Journal of Ecosystem & Ecography
Open Access

Mudflat area; Fluoranthen, Benzo [A] Pyerene, TOC

Oil is the main source of Poly Aromantic Hydrocarbons (PAHs). Besides other sources such as coal, wood combustion, and some usge in the pharmaceutical, agricultural, thermal and chemical industries also there are aromatic compounds in asphalt, tar and electronic parts. There are three types of PAH sources in the environment biological, petrogenic, and pyrogenic which is formed by pyrolysis process when the organic substance be under high temperatures and low concentration of oxygen where the temperature ranged between (350-1200)°C, otherwise PAHs can be formed under low temperatures like PAHs compounds in crude oil. Petrogenic PAHs original from manufacture process of crude oil, transport, storage and oil spill.PAHs are rarely came from biological original these result from decomposition of old plants, animals. PAHs may original from anthropogenic sources which represent by human activity such as automotive emissions, cigar smoke, petroleum product as well as oil spills. PAHs are constantly accumulated from deposited part to the earth as a wet or dry by deposition methods [1]. The octanolwater partitioning coefficient for PAHs are furthermore essential in determining the sorption of PAHs to soils that reflect correlation between the soil and Aqueous solubility. However, the solubility can affect PAH movement in soil. Soil conductivity have similarly a significant effect on PAH movement. Many studies on mudflat area some places on the world try to assessing the PAHs in the sediments of Langkawi, were they used Sediment Quality Guidelines (SQGs) and toxic equivalent factors, samples from jetties and fish farms were taken and they found a significant concentration of PAHs , the sources of PAHs in this sediment likely pyrogenic and petrogenic with low toxicity in the sediment. Sojinu (2010) study examine the sediment from canal and rivers near some oil sites in Niger Delta the results show the dominant compounds were tow-ring PAHs, mostly of PAHs from petrogenic origin came from the incessant oil pipeline outflows in the part [2]. The level of PAHs accumulated by fish captured in the northern part of Gulf has only been calculated in a few cases. One of the most contamination marine environment on the world is the Gulf region. This area product almost two-thirds of the world’s refined petroleum this place has shown a lot of development, urbanization, and industrialization, and port areas have become major pollutions in aquatic ecosystem. The level of PAHs accumulated by fish captured in the northern part of Gulf has only been calculated in a few cases. Many locale study in Iraq dell with mudflat area for different pollutant such as trace metal and hydrocarbon like the objective of this paper to evaluate the concentration of PAHs on mudflat area by depending technique (GC-Mass) [3].

Sediment sampling

Four different stations located in south part of Basra- Iraq (Mudflat area) in 2019, which covered totally by tidal of the Gulf water. They look like barren regions, no life except some organism such as mudskipper Figure 1 and Table 1. Four unplanned sediment samples (1, 2, 3) for Marian areas and fourth samples are estuarine sediment near the river (Shat AL-Arab), all samples were collected by Van Veen grab Sampler. The sediments were put in plastic container and shipped to the laboratory under frozen condition. The sediments were spread on aluminum foil paper for drying, then mechanical mortar was used to grind the samples after that, sieving by metal sieve about 62 μ bore to be ready for extraction and analyses [4].

Table 1:Dominant PAHs in four stations in few Island (Basrah).

Figure 1: Map showing the sample station.

The extraction method was done according to the technique described by Goutex and Saliot (1980) and by ioc/wmo (1982), 20g of dried ground of sediments put into the two recovery zones, Use the Soxhlet intermittent extraction device described by (Heraeus RE6 50D) using a mixture of methanol benzene (1:1) for (24-36) hours after that Saponification process has been done for two hours by using (25 ml of water solution for potassium hydroxide methanol) then transported to the separation funnel with adding 30 ml of hexane and keep on to stabilize. One of the two layers formed contains hydrocarbons. The final sample passed in a chromatography column contains glass-wool, a silica gel, and Al2O3 layers with a cover of anhydrous sodium sulfate. About 30 ml of benzene added to the column to get the aromatic compounds. The sample was kept for the drying and then added 0.1ml of hexane to make the sample ready to be measured by GC Mass [5].

GC Mass Condition

A MSD GC Mass Spectrometer Agilent 5977 A MSD, Mass Hunter GC/MS Acquisition software, and Mass Hunter qualitative program, Ion Source Temp, 230°C, Quad temperature 150°C, Interface Temp, (MSD Transfer Line) 290 C, Solvent Cut Time: 4.00 min., Start Time: 4.00 min., End Time: 45 min, ACQ Mode: Scan, Scan Speed: 1562 (N2) ,Start m/z: 40, End m/z: 700. The condition as follow Column Oven Temp. initial (40°C), hold 5 mint, Rate10 c/min, final temp 300°C to end run, Injection Temp. 290°C, Injection Mode: pulsed Splitless, Flow Control Mode: constant flow Pressure: 7.0699 psi, Total Flow: 19 ml/ min. Colum Flow: 1 ml/min. Purge Flow: 3 ml/min. Injection volume 1uL, Column type, HP-5MS 5% phenyl methyl siloxane 30m × 0.25 × 0.25 mm. Grain size tests were carried out allowing to British Standard (BS) 1377, 1990. The work done in engineering geology lab of Marine Science Center in university of Basra [6].

Incomplete combustion is the principal cause of PAHs. Natural, carbon, oils and timber, for example. PAHs don’t exist chemically synthesized for commercial applications. However, for a lot of PAHs, there are a few businesses uses. They are used mainly as intermediaries in medicinal, industrial, photographic, fiberglass, greasing and other chemicals industries. 16 Poly Aromatic Hydrocarbons were estimate in four stations, the results were show there some compounds appear as dominant in four stations [7].

