Study the Concentration of PAHS in Al-Rumayth River Water-Iraq

This study’s goals were to look into PAH concentrations and compositions as well as chemical and physical water characteristics. In Al –Rumaytha river. This study was conducted out during from November 2021 to October 2022. According to the results, sixteen PAHs compounds were found in the water, including According to the results, water contained sixteen different PAHs components including Acenaphthene and Acenaphthylene ranged between (47.1-91.5, 24.9-55.7) ppm, The values Anthracene, Naphthalene, phenanthene and fluorine results ranged (14.9-48.9 ppm,18.9 -68.7ppm,8.9-41.7 ppm,8.5-41 ppm) respectively, the minimum and maximum concentrations of Benzo[A]anthracen, Benzo[B]fluoranthene, Benzo [K] fluorantyene, Benz [G,H] perylen, Benz [A] Pryene, Chrysene, Dibenzo [A,H] Anthracene, Anthracene, Fluoranthene, Indeno and Pryene was 4.1-20.6 ppm, 20.1-69.7ppm, 30.1-97.4 ppm,4.1-36.9 ppm,0.29-1.6ppm 10.5-40.8 ppm, 8.9-36.9 ppm, 6.5-33.4 ppm,2.5-10.2 ppm,1.3-10.4 ppm. The results show that the Al-Rumaytha River is PAH-polluted, with human activities having the greatest negative effects on the river’s water quality and health.


Introduction
Two or more fused aromatic (benzene) rings with just carbon and hydrogen make up polycyclic aromatic hydrocarbons, often known as poly nuclear aromatic hydrocarbons (PAHs) [1].These polycyclic hydrocarbons fall into two main categories: Low and high molecular weights, as well as The difficulty of high molecular weight PAHs for macrophytes to absorb because of their lipophilia and cell wall composition [2].Despite the fact that it is known for macrophytes with thin cuticles to be able to consume bioactive substances [3].The two origins of PAHs in the aquatic environment are known to be pyrogenic sources, which include incompletely burned coal, oil, gas, trash, and other organic materials like tobacco or grilled meat, and secondarily, abiotic sources, which include soil and other organic matter [4,5].Second, anthropogenic sources such as crude oil spills from refineries that include fossil fuels, including petrol, are examples of petrogenic sources [6].The consequences of the almost 400 different forms of PAHs have been established [7].The complex class of chemical compounds known as PAHs consists of two or more aromatic rings arranged in linear, angular, or cluster arrangements with atoms of carbon and hydrogen.at standard temperature .In comparison to lower molecular weight PAHs, PAHs having a high molecular weight (more than 1259 (2023) 012037 IOP Publishing doi:10.1088/1755-1315/1259/1/012037 2 four rings) are more lipophilic, less volatile, and less water soluble [8].Numerous studies on PAHs in Iraq have been published, [9] PAH levels in the Euphrates River were reported.[10] Measuring the amounts of polycyclic aromatic hydrocarbons and their course in the Tigris River in Baghdad, Iraq.

Description of the Study Area
Al-Rumaytha river is a natural extension of the Al-Hilla River .Al-Hilla River is generally branches from the left side upstream of the New Hindiya barrage on the Euphrates River.As a result, Al-Hilla River water flows through Al-Hilla City before turning south and then up to Al-Diwaniya, which is located close to the Al-Hamz-al Shrqee River and runs for 30 miles from the Al Hamza bridge to the Alnajame regulator.The only source of water for Al-Muthanna Province is the Al-Rumaytha River.The River Al-Rumaytha irrigates an area of around 50000 acres through a network of distributaries and branch canals [11].

Sampling Methods
Water samples were obtained using a pre-cleaned bottle of dark glass at a 30 cm depth [12], a metallic holder was placed around the bottle that was dropped into the water and allowed to rest for a short

PAHs Analysis
For each liter of sample in the separator funnel, 30 ml of CCl4 was added, and the mixture was agitated for the organic layer was separated after an hour.The organic layer was then gathered and placed in a glass container that was dark and airtight.The organic extract was then evaporated using a rotary evaporator [13].

Physical and Chemical Properties
Water samples were collected monthly from November 2021 to October 2022 at each sampling site.Sample were preserved and analyzed according to [14].Air and water temperatures, salinity, Electrical conductivity.

