مقالات رزومه مهندس حسین قاسمی نژاد

Today, the progress of industries, health, energy and food security, which are the main components of the sustainable development of societies depend on water more than anything else. Moreover, water shortage is a serious problem for human survival and the natural ecosystem. The average amount of raw water consumption in Shahid Montazer Ghaem steam power plant is 25,000 m3/day, which is significant considering the production capacity and the existence of a cooling tower in this power plant. Therefore, it is important to provide effective solutions that is able to be implemented in order to modify the consumption pattern and prevent water wastage in this power plant. Effective proposed solutions according to the in-person visit, receipt of documents and consultation with specialists, experts and operators in this power plant in order to modify the consumption pattern is including the recycling of clean drain (boilers blowdown, backwash of filters, samplers) in the final stage of washing resin filters, purification and recirculation of cooling tower sludge, increasing the degree of concentration and optimization of cooling towers (replacing drippers, changing nozzles, changing the angle of lavers, etc.), the use of ozone in order to purify the water of the cooling tower, water storage during equipment repair, especially in the cooling towers, installation of the RO system in the inlet of the cooling tower's compensating water.  Finally, considering the technical-economic conditions and volume and quality of water, a high priority solution was proposed in this power plant in order to modify the consumption pattern and prevent water wastage.

The water of Persian Gulf, which is currently used as the water in the cooling tower for Bandar Abbas power plant has high alkalinity, conductivity and salinity. The examination of microbial tests for the cooling tower indicates the high concentrations of all kinds of microbial species which is related to the high level of fluoride, sulfate ions and sediments. The TBC shows 104 cfu/ml which is considered a high value.  On the other hand, the presence of magnesium and calcium ions in carbonate form is a reason for the huge amount of hardness. The high level of ions concentration especially chloride and magnesium in the cooling water increase the growth of microbial parameters. Furthermore, the reason of such a huge growth of sulfate-reducing bacteria (SRB) is the high concentration of sulfate. Therefore, the solution of reducing the general concentration of ions using methods such as reverse osmosis and ion exchange resins is suggested as the first priority to prevent microbial corrosion. Additionally, chlorination methods are proposed as the second priority due to economic efficiency and high-performance capability. Finally, ozonation method is presented as the third priority due to the higher cost compared to chlorination, high power and the absence of side products. Also, the high concentration of sulfate leads to the activity of SRB bacteria and causes various types of corrosion, and therefore, the use of methods for reducing the concentration and selective removal of sulfate as an effective and priority solution should be considered.

The water of cooling tower for Shahid Moftah power plant is supplied from treated wastewater. Therefore, chemical control of water in order to control corrosion in this cycle is very complicated.

The results of the TBC (total bacteria count) test of cooling tower indicate the approximate number of bacterial colonies equal to 103 cfu/ml, which is in the light range. According to the microbial tests, the amount of TRB, IRB and APB bacteria is very high and has values ​​of 1200, 500-2300 and 105 cfu/ml, respectively. Using treated wastewater as a feed of cooling tower due to the presence of high concentration of calcium ions leads to intensification of sedimentation and increase the growth of microbial organism. Moreover, the presence of high nitrate is predictable due to the origin of water supply, which causes the increase of nitrate and nitrite reducing bacteria (NRB). On the other hand, the presence of high phosphate and sulfate in the sample increase sedimentation and intensify microbial growth, especially sulfate-reducing bacteria (SRB) in the sample.

As a result, high concentrations of TRB, IRB, and APB bacteria is required to be selectively removed in the first priority. In the second priority, nitrate and sulfate ions, which are food for NRB and SRB bacteria, need to be removed by selective removal of nitrate ions using ion exchange resins and sulfate with biological regeneration method. Due to the high level of microbial agents TRB, IRB and APB as well as the high concentration of microbial agents feed, as the third priority, methods based on non-oxidizing biocides needs to be applied in this power plant.

The corrosion and especially microbial corrosion in thermal power plants due to the frequent use of contaminated water sources has long been a source of economic problems, efficiency reduction, equipment and technical failure. The main reasons of these problems are a of existence of microbial organism in the water of cooling tower. In this work, the aim is to collect information on the microbial corrosion in the cooling water of Shahid Beheshti power plant of Lushan and to provide several solutions to reduce the occurrence of microbial corrosion Therefore, physicochemical properties, microbial tests and ion measurement are conducted in order to investigate the parameters affecting this phenomenon for the cooling tower of Shahid Beheshti power plant of Lushan. The microbial tests include the TBC test to measure the total number of bacteria (general test) and specific tests to measure specific bacteria such as APB, FP, IRB, NRB, Aero, SRB and TRB. Moreover, physicochemical parameters (pH, electrical conductivity, salinity percentage, hardness and water temperature), anions and cations are determined. It is observed that the calcium ion in the sample is in the range of high concentration (517 ppm) which leads to increase sedimentation and retention of water in the cooling cycle. On the other hand, the high concentration of sulfate (2126 ppm) causes the growth of SRB in the sample. For this purpose, it is very important to control and tackle these problems by applying sediment-forming and destructive microbial agents in the cycle. Common methods such as chlorination and ozonation are the first priority to deal with microbial corrosion in this power plant. Due to the high concentration of sulfate ions, it is suggested that selective removal of sulfate ions counts as a second priority. High concentration of calcium ion might be resolved by applying the chemical regimes in the clarifier such as adding CaOH, FeCl3 and coagulant and control and inhibit the microbial corrosion.

Pharmaceutical industries, due to the production of a wide range of drugs, have pharmaceutical effluents and wastewater in various types of synthetic, chemical, biological drugs, etc. The entry of these substances into the cycle of the environment and human life is extremely harmful and carries serious risks. Therefore, pharmaceutical wastewater treatment is of great importance in industry. There are various methods on an industrial scale to remove contaminants and pharmaceutical effluents, among them, electrochemical and oxidation-based methods are very suitable for industrial and medical applications due to technical-economic justification. In this study, the removal of contaminants in drug effluents was investigated using the oxidation process. In order to evaluate and determine the characteristics of high-consumption drugs (aspirin, atorvastatin, metformin, metronidazole, and ibuprofen), using a potentiostat device with a three-electrode cell, a cyclic voltammetric diagram with a 100 mV/s scanning rate was performed until the initial and peak conditions were reached. Oxidation of drug samples were evaluated. Then, using the chronoamperometry process (constant potential application), the drugs were subjected to an electrochemical oxidation process (using three-electrode cells), and the drug removal process was performed for insoluble and liquid samples. At the end of the chronoamperometry method (drug removal), the samples were again subjected to cyclic voltammetry test, and the level below the oxidation peaks of the sample was calculated and compared with the level below the initial peak, thus determining the removal efficiency of the sample (removal rate). The results indicate that this method has shown about 70% efficiency for removing selected drugs with a high removal efficiency and for the atorvastatin sample specifically, it was about 100%. It should be noted that the oxidation time of each drug varies according to the type of drug and the concentration of the drug under study. About 100 to 500 seconds seems to be enough to remove the drug in most cases. The oxidation potential of selected drugs is in the range of -0.8 V. Therefore, according to the results obtained, this method has high and sufficient accuracy (RSD about 2%).