GC-MS Identification of PAHs

The total concentration of PAHs ranged between 89.80 μg/g dw to 21.98 μg/g dw. With a mean concentration of 44.625 μg/g dw, the sources of PAHs in nature are Pyrogenic PAH which comes from incomplete combustion of organic compounds such as fuels and biomass, the second sources of PAHs are Petrogenic PAH usually facilities with oil refinery and biogenic PAH mean sources result from changing of chemical and biological of organic substance in nature. Arabian Gulf is considered as perhaps the most contamination marine biological systems on the planet. Just about, 66% of the world’s demonstrated oil saves are situated in the Arabian Gulf. This area has gone through significant turn of events, urbanization and industrialization; port regions have become the significant wellspring of contamination in marine conditions. The assurance of PAHs levels aggregated by fish got from the Northern Arabian Gulf has been restricted. To guarantee the strength of the seaside waters around the Iraqi marine Inlet Arabian Gulf, there is a need to embrace reasonable checking programs [8].

Dominant PAHs compounds

Tenth of polycyclic aromatic hydrocarbon were recorded as a dominant compounds in four station samples Figure 2 and Table 2 the highest concentration was Benzo [B] Fluoran (14.468 μg/g dw), in station 1 near to the marine area this area influence with big Iraqi petroleum export (Basrah port). Benzo [A] pyrene reached to sediment by discharging to the river with wastewater special that came from industrial sewage, which is carcinogenic according to (IARC, 2009), Fluoranthene, Indeno (1, 2, 3-Ca and Benzo [K] Fluoran recorded in four stations respectively. similar result recorded by Dong (2021) in the study of southern Kaohsiung Harbor industrial port in Taiwan widely polluted by industrial urban Sewage using GC Mass. The main sources of Pyrene is automobiles produce about (1 μg/Km). Pyrene recorded (1.235-1.159-1.178) in stations (1, 2, 4) whereas ND in station 4, Pyrene of characteristic and anthropogenic sources and was represented one of the harmful, mutagenic Polycyclic Aromatic Hydrocarbons (PAHs) recorded as toxic [9].

Table2: Shows PAHs Pollution Index (PPI).

Figure 2: Different recordings of chemical compounds.

PAH Pollution Assessment (PPA) index

PAHs Pollution Index (PPI) by using the characterize of sediment quality was suggested by Baumard (1998):

In view of this grouping, PAHs in Iraq mudflat were (89.8-21.98 μg/g dry weight) could be considered as very high polluted with PAHs. In a few cases, it has additionally been shown that some of the PAH proportions are probably going to exaggerate the commitment of pyrogenic PAH to add up to PAH in silt tests in view of co-event of numerous PAHs in both pyrogenic and petrogenic sources [10].

Generally, a ratio of Ant/ (Ant+Phe) < 0.1 suggests a pollution with petroleum origin, while a ratio > 0.1 indicates a dominance of combustion Table 3 shows the ratio between Ant/(Ant + Phe) in all stations in the present work , station (1) appear Petrogenic PAHs origin about (1.00-0.275 ). Yunke (2002) suggested that BaA/ (BaA + Chry) ratio < 0.2 indicates petrogenic sources, a ratio between 0.2 and 0.35 indicates a mixed origin, and a ratio > 0.35 implies pyrogenic sources the result in Table 4. We can see the pyrogenic origin in stations (1, 2, 4). A ratio of Fla/ (Fla + - Pyr) < 0.4 is consistent with petroleum inputs; a value between 0.4 and 0.5 indicates liquid fossil fuel (vehicle and crude oil) combustion; and a ratio > 0.5 grass, wood, or coal combustion however the Table 5 shows the two stations 1and 4 origin from petroleum inputs while two stations 2 and 3 came from coal combustion. All these ratios were distinguished between samples containing petrogenic or pyrogenic PAHs.

Table 3:Shows the ratio of Ant/(Ant+Phe).

Table 4:Shows the ratio of BaA/(BaA+Chry).

Table 5:Shows the ratio of Fla/(Fla+- Pry).

Grain size

The size of particles is directly dependent on the type of environmental setting, transporting agent, length and time during transport, depositional conditions, and hence it possesses significant utility as an environmental proxy. Grain size examination is a major instrument for grouping unconsolidated materials and silt, sedimentary rocks, and sedimentary conditions. Quantitative examination of the rates of various particulate sizes yields quite possibly the most central actual properties of clastic silt and sedimentary rocks.

According to the particle size fraction in all stations the Clay fraction was dominant ranged between (15-30)% , whereas, the send was (2- 43)% Table 6 this percentage revealed weak acid, neutral and alkaline reaction, TOC levels in this study were (0.76-1.27)%. The highest was in station near river, anthropogenic waste conceded the main sources of TOC while the lowest value was in station 2 about (0.76%) (mudflat Marian area) receiving less sewage. AI-Manssory (2003) determined five trace metals pollutant the sediment in five station in the northern of Shatt Al P-Arab River and it is estuary during (1997-1998). They found high level of Ni reflected the contamination by hydrocarbon substance, similar study done by Abaychi and Dou Abal (1985), Al- Khafaji (1997) and Al-lmarah (1998) done on this area.

Table 6: The percentage of Sediments texture and TOC% in four stations in mudflat area.

I would like to thank my Professor for his support and encouragement.

The authors declare no conflict of interest

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