Uso de software Octave para o estudo do mecanismo de bloqueio de poros no processo de filtração por membrana

Abstract

One of the main problems found in membrane separation processes that use pressure as a driving force is the decay of the permeate flow as a function of filtration time, caused by the deposit of particles on the membrane (fouling). The study of the membrane pore blocking mechanism involves the non-linear fit of phenomenological mathematical models from experimental data. Thus, this work aimed to use the Octave software to study the pore blocking mechanism in the membrane filtration process. Octave was chosen because it is free and open source software. Four pore blocking mechanisms were studied to indicate permeate flux decay: (i) complete pore blockage (ii), partial pore blockage, (iii) internal pore blockage, and (iv) cake formation. A script was developed in the software using the mathematical equations of each mechanism, expressed as J=f(t), where J is the permeate flux and t is the filtration time. Experimental data from sugarcane juice filtration with different membranes were used to test the script. The parameters of each model were estimated from the nonlinear fit using the nlinfit function. The results showed that the developed script was able to estimate the parameters of the models and, from the sum of squares of the residuals (SSE) and the coefficient of determination R², establish the fouling mechanism for each tested membrane.