Stochastic Environmental Research and Risk Assessment
Lake Nasser is an artificial reservoir that represents the national freshwater reserve of Egypt a... more Lake Nasser is an artificial reservoir that represents the national freshwater reserve of Egypt and has a number of khors (side extensions) along its eastern and western banks. These khors covered approximately 79% of the lake’s total surface area and have an important effect on water quality and fish production in the lake. This study aimed to monitor and assess the water quality, distribution, and structure of the biotic community, including phytoplankton, zooplankton, macrophytes, epiphytes, and macrobenthos in two main khors (Tushka West and Dahmeit) during postflood and preflood periods. There was urgency associated with the study, as it was the last opportunity before the storing of the water behind the Grand Ethiopian Renaissance Dam (GERD), which had begun to fill in July 2020. Although the study confirmed that the water quality of Lake Nasser was good, it is classified as a eutrophic lake (depending on the levels of Chlorophyll-a and nutrients). This study found that pH, NO...
ABSTRACT Spatial recovery of a highly alkaline and ammonia-rich industrial effluent was assessed ... more ABSTRACT Spatial recovery of a highly alkaline and ammonia-rich industrial effluent was assessed along a wastewater receiving drain near Mansoura City in 2006. Spatial changes in physico-chemical characteristics and water quality index indicated a progressive downstream improvement of wastewater quality, and EC50 values revealed a downstream reduction in effluent toxicity. The diversity index and biomass development of Pseudokirchneriella subcapitata alga gave qualities congruent with those revealed by the physico-chemical characteristics.
The El-Ibrahimia Canal is one of the main irrigation sources in Egypt, that it supplies perennial... more The El-Ibrahimia Canal is one of the main irrigation sources in Egypt, that it supplies perennial irrigation to approximately 600 000 ha (one-fourth of the Egyptian cultivated land). An annual study on species composition of microalgae attached to the submerged hydrophyte Myriophyllum spicatum L. was carried out from midautumn 2016 to midsummer 2017. Epiphytic microalgae were represented by 109 species related to 66 genera. Diatoms were the most abundant group (66–95%) followed by green algae (3.3–25%). Aulacoseira granulata, Cyclotella ocellata, Cymbella affinis, Gomphonema parvulum, Navicula cuspidata, Navicula muralis, Nitzschia dissipata, Nitzschia hungerica, Staurosirella leptostauron, and Ulnaria ulna were the most dominant species. Regarding morphology-based functional groups (MBFGs) taxonomic approach, the epiphytic microalgae species were represented by six MBFGs (I, III, IV, V, VI and VII). The MBFG VI (mainly diatoms) was the leading group with a minimum average percentage of 59.9% during the summer season and a maximum of 95.06% during the winter season. The mean annual values of cell density fluctuated greatly between 8.6 × 106 (during the spring season) and 4.7 × 107 cells g−1 plant wet weight (during winter season). The changes in microalgae biovolumes have the same trend as cell density, with mean seasonal values of 3.89 × 109, 2.56 × 1010, 1.16 × 109, and 3.21 × 109 µm3 g−1 plant wet weight during autumn, winter, spring and summer seasons, respectively. Diversity index values ranged between 2.0 and 3.0, revealing a light pollution status of the canal. In general, the species composition and diversity of epiphytic algae along the El-Ibrahimia Canal are highly dependent on site and the physico-chemical properties of canal water affected by agricultural practice around it.
The aim of this work was to investigate and compare the phytochemical constituents and anti-algal... more The aim of this work was to investigate and compare the phytochemical constituents and anti-algal activities of crude extracts from dry macrophytes species, Potamogeton crispus and Myriophyllum spicatum. Organic solvents differed in polarity including petroleum ether, methylene chloride, chloroform, acetone and methanol were used to extract the phytochemical compounds and gas chromatograph–mass spectrometry (GC–MS) analyzer was used for the detection of these compounds. Generally, the results indicated that the composition and mass fraction of phytochemical constituents varied with plant species and extraction solvents. The growth inhibition effects of separate and mixed plants extracts on Pseudokirchneriella subcapitata were studied. In addition, the effects of mixed extracts on ten taxonomically different freshwater microalgae species, using the single-species and mixed culture species tests were also studied. Among the five different extracts tested chloroform extract and mixed extracts of the two plant species showed the highest anti-algal potential with P. subcapitata. The sensitivity of microalgae species tested in single-species cultures to P. crispus and M. spicatum extracts found to be group-specific, in which cyanophyte Anabaena flos-aquae var. treleasei and the diatoms Gomphoneis eriense var. apiculate and Tryblionella hungarica were more sensitive compared to the tested green microalgae species. In addition, the inhibitory effects of macrophyte extracts decreased for the mixed microalgae cultures. The extracts of P. crispus and M. spicatum showed the presence of some bioactive compounds that could contribute toward the phyto-algicidal properties of these plants.
