Evaluation for the optimization of two conceptual 200,000 m3/day capacity RO desalination plant with different intake seawater of Oman Sea and Caspian Sea.

Iran has faced with water scarcity problem for a long time. There is a strong tendency to desalinate seawater from Oman or the Caspian Sea as intake seawater and transfer it to central parts of the country. These projects face significant technical, economic, and environmental challenges. In this work, utilizing available economic theories about single-stage reverse osmosis (RO) desalination plants, the cost analysis of a conceptual plant with a production capacity of 200,000 m3/day, was accomplished assuming the use of Oman and Caspian seawater as feed. The effect of important parameters such as applied pressure, recovery ratio, total salt content of the feed, and produced water and the temperature has been studied theoretically. The results show that under the same working conditions, the final product price per cubic meter of freshwater from the Caspian Sea is $ 0.69 versus $ 1.24 for the Oman Sea, which is about 50% cheaper. The lower salinity of the Caspian Sea compared to the Oman Sea is the main reason, which lead to reduce in the capital cost of the RO membrane (62% difference), cost of the intake and pretreatment (20%), and cost of membrane elements replacement (13%) regardless of water transfer cost.

Separation and determination of ciprofloxacin in seawater, human blood plasma and tablet samples using molecularly imprinted polymer pipette-tip solid phase extraction and its optimization by response surface methodology.

By synthesizing a molecular imprinted polymer as an efficient adsorbent, ciprofloxacin was micro-extracted from seawater, human blood plasma and tablet samples by pipette-tip micro solid phase extraction and determined spectrophotometrically. Response surface methodology was applied with central composite design to build a model based on factors affecting on microextraction of ciprofloxacin; including volume of eluent solvent, number of extraction cycles, number of elution cycles, and pH of sample. Other factors that affect extraction efficiency, such as type of eluent solvent, volume of sample, type, and amount of salt were optimized with one-variable-at-a-time method. Under optimum extraction condition, pH of sample solution was 7.0, volume of eluent solvent (methanol) was 200 µL, volume of sample solution was 10 mL, and the number of extraction and elution cycles was five and seven, respectively, amount of Na2 SO4 (as salt) and MIP (as sorbent) were optimized at 150 and 2 mg, respectively. The linear range of the suggested method under optimum extraction factors was 5-150 µg/L with a limit of detection of 1.50 µg/L for the analyte. Reproducibility of the method (as relative standard deviation) was better than 7%.

Determination of phthalate esters in seawater of Chabahar Bay using dispersive liquid-liquid microextraction coupled with GC-FID.

Phthalate esters (PEs), a group of environmental pollutants which are possibly carcinogenic to humans, have been detected in seawater. Seven PEs in seawater were quantitatively determined by using gas-chromatography flame ionizing detection after executing dispersive liquid-liquid microextraction. The suggested method is optimized for microextraction and determination of PEs in artificial sea water. Factors affecting the microextraction procedure such as the type and volume of extracting and dispersive solvents (carbon tetrachloride, 20 µL; methanol, 0.5 mL), extraction time and pH (7) were investigated. Under optimum conditions, the limit of detection of the analytes were obtained between 0.04 and 4.52 µg·L-1, and linearity and linear range were of 0.999 ≥ R2 ≥ 0.994 and 10-560 µg·L-1 respectively. Enrichment factors were found in the range of 761-827 fold, while the relative standard deviations of the analytes were between 0.17 and 7.5% (n = 6) for real sea water samples. Using this method, total PEs content of seawater from several locations in Chabahar Bay (the southeast part of Iran) was estimated 2.33-90.45 µg·L-1.

Ultrasound-assisted extraction combined with reverse phase-dispersive liquid-liquid micro extraction as a new approach for preconcentration and spectrophotometric determination of total phenol in marine sediments of Chabahar Bay.

In this study, Reverse phase dispersive liquid-liquid micro extraction (RP-DLLME) technique have been successfully developed to preconcentrate trace amount of phenol from sediment samples as a prior step to its derivatization with 4-aminoantipyrine and enhanced determination by UV-Vis spectrophotometry after primary ultrasonic extraction. In this procedure, 50µL 0.7M NaOH solution was chosen as extraction solvent and other factors including pH, extraction time, concentration of 4-aminoantipyrine, type and volume of dispersive solvents were optimized. Under selected conditions, the limit of detection, the linearity range, relative standard deviation and enrichment factor of method were obtained 15µg·kg(-1), 50-1800µg·kg(-1), 4.8% (n=10) and 33, respectively. Finally, using the high sensitivity, low organic solvent consumption and waste generation method, total phenol content in marine sediments from several locations in Chabahar Bay (southeast Iran) was estimated at 55.8-73.2µg·kg(-1).

Assessment of concentration, bioaccumulation and sources of polycyclic aromatic hydrocarbons in zooplankton of Chabahar Bay.

The amounts and sources of polycyclic aromatic hydrocarbons (PAHs) and their bioaccumulation factors (BAFs) in the zooplankton community of Chabahar Bay were investigated. The highest amounts of total PAHs (tPAHs) in the water and zooplankton samples were 62.2ngL(-1) and 1478.6ngg(-1) dry weights, in near the Shahid Beheshti Port and desalination, respectively. The greatest amount of BAF (51,780) was obtained in the entry of Bay, and it was related to the phenanthrene accumulation. Using molecular ratio, the results showed that the major input source of PAH compounds in zooplankton of Chabahar Bay was pyrolytic (fuel) source.