جستجوی مقالات مرتبط با کلیدواژه « سرب » در نشریات گروه « مهندسی دریا »

This study intends to evaluate the accumulation of heavy metals such as lead and cadmium in the edible tissue of whitefish in Anzali Lagoon and comparewith international standards of FDA and FAO. Whitefish were caught from the west, central and east regions of Anzali Lagoon. Sampling was conducted in the fall season. Levels of heavy metals were measured using flame atomic absorption spectrometry. The average concentration of cadmium in whitefish from center of wetlands was 0.05 μg/g, in western and eastern parts of wetland was 0.03 μg/g dry weight, respectively. There was no significant difference (P> 0.05) in the levels of cadmium in different parts of the lagoon. The average concentration of lead in whitefish in the western parts of wetlands was 0.33 μg/g, in central and eastern parts 0.53 and 0.41 μg/g dry weight, respectively. No significant difference (P> 0.05) was noticed in the lead levels in different parts of the lagoon. Pb in central region of wetland showed no significant increase compared with international standards. Cd concentration in all parts of the lagoon was within the range of international standards

Persian Gulf waters remain heavily impacted by a number of pollutants originating from different sources such as direct and indirect discharge of land based pollutants, sewage etc. Millions of tons of industrial effluents are dumped into the gulf shallow waters every year and the environment is highly contaminated in many urban and industrialized areas of many countries. As a result, high concentrations of heavy metals occur in some areas.The aim of the present study is to determine the bioaccumulation of heavy metals such as lead in water, sediment, soft and hard tissues of Euchelusasper at four selected stations of Kish Island’s rocky shores in winter and summer of 2014. Lead in water samples were assayed (after preparation and chemical digestion) using Perkin Elmer 4100 atomic absorption spectrometer. Lead heavy metal concentrations obtained in four stations in winter and summer, respectively, in soft tissue were 2.57 ppb and 2.02 ppb, in hard tissue 2.28 ppband10,1 ppb, in sediment 2.23 ppb and 1.73 ppb and in water, lower than detection limit.

The aim of this study was to evaluate the toxicity effect of lead heavy metal on some serological parameters on Silver Carp in the vicinity with lead for a short term. In order to do this study a total of 135 fish with mean weight of 50±10 gand mean length of 13±1 cm were placed in adjacent to 0, 5 and 10 mg/l of Pb (NO3 )2 in 9 aquariums of 90 liter capacity.Sampling was done randomly each 12 hours for 96 hours from caudal vein of the fishes. The results showed that there was a significant difference in the amount of hemoglobin in 24 hours, between the control and treatments. The level of glucose was increased significantly by increasing the concentration of lead and passing of the time. The levels of triglyceride and albumin did not change significantly (P>0/05). The level of cholesterol increased significantly until 72 hours and after that decreased significantly. Amount of total protein increased significantly by increasing the concentration of lead and time. Based on the results, biochemical parameters are useful for monitoring of lead acute toxicity in Silver Carp.

This study is done to assess heavy metals pollution (cadmium , lead & copper) in Amirabad port area and its relation to foraminifera diversity and density .Therefor, samples were taken from twelve stations in NOV.2014 and amount of heavy metals after their readiness and chemical digestion were measured by absorb atomic machine(model spectra.200)made by Varian company in Australia, So the highest average of metals viscosity were 2.61 ,36.44 & 15.98 P.P.B. The dominate species detected are include: Ammonia beccarii caspica , Ammonia tepida & Elphidium littorale caspicus. That highest amount of foraminifera was A. beccarii about 87%, A . tepidada 16%& E.littorale 5% accumulation . highest amount of species was A.beccarii at station no:8 and its lowest amount at station no:5 .Highest amount of species was A . tepidada at station no:8 and its lowest amount at station no:9.Highest amount of species was E.littorale at station no:2 and its lowest amount at station no:9 . So station no: 9 has lowest amount of foraminifera samples. In comparison to standards, cd viscosity was higher than ERL sediment quality U.S.A and ISQGS Canada environment and other heavy metals were lower than international standards.

To survey and compare heavy metal (Pb, Cd) accumulation in Carangoides malabaricus in Persian Gulf waters (Hormozgan Province), sampling of this fish catches was done seasonally from Tiab port to Bandar Abass city during winter and summer of 2012. After biometry of the fish, muscle and liver tissues were separated. The amount of Pb and Cd were measured by an atomic absorption instrument (Varian - model GTA 100).The results of lead concentration in liver and muscle tissues were 0.1470±0.235 and 0.0399±0.0125 µg/g, respectivelyand Cd levels in liver and muscle tissues were 0.0297±0.0105 and 0.0036±0.0005 µg/g respectively.. The difference between the average concentration of Pb and Cd in liver and muscle tissues was significant (p<0.05). Average concentrations of Pb and Cd in liver and muscle tissues were not difference significantly between two seasons (p≥0/05). The comparison of the results with permissible limits of WHO, EPA and UK showed that the concentrations of these metals are lower than international permissible limits.

