Saadati N.,National University of Malaysia |
Saadati N.,Soil and Sediment Laboratories Center |
Abdullah M.P.,National University of Malaysia |
Zakaria Z.,Malaysia Japan International Institute of Technology |
And 3 more authors.
Chemistry Central Journal | Year: 2013
Background: Reliable values for method validity of organochlorine pesticides determination were investigated, in water by solid phase extraction and in sediment by Soxhlet extraction, followed by gas chromatography equipped with an electron capture detector. Organochlorine pesticides are categorized as Persistent Organic Pollutants. Hence, critical decisions to control exposure to these chemicals in the environment are based on their levels in different media; it is important to find valid qualitative and quantitative results for these components. In analytical chemistry, internal quality procedures are applied to produce valid logical results.Result: In this study, 18 organochlorine pesticides were targeted for analysis and determination in water and river sediment. Experiments based on signal-to-noise ratio, calibration curve slope and laboratory fortified blank methods were conducted to determine the limits of qualification and quantification. The data were compared with each other. The limitation values, following Laboratory Fortified Blank, showed significant differences in the signal-to-noise ratio and calibration curve slope methods, which are assumed in the results for the sample concentration factor to be 1,000 times in water and 10 times in sediment matrices. The method detection limit values were found to be between 0.001 and 0.005 μg/L (mean of 0.002 ± 0.001) and 0.001 and 0.005 μg/g (mean of 0.001 ± 0.001). The quantification limits were found to be between 0.002 and 0.016 μg/L (mean of 0.006 ± 0.004) and 0.003 and 0.017 μg/g (mean of 0.005 ± 0.003 μg/L) for water and sediment, respectively, based on the laboratory fortified blank method. Because of different slopes in the calibration methods, it was also found that the limitation values for some components from the internal standard were higher than from external standard calibration, because in the latter a factor for injection efficiency is applied for calibration.Conclusion: Technically, there are differentiations between detection limits for quality and quantity from component to component, resulting from noise, response factors of instruments and matrix interference. However, the calculation method is the cause of differentiation for each component of the different methods. The results show that for no matter what component, the relationship between these levels in different methods is approximately: Signal to Noise: Calibration Slope = 1:10. Therefore, due to different methods to determine LOD and LOQ, the values will be different. In the current study, laboratory fortified blank is the best method, with lower limitation values for Soxhlet and solid phase extraction of OCPs from sediment and water, respectively. © 2013 Saadati et al.; licensee Chemistry Central Ltd.
Shafai Bejestan M.,Shahid Chamran University |
Rezania A.,Khuzestan Water and Power Authority
Environmental Hydraulics - Proceedings of the 6th International Symposium on Environmental Hydraulics | Year: 2010
The outer banks in river bends are subject to severe bank erosion due to secondary flows. In this paper the effect of horizontal footing on movement and reduction of outer bank scour hole has been investigated. To reach such goals an experimental bend flume of 90 degrees was built and series of tests conducted. The 75mm wide horizontal footing was installed at the outer bank in four different elevations of 0, 20, 40 and 60 percent of maximum scour depth. By comparison of the bed topography with and without footing, a maximum scour reduction of 45% was obtained with footing installed at elevation of 40% of the maximum scour depth. The results of this study reveal that footing redistributed the bed topography in such a way that the point of maximum scour hole has been shifted from the outer bank to the center of the flume and bed topography became more uniform. © 2010 Taylor & Francis Group, London.
Alidadi S.,Khuzestan Water and Power Authority |
Hakami M.,Khuzestan Water and Power Authority
Geotechnical and Geological Engineering | Year: 2014
Flow rate of Karun river, which is the longest and largest river in Iran, decreased from 600 to 100 m3/s in average, due to the drought in early 2008. This reduction caused water from Persian Gulf to advance farup-river and reach a raw water supply basin and increase water electrical conductivity (EC) to 5,000 μmoh/cm. A temporary dam constructed from soil-sheet pile was installed to prevent salty water progress to the water supply location. Heavy rain fall and flooding with a flow rate of 1,000 m3/s destroyed one-third of the dam in November 2008 and therefore, the lives of nearly 300,000 people were in danger due to water shortcoming. In this paper a new and innovative method for repairing the aforementioned dam is presented considering constraints such as type of dam destruction, limited time and cost, and other operating limitations. In this method, the damaged section of the dam was restored by composite geo-box piles. The piles were installed in two rows against the water to create a corridor and then the corridor was filled with soil geo-boxes. Based on the seepage and overturning analysis, and considering implementation conditions, the geometry of proposed method was selected. After successful implementation of the plan, the dam was restored and consequently the EC of the water was reduced to 1,800 μmoh/cm and raw water quality improved significantly in <2 months with minimum cost. It was finally realized that the soil erosion inside the cells was reduced; the bed was stabilized and its integrity over the dynamic loads was sustained. Therefore, it can be said that there is a significant uniformity between the fixed part and the existing structure of the dam. It can be concluded that this method of rehabilitation is an innovative and fast method to fix the damaged dams with minimum cost. © 2014, Springer International Publishing Switzerland.
Mohammadpour Zalaki S.,Islamic Azad University at Ahvāz |
Fathian H.,University of Ahvaz |
Zalaghi E.,Khuzestan Water and Power Authority |
Hormozi F.K.,Azad University of Shushtar
Canadian Journal of Civil Engineering | Year: 2015
The simulation of flow behaviors before the construction of spillways using physical model and simulating packages is a crucial task. This paper investigates the flow behaviors in Kheir Abad flood release structure on Ab Shirin River, Iran by using Flow3D software and the results were compared with those of the physical model. First, by setting up a virtual model of spillway, the software performance was verified and calibrated. Then, by entering different flow discharge values, the two-dimensional flow hydraulics through the spillway was simulated by the software and flow depths, velocities and pressure were obtained for different flow discharges along the spillway. The cavitation was calculated based on the hydraulic parameters. The results show that Flow3D software is capable of simulating two-dimensional hydraulic flow over spillways. The results also indicate that the Kheir Abad flood release structure performs well during flood events considering cavitation.
Shahbazi A.,Khuzestan Water and Power Authority |
Radmanesh F.,Khuzestan Water and Power Authority |
Radmanesh F.,Shahid Chamran University |
Akhoond- Ali A.M.,Khuzestan Water and Power Authority |
And 2 more authors.
Research on Crops | Year: 2012
Simulation is one of the most useful methods in water resources system analyzes. There is still a strong need to explore simulation techniques that not only represent complex dynamic systems in a realistic way but also allow the involvement of end users in model development to increase their confidence in the modelling process. One of these techniques is system dynamics. System dynamic models have four structural units including Levels, Flows, Connectors and Converters. These four units are applied to simulate a variety of simple to very complex systems. In this article, system dynamic approach and Vensim software have been used to simulate a multipurpose reservoir operation. Developed models have been used to evaluate the agricultural demands allocation, hydropower generation and reliability at Abolfares dam. Optimization and sensitivity analyses were used on dam operational properties. Also different dam operations and inflow scenarios were used to evaluate water resource system feedback. Results showed that reservoir could meet the environmental and agricultural demands of existing farms in 100 and 99% of simulation period accordingly. Also results indicated that regulated water by the reservoir could extend existing land upto 1300 ha by shortage of water in only 2% of whole simulation period. Simulation of energy generation as second purpose of dam showed that hydro power plant could generate monthly average of 140 mwh peak energy and 430 mwh non-peak energy.