Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Phytoplankton response to changes of physicochemical variables in Lake Nasser, Egypt

100%

Hussian A.-E. M., Napiorkowska-Krzebietke A., Toufeek M. E. F., El-Monem A. M. A., Morsi H. H.

Journal of Elementology

2015

tom 20

nr 4

Seasonal and spatial changes of phytoplankton in relation to environmental variables affecting the water quality were investigated along the main channel of Lake Nasser throughout 2013. In total, 104 phytoplankton species, belonging to 7 classes, were identified. Phytoplankton assemblages were dominated by Bacillariophyceae, Cyanophyceae and Chlorophyceae, whereas Dinophyceae, Euglenophyceae, Chrysophyceae and Cryptophyceae were infrequent. Cyclotella glomerata, C. ocellata and Aulacoseira granulata represented the most abundant species among Bacillariophyceae. Cyanophyceae was dominated by Planktolyngbya limnetica and Eucapsis minuta, and Chlorophyceae by Ankistrodesmus fusiformis and Staurastrum paradoxum. The water column was thermally stratified during summer, while being mixed throughout winter. Phytoplankton features and physicochemical variables were analyzed with the principal component analysis. Electrical conductivity and water temperature were the most common factors negatively controlling phytoplankton density. Phytoplankton density was positively associated with NO3, whereas it was negatively correlated with PO4 and HCO3. Cyanophyceae were strongly adapted to the environmental variables and NO2 was limiting their growth. Chlorophyceae were more dependent on PO4 than NO3. The vertical distribution of Chl a was associated with the summer thermal stratification and its concentration increased southwards. Chl a was affected by NO2 and linked to Chlorophyceae. The regional variations of phytoplankton reflected its response to varying environmental conditions. The annual average of the trophic state index indicated eutrophic waters of Lake Nasser.

Biosorption of some toxic metals from aqueous solution using non-living algal cells of Chlorella vulgaris

86%

Goher M. E., Abd El-Monem A. M., Abdel-Satar A. M., Ali M. H., Hussian A.-E. M., Napiorkowska-Krzebietke A.

Journal of Elementology

2016

tom 21

nr 3

Dead cells of Chlorella vulgaris were used experimentally to remove cadmium (Cd2+), copper (Cu2+) and lead (Pb2+) ions from aqueous solution under various conditions of pH, biosorbent dosage and contact time. C. vulgaris was isolated from Lake Manzala, (Egypt) and then cultivated outdoors, in growth media, maintaining pH of nearly 7.5. After cultivation, the cells were harvested by coagulation and prepared to make an experiment with different variants of pH, contact time and adsorbent dose. The adsorption specific characteristics of C. vulgaris were examined using Fourier Transformation Infrared Spectroscopy (FTR) and Scanning Electron Microscopy (SEM). The FTIR and SEM data showed vibration frequency changes for the peaks corresponding to the surface functional groups and morphological changes of C. vulgaris, respectively, after its exposure to metal ion solution. The maximum removal efficiency for copper and lead at ambient room temperature was recorded at pH 5 and 20-minute contact time, while the contact time of 120 minutes at pH 6 created the most suitable conditions for cadmium biosorption. On the other hand, 2 g dm-3 of C. vulgaris under optimum conditions was sufficient to remove 95.5%, 97.7% and 99.4% of Cd2+, Cu2+ and Pb2+, respectively, from a mixed solution of 50 mg dm-3 of each metal ion. The removal trend was in order of Pb2+ > Cu2+ > Cd2+. The results suggested that the biomass of C. vulgaris is an extremely efficient and environmentally friendly biosorbent for the removal of Cd2+, Cu2+ and Pb2 from aqueous solutions, which may be applied on a large, industrial scale.

Ograniczanie wyników

2 Journal of Elementology

2 Hussian A.-E. M.

2 Napiorkowska-Krzebietke A.

1 Abd El-Monem A. M.

1 Abdel-Satar A. M.

1 Ali M. H.

1 El-Monem A. M. A.

1 Goher M. E.

1 Morsi H. H.

1 Toufeek M. E. F.

1 2016

1 2015

Wyniki wyszukiwania

Phytoplankton response to changes of physicochemical variables in Lake Nasser, Egypt

Biosorption of some toxic metals from aqueous solution using non-living algal cells of Chlorella vulgaris