المستخلص:
The present study was performed to have knowledge of hydrocarbon compounds pollution status in the water (dissolved and particulate fractions),sediments ,two species of aquatic plants (Ceratophyllum demersum and Paspalum pespaioides) ,two species of fishes(Liza abu and Carassius auratus) and one species of molluscs (Pseudodantopsis euphraticus) .The samples were collected monthly for the period November 2012 to October 2013 from four different stations ) Al - Magideh, Treatment unit, Al - Husaichi and Al - Zubair) distributed along Al - Kahlaa River in Missan province , in addition to Reference station lies on the Tigris River before entering Amara district about 25 Km .The sampling's months were divided into four typical seasons although this is incompatible with Iraq climate.As well as measures of some ecological parameters (water and air temperatures ,pH ,turbidity, electrical conductivity ,dissolved oxygen , biological oxygen demand BOD5 and total suspended solid) which ranged between 22 and 42 C˚ , 18 and 31 C˚ , 6.9 and 7.82 , 42 and 172 NTU , 12 and 118 μS/cm , 4.66 and 9.25 mg/l , 1.46 and 5.04mg/l ,33 and 108 mg/l respectively .In addition to that the Organic Matter(OM) and the texture were measured in the sediment samples. OM values ranged between 0.078 and 0.927% , whereas the percentage of the texture was ( 15 %clay, 71% silt and 14% sand),(31 %clay, 63% silt and 6% sand), (33 %clay, 57% silt and 10% sand) , (40 %clay, 47% silt and 13% sand) and (18 %clay, 55% silt and 27% sand) in Al - Magideh, Treatment unit , Al - Husaichi , Al - Zubair and Reference stations respectively .The concentrations of total petroleum hydrocarbons (TPHs)were measured by using spectrofluorometer. Concentrations of total petroleum hydrocarbons in dissolved fraction ranged between 1.36 μg/l in Reference station and 13.87 μg/l in Treatment unit station during summer and winter respectively ,and in particulate fraction between 2.69 μg/g dry weight in Reference station and 29.92 μg/g dry weight in Treatment unit station during summer and winter respectively ,while in sediments they ranged between 3.16μg/g dry weight in Reference station and 135.18 μg/g dry weight in Treatment unit station during summer and winter respectively. Concentrations of total petroleum hydrocarbons in C. demersum ranged between 5 μg/g dry weight during winter and 58.97 μg/g dry weight during summer , while in P. pespaioides between 3.18 μg/g dry weight during winter and 43.44 μg/g dry weight during summer. Concentrations of total petroleum hydrocarbons in L. abu ranged between 4.81 μg/g dry weight during spring and 37.3 μg/g dry weight during summer ,while in C. auratus between 2.51 μg/g dry weight during spring and 29.303 μg/g dry weight during autumn . Concentrations ofbtotal petroleum hydrocarbons in P. euphraticus ranged between 5.98 μg/g dry weight during spring and 119.75 μg/g dry weight during summer .The concentrations of Polycyclic Aromatic Hydrocarbons(PAHs) and n - alkanes were determined in the laboratories of Nihran Omer (South Oil Company in Basrah province ) ,using Gas Chromatography.Total concentrations of n - alkanes in dissolved fraction ranged between 0.027μg/l in Reference station and 0.192 μg/l in Al - Husiachi station during winter and between 0.016 μg/l in Reference station and 0.039 μg/l in Treatment unit during summer ,and for particulate fraction between 0.108 μg/g dry weight in Reference station and 2.096 μg/g dry weight in Treatment unit station during winter and between 0.101 μg/g dry weight in Reference station and 0.160 μg/g dry weight in Treatment unit station during summer ,while in sediments they ranged between 4.491 μg/g dry weight in Reference station and 51.32 μg/g dry weight Treatment unit station during winter and between 2.31 μg/g dry weight in Reference station and 19.31 μg/g dry weight in Treatment unit station during summer.The range of carbon chain length of n - alkanes in dissolved fraction ranged from C8 to C34 and in particulate fraction from C15 to C34 distributed in two patterns ,the first pattern included compounds between C8 and C25 with the abundance of C19,C21,C23 and C25 odd carbon number of and C18,C20,C22 and C24 for even carbon number ,while the second pattern included compounds with the range from C26 to C35 predominated by C27 and C29 odd carbon number and C26,C28 and C30 even carbon number.In sediments they ranged from C14 to C35 and distributed in two patterns, the first pattern included compounds between C8 and C25 with the abundance of C17,C19 and C21 odd carbon number and C18,C20 and C22 for even carbon number ,while the second pattern included compounds with the range from C24 to C35 with predominance of C31and C33 odd carbon number and from C24 to C34 even carbon number.Total concentrations of n - alkanes in C. demersum ranged between 6.467 μg/g dry weight during spring and 59.483 μg/g dry weight during summer ,whereas in P. pespaioides between 34.7 μg/g dry weight during winter and 166.6 μg/g dry weight during summer .The distribution of n - alkanes compounds in plants chain length ranged from C15 to C35 with bimodal from C15 to C27and from C28 to C35 with predominance of C17 to C25 odd carbon number and C18 to C24 even carbon number in the first one ,whereas in the second the dominance compounds were from C29 toC33 for odd carbon number and from C26 to C32 even carbon number.cTotal