Author name:
سارا حمود عبد الامير الاسدي
Supervisor name:
فكرت مجيد حسن | جاسم محمد سلمان
Abstract:
اجريت دراســة بيئية شاملة على مياه نهر الحسينية في الفترة الممتدة مـن تشــرين الاول 2012 ولغاية ايلول 2013، تم فيها دراسة الخصائص الفيزيائية والكيميائية لمياه النهر بالاضافة الى اجراء دراسة كمية ونوعية لمجتمع الطحالب الهائمة والملتصقة المتواجدة في المناطق | Acomprehensive ecological study was conducted on Al - Husseinia River during the period from October 2012 to Septemper 2013. This study includes measuring some chemical and physical properties of water and conduct quantitive and qualitative study of the Algal community which includes the phytoplankton and the periphyton algae , in addition to measuring some of pollutants types such as Heavy metals and Polycyclic Aromatic Hydrocarbons (PAHs) the water of the river and its sediments and some kinds of aquatic plants such as Ceratophyllum demersum, Hydrilla verticillta, Potamogeton pectinatus and Phragmites australis. The results of the present study showed temporal and spatial variations in the physical - chemical properties of water. The water temperature ranged between (12.7 - 31.3) °C which accompanied the variations of air temperature that ranged between (8.5 - 45.3) °C. The river was tending to the alkalinity and the PH was ranged between 7.5 - 8.8 were dominated by bicarbonate ions, the electrical conductivity and the Total Dissolved Solids and The Total suspended solids ranged between (840 - 1416.67) ?s/cm and (413.33 - 700) mg / l and (6.33 - 55.07) mg / l respectively. The river was oligosaline with a salinity ranged between (0.54 - 0.91) PSU. The water current velocity and light penetration recorded fluctuated during the period of the study, their values ranged between (11.68 - 37.77) cm / Sec and (33.67 - 148.67) cm, respectively. The Dissolved oxygen and biological oxygen demand increased during the cold months and decreased during the warm months where the values ranged between (4.97 - 12.63) mg / l and (0.4 - 4.48) mg / l respectively. The river was very hard, the total hardness ranged between (240 - 516.67) mg / l, and the Total alkalinity ranged between (106.33 - 162) mg / l. Calcium ions and Magnesium ions ranged between (40.08 - 162.32) mg / l and (13.67 - 64.73) mg / l. The values of sulfates ranged between (58.94 - 131.37) mg / l ; their values show an increase at the study sites which were under highly human activities, but they did not exceed the permissible levels of the drinking water quality. The nutrients such as silica and total nitrogen and total phosphorous showed variations during the study and their values ranged between (1.63 - 6.26) mg/l and (1.4 - 3.5) mg / l and (1.33 - 17.29) ?g/l, respectively. A total of 303 algal taxa of phytoplankton and periphyton was identified during the study belonged to six classes of Algae; they include Bacillariophyceae (196 taxa) , Chlorophyceae (59 taxa) , Cyanophyceae (33 taxa) , Euglenophyceae (6 taxa) , Dinophyceae (6 taxa) and Cryptophyceae (3 taxa). The Bacillariophyceae were a dominated class in the phytoplankton community, they constitute 62.4 % of the total number of species followed by Chlorophyceae by 20.66 % and Cyanophyceae by 11. 6 % respectively. The Dinophyceae and Euglenophyceae constitute 2.07 %, while the cryptophyceae constitute the lower percentage which amounted to 1.2 % of the total species. Some identified algae like as Nitzschia, Navicula, Cymbella, Fragilaria, Scenedesmus and Oscillatoria were dominated by their species numbers in the phytoplankton community , and the total numbers of the phytoplankton cells ranged between (446.8 × 10 3 - 9177 × 10 3) cell / l. In October recorded the highest number of the cells, while in March recorded the lower numbers of the algal cells during the study. A total of 203 taxa was characterized in the epipelic algal community dominated by Bacillariophyceae by 79. 