Air and Water Temperatures
Highest mean value 40.66 ºC recorded at St.3 in July , and lowest mean value 12 ºC recorded at St.1 in January (fig.2).Due to the lengthier summer days and shorter winter days, the air temperature varies on a monthly basis [15].this explanation was in agreement with [16].The statistical study revealed that the air temperature varied significantly between months and locations.Results of statistical analysis that demonstrated an association between Air temperature and WT (r=0.976), while negative correlation was found between AT and TPH, (r=-0.50).Where a temperature difference causes a change in the rate at which water evaporates, the result is a change in the amount of salt that is present in the water, which increases or decreases depending on the temperature [17].Water temperature ranged between highest mean value 32.66 ᵒC recorded in August at St.3, and lowest mean value7.66ᵒCrecorded at St.1 in January (Fig. 3) showed negative correlation (r= -0.505) was found between WT and TPH, due to the fact that the solubility of gases decreases as the temperature of the water rises, as demonstrated [18].The wide variety in air and water temperatures may be due to the different times sample collection was done at each site.Temperature variance is frequently influenced by the season, location, and time of the sampling.This result is in agreement with the result of [19][20][21].this may be due to warmer temperatures, which increase the solubility of the salts and increase evaporation, increasing the concentration of salts as a result [22].

Electrical Conductivity (EC) and Salinity
Highest mean of electrical conductivity (EC) was 3370 µS/cm recorded in July at St.2, while the lowest mean value 450.33 µS/cm was recorded in November at St.1,indicated that the highest electrical conductivity depends on the amount of TDS in water ( Fig. 4).The summer months of July and August were shown to have larger monthly fluctuations in water conductivity.This may be due to the summer's high temperatures, which evaporate water and raise the concentration of dissolved ions, enhancing electrical conductivity.[23].The highest mean of salinity 2.15ppt was recorded in July at St.2, in summer season saw the greatest salinity readings, which resulted from decreasing water levels and increasing evaporation ratios [24], while the lowest mean value 0.28 ppt was recorded in November at St.1( Fig. 5) The statistical analysis showed differences between the groups that were statistically significant (p≤ 0.05).monthsand sites..The increase in the value of EC may be caused by the direct discharge of domestic wastewater into rivers and the effects of agricultural activity on the land close to rivers.

