Intelligent modeling and experimental study on methylene blue adsorption by sodium alginate-kaolin beads

• Published in: International journal of biological macromolecules 2021-09, Vol.186, p.79-91
• Main Authors: Marzban, Nader, Moheb, Ahmad, Filonenko, Svitlana, Hosseini, Seyyed Hossein, Nouri, Mohammad Javad, Libra, Judy A., Farru, Gianluigi
• Format: Article
• Language: English
• Subjects: Adsorption; Alginates - chemistry; Chemical Fractionation; Intelligent approaches; Kaolin - chemistry; Kinetics; Methylene Blue - isolation & purification; Methylene blue adsorption; Neural Networks, Computer; Powders; Regression Analysis; Sodium alginate-kaolin beads; Surface Properties; Water Pollutants, Chemical - isolation & purification
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2021.07.006

As tighter regulations on color in discharges to water bodies are more widely implemented worldwide, the demand for reliable inexpensive technologies for dye removal grows. In this study, the removal of the basic dye, methylene blue, by adsorption onto low-cost sodium alginate-kaolin beads was investigated to determine the effect of operating parameters (initial dye concentration, contact time, pH, adsorbent dosage, temperature, agitation speed) on dye removal efficiency. The composite beads and individual components were characterized by a number of analytical techniques. Three models were developed to describe the adsorption as a function of the operating parameters using regression analysis, and two powerful intelligent modeling techniques, genetic programming and artificial neural network (ANN). The ANN model is best in predicting dye removal efficiency with R2 = 0.97 and RMSE = 3.59. The developed model can be used as a useful tool to optimize treatment processes using the promising adsorbent, to eliminate basic dyes from aqueous solutions. Adsorption followed a pseudo-second order kinetics and was best described by the Freundlich isotherm. Encapsulating the kaolin powder in sodium alginate resulted in removal efficiency of 99.56% and a maximum adsorption capacity of 188.7 mg.g−1, a more than fourfold increase over kaolin alone. [Display omitted] •Sodium alginate-kaolin beads were used to adsorb the methylene blue.•Kaolin powder encapsulated in sodium alginate is more efficient than the kaolin alone.•Regression analysis, genetic programming, and ANNs were used to predict the dye removal efficiency.•ANNs predicts best results for dye removal efficiency with R2 = 0.97 and RMSE = 3.59.