This study focused on the monitoring and assessment of aquatic ecosystem functioning based on the... more This study focused on the monitoring and assessment of aquatic ecosystem functioning based on the abiotic and biotic features of Lake Nasser in the post-flood and pre-flood periods as the last ones before water storing behind the Grand Ethiopian Renaissance Dam. The physicochemical parameters, distribution and structure of biotic communities, including bacteria, phytoplankton, zooplankton, macrophytes, epiphytes and fish were analyzed at 15 sites. The values of most parameters (primarily temperature, total suspended solids, pH, orthophosphates, carbonates, sulphates and some cations) were higher in the pre-flood period, whereas higher values of conductivity, total dissolved solids, total solids, nitrites, nitrates, chemical oxygen demand, bicarbonates and chlorophyll a were recorded in the post-flood period. Cyanobacteria-dominated phytoplankton and total coliform bacteria were more abundant in the pre-flood period, and especially at sites 10–15, whereas higher abundances of zooplan...
Water quality of El-Salam Canal was assessed using physico-chemical and certain biological charac... more Water quality of El-Salam Canal was assessed using physico-chemical and certain biological characteristics. Downstream increase of total soluble inorganic nitrogen (TSIN) and dissolved reactive phosphorus (DRP) indicated increasing downstream eutrophication. The significant (P ≤ 0.01) downstream increase of chloride indicated elevated pollution. Water quality index (WQI) down (53) and up-stream (48) stations indicated bad to moderate condition, respectively. The increase of N, P, heavy metals and WQI may be attributed to excessive input of wastewater from El-Serw and Hadous drains. The highest concentrations of Fe (0.138 mg/l), Mn (0.116), Zn (0.057), Cu (0.019), Pb (0.278) and Cd (0.016) were recorded at downstream stations. Accumulation of these metals by hydrophytes followed the order: Fe ˃ Mn ˃ Zn ˃ Cu ˃ Pb ˃ Cd. Fifteen different hydrophytes were recorded with marked decline in species richness during winter and at downstream stations. The epiphytic microalgae were represented ...
Passive Remote Study of the Aerosol in the Upper Atmosphere of the Earth
Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to... more Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considera...
Passive Remote Study of the Aerosol in the Upper Atmosphere of the Earth
Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to... more Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considera...
Passive Remote Study of the Aerosol in the Upper Atmosphere of the Earth
Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to... more Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considera...
Spirogyra species are one of the most common freshwater filamentous green algae reported to have ... more Spirogyra species are one of the most common freshwater filamentous green algae reported to have antimicrobial activities. However, their chemical constituents have not been entirely detected. In this work, the chemical constituents of Spirogyra longata, successively extracted with petroleum ether, methylene chloride, chloroform, acetone and methanol were determined by GC–MS. The extract percentage varied greatly between different solvents, with the highest one (4.83%) recorded for methanol. A total of 97 compounds were identified in different extracts, out of which there were, 5 alkaloids, 6 ketones, 8 terpenes, 4 phenolics, 20 hydrocarbons, 4 fatty acids, 5 fatty alcohols, 20 esters, 7 sterols and 18 others. Generally, the composition and mass fraction of phytochemical constituents in S. longata extracts were affected by the extraction solvent, in which, the ketone hexahydrofarnesylacetone and the phenolic, butylated hydroxytoluene (BHT) were dominant in S. longata chloroform extract with peak area% of 17.38 and 50.7. Meanwhile, neophytadiene and phytol were the dominant terpenes in methylene chloride extract with a peak area percentage of 24.32 and 30.43, while, hydrocarbons (C 10 –C 29) and sterols were found to maintain 0.624% and 0.46% of S. longata DW and were mainly detected in petroleum ether extract. Alkaloids were only detected in acetone and methanol extracts and comprise 0.399% of S. longata DW. Moreover, fatty acids and esters were found to represent about 30% of the total extracts, and were dominated by palmitic acid and its methyl and ethyl esters. In conclusion, S. longata was found to contain a variety of valuable compounds, which reflect its pharmaceutical and biofuel potentialities.
