Farhad Mahmoudi Jalali

Bio: Farhad Mahmoudi Jalali is an academic researcher. The author has contributed to research in topics: Response surface methodology & Bioremediation. The author has an hindex of 1, co-authored 2 publications receiving 1 citations.

Determining the chlorine kinetic behavior in surface water using evolutionary metaheuristic algorithms

Abstract: The use of a reliable technique in measuring the residual chlorine concentration is of particular importance. Because based on the results of these measurements, the water quality of the network is calculated and evaluated in terms of ensuring the health of the community. The concentration of residual chlorine in the effluent of the treatment plant decreases as water flows through the distribution network. Chlorine decay is divided into two categories: wall and mass decay. Various detectors such as DPD and Ortho-toluidine can be used to measure residual chlorine. This study is the first step in the spectroscopy of chlorine and Ortho-toluidine color complex. The results of this stage of the research indicate that to measure the residual chlorine concentrations, the absorbed values should be read at a peak of 450 nm. In the next step, after measuring the free chlorine concentrations remaining at different times, the degree of chemical reaction was determined using multivariate nonlinear regression methods. In the final step, the reaction coefficient was calculated by simulating the differential equation in the Simulink environment and optimizing the error of the initial values of the reaction constant to the real values using the genetic algorithm (GA). The results of the analysis showed; The mass decay of chlorine in the sample follows the quadratic and the reaction constant is equal to 0.005 .

Assessment and sensitive analysis of biological water risks in water resources with application of classical mass transfer computations

Abstract: Due to the urgent need for water in all parts of industrial or developing societies, water supply, and transmission facilities are suitable targets for biological risks. Given that even a short interruption in water supply and water supply operations has a great impact on daily activities in the community, the deliberate contamination of urban water resources has irreparable consequences in the field of public health, and the economy of society will follow. Unfortunately, most officials in the public health control departments in our country have received limited training in detecting accidental or intentional contamination of water resources and dealing with the spread of waterborne diseases both naturally and intentionally. For this reason, there is low preparedness in the responsible agencies to deal with waterborne diseases during biological risks. In the first step of this research, a review study has been conducted on water biological risks and operational strategies to deal with them. In the following, it has studied how Escherichia coli (E. coli) bacteria spread in aqueous media. In this regard, the kinetic model of the studied microorganism was analyzed based on the implementation of (Fick Law) in polar coordinates and the combination of (Dirac Distribution) with (Legendre polynomial) distribution. Finally, after studying the factors affecting the microbial pollutant emission coefficient, the effects of all three factors of linear velocity, linear motion time period, and angle of motion on the pollutant emission flux and biofilm diffusion time in the water supply network environment were investigated. Studies have shown that the linear velocity parameter of Escherichia coli with a nonlinear relationship has the greatest effects on the release of microbial contaminants.

