A Stochastic Model for Adsorption Kinetics
| Autor: | Silvia Rodríguez-Narciso, Rogelio Salinas-Gutiérrez, Netzahualcóyotl Castañeda-Leyva, Juan Antonio Lozano-Álvarez |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Article Subject
Chemistry Stochastic modelling General Chemical Engineering Physical and theoretical chemistry QD450-801 MathematicsofComputing_GENERAL Thermodynamics 02 engineering and technology Surfaces and Interfaces General Chemistry 010501 environmental sciences 021001 nanoscience & nanotechnology 01 natural sciences Adsorption Adsorption kinetics 0210 nano-technology 0105 earth and related environmental sciences |
| Zdroj: | Adsorption Science & Technology, Vol 2021 (2021) |
| ISSN: | 2048-4038 0263-6174 |
| Popis: | A novel stochastic model is proposed to characterize the adsorption kinetics of pollutants including dyes (direct red 80 and direct blue 1), fluoride ions, and cadmium ions removed by calcium pectinate (Pec-Ca), aluminum xanthanate (Xant-Al), and reed leaves, respectively. The model is based on a transformation over time following the Ornstein–Uhlenbeck stochastic process, which explicitly includes the uncertainty involved in the adsorption process. The model includes stochastic versions of the pseudo-first-order (PFO), pseudo-second-order (PSO), and pseudo-n-order (PNO) models. It also allows the estimation of the adsorption parameters, including the maximum removal capacity (qe), the adsorption rate constant (kn), the reaction pseudoorder (n), and the variabilityσ2. The model fitted producedR2values similar to those of the nonstochastic versions of the PFO, PSO, and PNO models; however, the obtained values for each parameter indicate that the stochastic model better reproduces the experimental data. Theqevalues of the Pec-Ca-dye, Xant-Al-fluoride, and reed leaf-Cd+2 systems ranged from 2.0 to 9.7, 0.41 to 1.9, and 0.04 and 0.29 mg/g, respectively, whereas the values ofknranged from 0.051 to 0.286, 0.743 to 75.73, and 0.756 to 8.861 (mg/g)1-n/min, respectively. These results suggest a variability in the parametersqeandkninherent to the natures of the adsorbate and adsorbent. The obtainednvalues ranged from 1.13 to 2.02 for the Pec-Ca-dye system, 1.0–3.5 for the Xant-Al-fluoride system, and 1.8–3.8 for the reed leaf-Cd+2 system. These ranges indicate the flexibility of the stochastic model to obtain fractionalnvalues, resulting in highR2values. The variability in each system was evaluated based onσ2. The developed model is the first to describe pollutant removal kinetics based on a stochastic differential equation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|