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Showing 20 results for rezaei
M. Eftekhar , A. Savari , H. Rezaei , A.r. Mahoori , R. Zare ,
Volume 20, Issue 2 (7-2011)
Abstract
The class Thaliacea belongs to Urochordata which branched from phylum chordata. Thaliacea have three orders: Doliolida (Cyclomyaria), Pyrosomatida and Salpida (Desmomyaria) and all are considered marine plankton, holoplankton and microphages. These animals feed by filtering water through their body. The aim of this research was to identify and study the ecological processes of the tunicates in coastal waters of the Hormuz Island in the Persian Gulf. We sampled water in an annual basis, starting from July 2007 and terminating in May 2008. Periodic sampling (Every 40 days) was applied and the use of plankton net with mesh size 300μm made it possible to collect plankton samples from four localities (south, north, east, west) of the Island each having two stations, one in the vicinity of the coastal waters and another away at about 2.5 miles. We found 4 species of Thaliacea: Doliolum denticulatum, Doliolum nationalis, Thalia democratica, Salpa cylindrica. In addition, we observed a life stage of Doliolum. The highest frequency was observed in May and in the south station. There was significant correlation between abundance of Doliolum denticulatum and its late oozoid or old nurse and between Thalia democratica and Doliolum denticulatum. *Corresponding author
A. Zamani , M. Rezaei , R. Madani ,
Volume 20, Issue 4 (1-2012)
Abstract
The in-vitro effects of biochemical factors on trypsin activity from intestine and pyloric caeca of common kilka (Clupeonella cultriventris caspia) was evaluated. Trypsin is known to cause belly bursting in common kilka. The assessments showed that in a range of 4-70°C, trypsin from pyloric caeca and intestine of common kilka had the maximum activity and the satiability at 60 and 55°C, respectively. The pH assessments indicated that maximum activity and stability for trypsin were at 8.5 at pH range of 4-11. The effects of metal ions on trypsin activity revealed that CaCl2, MgCl2 and MnCl2 increased trypsin activity while CuCl2 ،ZnCl2 and Al2(SO4)3 decreased its activity. The effect of inhibitors on trypsin activity also showed that SBTI and TLCK (specific inhibitors for trypsin) significantly inhibited trypsin activity. This study suggests that belly bursting in common kilka can be prevented by trypsin inactivation through application of low temperature (4°C), acidic pH, metals of CuCl2, ZnCl2 and Al2(SO4)3 and inhibitors of SBTI and TLCK. *Corresponding author
Gh. Taghizadeh Andevari , M. Rezaei ,
Volume 21, Issue 1 (4-2012)
Abstract
In this study, the effect of gelatin coating enriched with cinnamon oil for fresh fillet of rainbow trout on microbial were studied, chemical and sensory characteristics during storage at refrigerator condition. Fish fillet were treated in gelatin solution (4 percent) containing cinnamon oil and were stored in refrigerator. Total viable count was acceptable (7 log CFU/g) for coated fillets with gelatin coating containing cinnamon essential oil on day 15, but the control fillets also those that were covered with gelatin receipt to 7.88 and 7.44, respectively. In the tenth day. Psychrotrophic count values for the control and gelatin coated fillets significantly were increased more than other treatment. Total volatile bases nitrogen and Thiobarbituric acid values in gelatin with cinnamon coated fillet were less than other treatment. In general, results suggest successful inhibition microbial growth in refrigerated rainbow trout fillet is possible with gelatin incorporated cinnamon coating, as together they kept the sensory characteristics within acceptable limits throughout storage. Gelatin coating together with cinnamon oil provides a type of active coating that can be utilized as a safe preservative for fish under refrigerated storage.