Polycyclic Aromatic Hydrocarbons (PAHs)
Two or more aromatic rings in a linear, angular, or cluster configuration with carbon and hydrogen atoms orientations make up the diverse class of chemical molecules known as PAHs.compounds with two or three rings and lower molecular weight, such as acenaphthene, acenaphthylene anthracene, naphthalene, and fluorine [8].
The lowest mean value of dissolved Acenaphthene was 47.1 ppm at St.3 during October, while the highest mean value 91.5 ppm at St.2 during December (Fig. 6).Significant differences between sites and months were shown by statistical analysis.St.2 superior to St.3 in concentrations of Acenaphthene .The significant positive correlation Acenaphthene with acenaphthylene dibenz [a,h] anthracene, phenanthrene, r= ,r= ,r= ,P≤ Acenaphthene showed higher percentages at St.2 during December than other compounds.The lowest mean value of dissolved Acenaphthylene was 24.9 ppm at St.3 during October and 24.9 ppm at St.3 during June, while the highest mean value 55.7 ppm at St.2 during December (Fig. 7).Significant differences between sites and months were shown by the statistical analysis.The highest value at St 2,the and less value at St .3.The significant positive correlation Acenaphthylene with acenaphthene, benz [a] anthracene, naphthalene (r=0.90,r=0.91,r=0.92,P≤ ),concentrations acenaphthylene increase in December, while decrease in October and June .The high concentrations of Acenaphthene and acenaphthylene in water of river during winter was due to a number of factors, including low temperatures, which results in less evaporation of these compound [25].In addition, by decreasing the temperature and using an inverse ratio, less effective microbes can breakdown hydrocarbons [26].The lowest mean value of dissolved anthracene was 14.9 ppm at St.3 during June , while the highest mean value 48.9 ppm at St.2 during November (fig.8), Significant differences between sites and months were shown by the statistical analysis.The significant positive correlation anthracene with benz[a]anthracene, benzo[k]fluoranthene, naphthalene,(r=0.923,r=0.917.r=0.912,P≤ concentration anthracene increase in autumn and decrease in summer ,low concentration anthracene in summer due to the high temperatures, which, particularly for low molecular weights, promote the biodegradation of these chemicals by bacteria [27].The lowest mean value of dissolved naphthalene was 18.9ppm at St.3 during October, highest mean value 68.7 ppm at St.2 during December (Fig. 9) .The statistical analysis showed significant differences between sites & month, The significant positive correlation naphthalene with acenaphthylene, benzo[b]fluoranthene, chrysene, fluoranthene, (r=0.92,r=0.93, r=0.92,r=0.92).In Al-Rumaytha River the higher rate of naphthalene was recorded in St.2 May due to the release of pollutants from domestic sewage.Wintertime has higher concentrations of naphthalene because there is less evaporation and less microbial activity to analyse these chemicals at freezing temperatures.The first PAH in the group, naphthalene, is a typical water pollutant.The lowest mean value of dissolved phenanthrene was 8.9 ppm at St.3 during June , the highest mean value of dissolved phenanthrene was 41.7 ppm at St.2 during December (Fig. 10).Significant differences were shown by the statistical analysis among sites and month.The significant positive correlation phenanthrene with acenaphthene ,chrysene,fluorine (r=0.903,r=0.917.r=0.924,).The lowest mean value of dissolved fluorene was 8.5 ppm at St.3 during June .The highest mean value 41.7 ppm at St.2 during December(Fig.11), Significant differences between sites and months were shown by the statistical analysis.The significant positive correlation fluorene with benz[a] anthracene, benzo[g,h]perylene, chrysene, acenaphthylene, naphthalene, phenanthrene, fluoranthene, (r=0.92,r=0.91,r=0.90,r=0.90,r=0.93,r=0.92,r=0.91),increaseconcentrations phenanthrene and fluorine in St. 2 during December ,decrease concentrations phenanthrene and fluorine in St.3 during June .Fluorine can accumulate in aquatic sediments showing low concentrations, which could be dangerous for animals living at or near the bottom of lakes and rivers.asthey decreased in the summer and grew in the winter [28].It revealed that naphthalene and acenaphthene had larger percentages of lowmolecular-weight molecules than other chemicals.Lower water solubility is associated with higher molecular weight PAHs (PAHs with more than four rings), reduced volatility, and higher lipophilicity [8].13), Significant differences between sites and months were shown by the statistical analysis , The significant positive correlation benzo[b]fluoranthene with naphthalene anthracene, acenaphthylene, benzo[k]fluoranthene, fluoranthene, (r=0.93,r=0.90,r=0.90,r=0.90,r=0.92 ). the lowest mean value of dissolved benzo[k]fluoranthene was 30.1 ppm at St.1 during October ,The highest mean value 97.4 ppm at St.2 during November (Fig. 14).Significant differences between sites and months were shown by statistical analysis.The significant positive correlation benzo[k]fluoranthene with anthracene , benzo[a]anthracene ,naphthalene, Benzo[g,h]perylen, benzo[b] fluoranthene, and benzo[a] pyrene (r=0.91,r=0.93,r=0.91,r=0.90,r=0.93,r=0.91).The lowest mean value of dissolved benzo[g,h]perylene was 4.1 ppm at St.3 during June, the highest mean 36.9 ppm at St.2 during November(Fig.15).Significant differences between sites and months were shown by statistical analysis.The significant positive correlation Benzo[G,H]Perylen with Benzo[a]anthracene, Benzo[K]fluoranthene ,fluoranthene, fluorine, (r=0.93,r=0.93,r=0.90,r=0.91),Its presence implies the usage of petroleum derivatives in boat engines, as well as rainfall or atmospheric sedimentation and water contaminated with garbage from towns.[30,31] The lowest mean value of dissolved benzo[a]pyrene was 0.29 ppm at St.3 during October, the highest mean value was1.6 ppm at St.2 during November (Fig. 16).The statistical analysis showed significant differences between sites & month, The significant positive correlation benzo[a] pyrene with benzo[k]fluoranthene, benzo[g,h]perylene, (r=0.911,r=0.876).The lowest mean value of dissolved chrysene was 10.5 ppm at St.1 during October ,the highest mean value 40.8 ppm at St.2 during December (Fig. 17).The statistical analysis showed significant differences between sites and month, The significant positive correlation chrysene with acenaphthene, acenaphthylene, dibenzo[a,h]anthracene, fluoranthene, fluorine, phenanthrene ,Indeno, naphthalene (r=0.92,r=0.90,r=0.92,r=0.90,r=0.90,r=0.91,r=0.91,r=0.92).The highest rate of hydrocarbons was recorded in the St.2 due to the release of pollutants from electrical, because oil derivatives from power plants are one of the main sources of pollution [32] The lowest mean value of dissolved dibenzo[a,h]anthracene was 8.9 ppm at St.3 during June ,the highest mean value (36.9 ppm) at St.2 during December(Fig.18).Significant differences were shown by the statistical analysis between sites and month, The significant positive correlation dibenzo[a,h]anthracene with acenaphthene, chrysene, fluoranthene, naphthalene ,(r=0.91,r=0.92,r=0.92,r=0.91)The lowest mean value of dissolved, fluoranthene was 6.5 ppm at St.3 during June ,the highest mean value 33.4 ppm at St.2 during December (Fig. 19) Significant differences between sites and months were shown by the statistical analysis.,The significant positive correlation fluoranthene with dibenzo[a,h]anthracene ,benzo[b]fluoranthene, benzo[g,h]perylene, chrysene, naphthalene fluorine (r=0.92,r=0.92,r=0.90,r=0.90,r=0.92,r=0.91)Fluoranthene has a low water solubility of 265 ug /l and will quickly bind to silt and particle debris.By degrading and being transported to the sediments, it leaves the water column.The lowest mean value of dissolved indeno was 2.5 ppm at St.3 during November , the highest mean value 10.2 ppm at St.2 during December(Fig.20).Significant differences among the sites and months were shown by the statistical analysis, The significant positive correlation indeno with chrysene, phenanthrene (r=0.911,r=0.917).The lowest mean value of dissolved pyrene was 1.3 ppm at St.3 during June, the highest mean value (10.4 ppm) at St.2 during December (Fig. 21).The statistical study revealed important variations between sites & month, The significant positive correlation pyrene with phenanthrene, acenaphthene ,indeno (r=0.91,r=0.85,r=0.85),correlation relationships strong between pyrene with phenanthrene , acenaphthene ,indeno .Shown indeno and pyrene lower proportions from compunds other.The current study showed the presence of compounds(PAHs) with high molecular weight, benz Locations of the three sampling sites on the Al-Rumaytha River.The first site -E called Al-Arthiat area is located about 8 km north the center of Al-Rumyitha( Fig:1).The second site -12E) located at Al-Rumaytha center, (Fig 1).The third site northwest -E) located at Al-at Al-Dyoalim village is about 6 km form at Al-Rumaytha center (Fig 1).