Enhanced Mass Transfer of CO2 into Water: Experiment and Modeling

Abstract: Concern over global warming has increased interest in quantification of the dissolution of CO2 in (sub-)- surface water. The mechanisms of the mass transfer of CO2 in aquifers and of transfer to surface water have many common features. The advantage of experiments using bulk water is that the underlying assumptions to the quantify mass-transfer rate can be validated. Dissolution of CO2 into water (or oil) increases the density of the liquid phase. This density change destabilizes the interface and enhances the transfer rate across the interface by natural convection. This paper describes a series of experiments performed in a cylindrical PVT- cell at a pressure range of pi ) 10-50 bar, where a fixed volume of CO2 gas was brought into contact with a column of distilled water. The transfer rate is inferred by following the gas pressure history. The results show that the mass-transfer rate across the interface is much faster than that predicted by Fickian diffusion and increases with increasing initial gas pressure. The theoretical interpretation of the observed effects is based on diffusion and natural convection phenomena. The CO2 concentration at the interface is estimated from the gas pressure using Henry's solubility law, in which the coefficient varies with both pressure and temperature. Good agreement between the experiments and the theoretical results has been obtained. tion of CO2 in the atmosphere, geological storage of CO2 is considered. 2-4 When CO2 is injected into an aquifer, the competition between viscous, capillary, and buoyancy forces determines the flow pattern. Eventually, due to buoyancy forces CO2 will migrate upward and be trapped under the cap rock due to capillary forces. In this case an interface between a CO2- rich phase and brine exists. Subsequently, CO2 starts to dissolve into water by molecular diffusion when it is in contact with the brine. The dissolution of CO2 increases the density of brine. 5 This density increase together with temperature fluctuations in the aquifer (which may be only partially compensated by pressure gradients 6 ) destabilize the CO2-brine interface and accelerate the transfer rate of CO2 into the brine by natural convection. 5-10 The occurrence of natural convection signifi- cantly increases the total storage rate in the aquifer since convection currents bring the fresh brine to the top. Hence, the quantification of CO2 dissolution in water and understanding the transport mechanisms are crucial in predicting the potential and long-term behavior of CO2 in aquifers. Unfortunately there are only a few experimental data in the literature, involving mass transfer between water and CO2 under elevated pressures. Weir et al. 11 were the first to point out the importance of natural convection for sequestration of CO2. Yang and Gu 8 performed experiments in bulk where a column of CO2 at high pressure was in contact with water. The procedure was similar to the established approach in which the changes in gas pressure relate the gas to the transfer rate. 12-15 A modified diffusion equation with an effective diffusivity was used to describe the mass-transfer process of CO2 into the brine. Good agreement between the experiments and the model was observed by choosing effective diffusion coefficients 2 orders of mag- nitude larger than the molecular diffusivity of CO2 into water. However, the authors pointed out that the accurate modeling of the experiments should consider natural convection effects. Farajzadeh et al. 9,10 reported experimental results for the same system, in a slightly different geometry, showing initially enhanced mass transfer followed by a classical diffusion behavior in long times. A physical model based on Fick's second law and Henry's law was used to interpret the experimental data. It was found that the mass-transfer process cannot be modeled with a modified Fick's second law with a single effective diffusion coefficient for the CO2-water system at high pressures. Nevertheless, the initial stages and later stages of the experiments can be modeled individually with the described model. Arendt et al. 16 applied a Schlieren method and a three- mode magnetic suspension balance connected to an optical cell to analyze the mass transfer of the CO2-water system up to 360 bar. Good agreement between their model (linear superposi- tion of free conVection and Marangoni convection) and the experiment was obtained. The addition of surfactant suppressed the Marangoni convection in their experiments, while in the experiments of ref 9, addition of surfactant did not have a significant effect on the transfer rate of CO2. A similar mass- transfer enhancement was observed for the mass transfer between a gaseous CO2-rich phase with two hydrocarbons (n- decane and n-hexadecane) 9,10 due to the fact that CO2 increases the hydrocarbon density. 17 The effect becomes less significant with increasing oil viscosity. This has implications for oil recovery. Indeed in geological storage of CO2 the early time behavior is governed by diffusion before the onset of the natural

A decision support system for coagulation and flocculation processes using the adaptive neuro-fuzzy inference system

Abstract: Decision support system (DSS) is an approach to have a smart and sustainable management of facilities for monitoring, predicting and controlling sections. The mentioned platform can be useful in operation of complex facilities like the water treatment plant (WTP). This study proposes an adaptive neuro-fuzzy inference system (ANFIS) for prediction of energy consumption and outlet turbidity according to inlet turbidity and ferric chloride as coagulant in coagulation and flocculation unit process of WTP. The outcomes of ANFIS model are used in the Petri Net modeling as a smart conceptual control system. Therefore, the main purpose of this research is the development of a DSS model for coagulation and flocculation processes in WTP. The results of quantitative data analysis showed that the correlation coefficients of ANFIS model are more than 80% meaning that it can reliably predict the outlet turbidity and energy consumption’s variables. With regards to our findings, the first one is to provide a smart and sustainable control system to be implemented in operations of coagulation and flocculation processes in WTPs. It goes without saying that, our DSS model confirms that the variation of 15 ± 5% for turbidity values and the additive coagulant materials (ferric chloride) should be set, on 60–85 and 40–60 kg/day, respectively, for controlling energy consumption and outlet turbidity. At last but not least, the main benefit from our DSS model is to manage the operation of WTP with a high efficiency and low human-based errors.