s. m. abdoli

Detergents are one of the most widely used chemicals in the daily life of humans. Their entry into the environment, especially water, can increase the COD of water and cause serious problems for living organisms. There are different methods to reduce COD. The electrocoagulation process as an electrochemical method is a suitable solution to reduce COD. In this study, the effect of electrocoagulation to reduce COD caused by laundry detergent has been surveyed. Process voltage, the number of electrodes, along with coagulation time as key parameters were investigated as influential parameters. The results showed that the 2-electrode mode reduced COD by 70% in 40 minutes at a voltage of 15 volts. This value was the most optimal energy consumption in terms of process time and the amount of reducing the pollution index.

In this study, computational fluid dynamics simulation of liquid-liquid extraction of zinc was performed using trifluoroacetylacetone as a solvent in the hollow fiber membrane contactor. Mass and momentum balance equations (Navier-Stokes) were used to express the transport of zinc solutes through the membrane contactor. After applying the conditions, the governing equations were simulated using the finite element method. After validating the results, simulation was performed to study the distribution of zinc concentration in two-dimensional and three-dimensional form, as well as to investigate the effect of different parameters such as distribution coefficient and current intensity on the extraction efficiency. The results showed that by increasing the partition coefficient from 1 to 10, the amount of single-pass extraction increased from 10 to 100 percent. Also, the extraction efficiency in the counter-current flow of pipe and shell is 9% higher than in the co-current flow. Furthermore, this study showed that computational fluid dynamics could be used as an effective tool for the development of membrane-based extraction processes.

In this study, the porous media's morphological information, such as pore and particle size distribution, number of particles, and porosity, was extracted using image processing by imaging the spherical particle bed. The findings revealed that the ratio between the average pore diameter and the mean particle diameter is logarithmically related to porosity. The pore network model was used to measure the permeability in porous media. To create a pore network, all of the information derived from the image was used. The pressure distribution, flow rate, and consequently, the permeability have been determined after applying the governing equations in the network. The simulation findings for validation were compared to the permeability calculated in the experiment and the Carmen-Kozeny and Rabbani et al. equations. It was observed that the experimental results are more consistent with the results of the pore network model due to considering the internal structure of the porous media in the form of pores and throats.