D. Mohammadrezaei , B. Majazi Amiri , M. Farhangi ,
Volume 21, Issue 3 (10-2012)
Abstract
Salmo trutta caspius is an important and economic fish in the Caspian Sea has several morphological and physiological changes during smoltification. In this study, Hormonal (T3, T4 & Cortisol) and ionic (Na+, Cl- & K+) changes in the serum were determined during the period of smoltification in 5, 10, 15 & 20g of hatchery reared salmo trutta caspius in different seasons (spring, summer, autumn & winter). Hormones were measured by Eliza and Radio Immuno Assay, Na+ and K+ using flame photometer, Cl- by colorimeter. T3 and T4 were quite high in spring, especially in the juvenile of 20g. Cortisol was quite low in spring and summer in all of weight groups. Ionic changes showed no significant differences with weight, but it was significantly different among seasons. This result suggests that analyzing the plasma thyroid hormones and ionic provide useful information about the optimal time of transferring Caspian Sea trout from fresh water to sea water. It is concluded that the juvenile fish of 20g shows a better smoltification process in the spring.
N. Nejadrezaei , H. Khara , M.s. Allahyari , M. Sadeghzadeh , K. Gharra ,
Volume 24, Issue 3 (10-2015)
Abstract
The main purpose of this study was to investigate effective factors on adopting technologies among trout fish
farmers in Guilan province by Unified Theory of Acceptance and Use of Technology (UTAUT). Statistical
population of this research contained of all managers of trout fish farms of Guilan province (N=170) that
base on limitation of structural equation modeling in determining sample size, 97 of them were chosen as a
sample. Study tool was contained Vankatesh and et al. information technology questionnaire in six items. To
obtain validity of questionnaire; content, face, convergent and discriminant validity were used. As well, to
obtain reliability of questionnaire; principal component analysis, Cronbachs alpha, Dillon-Goldstein’s ʃ and
reagent stability were used. To accomplish analysis of data, SPSSV19 and SmartPLSV2 software were used in
descriptive and inferential statistics. For testing hypothesis, structural equation model (SEM) and partial least
squares (PLS) that focus on reagent variance were used. The results showed that there was significant
relationship between performance expectancy and behavioral intention. Also there was significant
relationship between intention to use and use behavior of aquaculture technologies. Model explains 28.8
percent of behavioral intention variance and 7.9 percent of use behavior of aquaculture technologies variance
among trout fish farmers. To increase willingness to accept the technology among trout fish farms in Guilan
province, it is suggested that extension-education courses for raising knowledge and awareness of
aquaculture technology to be held by organizations. Providing financial resources and adequate knowledge
will enable trout fish farms to equip with the aquaculture technologies.
M. Entesarian Bidgoli, M. Rezaei, A. Motamedzadegan, A. Daryaei,
Volume 24, Issue 4 (1-2016)
Abstract
D. Mohammadrezaei,
Volume 27, Issue 3 (8-2018)
Abstract
The vitellogenin gene expression can be altered by some estrogenic plant compounds like Genistein and β-sitosterol. Therefore, the measurement of vitellogenin gene expression can be used as an indicator to determine their effect on reproductive performance of aquatic animals. In order to evaluate the effects of genistein and β-sitosterol on the expression of vitellogenin gene in the liver and ovary of Rutilus frisii Kutum, the fish were separately exposed to 3 levels of genistein and beta-sitosterol (500, 50 and 10 ng/L). After 21 days, the RNA extracted and expression of vitellogenin gene in both the liver and ovary was investigated by Real-time PCR. The results showed the level of vitellogenin gene expression in fish exposed to genistein was higher in liver than control and β-sitosterol treatment. This difference was not observed in the ovarian tissue. Because the main site of vitellogenin synthesis expressed liver and it was controlled by endogenous estrogen (E2), so, it seems phytoesterogenic compound such as genistein has been able to increase the relative expression of this gene in fish Exposed to 500 ng/L.
