In order to determine the characteristics of two wastewater treatment systems by activated sludge method, extensive aeration and addition of activated carbon powder to aeration unit on a laboratory scale and compare their performance in reducing the organic load caused by benzene and Ethylene dichloride in synthetic wastewater The above two systems, one system using activated carbon powder and the other system without activated carbon powder, were designed and built on a laboratory scale with an aeration volume of 9 liters and a sedimentation unit of 4 liters. Using a synthetic wastewater with a known chemical composition based on benzene and ethylene dioxide with a COD between 300 and 1100 mg/l, the above two systems were operated for 6 months. Efficiency of reduction and removal of organic matter and changes of mixed solids as well as suspended solids of volatile mixed liquid in both systems in different conditions of change of input concentration along with keeping the amount of Iranian activated carbon powder constant at 2500 mg/l and time Hydraulic retention and solids were equal to 18 hours and 15 days, respectively. The results of this study show that the activated carbon powder selected for adsorption of ethylene chloride and benzene at 400 and 700 mg /l loads performed better than 900 and 1100 mg/l loads. It was also found that the use of activated carbon powder in the system with the powder causes faster incompatibility of the system than the activated sludge system in the aeration unit, the amount of volatile suspended solids of mixed liquid and suspended solids of mixed liquid is better than the system without activated carbon powder. If the percentage of COD removal in the system increases, the amount of the above materials will also increase. پرونده مقاله

In the present article, the existing problems in the water and sewage system of Ahvaz city have been studied. In this regard, all components of the system have been evaluated and their vulnerability in the event of unexpected events has been considered. According to the studies performed, among all the unexpected accidents, floods can cause the most damage to the water supply and sewerage network of Ahvaz. In this study, the system was identified for all contingencies. Finally, based on system deficiencies, operational problems, and network hardware, an emergency plan (EOP) was proposed to deal with anticipated accidents. In this project, the issue of training all personnel from operators to senior managers was examined and the program was proposed. According to the studies performed and also the analysis of the performance of different accidents and predicting the percentage of destruction of each of them on different parts of the water distribution and transmission network and considering the long life of most water transmission and distribution pipes in Ahvaz and severe decay in some parts Earthquake was identified as the most devastating event that could happen to the network and various parts of the treatment plant and water storage sources, followed by floods and finally fires as the third priority. This project is planned to cooperate with the staff of Ahwaz Water and Sewerage Company in response to emergencies of water and sewage system. The application and success of this program depends on the accuracy of its contents. This program is an application tool that must be maintained and regularly updated due to changes in the water and sewage system. پرونده مقاله

Sedimentation in the Tank’s dam is complicated phenomenon and If we don’t have any information about sediment transport and control method, It cause decrease duration of use dam and waste of huge popular wealth. Thesis goal is study on Estimate particles and Investigation and of tank`s sediment in olya Gotvand dam by using of CCHE2D software. To run this model use many base data like upstream river cross section specification, daily discharge statistics and air temperature, river discharge, varied reversion of flood water, river bed grain size and other need information’s. After insert all need data and run this model, the load sediment import in olia Gotvand dam`s tank is equal 89435 million cube meter per year and according to this result, after 100 year the sedimentation in order to trap coefficient 90 %, the whole sediment logs are jammed in the dam`s tank is equal 241 million cube meter and consequently this sediment to be formed 7.23% total volume of this dam`s tank. Most of Sediment Transport is kind of large silt with size 0.031-0.0625 mm and very small sand with size 0.0625-0.125. پرونده مقاله