Modeling and optimization of chromium adsorption onto clay using response surface methodology, artificial neural network, and equilibrium isotherm models

Abstract

Response surface methodology (RSM) was used for optimization of the adsorbent dosage, initial solution pH, initial ion concentration, and contact time in removal of Cr (III) with local nanoclay. The adsorption process was modeled by RSM and artificial neural network (ANN). The process was done in batch mode by central composite design (CCD) and the same design was applied for training ANN. The optimum condition was determined to be 500mg/L for adsorbent dosage, initial pH of 5, initial chromium concentration of 180mg/L and 20 min of contact time. In these conditions qRSM = 238.7780mg/g and qANN = 237.5152mg/g which indicate removal percentage of 72.45% and 72.07%, respectively. RRSM2=0.9784 and RANN2=0.9834 indicate that the two models can predict the adsorption of Cr3+ properly. The two parameter Langmuir, Freundlich, Dubinin‐Radushkevich (D‐R), Temkin and three parameter Redlich‐Peterson (R‐PT), Sips and Toth isotherm models were applied to equilibrium data by minimizing the sum of squared errors (SSE), sum of the absolute errors (SAE), average relative errors (ARE), Hybrid fractional error function (HYBRID), Marquardt's percent standard deviation (MPSD), and nonlinear chi‐square test error functions. The results showed that the HYBRID error function gives the lowest value and the R‐PT model fits the data better than other isotherm models.

Simultaneous adsorption of chromium and acidic dye from leather tannery model wastewater using a novel modified nanoclay

“…Where ç is the predicted response or output (depended variable), 4 is the number of the patterns, h and ü are the index numbers for pattern, ù r , ù û , … . , ù } are the input coded variables that affect the response ç, ù r 5 , ù û 5 , … , ù } 5 are the square effects, ù r ù û , ù r ù } and ù û ù } are the interaction effects, ú k is the free or offset term called intercept term, ú r (h = 1,2, … , 4) is the linear (first-order) main effect, ú rr (h = 1,2, … , 4) is the squared (quadratic) effect, ú rû (h = 1,2, … , 4; ü = 1,2, … , 4) is the interaction effect and Ü is a random error or allows for discrepancies or uncertainties between the predicted and measured values (Oskui, Aghdasinia and Sorkhabi, 2019b).…”

Adsorption capacity, isotherm, kinetic, and thermodynamic studies on adsorption behavior of malachite green onto natural red clay

“…One of these adsorbents is clay. Clays are hydrous alumina silicates having colloidal particles smaller than 2 μm 16 . They contain clay minerals and other minerals such as calcite, feldspar, and quartz.…”

Cadmium cation uptake through amine and acid post‐functionalized Santa Barbara Amorphous materials; comprehensive adsorption studies

“…This method can combine the statistical and mathematical techniques for optimization. RSM technique also are used to assess the extent of multiple variables effects and their interactions 10 . Modeling and optimization of chromium adsorption onto clay using RSM, artificial neural network 10 and optimization of the adsorption process using RSM technique for Cd 2+ sorption by dimethylethylenediamine‐modified zinc‐based MOF (ZIF‐8‐mmen) 11 were reported as the useful modeling techniques to simulate and to optimize the heavy metal removal process.…”

“…RSM technique also are used to assess the extent of multiple variables effects and their interactions 10 . Modeling and optimization of chromium adsorption onto clay using RSM, artificial neural network 10 and optimization of the adsorption process using RSM technique for Cd 2+ sorption by dimethylethylenediamine‐modified zinc‐based MOF (ZIF‐8‐mmen) 11 were reported as the useful modeling techniques to simulate and to optimize the heavy metal removal process. Nowadays, mesoporous materials such as ordered silicate with distinct characteristics including uniform pore size distribution, high surface area, proper mechanical and thermal stability are applied in various fields like catalysis, drug delivery, medical diagnostics, adsorption process and chromatography 12,13 .…”