Iranian Journal of

Background and Objective: one of the steps in water treatment to protect microbial quality of water network is disinfection. Chlorine is one of disinfectants. It is necessary to maintain Free Residual Chlorine (FRC) between minimum and maximum throughout the distribution system in accordance to health standards. This study was aimed to optimize Chlorine dosage in water distribution networks using GANetXL model.
Materials and Methods: In this paper for the first time using an add-in called GANetXL optimization that uses a genetic algorithm, the Chlorine injection was optimized in a reference network based on dynamic connection to EPANET2 hydraulic and qualitative analysis in Excel software. The objective function is formulated such that the squared difference between computed chlorine concentrations and the minimum residual concentration at all monitoring nodes at all times is minimum. The decision variables were the optimized injection dose at boosters’ locations.
Results: The injection rate was obtained (minimum: 0, average: 183.87, maximum: 776.57 and total 4412.84 mg/min per a day) at the station as the number of generation was reduced to 200. Critical nodes formed 20% of the total nodes of network.
Conclusion: Based on the results, minimization of Chlorine whilst comply with FRC standard has both health and economical effects. The results can help the water distribution system management in terms of water quality (by maintaining FRC), health promotion and monetary.
 
 

Background and Objective: Nitrate is one of the most important factors in determining the quality of vegetables. Today, due to the excessive use of nitrogen fertilizers to accelerate vegetative growth, many vegetables have a high percentage of nitrates in human diet. The purpose of this study was to investigate the concentration of nitrate in four vegetable species cultivated in Poldokhtar and Khorramabad cities.
Materials and Methods: In this research, the nitrate content of four vegetables including Iranian leek, Basil, Mint and Radish (tuber and leaves) cultivated from olericulture field on Khorramabad and Poledokhtare were measured. A 2kg edible portion of vegetables was randomly collected for each species in triplicate and carried out to the laboratory. The nitrate content was measured according to the instructions of the Institute of Water and Soil of Iran. For this purpose, after preparation of the samples, a spectrophotometer was used to measure absorption at 580 nm. The nitrate content in different vegetables was estimated using a standard curve.
Results: The nitrate mean concentration of the studied vegetables from khorramabad city was 27017 mg/kg for Radish tuber, 9500 mg/kg for Basil, 8408 mg/kg for Iranian leek, 98231 mg/kg for Radish leaves and 5450 mg/kg for Mint. The values for the samples taken from Poledokhtare city were 12933 mg/kg for Radish tuber, 9063 mg/kg for Basil, 6708 mg/kg for Iranian leek, 6296 mg/kg for Radish leaves and 5454 mg/kg for Mint (5454 mg/kg). The values were all higher than the recommended doses for consumption. In control field, the nitrate mean concentration were 1586, 1134, 906, 794 and 662 mg/kg for Radish tuber, Basil, Iranian leek, Radish leaves and Mint, respectively. The values were within the range of recommended doses.
Conclusion: The amounts of nitrate measured in 100g of green tissue in Radish tuber, Basil, Iranian leek, Radish leaf and Mint were 7.36, 3.37, 2.74, 2.64, and 1.98 times more than the daily allowance limit, respectively. Given the high nitrate content in the studied vegetables, it is recommended that cautious is taken for consumption of the vegetables and nitrate content of the vegetables produced in Lorestan province in different seasons should be monitored.