M. Mansurlakuraj, K. Rezaei Tavabe, A.r. Mirvaghefi, M. Nazemi, M.a. Nematolahi, M. Jahandideh,
Volume 28, Issue 3 (9-2019)
Abstract
Marine environment is the main source of natural bioactive products whose chemical-structural properties are not similar with other natural products of plants and other inland organisms. The present study was carried out to evaluate antibiotic properties of diethyl ether and methanol extracts of two marine species including starfish and carpet anemone. The samples of starfish and carpet anemone were collected from the Lark Island coasts. Extraction was done using diethyl ether and methanol solvents and antibiotic properties analysis on Escherichia coli and Bacillus subtilis were evaluated using agar diffusion method. Then tube dilution to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). According to the results, diethyl ether extract from carpet anemone had no inhibitory effect on E. coli bacteria. While, starfish methanol extract (40 mg/ml) showed a growth inhibitory effect on E. coli bacteria. The starfish methanol extract (30 and 50 mg/ml) had a growth inhibitory effect on B. subtilis bacteria. Carpet anemone methanol extract (40 mg/ml) cause a growth inhibitory effect on E. coli, but did not have a deleterious effect. Starfish methanol extract showed the highest growth inhibitory effect on B. subtilis and created a growth inhibitory circle zoon (12.1±0.8 mm diameter). The results showed that the methanolic extract of the starfish has higher growth inhibitory effect on the two studied bacterial species. In conclusion, methanolic extracts of the starfish were effective in inhibiting the growth of Bacillus subtilis bacteria and methanolic extract of carpet anemone in inhibiting E. coli bacteria growth.
Dr Davoud Mohammadrezaei,
Volume 28, Issue 6 (2-2020)
Abstract
Removing ammonia in recirculating systems is necessary to increase efficiency and reducing ammonia toxicity. So, the select appropriate type of media to reduce is very important. In this study, four different materials (bio-Ball, wood flake, seashell, and natural pumice) as media and guppies as fish sample were used for 40 days. The results showed that the level of ammonia decreased in all media, but this reducing was higher in wood flake than other treatments. Also, the growth indices showed that the fish in the aquarium with wood flake and seashell had a better performance than other media. Accordingly, it can be concluded that due to the better performance of wood flake to reduce ammonia and make more optimal environmental conditions than other media, it can be an appropriate media for bio-filters.
Matin Shakoori, Mansour Rezaei, Yadolah Chashnidel, Reza Safari, Hamed Gholipour,
Volume 29, Issue 2 (6-2020)
Abstract
This study was done to investigate the effect of microencapsulated and non-encapsulated spirulina (Spirulina platensis) powder on the antioxidant enzymes activity and nutrient digestibility of broiler chicks for 6 weeks. A total of 360 one-day old broiler chicks (male) Ross 308 strain was divided into 9 treatments, 4 replicates (10 chicks in each replicate) in a completely randomized design. Experimental treatments include: basal diet without any additives (negative control), basal diet + antibiotic (positive control), 1-basal diet + vitamin E, 2-basal diet + 0.33% spirulina microencapsulated, 3-basal diet + 0.66% spirulina microencapsulated, 4-basal diet + 1% spirulina microencapsulated, 5-basal diet + 0.33% non-encapsulated spirulina, 6-basal diet + 0.66% non-encapsulated spirulina and 7-basal diet + 1% non-encapsulated spirulina. Results showed that the blood super oxide dismutase activity increased in chicks fed with encapsulated spirulina powder and non-encapsulated spirulina powder at the level of 1 percent (p<0.05). But the activity of catalase and glutathione peroxidase enzymes did not show any significant difference (p>0.05). The effect of experimental treatments on nutrient digestibility showed that no significant different experimental groups (p>0.05). The addition of spirulina powder and encapsulated spirulina powder increased antioxidant activity in the diet of Ross 308 broiler chicks.