This study has been performed to measure Lead and Cadmium levels in Sillago sihama and Terapon Jarbua fish tissues in Qeshm Island. Twenty four samples from each species were randomly selected in October 2015 in the southern area of the island. After samples were biometrically determined; muscle tissues, skin and the liver were separated and chemically digested by wet digestion. To measure the amount of heavy metals in samples, ICP-OES model Liberty RL device was used. According to the results, the least amount of Lead in Sillago sihama and Terapon Jarbuawas was found in muscle tissues (57 mg/kg and 64 mg/kg respectively) and the highest amount was seen in the liver (1280 mg/kg and 1763 mg/kg) and the least amount of Cadmium was observed in muscle tissues (Sillago sihama and Terapon Jarbua, there is no significant difference at 95% confidence level between the metals in all three tissues. Comparing the tissues of two fish species on the absorption of Lead and Cadmium depicts no significant difference in the confidence level of 95%. To evaluate the safety of studied fish tissues for consumption, the amount of metals in the tissues were compared with WHO (Pb: 500mg/kg, Cd: 200mg/kg) standards, which indicated no significant differences. Based on the mentioned results and calculation of the acceptable daily intake, the consumption of these fish species, regarding health aspects, is confirmed.

The aim of the present study was to evaluate Pb, Cu and Cd contamination of the amphipod species, Pontogammarus maeoticus in southwestern coasts of Caspian Sea. Sampling was done in two seasons, spring (March 2014) and summer (June 2014) in 3 sites of the southwestern coasts of Caspian Sea (from Ramsar to Anzali). Results showed that Cu concentrations were much more than the other two metals, and there was no significant difference among sites in this regard (P>0.05). However, Chamkhaleh possessed the least amount of heavy metals in the body of the gammarid species; and Anzali had the most concentration in the coastal amphipod species body.Concentration of lead, copper and cadmium in the body of P. maeoticus was 1.02, 95.61 and 0.81 µg/g in spring and 1.46, 93.91 and 0.74 µg/g in summer, respectively. The results were compared with EU, US and Australian standards. According to these standards Cooper concentrations were at target values and is not considered polluted. Lead in P. maeoticus passed standard level according EU standard for edible cephalopods and Australian standard for fish flesh. This was not the case for Pb in spring in Anzali station, accouding to EU cephalopod standard only. Lead was in acceptable concentration if compared with EU standard set for edible bivalve molluscs, Australian standard for edible molluscs, and US standard of AET. Also cadmium concentrations were more than maximum allowable in edible lobster as stated by EU standards. While other standards AET of US, Australian standard for edible molluscs, and EU standards for edible cephalopods, bivalves and fish consider the concentration of Cd in the P. maeoticus within standard limits. Considering the Pb and Cd contamination levels in P. maeoticus and international standards, it can be concluded that these two heavy metals can be at threatening level. Especially that this species is consumed by fish fingerlings of some popular teleost fishes of Caspian Sea, such as Kutum and Mullet. They might be able to pass to fish flesh and cause health hazards for fish consumers. It is suggested that further study be conducted on possible transfer roots of Pb and Cd from P. maeoticus to fish flesh, and also there is a strong reason to control heavy metal pollution of the Caspian environment.

This paper presents a three- dimensional numerical model for prediction of the movement of oil slicks from a spill accident in the Strait of Singapore. The results of this model are compared with the results of the model which was run by Chao et al. This model has previously been developed for prediction of movement of gas condensates from spill accidents in the Assalouyeh marine Oil and Gas region and has achieved good results. The model is simulated based on the solution of the Navier-Stokes and the continuity equations. For the solution of advection term an upwind weighted multidimensional positive definite advection transport algorithm (MPDATA) used. This algorithm uses an explicit finite difference scheme with an anti-diffusive velocity for equilibrium diffusion. Comparison of the results of the two models showed good consistency that is considered for the introduced model as a reliable verification.

In this study concentration of Lead in water, sediment, hard and soft tissue of the gastropod, Turbo coronatus and algae, in winter and summer of 2011 were analyzed. There were four stations in Kish Island including the Greek ship, Arab market, seda va sima, and green tree. Samples were digested using MOOPAM protocol with atomic absorption in three replicates. The results indicated that the concentration of Lead in the four stations in soft tissue were 2/57 ppb, 2/02 ppb, hard tissue 2/28ppb, 1/10ppb, Algae 3/51ppb, 2/15ppb, sediment 2/45ppb, 1/73ppb and in Water<10ppb in winter and summer respectively. The concentrations of Lead were less than the WHO world standard. There were no significant differences between the amount of Lead in the samples of the two seasons and also among the stations.

