Iranian Journal of

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MicrosoftInternetExplorer4 Background and Objectives: Nanotechnology defined as understanding and controlling of materials at dimension between 1-100 nm, which show unusual physical and chemical properties. With Increasing development of nanotechnology, concerns associated with release of materials containing nanoparticles into the environment is rising. The purpose of this study is investigation of salinity effect on the acute toxicity of silver nanoparticles in rainbow trout fry (Oncorhynchusmykiss).
Materials and Methods: In order to conduct the toxicity tests, the Caspian Seawater(12±0.2 ppt) and (0.4 ppt) as sources of brackish water and freshwater were used, respectively. Toxicity of silvernano particles were evaluated in brackish water and freshwater at concentrations of1, 2, 4, 8, 16, 32and64ppm and  0.12, 0.25, 0.5, 1, 2, 4 and8 ppm, respectively. In addition, in order to investigate the quality of the used silver nanoparticles the Zetasizer, ICP, and TEM method were applied.
Results: Results of 96-hour median lethal concentration(LC50 96h), showed that toxicity of silver nanoparticles for rain bow trout fry in brackish water is 12 times less than its toxicity in freshwater.
Conclusion: According to the toxicity categories, analysis of the results showed that, for rainbow trout fry (1g), silver nanoparticles are classified as highly toxic agent substances in fresh water, and little toxic in brackish water, respectively.

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Background and Objectives: Due to population intensity and industrial activities, quality of groundwater is important in Bushehr province and in particularly in coastal areas. The salinity of groundwater in Asaluyeh plain is increasing from the heights towards the Persian gulf and in some places are not even applicable for irrigation.
Materials and Methods: In order to explore the source of the chloride anomaly, groundwater samples were analyzed and compared with the Persian Gulf samples. Also Water Samples Different diagrams were determined and the reasons of water salinity of Asaluyeh Plain were investigated.
Results: The results of chemical analyses showed the groundwater excessive salinity, especially near the sea. Based on correlation matrix, the highest correlation between the sodium and chlorine ions was observed.
Conclusion: The factors influencing on groundwater salinity in the plain varies and arising from solution of halite and gypsum from surrounding formations, suddenly increas sodium chloride in some parts of plain and forming Cl-Na water type. The results indicated that the Groundwater Type of Asaluyeh is Cl-Na and therefore it is classified as non-potable water.

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MicrosoftInternetExplorer4 Background and Objectives: The increasing demand for drinking water has led scientists to the use of saline waters, but existing desalinating processes are very expensive. carbon aerogel is a type of organic aerogel that is suitable for desalination owing to its unique porous structure. Low potential of fouling and deposits, very low wastewater production, electrostatic regeneration of aerogels and, in turn, no need to acid consumption, and lower power consumption are some of this technology benefits.
Materials and Method: In this experimental- analytical study, the purpose was survey of saline and brackish water desalination using carbon aerogel technology and its comparison with electrolysis.The community studied was synthetic salt water samples, using of TDS and EC indicators. The minimum synthetic samples were 243. In this regard, after polymerization of Resorsinol and Formaldehyde compounds under ambient pressure conditions and then its pyrolysis, we fabricated plates of carbon aerogel.
Result: With manufacturing in the pilot-scale, the effect of different parameters, including input salt concentration, current, water flow, distance of between electrodes and pH, on NaCl sorption amount of carbon aerogel electrodes were studied. Generally, adsorption amount increased with increasing of current and NaCl concentration and decreased with increasing of distance electrodes, flow and pH. 
Results: Fabricating reactor at pilot-scale, we studied the effect of different parameters, including input salt concentration, current, water flow, intra-distance of electrodes, and pH on the NaCl sorption using carbon aerogel electrodes. Generally, adsorption capacity increased with increasing of current and NaCl concentration in the inlet flow, and it decreased with increasing intra-distance of electrodes, flow, and pH.
Conclusion: Under the most optimal conditions, our results showed that the NaCl adsorption rate on carbon aerogel electrodes was about 1.43×10^-4 M NaCl per g of carbon aerogels indicating its cost-effectiveness.

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MicrosoftInternetExplorer4 Background and Objectives:The poor accessibility of microorganisms to PAHs in soil has limited success in the process of bioremediation as an effective method for removing pollutants from soils. Different physicochemical factors are effective on the rate of biodegradation. The main objective of this study is to assess effects of nutrient and salinity on phenanthrene removal from polluted soils.
Materials and Methods:The soil having no organic and microbial pollution was first artificially polluted with phenanthrene then nutrients and salinity solution in two concentrations were added to it in order to have the proportion of 10% w:v (soil: water). After that a microbial mixture enable to degrade phenanthrene was added to the slurry and was aerated. Finally, the residual concentration of Phenanthrene in the soil was extracted by ultrasonic and was analyzed using GC. We measured the microbial populationusing MPN test. This study was conducted based on the two level full factorial design of experiment.
Results: MPN test showed that the trend of microbial growth has experienced a lag growth. The full factorial design indicated that nutrient had the maximum effect on bioremediation the rate of phenanthrene removal in the maximum nutrients - minimum salinity solution was 75.14%.
Conclusion: This study revealed that the more nutrient concentration increases, the more degradation will be happened by microorganisms in the soils. However, salinity in the concentration used had no effect on inhabitation or promoting on the Phenanthrene removal.

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