Mina Ahangarzadeh, Hossein Houshmand, Simin Dehghan Madiseh, Seyed Reza Seyed Morezaei,
Volume 29, Issue 2 (6-2020)
Abstract
The Gargar River is the eastern brunch of the Karoon River, which is separated in north of Shoushtar by regulatory dam (Bandmizan) from its western branch, Shotaeit, and is about 78 km later, join to the Shotaeit and Dez and create the big Karoon. This river, while supplying drinking water to Shoshtar, Haftgel, and part of Ramhormoz and its villages, is one of the great poles of the province's fish culture. The aim of this study was to evaluate the microbial quality of surface waters of the Gargar River, compare the microbial contamination at upstream and downstream stations as well as comparisons with EPA standards to determine different uses. For this purpose, 6 stations were selected and sampling was conducted monthly within one year and microbial indices including total bacterial count, total coliform count and fecal coliform count were evaluated. The results showed that maximum of the 3 microbial indicators was at the station 2, after the sewage discharge of Shushtar (respectively 15.24×103 CFU/mL, 68181.82, 3380.91MPN/100mL) and the minimum value was at the station 1 at the upstream river (respectively 2.8×103 CFU/mL, 2627.27, 1062.73MPN/100mL). The microbial indices varied depending on seasonal variation, sampling time and location and the final results of this study showed that the water quality of river is inferior and not suitable for human use.
Samira Jeddi, Masoud Rezaei, Mehdi Alboofetileh,
Volume 29, Issue 6 (2-2021)
Abstract
Alginate is one of the unique polysaccharides present in brown algae which are widely used in textile, paper, and food, pharmaceutical, biomedical and cosmetic industries. There are many seaweed species in the southern coast of our country (Iran). However, very few studies have been done so far on the extraction of alginate from these indigenous resources. Therefore, in the present study, alginate was extracted and purified from a brown seaweed Sargassum ilicifolium. Then, yield, molecular weight, antioxidant activity (DPPH radical scavenging activity and reducing power (FRAP), and emulsifying properties (emulsification indices) of the isolated alginate were evaluated. Furthermore, FT-IR spectra were used to identify the functional groups of the extracted alginate. Alginate extraction yield was 20.84±1.24% (based on seaweed dry weight). FT-IR results showed that the extracted polysaccharide was mainly sodium alginate. The molecular weight of the extracted alginate was 1865 kDa. The DPPH radical scavenging activity and the reducing power of the extracted alginate at 1 mg/ml were 18.17±2.03% and 0.155±0.004 (Abs), respectively. The extracted alginate was able to emulsify sunflower, corn, and canola oils. The highest and lowest emulsification indices (E24) were observed in sunflower and canola oils, respectively. Overall, the results of the present study showed that the alginate extracted from S. ilicifolium has medium antioxidant and high emulsifying properties.
Saeedeh Bameri, Kamran Rezaei Tavabe, Gholamreza Rafiee, Zahra Amini Khoei,
Volume 30, Issue 1 (4-2021)
Abstract
The main objective of the current study was to investigate the effects of ethanolic extract of the Salicornia plant on growth indices, body composition and immunity of the western white leg shrimp juveniles. Experimental treatments consisted of 0 (control), 1, 3 and 5 grams of ethanolic salicornia extract per kg of base diet. Each treatment consisted of triplicates containing 50 juveniles at each tank. Shrimp were fed 3 times daily about 5% of body weight for 45 days experimental period. At the end of the experiment period, 5 shrimp from each tank were randomly selected and growth parameters, body composition analysis and immunity indices were measured. The results showed that there was a significant difference in each of the measured growth indices between the control and other treatments and the best performance was observed in the diet containing 5 grams of ethanolic extract (p<0.05). Body compositions and immunity indices results showed that the best performance was related to 5 g ethanol treatment and had a significant difference with other treatments (p<0.05). The output of the current research revealed that the usage of the Salicornia extract has positive effects on growth, body composition and immunity of the western white leg shrimp. Therefore, usage of salicornia extract of 5 g/Kg is recommended in the shrimp farms.
