Chemometrics approach for optimization of simultaneous adsorption of Alizarin red S and Congo red by cobalt hydroxide nanoparticles

Abstract

The present study deals with the simultaneous adsorption of Alizarin Red (AR) and Congo red (CR) by cobalt hydroxide nanoparticles in a batch system. Cobalt hydroxide nanoparticles as novel and efficient adsorbent are successfully used to remove two anionic dyes from aqueous solutions simultaneously. Partial least square regression as a multivariate calibration method is developed for the simultaneous determination of AR and CR in binary solutions, to overcome the severe spectral overlap. The influence of various parameters was investigated on dye adsorption such as pH, initial concentration of dyes, and sorbent mass. A response surface methodology was achieved through performing the central composite design approach to optimize the removal percent of dyes by cobalt hydroxide nanoparticles. The proposed quadratic model resulting from the central composite design approach fitted very well with the experimental data. The optimal conditions for dye removal were pH = 5.5, sorbent dose = 43 mg, CAR (initial AR concentration) = 351 mg/L, and CCR (initial CR concentration) = 616 mg/L. Isotherm modeling and thermodynamic studies were also conducted. Furthermore, the sorbent was characterized by the Fourier transform infrared, scanning electron microscopy, and X‐ray diffraction analysis.

Neuro-fuzzy logic system for prediction of dye removal from aqueous solutions by a polymeric nanocomposite

“…In this regard, comparison criteria are needed to quantify the difference between responses predicted by the NFS and the actual values. To evaluate the performance of the constructed NFS, some useful statistical criteria which are the root mean square error of prediction (RMSEP), mean squared error (MSE) relative standard error of prediction (REP) and coefficient of determination (R 2 ) were used [31,32]: (8) where xi was the predicted value of model, 𝑥 𝑖 ̂ as the experimental value, n was the number of data and x ̅ i is the average of the actual values. The RMSEP and REP values for NFS were found as 0.39 and 0.84, respectively.…”

“…Sips isotherm is a combined form of Langmuir and Freundlich expressions deduced for predicting the heterogeneous adsorption systems and circumventing the limitation of the rising adsorbate concentration associated with Freundlich isotherm model. At low sorbate concentrations, it reduces to Freundlich isotherm; while at high concentrations, it predicts a monolayer adsorption capacity characteristic of the Langmuir isotherm [30][31][32][33]. The Langmuir, Freundlich, and Sips isotherms are represented by the following equations, respectively:…”

Comparative study using design experiment to assess an anionic dye degradation in aqueous solution through the application of different advanced oxidation processes

“…26 The second one is to determine the DY9 concentrations based on the calibration curve, obtained at same wavelength over working concentration range. The yield of dyestuff degradation and the color removal is calculated by the Expressions ( 6) and (7), respectively 8 :…”

“…The treatment of these effluents is important to protect natural water protection as well as the environment. Many conventional methods have been applied to remove dyestuffs from aqueous solution, such as membrane separation (ultrafiltration, reverse osmosis), 5 electrochemical oxidation, 6 and adsorption 7–9 . Advanced oxidation processes (AOPs) are considered attractive techniques allowing decolorizing and mineralizing textile effluents into CO 2 , H 2 O, and inorganic salts or into biodegradable compounds 10 .…”

“…Many conventional methods have been applied to remove dyestuffs from aqueous solution, such as membrane separation (ultrafiltration, reverse osmosis), 5 electrochemical oxidation, 6 and adsorption. [7][8][9] Advanced oxidation processes (AOPs) are considered attractive techniques allowing decolorizing and mineralizing textile effluents into CO 2 , H 2 O, and inorganic salts or into biodegradable compounds. 10 Several systems have been used combining ozone + hydrogen peroxide (O 3 / H 2 O 2 ), ozone + UV-light (O 3 /UV), hydrogen peroxide + UV-light (H 2 O 2 /UV), catalyst + UVlight (photocatalytic oxidation), H 2 O 2 + Fe 2+ (Fenton system), H 2 O 2 + Fe 2+ + UV-light (photo-Fenton process [PhFP]), and so on.…”