3 %, followed by Cyanophyceae by 10.84 % and Chlorophyceae by 6.9 % respectively, while the Euglenophyceae and Dinophyceae constitutes the lower percentage formed 1.48 % of the total species. The total number of epipelic algal cells ranged between (9924.5 to 10.02 × 104) cells / cm2. Winter season recorded the highest average of the total number of cells, while Spring season recorded the lowest numbers of cells. Also, some genera such as Nitzschia, Navicula, Cymbella, Fragilaria and Oscillaroria were dominated in the study period. During this study some taxa of epiphytic algae have also identified on four types of aquatic plants, which included C.demersum , H.verticillata, P.pectinatus and P.australis, the numbers of algal taxa on each there were 124, 116, 77 and 114 respectively. The results showed dominated of Bacillariophyceae followed by Chlorophyceae and Cyanophyceae and other classes respectively. Some algal genera are dominated by their species of the studied plants such as Cymbella, Navicula, Nitzschia, Fragilaria and Gomphonema. In Autumn the highest numbers of epiphytic cells were recorded, where the total numbers of cells in these plants are 74.24 × 104 cells/g, 38.46 × 104 cells/g, 19.22 × 104 cells/g and 38.88 × 104 cells/g respectively. While the lower number of cells recorded during Summer in each of C.demersum by 8.07 × 104 cells/g and H.verticillata by 8.034× 104 cells/g and P. pectinatus by 3.74 × 104 cells/g, whereas the P. Australis recorded the lowest number of cells during Spring which was 22.51 × 104 cells/g. C.demersum contained the highest numbers of algal cells compared to other plants. The distribution and concentrations of some Heavy metals such as Cd, Cu, Pb, Fe and Zn are studied in each of the water (dissolved and particulate fractions), and sediments (exchangeable and residual fractions) and four aquatic plants. The average of these heavy metals concentrations in the dissolved phase of the water were (1.4, 1.15, 3.74, 5.46 and 7.66) ?g / l, respectively. While their concentrations in the particulate phase were (3.67, 110.23, 63.97, 732.98 and 167.2) ?g/g respectively. In the sediments the concentrations of these heavy metals in the exchangeable phase were (2.53, 38, 43.45, 169 and 42.16) ?g/g, respectively, whereas their concentrations in the residual phase were (2.54, 32.82, 50.33, 1452.75 and 53) ?g/g, respectively. The concentrations of the Cd, Cu, Pb, Fe, Zn in the aquatic plants are also measured during this study and the average of theirs in C.demersum were (11.09, 14.16, 48.58, 2202 and 65.42) ?g/g, respectively. While their concentrations in the H. verticillate were (10.17, 12.99, 43.58, 2921.98 and 60.45) ?g/g, respectively. In P. pectinatus were (11.58, 13.52, 50.06, 2315.47 and 77.88) ?g/g, respectively. Whereas their concentrations in P.australis were (9.29, 11.83, 39.84, 1845.21 and 52.76) ?g/g, respectively. The distribution of sixteen Polycyclic Aromatic Hydrocarbons is also determined in Al - Husseinia River during this study in each of water, sediments and aquatic plants. These organic compounds include Naphthalene، Acenaphthylene، Acenaphthene، Fluorene، Phenanthrene، Anthracene، Fluoranthene، Pyrene، Benzo(a)Anthracene، Chrysene، Benzo(b)Fluoranthene، Benzo(k)Fluoranthene، Benzo(a)Pyrene، Dibenzo(a, h)Anthracene, Benzo(ghi)perylene وIndo(1, 2, 3 - cd)Pyrene. Their concentrations in the water of river ranged between (0.24 - 58.72) ng/l recorded for each of Benzo(a)Pyrene and Benzo(ghi)perylene respectively, the total concentration of PAHs in the water was 152 ng/L, the results also showed that the source of water pollution of these compounds was pyrogenic and petrogenic origin. In the sediments the concentration of these compounds ranged between (0.36 - 119.06) ?g/g. For each of Naphthalene and Benzo(ghi)perylene, respectively. The total concentration of PAHs in the sediment was 257.71 ?g/gm., The results also showed that the source of sediment pollution with these compounds was also pyrogenic and petrogenic origin as the water. In aquatic plants, the concentration of these compounds in C.demersum and H.verticillata ranged between (0.12 - 152.3) ?g/g and (0.3 - 129.8) ?g/g for Fluoranthene and Benzo(ghi)perylene to each plants respectively , while their concentration in P.pectinatus ranged between (0.25 - 99.36) ?g/g for each Benzo(b)Fluoranthene and Benzo(ghi)perylene respectively, in P.australis PAHs concentration ranged between (0.37 - 134.85) ?g/g for Chrysene and Benzo(ghi)perylene, respectively. C.demersum recorded the highest total concentration of PAHs compared to other plants, and the results showed that the source of pollution in these plants was Pyrogenic origin. They also revealed that Benzo(ghi)perylene recorded the highest concentration during this study compared with other compounds.