Hanie Sadat Miramini, Seyyed Abbas Hosseini, Rasul Ghorbani, Farzane Noori, Hassan Rezaei,
Volume 30, Issue 3 (9-2021)
Abstract
In this study, the ability of Spirulina platensis microalgae in dairy wastewater treatment and nutrient removal associated with biomass production was evaluated. Therefore, two concentrations of Spirulina platensis (0/05 and 0/1 g/L) were cultured in three dilutions (25, 50, 75%) of dairy wastewater and the efficiency of nutrient removal and biomass production was evaluated with six treatments in three replications. Nutrient and biomass values were measured on every other day. The results showed that both factors of different concentrations of algae and different dilutions of wastewater had an important role in nutrient absorption and biomass production. The highest percentages of nitrate, phosphate, ammonia removal (99/85, 82/60, 99/83%) and maximum amount of biomass (1/690±0/01 g/l) in 25% dilution and concentration of 0/1 g/l microalgae was obtained. In this research, by decreasing percentage of dilution of dairy industry wastewater and increasing amount of nutrients available in microalgae and also by increasing the initial concentration of injectable microalgae in the wastewater, more nutrients were removed, and the nitrate and ammonia levels were almost 100% eliminated and the amount of biomass increased. As a result, according to the results, Spirulina platensis microalgae has a high performance in removing nutrients (nitrate, phosphate, ammonia) from dairy industry wastewater and can be considered for dairy industry wastewater treatment.
Maryam Rezaei, Nima Pourang, Ali Mashinchian Moradi,
Volume 31, Issue 2 (7-2022)
Abstract
Considering the importance of using biosorbents to remove metal ions from wastewater and aquatic ecosystems, in this study the potential of using scales of two fish species (rainbow trout; Oncorhynchus mykiss and Caspian kutum; Rutilus kutum) to reduce the concentration of lead in aquatic environments were evaluated based on Box-Behnken design. The effects of some important parameters (biosorbent dose, biosorbent size, contact time, temperature, initial concentration, pH and salinity) on the adsorption capacity of the biosorbents were also evaluated. Among the seven studied factors, the effect of initial concentration, pH and adsorbent dose on the concentration of lead adsorbed by the two adsorbents was significant (P<0.05), while temperature and adsorbent size had no significant effect on the adsorption of lead by the sorbents. The initial concentration was the most effective independent variable (with a positive effect). The maximum adsorption capacities of lead by the two adsorbents are comparable to those of other adsorbents of aquatic origin, evaluated by other researchers. The maximum adsorption capacity of lead by scales of rainbow trout was higher than Caspian kutum. The characteristics of the adsorbents before and after adsorption were analyzed by SEM, EDX, XRF and FTIR. The lead ion concentrations were measured using AAS. The SEM-EDX and XRF analyses clearly revealed the presence of lead ions on the surfaces of both biosorbents after the adsorption experiments. The FTIR results showed that the two sorbents are composed of different functional groups, which could possibly play a significant role in their lead uptake capacity.
