204 research outputs found

    Initial salinity tolerance and ion-osmotic parameters in juvenile Russian sturgeon, Acipenser gueldenstaedtii, Brandt, 1833

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    The salinity tolerance, hematological and hydromineral regulation capabilities of juvenile Russian sturgeon (Acipenser gueldenstaedtii) were investigated in different ages and sizes in freshwater (FW: 0.05) but differed in experimental media (p0.05). However, the results showed that the above parameters in fish fingerlings did not return to initial values in the new environment and then physiological changes happened

    Quantification of individual phosphorus forms in surface sediments of the Southern Caspian Sea - Iranian Coast: A sequential extraction procedure

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    Seventy-two sediments from four stations (Anzali, Tonekabon, Noshahr and Amirabad), located in Caspian Sea-Iranian coast were examined on the basis of P-fractionation in autumn and winter of 2013-2014. Several forms of the phosphorus in sediment were separated and extracted according to sequential extraction method. Then the extracted phosphorus in each fraction was determined by UV–Vis spectrophotometry. In addition, total concentrations of Ca, Fe and Al in sediment fractions were also measured by atomic absorption spectroscopy. In autumn the rank order of P-fractions was: Ca-P>Residual-P>BD-P>Al-P>loosely-P and in winter it was: Ca-P>BD-P>Residual-P>Al-P>loosely adsorbed-P. In both season the loosely adsorbed phosphorus (NH4Cl–P) represented < 1% of the sedimentary inorganic phosphorus, while the reductant phosphorus (BD–P) ranged from 2.7 to 4%. The calcium bound phosphorus (Ca-P or HCl–P) showed considerable contribution (89-91%) to the sedimentary inorganic P-loads. The metal oxide bound phosphorus (Al-P or NaOH–P) was 1.2-1.5% and Residual-P was 2.3-4.5%. Concentration of BD-P increased with increasing depth in all stations and the concentration of other fractions increased in most stations. Sampling seasons had significant effect on variance of most P-fractions and other sediment features. TP and BD-P were positively correlated with Fe_tot (p<0.05)

    Identification of native fishes of west Azarbaijan province phase 2

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    The aim of this research was to identify the species of freshwater fishes in the water rssoureces located at Urmieh Lake and Zagros catchment area of West Azarbaiigan Province. Sampling was done seasonally with the determination and selection of sampling station on main and secondary branches of different rivers including; Zarineh rud, Simineh rud, Mahabad chay, Shahr chay, Nazlu chay, Baranduz chay, Godar and Zab river. Fish samples catched with different tools include Electroshoker, Cast net and buy from local fisherman, fixed in 10 % formalin and transferred to the laboratory for biological and identify hnvestigation. 42 fish species belonging to 7 family comprising of Syprinidae, Balitoridae, Cobitidae, Siluridae, Poeciliidae, Salmonidae and Mastacembelidae have been identified. Among them Syprinidae family with 32 species had a highest diversity

    Assessment of resistance and non-resistance fractions of heavy metals concentration (Fe, Mn, Cr, Ni) in surface sediments from the southern of Caspian Sea of two stations (Tonekabon and Amirabad)

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    This study was conducted to determine some heavy metals (Fe, Mg, Cr, Ni) of surface sediment in the southern Caspian Sea during two seasons (Summer and Winter) in 2014-2015. 36 surface sediments samples (with triplicate) were collected at two stations (Tonekabon and Bandar Amirabad). All samples were analyzed using sequential extraction to indicate natural and anthropogenic sources. The results indicated that the percentage of non-resistance fraction in Tonekabon area were measured 3.5,45.0, 22.1 and 6.0 for Fe, Mg, Cr, Ni, respectively and in Amirabad area were 23.0,2.6,1.8 and 4.0, respectively. On the other hand, the percentage of resistance fraction values were obtained 96.5, 55.0, 77.9 and 94.0 in Tonekabon, and 77.0, 97.4, 98.2, and 96.0 in Amirabad region. The chemical speciation of Fe, Mg, Cr, Ni in most sampling stations were in the order of residual> oxidisableorganic > acid-reducible >exchangeable. The order of total concentration, non-resistance and resistance fraction were observed Fe>Mn>Ni>Cr, Mn>Fe>Ni>Cr and Fe>Mn>Ni>Cr, respectively. As a conclusion, results of total concentration, resistnace and non-resistance of Fe, Mn, Ni and Cr were lower than standard and earth shell (Igeo) in this area. This is shown that surface sediments of this area were not polluted with these heavy metals and bio available fraction provides little indication of potential interactions with the biotic components present in this environment

