb3+), Manganese (Mn2+), Copper (Cu2+), Nickel (Ni2+), Phosphate (PO43-) and Nitrate (NO3-) which are prepared in aqueous solutions at conc. 0.1–1 mM for PO43--; 5–30 mM for NO3-; 2,5–100 ppm for heavy metals. Besides, the effects of heavy metals and inorganic nutrients on the cells total carbohydrate and chlorophyll a-b content were investigated during 24 hours exposure. According to the results, the average removal efficiency of Phosphate, Nitrate, Antimony, Manganese, Copper and Nickel on C. vulgaris biomass was determined 95.91 %, 21.63 %, 28.64 %, 49.41 %, 33.38 % and 29.96 % while 98.15 %, 14.28 %, 10.05 %, 8.52 %, 30.18 % and 20.62 % on Scenedesmus sp. cells, respectively. On the other hand, the average adsorption capacities of Sb3+, Mn2+, Cu2+, Ni2+, PO43- and NO3- ions were confirmed 0.18, 0.38, 0.28, 0.15, 1.18 and 9.30 mg/g by C. vulgaris and 2.99, 0.96, 11.50, 11.33, 0.75 and 4.56 mg/g by Scenedesmus sp. biomass. According to the results obtained in the study, C. vulgaris and Scenedesmus sp. were found to be very effective on removal of excessive nutrients and heavy metals at laboratory conditions.