Reza Safari, Hasan Nasrollahzadeh, Soheyl Reyhani Poul, Zahra Yaghoubzadeh, Marzieh Rezaei,
Volume 31, Issue 3 (9-2022)
Abstract
The aim of the present study was to extract, saponify and purify astaxanthin pigment from Haematococcus microalgae (Haematococcus pluvialis) and evaluate its antioxidant activity (DPPH free radical scavenging activity and reduction of ferric ions). For extraction, two single (extraction using acetone solvent or ACE) and combined (extraction by pretreatment with hydrochloric acid and then extraction with acetone or HCl-ACE) methods were used. According to the results, amount of extracted astaxanthin (mg/g) by two methods of acetone (ACE) and hydrochloric acid pretreatment (HCl-ACE), in the extraction, saponification and final purification stages were 4.09 (13.65%), 8.49 (28.30%), 14.59 (48.65%) and 9.49 (31.65%), 13.59 (45.30%) and 25.09 (83.65%), respectively. DPPH free radical inhibition activity of extracted astaxanthin with two ACE and HCl-ACE methods (50 to 300 μg/ml) ranged from 66.25 to 76.26% and 85.39 to 94.06%, respectively. These values for ferric ion reduction power were in the absorption range of 0.61 to 0.75 and 0.78 to 0.92 at the wavelength of 700 nm, respectively. The pigment extracted using the combined method (compared to the single method) had significantly more antioxidant activity (p<0.05). In addition, in both tests, increasing the concentration of astaxanthin up to 100 μg/ml, the trend of antioxidant activity was recorded as increasing and then constant (no significant difference between the concentrations of 200 and 300 μg/ml). Comparison of the antioxidant activity of astaxanthin with synthetic antioxidants showed that the pigment extracted by combination method (at high concentrations) had the activity closer or even more than BHA and BHT. According to the findings, the combined method (acid-acetone) compared to the single method (acetone) can improve the extraction efficiency and antioxidant activity of this pigment. Therefore, the method used for the extraction and purification of astaxanthin potentially affects its extraction efficiency and antioxidant activity, and by choosing the extraction optimum method, the mentioned two indicators can be improved in the pigment.
Horiyeh Younesipour, Hasan Nasrollahzadeh Saravi, Mohamad Ali Afraei Banpei, Shaban Nagafpour, Soleyman Gholamipor, Ahad Ahmadnejad , Maryam Rezaei,
Volume 32, Issue 1 (4-2023)
Abstract
The Caspian Sea is a unique brackish system in terms of water salinity, so evaluation of pollution criteria based on the water quality of the same sea is past and present. In this study, information was collected from 2008 to 2010 and analyzed during the project during these years, sampling of eight transects shorelines was performed seasonally at stations 10, 20, 50 and 100 m of depth in two summer and winter seasons for water and sediment. The results showed that the concentration of organochlorine toxins in the aquatic environment depends on its entry through the rivers leading to it and its concentration in water varies in different seasons and regions. The results showed that the concentration of organochlorine pesticides in the aquatic environment increased in winter of 2008 with the highest percentage of pesticides in spring, summer, autumn and winter in middle, middle, east and west and maximum percentages, respectively. Toxins were found in the water samples of the eastern part of the region by 75% in spring. Also the maximum concentration of organochlorine toxin belonged to α-Endosulfan toxin with a concentration of 3.86μg/l which was recorded in Nowshahr at 50 m depth of surface water. Conclusion: In the current situation, the concentration of chlorine toxin compounds in the appropriate range and distance from the shore of water quality conditions is more suitable for fish farming in cages. Therefore, it is suggested to consider the establishment of fish cage culture at 50 m of depth.
Mohammad Akhavan-Bahabadi, Hamed Paknejad, Aliakbar Hedayati, Mehran Habibi-Rezaei3,
Volume 32, Issue 3 (9-2023)
Abstract
Fish epidermal mucus protein extraction for bioassay-guided screening is challenging and variable. In this study, four different protein extraction methods, including acetone, trichloroacetic acid (TCA)-acetone, methanol, and solid-phase extraction (SPE), were investigated to study their efficiency in ultrafiltration and to obtain the appropriate peaks in HPLC to measure biological activities. The presented data shows that the solid phase extraction method is better than the other three tested methods in quantity (total protein yield) and quality (protein profile observed in SDS-PAGE) of proteins and peptides from the epidermal mucus of Caspian monkey goby. On the other hand, due to the epidermal mucus hydrophobic nature, all three extraction methods including acetone, (TCA)-acetone and methanol led to the irreversible proteins aggregation, makes ultrafiltration, HPLC, and consequently bioactivity screening impossible. In this study, the highest amount of protein (4.676 μg/ml) (P<0.01) and the best protein profile (13 bands) were related to solid phase extraction. Also, this method simultaneously leads to the extraction, concentration, and initial purification of the samples and therefore improves the efficiency ultrafiltration and HPLC. Thus, we introduce this method for the isolation of active proteins and peptides from various complex biological samples, including fish epidermal mucus.