    The Environmental Effect on Spawning Time, Length at Maturity and Fecundity of Kutum (R u t i l u s f r i s i i k u t u m , Kamensky, 1901) in Southern Part of Caspian Sea, Iran

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    Fish sampling were carried out using beach seines during the fishing season from early October 2006 to mid April 2007. The gonadosomatic indexes (GSI) in range and average for female and male were 0.03 to 40.28 (5.70 ± 6.48) and 0.13 to 16.71 (3.39 ± 2.33), respectively. The GSI indicated that the reproductions of R. f. kutum were occurred during March-April, with the highest average value of 6.52 for males and of 17.00 for females in April. Fifty percent of length maturity (Lm50%) at FL = 37.78 cm was recorded. The absolute fecundity ranged from 15,723 for a three-year old to 130,737 eggs for an eight-year old female, with a mean of 60435 ± 24889. The relationship between fecundity (F) and fork length (cm) was represented by the formula: Fec. = 6616FL+25916. The von Bertalanffy growth parameters was: L∞=67.5cm, K=0.21 year-1, t0 =-0.10 for throw population of kutum. The maximum spawning migration into the rivers based on GSI occurred significantly in April but it may effects by environment of sea water layers. The results showed that the length at first maturity and fecundity of R. f. kutum is reduced in southern part of Caspian Sea

    Survey on environmental pollutants (heavy metals, hydrocarbons, surfactant and chlorinated pesticides) in southern part of the Caspian Sea

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    Recently, the ecology of the Caspian Sea coastal has undergone with increasing development of human activities and industrial wastewater discharge. Therefore, considering the current situation, evaluate of pollutants issue in the Caspian Sea is very important. Results of this study showed that levels of heavy metals (Cd, Cr, Cu, Fe, Pb, and Zn) of water had lower than standard and also acceptable for aquatic life. Significant accumulation of metals such as Co, Cu and Cr in the sediment was observed at transect Sefidrood and Anzali in comparison with six other transects (Turkmen, Amirabad, Babolsar, Noshar, Tonekabon and Astara) and for Ni at transects Sefidrood and Astara compared with six other transects (Turkmen, Amirabad, Babolsar, Noshahr, Tonekabon and Anzali) (P<0.05). The amount of Zn in fish muscle Liza saliens was maximum and then metals such as Fe, Cu, Pb, Cd, Ni, Hg and Co were recorded (P<0.05). In the north of Iran, two kind of bony fish, such as R..frisii kutum and Liza.s have maximum catchments as compared with other bony fish in the Caspian Sea. Based on calculation of risk of Target Hazard Quotient (THQ), we obtained THQ was less than one for all metals in young and adults human. Thus, consumption of R..frisii kutum and Liza.s per capita with 6 kg will not be at the risk for young and adults. Among of oil derivatives, polyaromatic hydrocarbon (PAHs) is hazardous compounds in the environment. Environmental Protection Agency (EPA) was announced 16 compositions of PAHs as an index. The results of this project showed that concentration of two and three rings of PAHs was lower than 4, 5 and 6 rings of water, sediment and fish at most stations and seasons. Among of 16 PAHs, only Benz(α)anthracene, chrysene, Benzo(α)pyrene and Dibenz (α, h)anthracene compounds were contained with ecological risks (HQ) more than one in the water and sediment. In addition, three compounds such as Chrysene, Benz(α)anthracene and Benzo(α)pyrene were observed in the edible fish tissues (Liza.s and R..frisii kutum) which have high ecological risks in the water and sediment. During four seasons (spring, summer, fall and winter), maximum concentration of organochlorine residue in the surface water (5m depth) were belong to ÎČ-Endosulfan (Turkmen), Dieldrin (Babolsar, Tonekabon) and endosulfan sulfate (Astara) and at 10m depth were Îł-BHC, Dieldrin compounds (Tonekabon), DDT (Turkmen) and Aldrin (Babolsar). This values at 50m depth were belong to Îł-BHC (Anzali), ÎŽ-BHC (Tonekabon), Dieldrin (Amirabad), and heptachlor (Amirabad). Maximum percentage of organochlorine pesticides residue in the sediments was belonging to only Aldrin compound at stations Turkmen, Babolsar and Tonekabon. In addition, maximum concentration organochlorine pesticides residue in fish tissue (Liza.s and R..frisii kutum) was DDT and Endrin aldehyde compounds. Mean surfactant concentration (LAS) of surface water (5, 10 and 50 m depths) at eight transects was 0.017±0.049 mg/l. The maximum concentration of LAS were 0.084 mg/l and 0.082 mg/l in spring and summer (Anzali transect), respectively. This value was 0.035 mg/l and 0.060 mg/l in autumn and winter (Sefidrood transect), respectively. As a conclusion, the concentration of surfactant in the Caspian Sea basin is not critical as compared with standard level