concentrations of n - alkanes in muscles of L. abu ranged between 14.60 μg/g dry weight during winter and 73.15 μg/g dry weight during summer and C. auratus between 34.76 μg/g dry weight during winter and 166.61 μg/g dry weight during summer . The distribution of n - alkanes compounds in fish muscles chain length ranged from C16 to C35 with bimodal from C16 to C25 and C26 to C35 with predominance of C17 to C25 and C18 to C24 for the first one ,and from C27 to C33 and from C26 to C34 for the second. These reflected nutrition nature for these kinds of fishes which depend on algae ,phytoplankton ,zooplankton ,diatoms ,insects and crustacean . While in the mollusc (P. euphraticus) ranged between 95.16μg/g dry weight during spring and 220.36 μg/g dry weight during summer. The distribution of n - alkanes compounds in P. euphraticus chain length ranged from C14 to C35 with bimodal from C14 to C27 and from C28 to C35 with predominance of C17 to C21 and from C18 to C24 for the first one ,and from C29 to C33 and from C30 to C34 for the second.The values of Carbon Preference Index (CPI) and pristane to phytane ratio was calculated to know the hydrocarbon compounds source in water ,sediments and biota of Al - Kahlaa River ,since the CPI value ranged between 0.142 and 1.314 in dissolved fraction and between 0.045 and 2.193 in particulate fraction , 0.160 and 1.872 in sediments,1.075 and 8.638 in plants , 0.285 and 1.537 in fishes and between 0.354 and 4.457 in mollusc .Whereas the values of pristane to phytane ranged between not detected and 1.579 in dissolved fraction , not detected and 0.601 in particulate fraction , 0.447 and 3.008 in sediments, not detected and 0.821 in plants , not detected and 2.176 in fishes and between 0.822 and 1.347 in mollusc .These indicate that there are two sources of hydrocarbon compound in water ,sediments and biota ,biogenic from living organisms and anthropogenic from domestic ,industrial and petroleum pollutants except in plants .Total concentrations of PAHs in dissolved fraction varied from 0.739 ng/l in Reference station to1.974 ng/l in Treatment unit during winter ,and from 0.300 ng/l in Reference station to1.125 ng/l in Treatment unit during summer ,and in the particulate fraction they varied from 0.79 ng/g dry weight in Reference station to 24.42 ng/g dry weight in Treatment unit during winter ,and from 4.369 ng/g dry weight in Reference station to10.545 ng/g dry weight in Al - Husaich during summer ,while in sediments they varied from 4.906 ng/g dry weight in Reference station to 35.479 ng/g dry weight in Treatment unit during winter ,and from 2.391 ng/g dry weight in Reference station to 25.886 ng/g dry weight in Treatment unit during summer.It had been noticed that there were a predominance of high molecular weight PAHs on low molecular weight PAHs ,while Benzo(a)dAnthracene/(Benzo(a)Anthracene+ Chrysene) BaA/(BaA+Chr) ratio ranged from 0.218 to 0.804 in water and 0.520 to 0.66 in sediments. The Indeno (1,2,3 - cd)pyrene /(Indeno (1,2,3 - cd)pyrene + Benzo(ghi)perylene) InP/(InP+BghiP) ratio ranged between not detected and 0.578 in water and between not detected and 0.681 in sediments .The Fluoranthene/ Pyrene (Fl/Py)ratio ranged between 0.150 and 2.47 in water and between 0.10 and 8.490 in sediments ,this give an indication of the source of PAHs compounds in water and sediments which were mainly pyrogenic and few from them petrogenic .Total concentrations of PAHs in C. demersum ranged between 24.124 ng/g dry weight during winter and 87.289 ng/g dry weight during summer ,whereas in P. pespaioides between 1.616 ng/g dry weight durig winter and 16.661 ng/g dry weight during summer .The Lower Polycyclic Aromatic Hydrocarbons to Higher Polycyclic Aromatic Hydrocarbons ratio ranged between 0.006 and 0.009 in C. demersum and between 0.008 and 0.103 in P. pespaioides. TheBaA/(BaA+Chr)ratio ranged from 0.995 to 0.997 in C. demersum and 0.756 to 0.995 in P. pespaioides. The InP/(InP+BghiP) ratio ranged between 0.342 and 0.807 in C. demersum and between 0.19 and 0.645 in P. paspaloides . The Fl/Py ratio ranged between 0.096 and 0.988 in C. demersum and between 0.018 and 5.018 in P. pespaioides. These indicate that the sources of PAHs in these plants were both pyrogenic and petrogenic .Total concentrations of PAHs in muscles of L. abu ranged between 2.301 and 16.661 ng/g dry weight during winter and summer respectively and in C. auratus between 1.095 and 8.675 ng/g dry weight during winter and summer respectively ,whereas in mollusc (P. euphraticus) ranged between 1.86 and 6.88 ng/g dry weight during spring and summer respectively. According to ratios of Low Polycyclic Aromatic Hydrocarbons(LPAHs) to High Polycyclic Aromatic Hydrocarbons (HPAHs), BaA/(BaA+Chr), InP/(InP+BghiP) and Fl/Py ,they certainly reflected that the PAHs sources in fishes and mollusk are pyrogenic as a main sources and petrogenic as a small part .Also results of this study revealed the presence of seasonal and spatial variations in concentrations of TPHs ,n - alkanes and PAHs in water ,sediments and aquatic biota from Al - Kahlaa River ,the highest concentrations were recorded during winter whereas the lowest during summer ,also the highest values of these compounds were recorded in Treatment unit station in comparison with other stations.
اسم المشرف:
عبد الحسن يوسف العضب
حامج طالب السعد
اسم المؤلف:
صالح حسن جازع
