The present work was aimed to evaluate the adsorption properties of activated carbons based on prickly pear seeds (PPS) and conductive polymer matrix based on polyaniline (PANI) for the removal of anionic Congo red (CR) dye from aqueous solutions. The adsorbent was prepared by polymerization of aniline in the presence of activated PPS by phosphoric acid and sodium hydroxide. The samples were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and the Brunauer–Emmett–Teller (BET) methods. The adsorption kinetics were studied using UV-visible (UV/Vis) spectroscopy. The characterization data suggest that the adsorption of the Congo red dye is enhanced because PANI chain molecules, which are especially accountable for removal through π—π interaction and H-bonding with the CR, are adsorbed/tethered onto the acid-activated PPS (PPSH), and thus surmount the mass transfer limitation by being best exposed to the CR-adsorbed molecule. The adsorption kinetics follows the pseudo-second order process. The correlation coefficients (R2) for Langmuir, Freundlich and Tempkin showed that the adsorption values obey Freundlich and Tempkin isotherm models. Moreover, the isotherm was most accurately described by the Freundlich model, and the maximum removal percentage was calculated to be 91.14% under optimized conditions of pH 6.6, 1 g/L of adsorbent dosage, and an initial CR dye concentration of 20 mg·L−1. Importantly, the hybrid adsorbent exhibited the highest adsorption capacity (80.15%) after five cycles of the adsorption–desorption process. Thermodynamic parameters, such as entropy changes, enthalpy changes and Gibbs free energy, were also evaluated. These results indicated that the PANI matrix can generally be better utilized for the removal of Congo red dye when appropriately dispersed on the surface of suitable support materials. These results provide a new direction to promote the separable adsorbents with increasing performance for adsorption of dye impurities from wastewater.
This study investigated the preparation of new adsorbent based PANI and Kieselguhr (KG). The produced materials were characterized by XRD, XPS, TEM, FTIR, TGA and BET. Thereby, hybrid material PANI@KG highest SBET values (about 47.82 m2.g−1). The adsorption capacity of the PANI, KG and PANI@KG were tested on BPA ions from aqueous solutions at ambient temperature and pH 6.0, the maximum capacity of adsorption was observed to be 63.68 mg.g−1 which is obtained from Langmuir adsorption isotherm by hybrid adsorbent PANI@KG. Besides, the pseudo-2nd order kinetics was more consistent with the obtained experimental data. Furthermore, the hybrid material possessed highest adsorption capacity after six cycles of adsorption-desorption process. Moreover above 80% of removal percentage was obtained even after three recycles. Hence we expect that this organic-inorganic adsorbent can be selected as a potential candidate for water treatment.
<span>Electric <span>resistance furnaces are the most popular and widely used industrial electro thermal equipment which continues to be the subject of many improvements. The aim of this paper is to control the temperature of electrical furnace for noisy thermocouple sensors. It can be assessed by observing some variables, which are very difficult to observe. Due to limitations, mainly the location of thermal sensors and their noises. In this case, the temperature measurement is trained with centered Gaussian white noise. The problem of accurate temperatures estimation for such sensors is solved using Kalman filter, which is an optimized estimator that provides a computationally efficient way to estimate system state. Thus, variables that are not directly measurable can be reconstructed from the algorithm. Kalman stochastic reconstructor (KSR). We cannot use with fixed parameters to control the temperature. For this reason, this paper comes up with a KSR approach based pole placement (PL) hybrid controller to realize an algorithm for the temperature control electrical furnace. Results based on Matlab simulation show that the improved algorithm has well produced an optimal estimate of the temperature. Evolving over time from noisy measurements. Hybrid algorithm KSR approach based PL give good performance compared to PL controllers.</span></span>
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