    Determination of pollution condition in Babolroud River from viewpoint of pesticides and agrochemicals fertilizers

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    Babolroud River is one of the important rivers for fisheries and environmental aspect that locared in center part of Mazandaran province. The river has a span of 92 km starting from Albourz mountainous and end up at the southern part of Caspian Sea. This study was done for five months (3rd Feb. through 5th July, 2008) for the better understanding of pollution situation such as organophosphorous, organochlorine pesticides and agrochemical fertilizer that drainage from paddy fields and horticultures to the river. A total of three main sites for pesticides and plus five sub-sites for drainage were selected for observation in three different regions of the river (mountainous, plain and estuary). The organochlorine and organophosphorous pesticides measured by GC (ECD and TSD detectors) with US-EPA (508) and AOAC procedure and agrochemical fertilizer parameters were measured by ASTM method. The maximum concentrations of aldrin, lindane, heptachlor epoxyde, DDE and ÎČ- BHC (period 1), ÎŽ- BHC and endrin (peiod 2), heptachlor and DDT (period 3), α- BHC (period 3 & 4), dieldrin (period 4) were 6.02, 0.85, 0.51, 0.50, 0.22, 0.35, 0.23, 0.50, 0.46, 0.19 and 0.16 ”g/l, respectively. The maximum concentrations of four components of organophosphorous such as Diazinon and Chlorpyrifos (period 1), Malathion (period 2), Azinphos methyl (period 3) were 1.36, 0.46, 0.44 and 2.56 ”g/l, respectively. The maximum amounts of tree components of parameters of agrochemichals fertilizers indictor such as total nitrogen (period 2, sub-site 5), total phosphorus and orthophosphate (period 4, sub-site 5) and organo-phosphorus (period 3, sub-site 4) were 5990, 1290, 1220 and 336 ”g/l, respectively. The maximum concentrations of organochlorine pesticides components in sediments of the river such as lindane (period 2, site 2), ÎŽ- BHC (period 1 site 3), α- endosulfan (period 1, site 2), endrin and heptachlor epoxide (period 2, site 2) and DDE (period 2, site 1) were 0.99 0.54, 0.29, 0.19 and 0.19 ”g/l, respectively. The maximum concentrations of organochlorine pesticides components in fish tissue of the river such as endosulfan sulfate, lindane, endrin, ÎŽ- BHC and DDE were 0.32, 0.29 0.27, 0.25 and 0.21 ”g/l, respectively

    A study on environmental pollutants (Organochlorine pesticides (OCPs), heavy metals, hydrocarbons and surfactants) in the southern part of Caspian Sea