In this study, three hot springs were examined including Karimi (1), Iranzamin (2), and Hosseini (3) located in Lavij region of Chamestan in Mazandaran Province located at 51˚, 58΄, 17˝-52˚, 04΄, 27˝ longitude from the east and 36˚, 59΄, 12˝-36˚, 24΄, 16˝ latitude from the north. Sampling of the springs was done to determine physical/ chemical features such as total desolved mineral materials (TDS), electrical conductivity (EC), acidity (pH), temperature, taste, odor, quantity of lead (pb2+) and cadmium (cd2+) cations. Comparison of average TDS of the spring indicates that more mineral materials were desolved in the spring No.1 . The cations concentrations were measured by atomic absorption device. Results of statistical study of the data (with the aid of SPSS application) indicated that there was no significant difference between concentrations of lead/cadmium cations in three Springs and sampling site would not affect average concentration of the two cations, therefore, there is a statistical relationship between lead (x) and cadmium (y) cations. But there is no relationship/correlation between lead/cadmium cations and the temperature of springs. Results of statistical study of the data (with the aid of SPSS application) indicated that there was contamination of lead/cadmium cations in the three springs considering the standard allowable quantity of cations for lead (0.05 ppm), cadmium (0.01 ppm), declared by the Department of the Environment.

This study was done on Yellofin seabream (Acanthopagrus latus), caught from Persian Gulf in Bandar-e-Mahshahr in Summer,2009. After biometrical measurements, the skin and muscle tissue of 15 randomly selected fish were separated using standard method of MOOPAM 1999. The two metals were extracted from skin and muscle tissues using Closed Digestion method and asidic mixture.  Concentrations of the heavy metals were measured by Flame Atomic Absorption Spectrophotometry (FAAS PERKIN ELMER4100). Mean concentration for  lead in  skin and muscle tissue in Yellofin seabream were 1.98 ± 0.7 and 2.96 ± 0.71ppm/dry weight, respectively. Also, The Mean concentration for  cadmium in  skin and muscle tissue in Yellofin seabream were 1.87 ± 0.43 and 1.03 ± 0.33, respectively. The results showed that there is a significant difference between lead and cadmium concentrations in skin and muscle tissue in Yellofin seabream (P <0.05). Also, the results showed that Pb and Cd concentrations in Yellofin seabream was higher than levels of recommended by World Health Organization WHO, NHMRC and the UK (MAFF).

Ninety meat samples of fishes caught from BeheshtabadRiver including Cyprinus carpio (n=29), Carassius auratus gibelio (n=15), Alburnus alburnus (n=27) and Capoeta aculeata (n=19) collected and used for determination of lead and cadmium with the graphite furnace atomic absorption spectrometry after wet digestion. Fish sampling was done by cast net during summer, autumn and winter 2007 and spring 2008. The results showed that the mean concentrations of lead and cadmium was 181.6 and 91.03 in Cyprinus carpio, 191.07 and 88.13 in Carassius auratus gibelio, 145.7 and 70.85 in Alburnus alburnus and 117.92 and 60.68 µg/kg in Capoeta aculeata. The mean concentrations of lead and cadmium in total samples were 159.02 and 78.09 µg/kg, respectively. The mean concentration of cadmium in samples examined exceeded acceptable threshold established in the European Commission (EC). Lead and cadmium concentration in 10% and 57.5% of samples exceeded the tolerance limits established in EC respectively. The results showed that there is significant difference between cadmium levels in meat of fish species (P<0.05). The high concentration of cadmium and lead in fish meat is probably due to missusing of phosphate fertilizers in agriculture affairs and entry of agricultural sewage into the river. 
Ninety meat samples of fishes caught from BeheshtabadRiver including Cyprinus carpio (n=29), Carassius auratus gibelio (n=15), Alburnus alburnus (n=27) and Capoeta aculeata (n=19) collected and used for determination of lead and cadmium with the graphite furnace atomic absorption spectrometry after wet digestion. Fish sampling was done by cast net during summer, autumn and winter 2007 and spring 2008. The results showed that the mean concentrations of lead and cadmium was 181.6 and 91.03 in Cyprinus carpio, 191.07 and 88.13 in Carassius auratus gibelio, 145.7 and 70.85 in Alburnus alburnus and 117.92 and 60.68 µg/kg in Capoeta aculeata. The mean concentrations of lead and cadmium in total samples were 159.02 and 78.09 µg/kg, respectively. The mean concentration of cadmium in samples examined exceeded acceptable threshold established in the European Commission (EC). Lead and cadmium concentration in 10% and 57.5% of samples exceeded the tolerance limits established in EC respectively. The results showed that there is significant difference between cadmium levels in meat of fish species (P<0.05). The high concentration of cadmium and lead in fish meat is probably due to missusing of phosphate fertilizers in agriculture affairs and entry of agricultural sewage into the river.