Stochastic Environmental Research and Risk Assessment
Lake Nasser is an artificial reservoir that represents the national freshwater reserve of Egypt a... more Lake Nasser is an artificial reservoir that represents the national freshwater reserve of Egypt and has a number of khors (side extensions) along its eastern and western banks. These khors covered approximately 79% of the lake’s total surface area and have an important effect on water quality and fish production in the lake. This study aimed to monitor and assess the water quality, distribution, and structure of the biotic community, including phytoplankton, zooplankton, macrophytes, epiphytes, and macrobenthos in two main khors (Tushka West and Dahmeit) during postflood and preflood periods. There was urgency associated with the study, as it was the last opportunity before the storing of the water behind the Grand Ethiopian Renaissance Dam (GERD), which had begun to fill in July 2020. Although the study confirmed that the water quality of Lake Nasser was good, it is classified as a eutrophic lake (depending on the levels of Chlorophyll-a and nutrients). This study found that pH, NO...
ABSTRACT Spatial recovery of a highly alkaline and ammonia-rich industrial effluent was assessed ... more ABSTRACT Spatial recovery of a highly alkaline and ammonia-rich industrial effluent was assessed along a wastewater receiving drain near Mansoura City in 2006. Spatial changes in physico-chemical characteristics and water quality index indicated a progressive downstream improvement of wastewater quality, and EC50 values revealed a downstream reduction in effluent toxicity. The diversity index and biomass development of Pseudokirchneriella subcapitata alga gave qualities congruent with those revealed by the physico-chemical characteristics.
The El-Ibrahimia Canal is one of the main irrigation sources in Egypt, that it supplies perennial... more The El-Ibrahimia Canal is one of the main irrigation sources in Egypt, that it supplies perennial irrigation to approximately 600 000 ha (one-fourth of the Egyptian cultivated land). An annual study on species composition of microalgae attached to the submerged hydrophyte Myriophyllum spicatum L. was carried out from midautumn 2016 to midsummer 2017. Epiphytic microalgae were represented by 109 species related to 66 genera. Diatoms were the most abundant group (66–95%) followed by green algae (3.3–25%). Aulacoseira granulata, Cyclotella ocellata, Cymbella affinis, Gomphonema parvulum, Navicula cuspidata, Navicula muralis, Nitzschia dissipata, Nitzschia hungerica, Staurosirella leptostauron, and Ulnaria ulna were the most dominant species. Regarding morphology-based functional groups (MBFGs) taxonomic approach, the epiphytic microalgae species were represented by six MBFGs (I, III, IV, V, VI and VII). The MBFG VI (mainly diatoms) was the leading group with a minimum average percentage of 59.9% during the summer season and a maximum of 95.06% during the winter season. The mean annual values of cell density fluctuated greatly between 8.6 × 106 (during the spring season) and 4.7 × 107 cells g−1 plant wet weight (during winter season). The changes in microalgae biovolumes have the same trend as cell density, with mean seasonal values of 3.89 × 109, 2.56 × 1010, 1.16 × 109, and 3.21 × 109 µm3 g−1 plant wet weight during autumn, winter, spring and summer seasons, respectively. Diversity index values ranged between 2.0 and 3.0, revealing a light pollution status of the canal. In general, the species composition and diversity of epiphytic algae along the El-Ibrahimia Canal are highly dependent on site and the physico-chemical properties of canal water affected by agricultural practice around it.
The aim of this work was to investigate and compare the phytochemical constituents and anti-algal... more The aim of this work was to investigate and compare the phytochemical constituents and anti-algal activities of crude extracts from dry macrophytes species, Potamogeton crispus and Myriophyllum spicatum. Organic solvents differed in polarity including petroleum ether, methylene chloride, chloroform, acetone and methanol were used to extract the phytochemical compounds and gas chromatograph–mass spectrometry (GC–MS) analyzer was used for the detection of these compounds. Generally, the results indicated that the composition and mass fraction of phytochemical constituents varied with plant species and extraction solvents. The growth inhibition effects of separate and mixed plants extracts on Pseudokirchneriella subcapitata were studied. In addition, the effects of mixed extracts on ten taxonomically different freshwater microalgae species, using the single-species and mixed culture species tests were also studied. Among the five different extracts tested chloroform extract and mixed extracts of the two plant species showed the highest anti-algal potential with P. subcapitata. The sensitivity of microalgae species tested in single-species cultures to P. crispus and M. spicatum extracts found to be group-specific, in which cyanophyte Anabaena flos-aquae var. treleasei and the diatoms Gomphoneis eriense var. apiculate and Tryblionella hungarica were more sensitive compared to the tested green microalgae species. In addition, the inhibitory effects of macrophyte extracts decreased for the mixed microalgae cultures. The extracts of P. crispus and M. spicatum showed the presence of some bioactive compounds that could contribute toward the phyto-algicidal properties of these plants.
