نشریه مهندسی آب
سال هشتم شماره 2 (تابستان 1399)

Among surface water sources, rivers have a greater potential for pollution due to their long length and passage through various urban and industrial areas. Monitoring and control of surface water for its various uses is necessary and essential in order to make high quality water available to consumers for various uses. The main purpose of this study is the qualitative zoning of Karun River in the range of Shahid Abbaspour Dam to Ahvaz. In this study, using nine quality measuring stations, changes in water quality of Karun River in the period of 12/1396 to 06/1397 were investigated. Then the quality for agricultural consumption was determined using the Wilcox index. Then, with Chemistry software, the quality for industrial consumption and based on the total hardness was also evaluated. The results showed that, in the period of 12/13/2017 to 06/06/1397, the stations of Mollasani, Ahvaz, Valiabad and Indika Tang Dolab with very salty quality - were unsuitable for agriculture and the rest of the stations were in the appropriate category. For industrial use, the stations of Shahid Abbaspour Dam Lake and Shahid Abbaspour Dam spring have water corrosive quality, the other stations have sediment quality. Quality assessment based on total hardness, Shahid Abbaspour Dam Lake, Gotvand and Cheshmeh stations of Shahid Abbaspour Dam have hard water quality and other stations have very hard quality. The amount of BOD parameter in March 2017, all stations in the region are in good condition.

Due to the expansion of the use of water resources, the use of water transfer structures is increasing day by day. Due to the sedimentation of sediments and their movement in water transfer structures, they are damaged. Therefore, scientists decided to use different methods to control sediments. One of these methods is the use of submerged plates. These plates act in a way that directs the sediments along the direction of the flow and reduces the sediment entering the reservoirs. In this study, we try to investigate the use of modified plate shapes by numerical modeling with CCHE 2D software in a laboratory model and its effect on the management of diversion sediment to the lateral catchment. In this study, we used 5 different shapes, one of which is a simple rectangular plate as a control that other plates have been compared with this plate without using submerged plates. Sediment to the lateral reservoir is effective. The present study investigated the simulation of a laboratory flume with a 60 degree reservoir and an average sediment particle size of 1.59 mm with four landings of 0.45, 0.55, 0.6 and 0.66.

The water flow enters the supercritical state after passing over the overflow, which is accompanied by high and destructive energy for downstream facilities and natural features. Consumables are used to control this energy. The most common and almost a permanent and widely used member of energy consuming facilities is the relaxation pool. These pools form a hydraulic jump at a specific distance, which is the length of the pool, to deplete the jump energy and thus flow. The pond, with the help of its accessories, does this, which are called calming blocks. Different types of these blocks have been used that in recent research, the use of even or continuous continuous or single wall or the use of even or single perforated wall has had better results. Therefore, in this research, using FLOW 3D software, we have attempted to simulate the simultaneous use of a continuous wall and a perforated wall to design a pond with a shorter length, resulting in cost depreciation.

Protection of the downstream of culvert outlets against scour process, as a water conveyance structure, is a highly significant issue in design of culverts. In this study, the effect of bed litter length on downstream scour depth is investigated. For this purpose, experiments were carried out on the laminate with different lengths. According to the results, the particle landing at 22%, 33% and 66%, respectively, and the landing at particle landing of 2.5%, respectively. 15%, 20%, and 40% decreased particle depth by 20%, 25%, and 31%, respectively, indicating that bedding has a positive effect on decreasing downstream scour depth. The scour for the flooring considering the length of the layer showed that the scour depth decreases with the increase of the layer length due to the constant landing number.

Local scouring is one of the most important phenomena and factors in the destruction of the bridge bridges, which was studied in order to reduce the destructive effects of this phenomenon using the experimental model and the effect of the combined stone and chipping of the submerged plates in this study. In this research, a laboratory model of a cylindrical base group of 5 cm in diameter and a stone of china with grains of 1, 1.5 and 2.5 cm in diameter, and submerged plates in numbers (2, 4 and 6) of a plate of 10 × 15 in a flume An experimental laboratory and a landing number (0.25, 0.22 / 0.20 / 0.2) were tested and analyzed. The main objective of this study was to investigate the combined effect of Chinese stone and submerged panels on reducing the scour depth of the group The bridge is a cylindrical bridge and, using Buckingham's dimensional analysis, the parameters The results of this study showed that by increasing the diameter of the stone and the number of submerged plates, the percentage of the depth of water washed to the diameter of the base was significantly reduced. Which was found to be the highest for bases 1, 2, 3 (69%, 72%, 74%) and the lowest values (49%, 50%, 57%), which showed that by increasing the flow rate of erosion Also increased.

Chlorpyrifos and 2,4, D toxins are chlorine toxins. Organo chlorine pesticides are a class of toxins Their most important feature is the accumulation in the environment and have a very strong effect on the central nervous system of insects.This study examines and identifies chloropyrifos and 2,4, D toxins in the Susangerd water treatment plant and the effect of the Susangerd water treatment process on the removal of these toxins.In this way, at the entrance of the treatment plant, the output of the treatment plant and a middle stage, sampling is done and the amount of chlorine toxins in each stage is measured.The sampling period is September, October and November 2018. In order to identify and determine the amount of toxins studied, the GC-MS device of the American manufacturer Agilent 7890 was used. Based on the results of this study, chloropyrifos and 2,4,D toxins were detected in the raw water of the treatment plant and with the measurements made, it became clear that Chlorpyrifos 92.38% and 2,4, D 98.2% were removed by the Susangerd refinery process and the residual value was very small and standard. This indicates the efficiency of the said treatment plant.

One of the major challenges in designing under pressure water transmission pipeline is the system protection against water-hammer pressures due to a pump trip. The best strategy is to use air-chamber; which imposes considerable costs. To mitigate the air-chamber volume, the use of air-inlet valves is also suggested. Determination of air-chamber volume as well as the type and proper locations of air-inlet valves, aiming at the cost reduction, introduces an optimization problem. To solve this problem, this study exploits the central force optimization (CFO) method. Herein, a case study pipeline is optimized using the proposed model based on the CFO and is compared with results of a genetic algorithm (GA) based model. Both methods yielded almost the same results and led to about 30% saving in the system protection cost. However, a comparison between the methods showed that the CFO dramatically outperforms GA in both terms of computational efficiency and reliability of the results.