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    At the present study, the environmental pollutants such as organochlorine pesticides (OCPs), heavy metals, hydrocarbons and surfactants were done during 22 months (Sept. 2009 through May 2011) located in southern part of Caspian Sea with longitude and latitude 48°-54° N and 36°-39° E, respectively. The aims of this study were to determine the seasonal pollutants matters in water layers and bed sediments of eight transect (24 stations) and the results are as follow: The maximum seasonal percentage range of OCPs were detected in spring water samples from 10, 50, and 50m depths such as (DDD, ÎŽ-BHC, heptachlor epoxide, endrin aldehyde),(DDD) and (aldrin, ÎČ-endosulfan) compounds about 62.5, 75 and 100%, respectively. The maximum seasonal residues fluctuation of OCPs were determined in spring water samples from 10, 50, and 50m depths such as aldrin (Babolsar station), aldrin (Tonekabon station) and heptachlor epoxide (Astara station) compounds about 5.03, 3.08 and 31.43 ”g/l, respectively. The maximum percentage range of OCPs were detected in sediments samples from 10, 50, and 50m depths such as aldrin and α-BHC (winter), α-BHC (summer and winter) and aldrin (summer) compounds about 100, 75 and 87.5%, respectively. The maximum residues fluctuation of OCPs were determined in sediments samples from 10, 50, and 50m depths such as α-BHC (summer in Nushahr station), α-BHC (summer in Sefidroud station) and α-BHC (winter in Tonekabon station) and compounds about 5.96, 3.77 and 3.07 ”g/l, respectively. The fluctuation and distribution of Total Petroleum Hydrocarbons (TPHs) concentration in different water layers samples were reduced from summer>spring> fall > winter, respectively. Also this trend occurred for bed sediments and reduced from winter > summer, respectively. The mean concentrations of TPHs in water samples of all seasons, regions, depths and transects were less than maximum permissible concentration (MPC). In this research, a comparison of TPHs with EPA standards shown that the desile range organic (DRO) was close to EPA standards such as TPHs and also 95 percent of water data were less than MPC. But gasoline range organic (GRO) concentrations in all stations were less than the amount of EPA standard. A comparison of TPHs concentration in sediments shown that the concentration of all stations were less than of national research council (NRC) range except west part. The maximum annual mean concentrations of Hg and Pb elements were detected in surface station (50m) at Nushahr and Amirabad transects. The most water data of Cd, Pb and Hg elements in comparison with critical concentrations with Europe, the USA and Japan standards were less than amounts of those standards. The distribution and abundance of Cd, Pb, Hg and Ni elements in water samples were detected 98, 96, 77 and 6%, respectively less than the ISQGs (Interim marine sediment quality guidelines) standards. In sediments samples, the mean and maximum concentration of Hg element detected in winter in comparison with ISQGs standards was more. But the concentrations of Cd and Pb in sediments samples of all stations were low and less than of ISQGs standards. The maximum concentration of linear alkyl benzene sulfonate (LAS) from spring through winter in Anzali (spring), Tonekabon (summer), Anzali (fall) and Nushahr (winter) were 0.07, 0.45, 0.145 and 0.087 mg/l, respectively. The maximum concentrations of LSA were detected in spring and fall in west part and summer and winter in middle part. But the lower concentration was occurred in west of southern part of Caspian Sea. According to standards of surfactants and comparison with LAS concentration of this study were less than the critical points

    Proton Transfer, Hydrogen Bonding, and Disorder: Nitrogen Near-Edge X-ray Absorption Fine Structure and X-ray Photoelectron Spectroscopy of Bipyridine-Acid Salts and Co-crystals

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    The sensitivity of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to BrĂžnsted donation and the protonation state of nitrogen in the solid state is investigated through a series of multicomponent bipyridine–acid systems alongside X-ray photoelectron spectroscopy (XPS) data. A large shift to high energy occurs for the 1s → 1π* resonance in the nitrogen K-edge NEXAFS with proton transfer from the acid to the bipyridine base molecule and allows assignment as a salt (C═NH+), with the peak ratio providing the stoichiometry of the types of nitrogen species present. A corresponding binding energy shift for C═NH+ is observed in the nitrogen XPS, clearly identifying protonation and formation of a salt. The similar magnitude shifts observed with both techniques relative to the unprotonated nitrogen of co-crystals (C═N) suggest that the chemical state (initial-state) effects dominate. Results from both techniques reveal the sensitivity to identify proton transfer, hydrogen bond disorder, and even the potential to distinguish variations in hydrogen bond length to nitrogen

    Rotating biological contactors : a review on main factors affecting performance

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    Rotating biological contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency. The present review of RBCs focus on parameters that affect performance like rotational speed, organic and hydraulic loading rates, retention time, biofilm support media, staging, temperature, influent wastewater characteristics, biofilm characteristics, dissolved oxygen levels, effluent and solids recirculation, stepfeeding and medium submergence. Some RBCs scale-up and design considerations, operational problems and comparison with other wastewater treatment systems are also reported.Fundação para a CiĂȘncia e a Tecnologia (FCT
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