This study focused on the monitoring and assessment of aquatic ecosystem functioning based on the... more This study focused on the monitoring and assessment of aquatic ecosystem functioning based on the abiotic and biotic features of Lake Nasser in the post-flood and pre-flood periods as the last ones before water storing behind the Grand Ethiopian Renaissance Dam. The physicochemical parameters, distribution and structure of biotic communities, including bacteria, phytoplankton, zooplankton, macrophytes, epiphytes and fish were analyzed at 15 sites. The values of most parameters (primarily temperature, total suspended solids, pH, orthophosphates, carbonates, sulphates and some cations) were higher in the pre-flood period, whereas higher values of conductivity, total dissolved solids, total solids, nitrites, nitrates, chemical oxygen demand, bicarbonates and chlorophyll a were recorded in the post-flood period. Cyanobacteria-dominated phytoplankton and total coliform bacteria were more abundant in the pre-flood period, and especially at sites 10–15, whereas higher abundances of zooplan...
Water quality of El-Salam Canal was assessed using physico-chemical and certain biological charac... more Water quality of El-Salam Canal was assessed using physico-chemical and certain biological characteristics. Downstream increase of total soluble inorganic nitrogen (TSIN) and dissolved reactive phosphorus (DRP) indicated increasing downstream eutrophication. The significant (P ≤ 0.01) downstream increase of chloride indicated elevated pollution. Water quality index (WQI) down (53) and up-stream (48) stations indicated bad to moderate condition, respectively. The increase of N, P, heavy metals and WQI may be attributed to excessive input of wastewater from El-Serw and Hadous drains. The highest concentrations of Fe (0.138 mg/l), Mn (0.116), Zn (0.057), Cu (0.019), Pb (0.278) and Cd (0.016) were recorded at downstream stations. Accumulation of these metals by hydrophytes followed the order: Fe ˃ Mn ˃ Zn ˃ Cu ˃ Pb ˃ Cd. Fifteen different hydrophytes were recorded with marked decline in species richness during winter and at downstream stations. The epiphytic microalgae were represented ...
Passive Remote Study of the Aerosol in the Upper Atmosphere of the Earth
Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to... more Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considera...
Passive Remote Study of the Aerosol in the Upper Atmosphere of the Earth
Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to... more Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considera...
Passive Remote Study of the Aerosol in the Upper Atmosphere of the Earth
Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to... more Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considera...
Spirogyra species are one of the most common freshwater filamentous green algae reported to have ... more Spirogyra species are one of the most common freshwater filamentous green algae reported to have antimicrobial activities. However, their chemical constituents have not been entirely detected. In this work, the chemical constituents of Spirogyra longata, successively extracted with petroleum ether, methylene chloride, chloroform, acetone and methanol were determined by GC–MS. The extract percentage varied greatly between different solvents, with the highest one (4.83%) recorded for methanol. A total of 97 compounds were identified in different extracts, out of which there were, 5 alkaloids, 6 ketones, 8 terpenes, 4 phenolics, 20 hydrocarbons, 4 fatty acids, 5 fatty alcohols, 20 esters, 7 sterols and 18 others. Generally, the composition and mass fraction of phytochemical constituents in S. longata extracts were affected by the extraction solvent, in which, the ketone hexahydrofarnesylacetone and the phenolic, butylated hydroxytoluene (BHT) were dominant in S. longata chloroform extract with peak area% of 17.38 and 50.7. Meanwhile, neophytadiene and phytol were the dominant terpenes in methylene chloride extract with a peak area percentage of 24.32 and 30.43, while, hydrocarbons (C 10 –C 29) and sterols were found to maintain 0.624% and 0.46% of S. longata DW and were mainly detected in petroleum ether extract. Alkaloids were only detected in acetone and methanol extracts and comprise 0.399% of S. longata DW. Moreover, fatty acids and esters were found to represent about 30% of the total extracts, and were dominated by palmitic acid and its methyl and ethyl esters. In conclusion, S. longata was found to contain a variety of valuable compounds, which reflect its pharmaceutical and biofuel potentialities.
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Papers by Eman I Abdel-Aal