Yazdan Morady, Hassan Nasrollahzadeh Saravi, Mina Seifzadeh, Maryam Rezaei, Gholamrezad Daryanabard, Sharareh Firuzkandian,
Volume 32, Issue 6 (2-2024)
Abstract
In this article, the total concentration of toxic heavy metals such as lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As), which are mandatory elements of the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO), were determined to measure the health of the edible tissue of the Caspian Sea Rutilus kutum. 90 samples of Rutilus kutum were collected in three northern provinces (Gilan, Mazandaran, and Golestan) during 2021-2022. The concentration of Pb, Cd, Hg, and As of Caspian Sea Rutilus kutum samples were prepared by standard method and acid digestion. All samples were analyzed using flame, graphite furnace, and cold steam of the atomic absorption spectroscopy instrument. The results showed that 90% of all data samples (90th percentile) concentration of toxic metals in Rutilus kutum tissue decreased in the order of Cd >As>Hg>Pb. The amounts of Cd, As, Pb, and Hg in Rutilus kutum tissue were observed at not detected-0.31, 0.001-0.15, 0.001-0.060, and 0.001-0.020 mg/kg wet body weight, respectively. Also, the statistical analysis showed that two types of correlations were found between the concentration of metals and the total length and weight of Rutilus kutum: for Cd with total length (r=-0.46) and with fish weight (r=-0.51), for As with total length (r=0.30) and with fish weight (r=0.27), It showed negative and positive, respectively, but mercury and lead metals did not show correlation with biometric parameters. Comparing the current results with international standards showed that the four toxic metals Cd and As, Pb, and Hg were lower than the FAO and WHO standards concentration. The findings showed that the health risk assessment parameters (EDI, HQ, and THQ) for all metals were much lower than the recommended values. This showed that the consumption of Caspian Rutilus kutum in the study area did not have any adverse effects on human health due to the contamination of toxic metals.
Hourieh Younesipour, Hassan Nasrollahzadeh Saravi, Mohammad Ali Afraei, Maryam Rezaei, Ahad Ahmadnejad, Marzieh Rashidi Goolroyeh,
Volume 33, Issue 3 (8-2024)
Abstract
The purpose of this research was to determine the concentration of poly aromatic hydrocarbons (PAHs) in the surface sediments during four seasons at different transects of the southern basin of the Caspian Sea and to investigate the causes of their temporal and spatial changes, to compare with the standard limits, and to find the origin of these compounds. The samples from the surface sediments were collected using a grab (van Veen grab) from depths of 10 and 30 m in the coasts of Guilan, Mazandaran, and Golestan provinces at eight transects (Astara, Anzali, Sefidroud, Ramsar, Nowshahr, Babolsar, Amirabad, and Torkaman) during the autumn and winter seasons of 2018, spring and summer of 2019. The sediment samples were prepared in order to investigate PAHs using a standard method (extraction with organic compounds by the Soxhlet apparatus). The results showed that the mean (±SE) annual concentration of PAHs in the four seasons of autumn, winter, spring, and summer was 29.6±11.5, 2125±611, 4.2±3.0, and 5.3±3.1 µg/kg dry weight, respectively, and the maximum concentration of PAHs was recorded in the Nowshahr transect in the winter season. The results of the current research showed that 2 and 6 rings compounds had a low percentage of abundance in the sediments and the mean concentrations of PAHs and BaP in most of the samples were lower than the international threshold standards. The origin of PAHs compound in the sediment was recorded in more pyrogenic sources based on the diagnostic ratio (LMW/HMW=0.3).
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