Figure 1 .
Figure 1.Map showing sampling sites in Al-Rumaytha River.

Figure 2 .
Figure 2. Monthly variation of air temperature means in Al-Rumaytha river during the study periods.

Figure 3 .
Figure 3. Monthly variation of water temperature means in Al-Rumaytha River during the study.

Figure 4 .Figure 5 .
Figure 4. Monthly variation of Electrical conductivity means in Al-Rumaytha River during the study periods.

Figure 6 .
Figure 6.Monthly variation of Acenaphthene means in Al-Rumaytha River during the study periods.

Figure 7 .Figure 8 .
Figure 7. Monthly variation of Acenaphthylene means in Al-Rumaytha River during the study periods.

Figure 9 .
Figure 9. Monthly variation of naphthalene means in Al-Rumaytha River during the study periods.

Figure 10 .
Figure 10.Monthly variation in phenanthrene mean value in Al-Rumaytha river.
[a]anthracene Benzo[G,H]perylen, chrysene, Benz[b]fluoranthene ,Benz[k]fluoranthene, Dibenzo[A,H]anthracene , fluoranthene , indeno, and benzo[a]pyrene , The reason for this is that they are compounds with high environmental stability and resistance to microbial crushing in the environment[33].It was found that the highest of all compounds PAHs at St.2 and the lowest a tSt.3 .

Figure 12 . 10 Figure 13 .
Figure 12.Monthly variation in benz[a]anthracene mean value in Al-Rumaytha River during the study.

Figure 14 .
Figure 14.Monthly variation in benzo[k]fluoranthene mean value in Al-Rumaytha River during the study periods.

Figure 15 .
Figure 15.Monthly variation in benzo [g,h]perylene mean value in Al-Rumaytha River during the study periods.

11 Figure 16 .
Figure 16.Monthly variation in benzo [a] pyrene mean value in Al-Rumaytha River during the study periods.

Figure 17 .
Figure 17.Monthly variation in chrysene mean value in Al-Rumaytha River during the study periods.

Figure 18 .
Figure 18.Monthly variation of dibenzo[a,h]anthracene means in Al-Rumaytha River during the study periods.

Figure 19 .
Figure 19.Monthly variation in fluoranthene mean value in Al-Rumaytha River during the study periods.

Figure 20 .
Figure 20.Monthly variation in indeno mean value in Al-Rumaytha River during the study periods.

Figure 21 .
Figure 21.Monthly variation of pyrene means in Al-Rumaytha River during the study periods [13]uarantee that it is filled with water.The bottle was then moved to a lab dark bottle that contained 30 ml of carbon tetra chloride CCl4 solvent.Using an Ekman grab sampler, sediment was collected and then kept froze -[13].
3 period of time [29]decrease in temperature leads to a reduction in the number of petroleum-breaking bacteria, which is the same result[29].Benz[a]anthracene is less soluble than either methyl -or ethylbenz[a].The lowest mean value of dissolved benzo[b]fluoranthene was 20.1 ppm at St.3 during October .the highest mean value 69.7 ppm at St.2 during December(Fig.